This story originally featured on Dirt Rider.

Many questions are likely to run through your head the second you think about purchasing a playbike. But, first, what is a playbike? If you are a first-time buyer and not aware of the term, a playbike is a smaller-displacement dirt bike suitable for off-road riding with an intended audience of younger or shorter-statured riders between the ages of 4–16. These machines come in a variety of different displacement levels from 50cc to 125cc.

Take the rider’s age, height, weight, and skill level into consideration. Manufacturers design each displacement level of bike with suitable engines, tech, and safety features in mind. But as a shopper, it is up to you to research what the best option would be for your young rider and understand what they need to have a successful start to a life on two wheels.

What to expect at each experience level

The dirt bike/playbike’s engine displacement is one of the key elements to investigate, because it helps you gauge which power output is appropriate for the age/skill level of the rider.

Bikes like the Honda CRF50F and Yamaha PW50 have very approachable 49cc engines (four-stroke and two-stroke, respectively) that deliver the most manageable power for young newbies—these also have automatic clutch systems, but differ in that the CRF50F has a three-speed transmission while the PW50 is a single-speed.

When you graduate to 65cc, a bike like Kawasaki’s two-stroke KX65 is not so much a playbike as it is a full-on competition motorcycle; it brings a much different engine character than the aforementioned 50cc models with a strong, aggressive power delivery that is intended for youth-class motocross racing. And 85cc machines bring even more dirt-shredding capability with a focus on a widespread powerband, as Kawasaki states regarding its KX85.

Then come 110cc and 125cc four-stroke playbikes, where you start to get closer to power outputs and deliveries suitable for tweens, teenagers, and in some cases, adults, who are looking to do more casual riding as opposed to racing.

As briefly mentioned before, different displacements are also paired with clutch systems that accommodate the skill level of the intended rider. The youngest beginners on 50cc dirt bikes will have automatic transmissions—twist-and-go options. KTM has even specified that a bike like its 50 SX Mini is suitable for 4- to 10-year-olds. The 65cc and up bikes start to introduce manual clutches and require more rider skills to modulate the clutch lever and click through gears via the shifter. A bike like the KX65 has a six-speed transmission with both clutch and shift levers to manage, but a 110cc machine like the CRF110F has a semi-automatic transmission which has a shifter but not a clutch lever, making it a great transition bike for riders who are getting older, easing into shifting, or working their way up to a manual clutch system. Then finally, 125cc and above have manual clutches and four-to-six-speed transmissions, putting them the closest to full-size dirt bikes in terms of required techniques.

How to figure out sizing

Generally speaking, the lower the displacement, the lower the seat height. When deciding on which size is most suitable, you have to take into account the rider’s inseam. A 50cc is the most approachable for any age, with claimed seat heights of 18.7 inches for the PW50 or 21.6 inches for the CRF50F.

The KX65 steps it up to a claimed 29.9-inch seat height, while an 85cc moto machine like the Suzuki RM85 is said to be 33.5 inches. These seat heights are a little taller than their playbike counterparts because 65cc and 85cc two-stroke models are competition-oriented machines and thereby feature more suspension travel to absorb the bumps and jumps that are ever-present on a motocross track.

Trailbikes like the KLX110R L—as signified by the L in the name—suits taller riders with a 28.7-inch seat height compared to the base KLX110R’s 26.8 inches. Another model for taller riders is the Honda CRF125F Big Wheel with larger wheels that bring the seat height up to a claimed 30.9 inches versus the base CRF125L’s 29.1.

It could also be a given, but the smaller the bike, the lighter the weight. Can the rider manage the weight of the machine you are going to buy them? Consider that 50cc bikes have claimed weights of around 90–110 pounds, 65cc are around 130 pounds, 85cc tip scales at 165 pounds, 110cc about 159–170, and 125cc machines weigh approximately 196–207 pounds.

Dirt Rider is working on measuring 50cc, 85cc, and 110cc dirt bikes in house, so keep an eye out for those published stories to find out the real measurements.

How much do playbikes cost?

Well, there are plenty of options that range under the $5,000 mark, but prices really vary between applications; trailbikes tend to be on the lower end of the price range, and bikes focused more on motocross/competition tend to be more expensive. Here is a general breakdown of pricing by displacement:

50cc: $1,599–$4,399

65cc: $3,749–$5,099

85cc: $4,249–$6,299

110cc: $2,299–$2,499

125cc: $3,199–$7,499

This story originally featured on Saveur.

In the cocktail world, salt can go far beyond the rim of a margarita glass. And a drink doesn’t necessarily have to fall into the savory category to benefit from a pinch. While classics like Bloody Marys, micheladas, and bull shots may be the first that come to mind, these days they aren’t the only cocktails to include a touch of saline. Bartenders around the world are incorporating the mineral in various forms to enhance more delicate flavors in their concoctions.

“As in food, a pinch of salt can greatly enhance the overall flavor experience of a drink,” says Alex Smith, the bar manager at Cecconi’s Dumbo in Brooklyn. “Salt can help bring balance of flavor to a cocktail,” he continues, adding that it brightens sweet and sour notes while reducing bitterness. Smith makes a saline solution with sparkling water instead of tap water—he prefers San Pellegrino for its crisp minerality. Opting for a solution over a salt rim, according to Smith, “allows you to control consistency, ensuring that every sip tastes exactly the same.”

Salt also stabilizes the proteins in egg whites (which are typically added to sours, fizzes, and flips as a texture enhancer), while subtly activating the taste buds and enticing the drinker to continue sipping. It’s a go-to ingredient for Will Wyatt, the owner of Mister Paradise in New York’s East Village––five salted cocktails appear on his current drink list. “Salt makes the back palate water and causes you to experience flavor more intensely,” he says. “I love how it can take any flavor and change how you perceive it.”

“Salt has become a general and almost indispensable ingredient in the cocktail world,” says award-winning bartender Ryan Chetiyawardana, perhaps best known for London’s Lyaness. He and his team keep a glass dasher bottle of saline solution, which calls for one part Maldon sea salt to five parts water, at the bar to season all kinds of cocktails and even make a salted absinthe, for a twist on the Hemingway Daiquiri.

Here are three ways to salt your cocktails at home—each bartender-approved technique is sure to give you a new perspective on salt.

Shake it in

Start with the easiest method: add a pinch of your favorite salt to any citrusy cocktail before shaking—and don’t be afraid to experiment. Kosher salt and fleur de sel will get the job done, acting as a neutral balancing and brightening agent, but if you’re feeling more adventurous, try a flavored salt, such as the bartender cult-favorite sal de gusano (worm salt). Seasoned with smoky dried chiles and ground agave worms, this classic Mexican ingredient is most often served alongside neat mezcal or tequila, but at Deadshot in Portland, Oregon, bar manager Natasha Mesa mixes it into cocktails directly, including her mezcal-based Grey Gusano. Pick up some sal de gusano at your local specialty grocery store (or order it from Amazon) and try the recipe at home.

Make a saline solution

Saline solution, a simple mixture of salt and water, is one of the most common methods used by bartenders. At Saffron in New Orleans, bar director Ashwin Vilkhu keeps a kosher salt solution on hand for a variety of drinks, including the Junglee Bird. A riff on a classic tiki cocktail inspired by Vilkhu’s childhood, it combines rum, Campari, fresh lime, falernum, passionfruit liqueur, and homemade roasted mango syrup with a dash of the solution. Pro tip: store saline solution in an airtight glass bottle in a cool, dry place to prevent crystallization.

Salt your spirit

Salting a key cocktail component, such as a liqueur, is certainly more labor-intensive than using a saline solution or adding a pinch of salt, but the technique both reimagines the ingredient and allows for more control when mixing. At London’s American Bar at The Savoy, a housemade salted chestnut liqueur is the star of the Radio Hurricane cocktail, which also contains bourbon, Pedro Ximénez sherry, dry vermouth, toasted oak bitters, and lime. Our version of the spirit streamlines the process for the home bar but still brings out the chestnuts’ rich, toasty qualities. Add a splash to your favorite classic whiskey cocktail or try it in a mixed drink with ginger beer or ale (chestnut and ginger are a match made in heaven). The liqueur also stands up well on its own, so sip it neat after dinner or drizzle it over a slice of cake or a scoop of vanilla ice cream for an unforgettable dessert.

Whether you’re on an adventurous hiking trip or enjoying a low-key hang with the family, first aid kits are a key accessory for taking care of unexpected accidents. Portable and compact, these boxes are packed with helpful items, including gauze pads, exam gloves, and antiseptic towelettes.

We found four kits that’ll help you take care of all the bumps, cuts, and bruises.

This plastic case is equipped with 100 first aid resources, including six antiseptic towelettes, 12 alcohol wipes, and 30 adhesive bandages. There’s a storage divider that neatly organizes the kit’s content and side latches that make it super easy to open and close. An instant cold press will help soothe inflammation and exam gloves allow you to safely treat wounds.

There’s a lot of medical equipment packed into this compact zipper bag. Among the 160 items, you’ll get a CPR mask, metal tweezer, eye wash, emergency blanket, knuckle adhesive bandages, and plenty of cotton tip applicators. The small, durable design means you can take it along on all your down-and-dirty wilderness adventures.

This kit doesn’t just help you prepare for scrapes and bruises. It also comes with two aspirins, two ibuprofens, and two extra-strength non-aspirin tablets. The zip-up case has clear compartments, so you can easily see and organize all of the contents. Equipped with 130 items, you’ll get 50 adhesive bandages, an instant cold press, and a sterile eye pad.

If you’re looking for a weatherproof, heavy-duty case with plenty of first aid supplies, this one’s for you. Complete with 348 items, organized neatly into 20 inner compartments, you’ll get a comprehensive kit including 28 sting relief pads, 10 large sterile gauze pads, and one emergency glow stick. There’s also a mini kit included, with extra items including cotton swabs and alcohol prep pads.

For students, the start of a new school year is often synonymous with the revamping of wardrobes and style. Yet perhaps the most important accessory of all is a graphing calculator. Used in middle school and college mathematics and science courses, graphing calculators have the ability to display plotted graphs for multiple complex equations and are necessary tools for algebra, geometry, calculus, and standardized tests. Here are the most advanced and accessible graphing calculators.

The TI-84 Plus CE makes comprehension and mastery of math and science topics quicker, easier, lighter, and brighter with color graphing and a slim design. Ideal for middle school through college, this enhanced calculator has a vivid backlit display, rechargeable battery, preloaded apps, and MathPrint mode. Not only are the high-resolution graphs colorful, but the calculators also come in a variety of mesmerizing colors like radical red, rose gold, and more. Like all Texas Instruments devices, the TI-84 Plus CE is approved for SAT, ACT, AP, and IB.

The Casio fx-9750GII has all the standard features of an entry-level graphing calculator, capable of graphing x= relations, rectangular, polar and parametric functions and inequalities, and conic sections with streamlined solving for intercepts and complex number calculations. Its icon-based menu is easy to navigate and the soft-menus makes it easy to access functionality for common tasks and encourages student engagement with Pre-Algebra, Algebra I & II, Geometry, Trigonometry, AP Calculus, AP Statistics, Biology, Physics, and Finance.

The TI-89 Titanium CAS features advanced functionality that makes problem-solving for mathematics and engineering courses easier. Graphing functions include basic function graphing, parametric graphing, polar graphing, sequence graphing, 3-D graphing, and differential-equation graphing. There are 16 preloaded graphing calculator software apps, including EE*Pro, CellSheet, and NoteFolio. Plus its flash technology allows upgrades to future software versions so you won’t have to continually invest in new calculators.

A predecessor to the TI-84 Plus CE, this TI-84 model still possesses advanced functions and software that meet students’ critical math and science requirements from high school through college. With over a dozen preloaded apps, clear display, and fast processing, the TI-84 Plus encourages exploration of interactive geometry, inequality graphing, real-world data collection and analysis, and other tools for math and science coursework.

After using a Turkish towel, also known as a pestemal or fouta, you’ll never want to go back to your bulky, traditional bathroom towel. They’re flat woven with Turkish cotton, which means they’re super lightweight, extremely portable—great for throwing into a tote bag or backpack—and quick to dry, which is a huge bonus for avoiding mildew. And don’t be fooled by their slender profile, thanks to long cotton fibers, these towels are super absorbent. Best of all, they become softer with every wash.

Here are some of our favorite Turkish towels.

These 100 percent cotton Turkish towels come in every color you could imagine, and are deeply absorbent despite packing down to a small size. They even come pre-washed for increased softness. The five stripe design was inspired by the owner’s cat, and is meant to signify her claws.

This set of six towels is perfect for the beach—they come in vibrant colors, and are 39-by-70-inches each. Thanks to their size, any one of these can easily double as a bathing suit cover up—the material is lightweight enough to tie at the hip—or as a blanket, after sunset. The material is soft, and will only get softer every time you wash it.

If bright colors aren’t your thing, this classic black set should be your go to. These are simple and elegant, and would look great in a bathroom or as a living room throw in a seaside abode.

These smaller Turkish towels give you the same lavish experience in an even smaller form. They’d look handsome as hand towels in a bathroom, or hanging on the oven door in the kitchen. They’re also perfect gym towels, thanks to their small size, ability to absorb, and quick dry time.

If you’ve treated yourself to a scalp scrub lately, then you know how thoroughly rejuvenating the small luxury can be; and if you haven’t, welcome. Scalp scrubs help improve your overall scalp hygiene by removing buildup that a basic shampoo massage can’t achieve. With the right ingredients and composition, a scalp scrub can bring you relief from itchiness and dryness as well as lasting satisfaction by improving your overall hair health. Below are a range of options to tackle the trickiest of scalp problems.

Bring the salon experience to your own bathroom with this professional-grade, cult-favorite scalp scrub. You can use this 250-milliliter scrub once or twice a week to invigorate your hair follicles and add a new level of hydration to your thirsty strands. It contains sulfate and sodium chloride, which for many enthusiasts packs a layer of detoxification benefits that they can’t get with any old shampoo.

Head & Shoulders is known as a leader behind shampoos to combat dandruff and dryness. So naturally, the brand also makes a magnificent, highly affordable scalp scrub. This sulfate-free and dye-free option contains coconut oil to soothe any aches and moisturize your hair. At such a great value, this scrub’s rejuvenating qualities will not disappoint.

If you’re looking to avoid sulfates, parabens, or sodium chloride, then this nourishing scrub is for you. This leave-on treatment absorbs quickly into your scalp, so you can continue on your day after a shower and tangibly feel the nourishing effects of its subtle ingredients such as chamomile and lavender. It also contains caffeine to wake up your scalp and includes an applicator to ensure you don’t waste product.

This scrub also boasts a string of household ingredients such as pink Himalayan sea salt and apple cider vinegar to remove even the most stubborn dry patches. With substances like aloe and avocado, your scalp pH will be more balanced than it has been in ages, and your hair will benefit from a fresh shine. This gentle workhorse of an exfoliant can clear scalps with dry, combination, or oily skin.

When a patient climbs into an MRI scanner, it peers inside their body to reveal the complex anatomy within, like the ligaments and tendons in a knee. But in January, before COVID struck, some patients who needed their knee scanned at NYU Langone Health started getting intentionally scanned twice. A scan for a typical human knee takes around 10 minutes, and these subjects—who had consented to taking part in a study—had their joint scanned at the normal speed, as well as about twice as fast (with the help of AI). After the coronavirus interruption, the work has since resumed using one scanner at the hospital.

That initiative is part of an ongoing effort at the medical center, in partnership with Facebook Artificial Intelligence Research, to see if running an MRI machine faster—and grabbing less data in the process—can produce images that are just as good those that arise the normal way. Reducing an approximately 10-minute knee scan to about 5 minutes, or shortening the scan time for other body areas, has obvious benefits: A patient could spend less time in a clanging tube (a procedure that demands they hold as still as possible) and hospitals could do more with the expensive, limited hardware they have.

To make this possible, radiologists and computer scientists need to employ artificial intelligence. If they were to run an MRI machine twice as fast as usual and then try to spin the data they collected into an image with the normal method, the result would be unusably bad. Enter AI: Using machine learning to analyze that comparably scant data and then create a picture produces something that is indeed usable, and in fact, looks to be of nicer quality to some radiologists’ eyes than the alternative.

The project reported good news last month. The researchers involved published the results of another study that aimed to determine if radiologists could tell the difference between typical MRI images and those that used AI, and if those scans were interchangeable diagnostically. Last year, Popular Science took a deep, exclusive dive into that process, shadowing a physician who took part in the experiment. The study’s results were published in the American Journal of Roentgenology last month.

What the study showed was encouraging. Dr. Michael Recht, the first author on the published study and the chair of the radiology department at NYU Langone Health, says that the images created by artificial intelligence (from a slimmer amount of data than is usually gathered) held up well compared to images made via the normal process. “There is no difference in how people read the scans, whether they’re reading the accelerated or the clinical [traditional] sequences,” Recht says. “They’re able to make the diagnosis equally well on either of the scans.”

In fact, he says he would rely on an AI-generated image of a patient’s knee to arrive at a diagnosis—a conclusion that a surgeon may then use when deciding whether or not to operate. “The sequences really are interchangeable, and I’m very, very comfortable using those sequences to make a diagnosis,” he says. Of the six radiologists in the study, only one of them was able to discern whether the scans were made the normal way or with AI.

With this recently published study, patients were not actually scanned twice. Instead, the team took MRI scans of patients’ knees and simulated the process of what a faster imaging process would have created by stripping some of the raw data out, and then used AI to knit that data into a complete picture.

But the current work is indeed scanning patients twice, and Recht hopes to then use what they learn from patients who go on to have arthroscopic surgery on their knee as a “gold standard.” That way, they can look at the two different scans—one created the normal way, and the other created through a faster, five-minute AI scan—and then ideally compare them with what a surgeon ultimately sees on the table.

Eventually, the process could help MRI machines take the place of X-rays or CT scanners in some cases—meaning that someone who needs brain imaging, for example, from a CT scanner could instead skip the ionizing radiation that machine produces and opt instead for a speedy MRI.

Even with gyms reopening at limited capacity, it’s still safer to exercise at home or outdoors. So, we’re dubbing this September Muscle Month to help you keep up your fitness, power, and health in socially distant times.

You may have heard already that abs are made in the gym and revealed in the kitchen. You may have also clicked on this article hoping to hear that that’s not true.

Here in the inconvenient truth: you can have a full 8-pack, but you’ll never see it if it’s buried under fat.

That’s not to say that you need to lose body fat just because your abs aren’t on display. If you do an image search right now of “body fat abs,” you’ll get some non-scientific images showing roughly what men and women tend to look like at different body fat percentages. The norm for men is around 18-24 percent, while women are around 25-31 percent. This is perfectly healthy, as are a variety of body fat percentages lower than that (and some above it as well). You can be healthy, unhealthy, fit, or out of shape at just about any size.

Regardless, you’ll notice that images of folks with ‘normal’ amounts of body fat don’t tend to have visible abs, nor do many of the people below that mark. That’s because a stereotypical six-or-eight pack requires you to be exceptionally lean. You can get an extremely strong core without having a six pack, and there is truly no reason to strive for one unless you want to show one off. There’s nothing wrong with that! But if your primary goal is to be fit and have a strong core, washboard abs don’t have to be on your radar.

But hey, the heart wants what it wants, and maybe you’re really committed to seeing defined abs when you look in the mirror. There are two basic requirements to getting a four, six, or eight pack. One is to actually have the muscles. Two is to have low body fat. The good news is that this is a simple equation. The bad news is that simple does not equal easy.

Let’s break it down a little more.

Make them

When we talk about abs, what we’re really talking about is the rectus abdominis, which is the panel of muscles covering the front of your torso below your chest. A piece of tissue, called the linea alba, separates that muscle down the center into the individual “packs.”

But despite being a large chunk of muscle, your abs have different sections that get engaged by different exercises. To get a full six pack, you’ll need to work the full rectus abdominis—so you won’t get there by doing 1,000 crunches a day. Make sure to pick a variety of movements to work all parts of the muscle (there’s a great guide here).

It’s worth noting that there are lots of movements that engage your core muscles that don’t necessarily translate into having separated, defined abs. Heavy squats and deadlifts require immense core strength, but crucially they don’t require moving your abs. You want your abs to move if you want them to get more defined, so go for leg raises or X man crunches or alternating jackknifes in addition to heavy lifting and planking.

Reveal them

The general consensus of unscientific collections of photos seems to be that to get defined abs, men need to get down to the 10 percent body fat range, while women might be more like 14 or 15, though it depends on how you personally carry fat and muscle. Your abs might poke through at higher levels of body fat, or they might not. How visible they are has nothing to do with how strong you are or how hard you’re working.

Don’t go about this cavalierly. Having very low body fat can come with its own issues—many women end up with hormonal problems, for instance—and it’s easier than you might think to get nutritional deficiencies by cutting out the wrong foods. Don’t just pursue less and less body fat. Getting into the single digits for body fat percentages is something that even professional bodybuilders and fitness models only do for short periods of time, precisely because it’s unhealthy and unsustainable. It’s possible to have very little body fat and be healthy, but it takes careful consideration of your diet and eating habits—check with a nutritionist or physician if you’re pursuing something like this. For almost everyone, getting down to low levels of body fat will require losing some weight, and that won’t necessarily be a good thing. Every individual is different, and can end up with varying problems in their pursuit of fat loss.

Once you commit to losing weight, you may be overwhelmed by all the potential tips and tricks out there for slimming down. There are a lot of theories on weight loss, and you can find proponents of almost every strategy, from zero carbs to zero fat and everything in between. The truth, as ever, is more complicated. Here’s what all the scientific evidence actually agrees on:

1. Lowering your calorie intake will pretty much always lead to some kind of weight loss
2. <a href="https://www.popsci.com/best-diets-according-to-experts/">The best diet is the one you can stick to</a>

That means adjusting your diet to lose weight will require eating less, but doing so in a way that’s sustainable. If you love sweets, you will never maintain a diet that cuts out all sweets. So don’t! Eat the stuff you enjoy in moderation, focus on whole foods over processed ones, and make small adjustments that you’re able to stick to. Even small daily cuts will add up over time. If you’re at a loss for how to lose weight, one of the simplest methods is to count calories. When you start it will feel exhausting, but the good news is that research suggests even people who end up only roughly tracking their calories lose weight. Knowing how many calories are in your food seems to make you more aware of what you consume, and if you’re trying to lose weight that awareness is likely to translate into eating less.

It’s also important to remember that eating less is not always better, especially when you also want to have lots of muscle, which requires more calories to maintain than fat. There is not a linear relationship between health and lower calorie counts. Food is fuel—treat it like that. Not eating enough will just cause you to lose muscle mass anyway, so without sufficient calories you’ll reverse your gains. Get plenty of protein and carbs.

Once you figure out a solid diet, the advice is simple: just stick to it. Weight loss is not an overnight thing. It will take time, but if you stay the course it will happen. And if you’re still working those abs and consuming plenty of fuel, you may just start to see some abs come out to say hello.

This story originally featured on Working Mother.

Alisha Morris, a theater teacher in Olathe, Kansas, wanted to know how many coronavirus cases were being reported in schools, but as she scoured the internet, she couldn’t find the information all in one spot. So she started keeping track herself.

Now, her database is available on a website hosted by the National Education Association. You can search by state to find a list of confirmed COVID-19 cases at public K-12 schools across the US. The tracker provides the number of known cases and deaths for students, teachers, and administrators, as well as a link to a news story where the information originated.

Morris began keeping tabs of the confirmed cases she stumbled across online on August 6. "I put in the words 'school, positive,'" she told NPR's Morning Edition. "I clicked on the news tab and would search the articles from the past week or the past 24 hours and then I would input those articles into my spreadsheet."

After she made her database public, teachers began sharing it, and she started receiving personal anecdotes about cases that hadn't been covered by the news.

“Based on the anecdotes that people have sent me, there have been tons of schools that have been purposely trying to keep this on the down low,” Morris told NPR. “They will tell the close contacts and maybe the staff, but then they won't publicize it any further than that. So a lot of the submissions I received were screenshots of staff emails or parent emails telling about the case. But then when I went to go find an article about it, there wasn't anything about it.”

At first, she wasn’t sure if she should include those cases in her spreadsheet, because they weren’t verified by a news organization. But in the end, she decided to add a section for “possible” outbreaks. That section is included on the NEA spreadsheets, and there’s a link to report COVID-19 cases, although you must have a verifying source. “Examples of verifying sources include news articles and district websites/press releases,” the site states. “Only publicly verifiable information is published in our public reports.”

She handed the project over on August 23 to the NEA, where a team will keep the information up to date. By then, she and volunteers working with her had recorded nearly 4,300 cases at more than 1,000 schools. Florida schools had the most cases, followed by Texas and Georgia.

This isn’t the first time a private citizen has started a COVID-19 data collection because no publicly available official information exists: Brown University economist Emily Oster started maintaining a tally on COVID-19 cases at day cares and camps after she couldn’t find national numbers online. “I held off doing this data collection for a long time thinking, surely, someone else will start doing this and do it better,” she told Working Mother in July. “And then they didn’t, and didn’t, and didn’t, and I finally pulled the trigger. But it’s really frustrating that this is how we got to this. It seems like most places are planning to open schools, and yet they really haven’t collected the data that would help them do it safely.”

Now, thanks to the efforts of Morris and Oster, we have a clearer picture of where outbreaks are happening and how much they’re impacting kids and staff—information parents desperately need to make fully informed decisions about how to handle work and childcare this fall.

The Centers for Disease Control and Prevention has notified public health officials in every state and five major cities to prepare to begin distributing a COVID-19 vaccine as soon as late October or early November, The New York Times reported on September 2. The planning documents include detailed guidance for how to roll out two unidentified vaccine candidates to healthcare workers and other groups at particularly high risk from COVID-19.

Since the beginning of the pandemic, vaccine developers have raced to bring a COVID-19 vaccine to market at unprecedented speeds. More than 150 vaccine candidates are under development, with 37 already being tested in people. This process includes three phases of clinical trials that determine whether a vaccine is safe and effective. To begin distributing a COVID-19 vaccine on such a short timeline could mean cutting short the final phase of these trials, which involves monitoring tens of thousands of volunteers who have received the vaccine candidate.

The CDC regularly works with states to come up with plans for how to carry out immunization programs, says Bruce Gellin the president of global immunization at the Sabin Vaccine Institute in Washington, D.C. “If you spend billions of dollars to develop a vaccine so you can vaccinate people, you’d better have a plan for how you’re going to [distribute] it,” he says. “You don’t want to start coming up with a plan when the vaccine is sitting in a warehouse.”

We cannot depend on herd immunity to stop the spread of COVID-19; a vaccine will be necessary to end the pandemic, says Stacey Schultz-Cherry, an infectious disease researcher at St. Jude Children’s Research Hospital in Memphis.

“The CDC asking states and cities to be prepared to distribute a vaccine is not a bad idea, because you’d rather have them doing it now and being prepared than scrambling at the last minute,” she says. “It’s been very exciting to see how quickly the vaccines have developed—but we absolutely cannot release a vaccine unless we’re sure it’s safe.”

Some experts are concerned that distributing a vaccine as early as the end of October would be overly ambitious. “It’s hard not to see this as a push for a pre-election vaccine,” Saskia Popescu, an infection prevention epidemiologist in Arizona, told the Times.

Anthony Fauci, the nation’s leading infectious disease expert and director of the National Institute of Allergy and Infectious Diseases, has recently said that phase 3 clinical trials for a COVID-19 vaccine could be stopped early if a Data and Safety Monitoring Board—an independent committee of physicians and other experts—determines that there is enough evidence that the candidate is both safe and effective.

Still, there are consequences to terminating trials early, says Schultz-Cherry. “The worst thing that could happen would be to release a vaccine that’s not safe…imagine for all of our vaccine programs the impact that would have on public health and consumer confidence.”

One concern is that ending trials too soon would prevent researchers from recruiting a diverse enough pool of volunteers—particularly from groups that have been hit hardest by COVID-19, such as the elderly, people of color, and people with underlying conditions—and investigating the vaccine’s effects over a long period of time. “You want to make sure that this vaccine is safe and is going to be effective in all populations,” says Schultz-Cherry.

Extremely rare side effects can go unnoticed if the vaccine is not tested over a long enough time period in a large enough group of people. To justify ending these trials early, Schultz-Cherry says, “It has to be overwhelmingly positive data.”

The CDC did not specify which vaccine candidates the states should begin preparations for. However, the descriptions in the planning documents match up well with two vaccines currently undergoing phase 3 clinical trials that each include 30,000 volunteers, according to the Times report. One vaccine, developed by the Massachusetts-based biotech company Moderna, is being tested at about 89 sites across the United States. The other, from the New York-based pharmaceutical company Pfizer, is being investigated in volunteers in the United States, Argentina, Brazil, and Germany.

Both vaccines are made of genetic material from the novel coronavirus, SARS-CoV-2. The vaccine works by delivering messenger RNA (mRNA) that the recipient’s own cellular machinery uses as instructions to build copies of the spike-shaped protein on the surface of the virus. This spike protein, which doesn’t cause disease on its own, appears to be the part of the pathogen that the immune system responds most strongly to. “It’s basically giving your body the ability to make that [SARS-CoV-2] protein and then generate natural antibodies to it,” Schultz-Cherry says.

No gene-based vaccines to prevent or treat any disease have been approved by the Food and Drug Administration as of now. However, they are expected to be quick and cheap to design and manufacture once researchers identify the genetic sequence they need to include in the vaccine. Plus they can be easily tweaked if the virus mutates.

“So far the vaccines look promising—they look like they’re safe, and they look like they’re generating good…immune responses,” Schultz-Cherry says. Preliminary data indicates that the vaccines stimulate multiple parts of the immune system, including antibodies and T-cells.

One drawback, however, is that RNA vaccines must be stored at extremely cold temperatures to prevent the genetic material from breaking down—minus 70 and minus 20 degrees Celsius for the Pfizer and Moderna vaccines, respectively.

“If these are the vaccines that are going to be deployed, one of the really important reasons why logistically the states need to be prepared is because you can’t just take it to a workplace or a doctor’s office…if they don’t have the proper storage conditions,” Schultz-Cherry says. “It would be like…if I say I’m going to buy you some ice cream and I’ll bring it to you, you have to be prepared to either eat it right then or store it somewhere because it’s not going to last.”

This means that states must prepare facilities with freezers that can store these vaccines and decide where people will need to go to receive them. Additionally, they must figure out who will receive the vaccine first, ensure that they have enough syringes and other supplies, and set up databases to track who is receiving the vaccine. Both candidates are given in two doses several weeks apart, so it’s also important to communicate to people that they need to receive both for the vaccine to be effective.

“Whether it’s under an emergency use authorization or a full license, when vaccines are starting to be given to people outside of clinical trials, it’s critical that we understand how they are performing,” Gellin says. This means that, in addition to everything else, it will also be important to set up a system to continue monitoring the vaccines after they become available.

“There’s a lot to do if the results continue to look very promising and it’s safe,” Schultz-Cherry says. “It’s not insurmountable by any means, but it needs to be coordinated.”

This article has been updated.

Some 7 billion light-years away, two black holes swirled closer and closer together over eons until they crashed together with a furious bang, creating a new black hole in the process. This disturbance in the cosmos caused space-time to stretch, collapse, and even jiggle, producing ripples known as gravitational waves which reached our Earthly abode on May 21st of 2019.

Using LIGO (Laser Interferometry Gravitational-wave Observatory), a pair of identical, two-and-a-half-mile-long interferometers in the United States, and Virgo, a roughly two-mile-long detector in Italy, an international team of scientists announced Wednesday that they had detected this cosmic collision, and it’s racking up superlatives: it’s the biggest, the farthest, and the most energetic black hole merger observed to date. This is also the first definite sighting of an intermediate-sized black hole, clocking in at about 142 times more massive than the Sun, forged from a black hole merger. The findings were published on Wednesday in a paper detailing the discovery in Physical Review Journals and another detailing the implications of the event in the Astrophysical Journal Letters.

The merger signal, called GW190521, lasted only a tenth of a second—but scientists immediately realized it was extraordinary in comparison to the low chirp of two colliding black holes LIGO detected in 2015, which confirmed Einstein’s ineffable notions on space-time. “It’s the biggest bang since the Big Bang that humanity has ever observed,” says Alan Weinstein, an astronomer at the California Institute of Technology who was part of the study. It could offer clues as to why the Universe looks the way it does.

Computer algorithms analyzed the signal, ultimately allowing scientists to pinpoint the masses of the merger and just how much energy was released. The two progenitor black holes weighing in at about 66 and 85 solar masses merged into a black hole of 142 Suns. The remaining eight solar masses would have been converted into gravitational wave energy.

Up until now, scientists have been able to detect and indirectly observe black holes in two different size ranges: stellar-mass black holes, which measure from a few solar masses up to tens of solar masses, and supermassive black holes that range from hundreds of thousands to several billions of times the mass of our sun. However, astronomers that detected GW190521 witnessed the birth of a special breed of black hole: an “intermediate-mass” black hole. A few potential intermediate black holes have been spotted, but this is the first direct evidence of their existence.

This strange signal was produced by the merger of two equally weird black holes: The heavier of the two merging black holes, at 85 solar masses, is the first black hole so far detected smack-dab in what is known as the “pair-instability mass gap.” A star that collapses shouldn’t be able to produce a black hole between the range of 65 to 120 solar masses because the most massive stars are obliterated by the supernova that comes hand in hand with their collapse. According to Weinstein, a possible explanation might be what astronomers call hierarchical mergers—when lighter stellar-mass black holes merge into heavier ones, which then merge into heavier ones still,” consolidating until they become gargantuan black holes.

Astrophysicist K.E. Saavik Ford of the Graduate Center at City University New York who was not involved in the study says this finding is particularly exciting: “It’s a bridge between the black holes that are formed directly when stars collapse and supermassive black holes that we find in the centers of galaxies.” As Saavik Ford points out, it’s actually very hard to make hierarchical mergers since black hole remnants have to find each other, and then merge together. “That takes many, many, many lifetimes of the universe under anything like normal circumstances,” Saavik Ford says, “so it had to have happened in a very dense stellar environment” like an active galactic nucleus or AGN.

Earlier this summer, Saavik Ford and her team published a paper about a black hole merger exploding with light coming from the same general part of the sky as the one detailed this week. Though there could be a connection between the flare and the merging black holes outlined in the recent papers, Ford is waiting for the full dataset of the new findings to be shared to tease out some answers.

Right now, LIGO and Virgo are not making observations, but the two facilities will be back online by the end of next year with some upgrades. Gravitational-wave astronomers like Weinstein hope these Earth-bound gravitational wave detectors become all the more sensitive in order to probe more distant sources and look farther back in time in the evolution of the universe. “We need to look for more exotic events like this one—and for more exotic events like nothing we have ever seen before,” Weinstein says. “Wouldn’t that be great?”

Deepfakes can be fun. Those videos that perfectly inserted Jim Carrey into Jack Nicholson’s role in The Shining were endlessly entertaining. As the upcoming U.S. election closes in, however, analysts expect that deepfakes could play a role in the barrage of misinformation making its way out to potential voters.

This week, Microsoft announced new software called Video Authenticator. It’s designed to automatically analyze videos to determine whether or not algorithms have tampered with the footage.

The software analyzes videos in real-time and breaks it down frame-by-frame. In a way, it works similarly to familiar photographic forensic techniques. It looks for inconsistencies in edges, which can manifest as subtle changes in color or small pixel clusters (called artifacts) that lack color information. You would be hard-pressed to notice them with your own eyes, especially when dozens of frames are zipping by every second.

As the software performs its analysis, it spits out either a percentage or a confidence score to indicate how sure it is about an image’s legitimacy. Faking an individual frame is relatively simple at this point using modern AI techniques, but movement introduces an extra level of challenge, and that’s often where the software can glean its clues.

Research has shown that errors typically happen when subjects appear in profile, quickly turn more than 45 degrees, or if another object rapidly travels in front of the person’s face. While these happen relatively commonly in the real world, they rarely happen during candidate speeches or video calls, which are prime targets during an election season.

To train the Video Authenticator, Microsoft relied on the FaceForensics++ dataset—a collection of manipulated media specifically to help train people and machines to recognize deepfakes. It contains 1.5 million images from 1,000 videos. Once built, Microsoft tested the software on the DeepFake Detection Challenge Dataset, which Facebook AI created as part of a contest to build automated detection tools. Facebook paid 3,426 actors to appear in more than 100,000 total video clips manipulated with a variety of techniques, including everything from deep learning methods to simple digital face swaps.

Facebook’s challenge ended earlier this year and the winning entrant correctly identified the deepfakes 82 percent of the time. The company says it’s already using internal tools to sniff out deepfakes, but it hasn’t publicly given any numbers about how many have shown up on the platform.

For now, average users won’t have access to Microsoft’s Video Authenticator. It will be available exclusively to the AI Foundation as part of its Reality Defender 2020 program, which allows candidates, press, campaigns, parties, and social media platforms to provide suspected fake media for authentication. But, down the road, these tools could become more available to the public.

Another big tech company—Google—has been hard at work on ways to detect face swaps; last year it hired actors and built its own dataset using paid actors similar to Facebook’s methods. While Google doesn’t have public plans for a specific deepfake detection site for everyday users, it has already implemented some image manipulation tools as part of its Image Search function, which is often the first step in trying to figure out if a photo is fake.

Microsoft didn’t share specific numbers about the success rate its AI-driven tool achieved, but the benchmark isn’t all that high when you survey the top performing players. The winner of Facebook’s challenge achieved its 82-percent success rate on familiar data—once it was applied to new clips taken in the real world with fewer controlled variables, its accuracy dropped to around 60 percent. Canadian company Dessa had similar success with the Google-produced videos with controlled variables. With videos pulled from other places on the web, however, it struggled to hit the 60 percent success mark.

We still don’t know how big a role deepfakes will play in the 2020 election, and with social media platforms doing their own behind-the-scenes detection, we may never know how bad it could have been. Maybe by the next election, computers will be better at recognizing the handiwork of other automated manipulators.

Three original papers published this week in the Journal of the American Medical Association (JAMA) alongside an editorial represent an unprecedented international effort from the world’s medical community to synthesize reliable new knowledge about COVID-19, the disease caused by SARS-CoV-2, a pathogen that emerged eight months ago. The papers all examine whether steroids are a useful treatment for critically-ill COVID-19 patients, including those who have acute respiratory distress syndrome, or ARDS. The most notable is a meta-analysis of seven existing studies on the subject, sponsored by the World Health Organization. It found a clear signal that COVID-19 patients with ARDS who were treated with corticosteroids had a significantly better chance of surviving, in the short term at least, than those who did not.

“These trials published today show more global collaboration than we’ve ever seen in critical care,” says Christopher Seymour, a doctor and professor of critical care at the University of Pittsburgh who co-authored one of the papers published in the package.

A total of 1703 patients were studied in the seven randomized trials that were included in the WHO meta-analysis. 647 of those severely ill patients died during the trial period, which ranged from 21 to 30 days across all the trials. Importantly, the meta-analysis found that the patients that experienced severe cases of COVID-19 were about one third less likely to die if they received treatment with a corticosteroid.

Trial enrollees had a median age of 60 years. 29 percent of them were women. They were located in 12 countries, including Australia, Brazil, Canada, China, the United Kingdom, and the United States. Several common corticosteroids were used in the different trials, including dexamethasone, hydrocortisone, and methylprednisolone.

Corticosteroids are commonly used in medical practice, as they are inexpensive and potent anti-inflammatories, but they have a host of side effects. They’ve been studied before for use in patients with ARDS, a syndrome that can be caused by a host of things including trauma and disease, since the 1960s. But until now, there’s never been any definitive results showing these powerful anti-inflammatories definitely help patients with ARDS, says Benjamin Singer, an intensive care doctor at Northwestern University who was not involved with any of the studies.

“The idea of using steroids in critically ill patients with ARDS has a very long history,” he says. “Now we have accumulating evidence, particularly focused around the group of patients with COVID-19, that there appears to be a nice [sign] of benefit when they’re given corticosteroids.”

Previous trials of corticosteroids in ARDS patients had both positive and negative results, and doctors did not regard the drugs as a front-line treatment for the condition, says Singer. The fact that a clear signal emerged in all the trials that were part of the COVID-19 ARDS meta-analysis is probably related both to the fact that all the patients in these trials had the same illness (COVID-19), he says.

Additionally, “there is some indication that the biology underlying ARDS [associated with] COVID-19 may be a bit different than ARDS and we’ve known it before,” says Seymour.

There’s still a lot scientists don’t know about using corticosteroids with COVID-19 ARDS patients. Namely, there’s no data yet on the long-term impacts of using these drugs on patients with this severe form of COVID-19. This makes it hard to weigh the benefits versus the risks of using these drugs to treat ARDS. But these papers represent hopeful progress, both because they advance the science of COVID-19 treatment and because they provide evidence of unprecedented international scientific cooperation in fighting this disease.

When Singer last spoke to Popular Science in May, he raised concerns that intensive care doctors had about trying too many unproven treatments to address COVID-19 related ARDS, and the need for gold-standard controlled trials and evidence in treating the sickest COVID-19 patients.

“Now,” he says, “we have convincing data from well-done, rigorous randomized-control trials that, broadly speaking, corticosteroids are beneficial for patients with COVID-19 ARDS.”

What better way to spice up your waterfront vacation than with a bright boating tube? They are always a great, safe way to add some spice to your boating adventure. A towable tube will guarantee a wild ride for any seafarer, young and old. If you are ready to commit to tubular fun, you should know it’s important to find the right water toy to fit your needs; you need a tube that will support the correct number of riders with the right amount of durability, comfort, and safety features. Here are some good options to get you started.

The Super Mable is a great way to lounge on the lake. It can fit up to three riders and hold an estimated 510 pounds. It measures an almost even 78 by 79 inches for extreme space and comfort. This tube comes with two tow points, which means you can sit back and relax as your boat pulls from your feet or go for a more adventurous ride by lying on your belly and holding onto the chariot. This tube is equipped with three EVA foam seating pads, neoprene handles, and a “kwik-connect” system for an easy hook-up. If you don’t feel the need for speed, the Super Mable makes a great pool or off-shore float.

There are very few water toys as exciting as the Poparazzi from Airhead. It can support up to three riders and features a “kwik-connect” hook-up system for an easy connection to you towline, a heavy-duty nylon cover, and a speed safety valve for easy inflation. This unique design means you can ride the waves in almost any position: lie flat on your belly, sit on your bottom, take a risk and kneel, or be your bravest self and stand up while holding tight to the arch. There are more than enough built-in handles covering this vessel to keep you safe and sturdy while exploring the seas.

WOW is right because the Word of Watersports has created a great two-person tube that’s going to get your heart racing. This tube measures 74 by 62 inches and can hold up to 340 pounds at one time. It has eight reinforced foam handles, a zippered valve cover, and a reinforced tow point for a safe and secure ride. The most impressive feature, however, is the embedded cockpit seating which means you can sit or kneel with a greatly reduced risk of being bounced out by a rogue wave. Despite this added security, you can still try your luck lying down on your stomach and holding on tightly to the handles at the top of the tube—if you dare.

If your little one wants to get out on the water, but they aren’t quite ready to take on the waterskis, this towable tube is a super fun option. It has a 70-pound weight limit, so it’s off-limits for mom and dad but great for younger children. It is easily inflated and features integrated wooden ski trainers and bindings to get your future back-flipper on their way. Kids can stand or sit depending on their comfort level. It’s designed for you to drive at speeds up to 10 miles per hour on the water and measures 46 by 34 by 13 inches. Airhead also makes a training tube that can handle up to 120 pounds, so check that one out if some of the older kids start getting jealous.

Pancakes are good, waffles are great but there is nothing better than a wonderfully thin, light crepe. You can pack them with pretty much anything: your favorite fruit preserve, savory meat and cheese, chocolate, fluffy eggs, and so much more. If you are looking to serve up a great crepe, you’ll need the right pan for perfect execution. Whether you need something non-stick or carbon-based there are so many options to choose from. We have selected the best of the best to give you a perfectly flat “French pancake”.

This classic non-stick crepe pan from Cuisinart can’t be beaten. The surface is ideal for sliding and tossing crepe batter with ease. The triple-ply, stainless steel design has an induction ready exterior while the aluminum core provides optimal, evenly distributed heat to your batter. This 10-inch pan weighs just over 2.5 pounds and is dishwasher safe, so it will fit in nicely with all your other cookware. The riveted handles are designed to give you a great grip and remain cool while you work your way through a stunning stack of crepes.

This beautiful, 11-inch, nonstick pan from WaxonWare will make a great addition to your cookware collection. It is made from die-cast aluminum with a magnetized induction bottom so you can use it over any cooking surface for evenly distributed heat. This pan comes with a wooden batter spreader and a long “bakelite” handle to keep your hands away from the heat. Not only is it great for crepes, but it can also handle omelets, sausages, french toast, and more. You don’t always need stainless steel to get a satisfying stovetop experience and this pan will show you the way.

A simple, traditional way to make your crepes, this carbon steel pan from de Buyer comes in three different sizes: 11.8-inch, 10.2-inch, and 9.4-inch each designed to produce a great sweet treat or savory galette. This pan is designed to last, and become naturally non-stick. It is free of any chemical treatments and coated in beeswax which protects against oxidation and helps with seasoning. The more you use this pan, the more naturally nonstick it will become. It features an ergonomic handle with a signature french curve for flipping, stirring, and sautéing.

The electric crepe maker from Chefman is a 12-inch, multifunctional masterpiece. It’s super easy to use, just plug it in, set your desired temperature with the control knob, wait until the “ready” indicator light turns on, and pour your batter. This griddle comes with a wooden batter spreader and spatula to help you get your crepe cooking in seconds. It’s easy to store and easy to transport so you can take it with you if you need crepes, blintzes, or bacon on your next adventure.

There was a time when scootering was considered a children’s activity, but times are changing and scooters are becoming more and more popular amongst adults. A kick scooter is a great way to get where you need to go, breeze through traffic, and have fun while doing so. Kick scooters are often more portable than a standard bicycle or electric scooter and definitely less expensive than a car or frequent rideshares. They just might be the perfect way to get some exercise and get to your next meeting on time. There are a number of things to look for when finding the right ride: weight capacity, adjustability, and overall style for example. Here are a few of the best scooters available for quick, convenient travel.

This scooter is top of the line when it comes to features, safety measures, and design. It can support up to 220 pounds and its handlebar can extend up to 42.5 inches so you won’t ever have to worry about the “fit.” The PU cast wheels measure 205 millimeters so you can feel confident going over curb cuts, bumps, and bits of debris. The wide deck and front suspension provide a bounce-free ride while the heat-treated brake means you’ll always be in control. This scooter has a dedicated press button for easy folding, a mudguard to protect from any flying dirt, and rubber handles for a secure grip. Perhaps best of all, this scooter comes with a carrying strap so you can stay handsfree, or carry coffee for you and a pal without leaving your new favorite mode of transportation behind. Pick your favorite out of the ten bold color options and hit the road.

This commuter scooter from Micro Kickboard is one of the best out there. It features a weight capacity of 220 pounds, a reliable two-way kickstand, and a low deck that prevents you from having to bob up and down to get a good kick. The wheels are 200 millimeters thick, and can maintain great speed and a smooth ride over almost any city street or sidewalk. The T-bar handle is adjustable and can extend up to 41 inches off the ground so you are good to go at almost any height. This scooter weighs just over 10 pounds and is easily foldable so you can quickly hop off and pack it up whenever you reach your next destination.

Razor scooters are a tried and true classic for kids and adults alike. The A5 Lux takes everything you know and love about a kick scooter and amplifies it for a truly satisfying ride. It comes in three fun colors: blue, pink, and silver with a red accent so you can feel bold and bright as you cruise. It is designed for folks ages 8 and up and can support up to 200 pounds, so your entire family can ride together in style. This scooter has an adjustable handlebar up to 38 inches and large 200-millimeter urethane wheels that will deliver a smooth, comfortable ride. The A5 Lux weighs around 8.5 pounds and easily folds up for portability.

Get ready to hit the town with this kick scooter from Hudora. It is ergonomically designed with a low deck that can support up to 265 pounds and a high T-bar that can extend up to 41.5 inches. The 230-millimeter, shock-absorbing front wheel is a great way to maintain an upright stance while gliding over bumps and the 205-millimeter back wheel is covered by a specially hardened, steel brake for added security. It weighs a little under 11.5 pounds and comes with a three-second folding system, plus a shoulder strap for all your travel needs.

Even with gyms reopening at limited capacity, it’s still safer to exercise at home or outdoors. So, we’re dubbing this September Muscle Month to help you keep up your fitness, power, and health in socially distant times.

Working out at home is the best alternative to going to the gym, but if you don’t happen to have a dedicated space for it, chances are your living room will start to smell. That sweaty stench is definitely a downside of doing your push-ups on that bouncy carpet of yours, but it’s also easily avoidable and manageable.

Why do we stink?

At least when it’s fresh, human sweat is odorless. The distinct smell only starts when bacteria living on our skin break down the proteins in it. This is why you rarely smell when you’re blasting through a workout but no one wants to be around you an hour later.

When you exercise, sweat doesn’t only accumulate on your skin, but it also flies everywhere—think about the fine mist you release every time you swing a kettlebell. When you workout at home, that means sweat settles into your upholstery, the carpet, and that one spot you never dust behind the TV. There, bacteria get busy breaking it down and, thus, the pong.

Stop the smells before they start

Your grandmother may have covered this one when you were young, but in case you need a reminder, keep in mind that an ounce of prevention is worth a pound of cure. In this case, the saying definitely applies, since it’s a lot harder to get the smell of sweat out of everything, than it is to stop things getting smelly in the first place.

The best way to guarantee your living room won’t stink is to avoid working out there. If the weather’s good and you have access to a garden or a park nearby, take your workout outside—grass doesn’t need a thorough de-stink after your air squats.

If that’s not possible, avoid working out on a carpet or rug, since it will literally soak up your sweat. If you have wooden floors, they won’t get stinky, but they might get scuffed or damaged. There are other drawbacks to this as well—doing burpees and other similar movements on a hard surface can hurt you, not to mention that accumulated sweat on wooden or ceramic floors pose a serious slip hazard. The best option to take care of your joints and your floors is a good yoga mat. They’re soft, grippy, and designed to be easy to wipe down after a sweaty session. Just make sure it’s fully dry before you roll it up again after your workout to avoid smells and bacteria.

Odor expert Marilee Nelson, co-founder of Branch Basics, suggests buying a cheap 20-inch x 20-inch box fan and a matching air filter. Tape the filter to the back of the fan and run it while you workout. Not only will you get a refreshing breeze to keep you cool and stop you sweating so much, but you’ll be filtering the sweat particles evaporating from your skin, and the odor from the air.

Let nature take its course

What we smell are the volatile compounds sweat-loving bacteria release into the air—and it doesn’t take a high concentration to detect them, since the human nose is surprisingly sensitive. But this also means there might not be that much odor to get rid of in the first place.

After a workout, Nelson recommends simply throwing open your windows and getting a breeze going through your living room. It might seem obvious, but it will clear out a lot of lingering odors.

Clean up after yourself

As well as letting nature do its thing, you should probably put in a bit of clean up effort yourself.

Having a spray bottle with 70% rubbing alcohol is a great, easy, and cheap solution. This is enough to kill the bacteria that cause the bad smells but you really should be careful when spraying it, because it might be too abrasive on more delicate surfaces, like wood. Nelson suggested using vodka, which only goes up to 50% alcohol. This will in fact be gentler on your furniture, but it won’t be as effective against bacteria, so a few passes may be necessary.

To use it, Nelson recommends gently misting any carpets or couches you’ve sweated on and leaving the alcohol to evaporate. If you’ve been working out a while and not deodorizing, it might take a few passes to totally get rid of the stink. Just make sure the alcohol is totally gone—it’s odorless when it evaporates, so you’ll know when you no longer can smell it—and then repeat.

Nelson also notes that, as well as furniture and decor, odors cling to dust, fluff, and other detritus, so a good vacuuming every few days goes a long way.

For your equipment, a quick scrub with soapy water removes any dirt or grime, and a spray of your rubbing alcohol spray will bust the remaining bacteria. It’s the protocol both Nelson and the CDC recommend.

Shower and do your laundry

Just finished a tough workout? Get in the shower. Oh, was it just some light exercises? Get in the shower. Nice yoga flow? Yeah, get in the shower.

It takes time for bacteria to multiply and release that horrendous sweat smell. So if after a workout you kick your feet up on the couch, and throw on Netflix for an hour or two, you’re just giving them time to breed.

Instead, make the habit of throwing your workout gear into a closed hamper and hop straight in the shower after you’re finished exercising. You’ll feel better, be back on your couch bingeing Selling Sunset before you know it, and you won’t be stinking up your pad. Just a win-win-win of a situation.

Witnessing a hazy summertime sky in Los Angeles, you might be tempted to blame the cars and trucks that teem on the region’s roadways. And that’s mostly right, but an increasing share of air pollution is coming from the stuff below those vehicles: asphalt.

A new study published yesterday in Science Advances finds that asphalt pavement and roofing give off lots of gases that go on to form air pollutants. In summertime, asphalt in cities might contribute more to pollutants called secondary organic aerosols than cars and trucks.

A large chunk of the fine particulate matter pollution in urban areas—ranging from 20 to 70 percent—is secondary organic aerosols, or SOAs. Though air pollution vastly improved in recent decades—thanks largely to technology and policy aimed at motor vehicles—it remains a problem in many large cities. Parts of Southern California, for example, still can’t meet EPA standards for fine particulate matter.

As aerosol pollution from vehicles has declined, the relative contribution from other sources has grown. Atmospheric scientists have measured a gap between emissions from known polluters on the ground and the actual pollution in the air. “Atmospheric scientists and air quality managers have been on the hunt for ‘missing [secondary organic compound] sources’ for decades,” Jessica Gilman, a tropospheric chemist with the National Oceanic and Atmospheric Administration, wrote in an email to Popular Science. “It’s labeled as a ‘missing’ source because we have generally observed more SOA mass than what we know can be formed from the typical/traditional precursor/ingredients.”

Drew Gentner, a chemical and environmental engineer at Yale University, wanted to see how much asphalt contributed to this mysterious mix. If you recall that distinctive tang of fresh pavement, what your nose is picking up is the volatile organic molecules emanating from the petroleum-based material. So, Gilman says, it’s intuitive that asphalt could be a source for those aerosols of unknown origin.

Gentner and his team put samples of a common asphalt mixture into a furnace and warmed it up through a range of temperatures. They also subjected the pavement to UVA and UVB light—simulating the effect of sunshine. The researchers measured the emissions and types of chemicals gassing off from the pavement chunks.

Both heating up and bathing asphalt in light spiked the emissions it produced. With heating, emissions doubled as the material warmed from 40 to 60ºC (104 to 140ºF)—a realistic summertime pavement temperature in many urban areas. Sunlight also increased emissions, by almost 300 percent over a sample without light. Heat and sunlight also seem to cause different chemical responses. After a sample had been warmed for nearly two days it was releasing a low but constant amount of volatile compounds, and adding sunlight caused a new spike.

Next, the researchers calculated what that could mean for a large developed area—Southern California. Using their experimental findings together with known values of asphalt use in the area, they estimated how much all that pavement could be impacting the air. They found that asphalt from roofs and roads may contribute as much secondary organic compounds as all the vehicles in the region on an annual basis.

To be clear, this finding applied to just one type of pollutant. Cars still add a lot of pollution, and are a dominant source of ozone. But, in urban areas in the summertime, these aerosols from asphalt and other non-vehicle sources contribute to smog. “[Secondary organic compounds] have been of great interest to air quality researchers,” says Gentner. “Especially in the summer and in urban areas, it’s a significant component of smog.”

This category of pollutants is challenging to understand. Not only do they come from myriad sources—asphalt is a big one, but paints and other products also release the precursor compounds to pollutants—but the chemical reactions that create these secondary compounds are also complex. While there’s been a lot of progress in understanding and reducing vehicle emissions, unraveling non-combustion pollutant pathways remains a major challenge. “If we want to solve our air quality problem, we’re going to need to expand our view to include less traditional sources,” says Allen Robinson, a civil engineer studying fine particulate matter at Carnegie Mellon University, who was not involved in the study.

“These emission factors and emissions estimates are so essential for understanding air quality and there are many missing sources that we need to get a better understanding of,” adds Eri Saikawa, an environmental scientist at Emory University who was not involved in the research, in an email to Popular Science. “There is still so much that we do not understand about secondary organic aerosols, and these studies are very important to push the field forward.”

Gentner says that future research could help reveal how different types of asphalt and ways of applying it could reduce emissions. It’s also possible that so-called cool pavements—which use reflective materials to avoid absorbing heat—could reduce the amount of pollutants that form from asphalt.  “It’s clearly something that needs some work,” says Robinson. “We still have 100,000 premature deaths each year in the U.S. from elevated fine particulate levels. If we’re going to make progress on that, we’re going to need to think about these types of sources and how we control them.”

This story originally featured on Flying Magazine.

I was quite young when I first fell in love with gliding. It may have been even before I fell in love with Cecilia Revilla, who sat in front of me in the fourth grade. When I say gliding, I don’t mean flying a sailplane; I was much too young for that. I mean just the fact of something gliding—a butterfly, a model airplane, a folded-up sheet of paper. That a balsa-and-tissue model my father had made would sail out, bobbing on the ripples of the air, circling, swooping or even merely tracing a long, straight, gently descending line from the brow of a hill as if it were rolling on invisible wheels down an invisible road – that was sweet, magical and, as it turned out, life-shaping.

It was a lucky thing for the pioneers of flight that birds existed. Without them, it would not have been apparent that something rigid could fly. Birds flapped their wings to take off and land, so flapping must have seemed somehow essential to their mysterious powers of levitation; yet they could obviously stay up, and even ascend, while holding their wings perfectly motionless. How did they do it?

Five centuries ago, Leonardo da Vinci sketched a hang glider. It was an odd-looking thing, essentially an oval kite, quite a bit longer than it was wide, and lacking—as birds did—a fin or rudder to keep it pointed in the right direction. Strangely, for such an acute observer of nature, Leonardo apparently did not perceive the importance of wingspan for reducing the effort needed to fly. But his glider was still a plausible improvement upon the proverbial barn door.

Da Vinci recognized that it is not necessary to flap in order to fly: A flat surface with a weight suspended from it in the right place would slide forward along the air rather than drop vertically. This was a foundational insight, but another 400 years would pass before Otto Lilienthal built the first practical hang gliders. These were strikingly similar to da Vinci’s batlike ornithopters, which tried harder than his hang glider did to mimic the shape and anatomy of natural wings. Lilienthal successfully flew his gliders 2,000 times before an untimely gust upset one and killed him.

Today, gliding is so commonplace, we do not ask ourselves what’s happening when an airplane glides or, for that matter, when a helicopter does.

Go back to the basic ground-school diagram of the four forces—lift, weight, thrust and drag—that must be in equilibrium. Lift is an arrow pointing upward, and drag is one pointing backward. Gravity—no surprise—points downward. But the glider has no thrust. So why does it go forward?

One way to look at it is to remember that “lift” and “drag” are defined with respect to the airstream. Drag is parallel to the direction of flight; lift is at a right angle to it. So, when the glider is going downhill, its lift arrow is tilted a little bit forward and counteracts its drag.

That, at least, is the official explanation. A skeptical person will object that the definition of lift as a force acting at a right angle to the airstream is arbitrary. It’s just a verbal convenience. Why shouldn’t lift be defined as a vertical force, like gravity, or one acting at a right angle to the chord line? For that matter, why should we think of it as a single arrow at all? Physical reality holds no lift arrows. There is only pressure and friction on the surface of the wing—also on the rest of the aircraft, but for the purposes of thinking about gliding, it’s enough to consider only the wing. These forces can be represented as one arrow or two arrows, or a whole slew of arrows bristling from the airplane, porcupine fashion.

If we forget the arrows and consider only the pressures, we discover that high-velocity air flowing around the leading edge of the wing creates low pressure there, pulling it forward. At any sufficiently downward-inclined flight-path angle, there is some angle of attack at which the forward pressures acting on the wing and the backward ones on the rest of the airframe are in equilibrium, and the airplane does not speed up or slow down. Furthermore, its rate of descent at any speed is such that the potential energy it gives up by losing height is precisely equal to the energy needed to overcome its drag.

Wait, isn’t this perpetual motion—and illegal? No. The wing has to be descending for this to happen, and it cannot descend indefinitely. Eventually, it will reach the ground.

The case of a gliding helicopter is somewhat more perplexing. Think of a fan. When a fan is driven by a motor, air enters the back and accelerates out the front. But if you blow air at the fan from the front, it spins in the opposite direction. The rotor of a helicopter is analogous to a fan, but obviously, it does not stop and begin turning in the opposite direction if the engine quits and the helicopter starts to descend. It continues turning in the same direction, and at the same speed, as before.

The rotor blades glide just as an airplane does. It would be more precise, however, to say that only part of each blade glides because only part of each blade has the right combination of speed and angle of attack to achieve the proper balance between thrust and drag. The outermost portion of a rotor blade is moving too fast, and its angle of attack—the resultant of its circumferential velocity and the helicopter’s rate of descent—is too small; the sum of its forces is drag. The innermost portion is moving too slow; its angle of attack is too large, and it is stalled. Again, it exerts drag.

The middle portion of the blade is the sweet spot, generating enough excess thrust to keep the rotor spinning against the drags of the tip and the root. Unlike an airplane, a helicopter can even glide vertically because the blades do not see a vertical descent as truly vertical. For example, consider a hypothetical helicopter with a 30-foot rotor turning at 400 rpm. The circumferential speed of a blade at the midspan point is 315 feet per second. If the helicopter is descending vertically at 1,800 fpm, the angle of attack at midspan is about 6 degrees, which is a typical angle of attack for a gliding airplane. Adding, say, 50 knots of forward speed requires cyclic adjustment—that is, the pitch angle of the advancing blade, relative to the rotor disk, needs to be reduced and that of the retreating blade increased—but the average angle of attack remains around the same 6 degrees.

Gliding is the visible manifestation of invisible forces, the solution of a puzzle in which speed, rate of descent and angle of attack are the clues. The riddle would be maddening, but nature is kind: She gives us birds. And even a folded paper airplane, tossed from a third-floor window, instantly solves the equations of flight and knows, without instruction, how to glide.

One of the White House’s top medical advisors has recommended that the administration adopt an approach to handling the pandemic that would allow the novel coronavirus to quickly infect massive numbers of people in hopes of reaching herd immunity, The Washington Post reported on August 31. The plan, reportedly advocated by Scott Atlas, a neuroradiologist at Stanford University’s Hoover Institution, has drawn swift criticism from infectious disease experts.

“We’re talking about something that...basically would be relying upon an outbreak that would lead to the deaths of hundreds of thousands of Americans,” says William Hanage, an epidemiologist in the Center for Communicable Disease Dynamics at the Harvard T.H. Chan School of Public Health. “The numbers of people who would be rendered vulnerable to this are surely larger than anybody should be prepared to accept.”

Herd immunity is the point at which enough people in a population are immune to a disease—whether because they have already recovered from infection or been vaccinated—that the pathogen cannot easily spread through the community and cause new outbreaks. Trying to achieve herd immunity without a vaccine’s help, as Atlas is proposing (though he later denied that he pushed for this measure after The Post’s story was published), would entail lifting social distancing restrictions on businesses and gatherings so the disease could spread among young, healthy people. Meanwhile, other steps would be put in place to protect particularly vulnerable populations. However, the course of action would put truly staggering numbers of people across all age groups at risk of serious illness and death.

There’s also no evidence that a single sweep of the virus through the population would lead to herd immunity, says Sten Vermund, dean of the Yale School of Public Health.

“It’s a complete myth that you can just let the epidemic rage, protect the vulnerable, and achieve herd immunity. What may happen is…you fill the hospitals, you fill the morgues, and then the next year it happens again,” he says. “You’re not going to get enough people infected to achieve herd immunity and therefore you’ll have done it all for nothing.”

Typically, herd immunity is reached when the majority of people in a population are vaccinated. This threshold varies depending on the disease; about 95 percent of a population must be vaccinated to control an extraordinarily contagious disease like measles. It’s not certain yet what proportion of the population would have to be immune to COVID-19 to prevent the disease from spreading, Hanage says. He estimates that roughly 50 to 66 percent of the population would have to catch COVID-19 to reach herd immunity without a vaccine.

There have been more than 6 million confirmed cases of COVID-19 in the United States and more than 184,000 deaths. For a country with a population of about 330 million people, this means that herd immunity is still a very long ways off. Even cities that were struck hard at the beginning of the pandemic, such as New York, haven’t reached that point. There may be tiny pockets where enough people have been infected that their family members or neighbors are unlikely to catch the disease, Hanage says. But that doesn’t prevent these people from becoming infected when they venture beyond their homes or city blocks.

Sweden, a country that imposed only minimal restrictions at the start of the pandemic, similar in some ways to what Atlas is advising, has also not reached herd immunity. Meanwhile, the number of COVID-19 fatalities per million people is much higher in Sweden than in neighboring countries such as Denmark or Norway.

“Sweden is one of the most medically privileged and healthcare privileged nations on the planet,” Vermund says. The United States has high rates of heart disease and other conditions that put people at higher risk of becoming seriously ill should they catch COVID-19. Many people in the U.S. face other inequities, including lack of access to health insurance and living in areas high in air pollution, that compound their risks. In Sweden, Vermund says, “You don’t have the profound subpopulation of vulnerable individuals that we do in the U.S., so it would have been even worse in the U.S. if we had simply let the epidemic rage.”

If the United States actively pursued a herd immunity strategy, many of these vulnerable populations would bear the brunt of the epidemic. “Some of the people who have been most infected in the first surges of this have been people of relatively low socioeconomic status, people who are living in communities or in very crowded settings where it’s difficult for them to socially distance,” Hanage says.

Recent data released by New York City’s Department of Healthfound that, across the five boroughs, around 27 percent of those tested had antibodies to the novel coronavirus. The one zip code where more than 50 percent of participants tested positive for antibodies was Corona, a predominantly Hispanic neighborhood in Queens where many residents are construction and restaurant workers who could not work remotely during the pandemic, The New York Times reported on August 19.

“A higher proportion of those people who are already vulnerable for other reasons would need to be immune in order to achieve herd immunity for the community,” Hanage says. “That’s disturbing in various ways because it means that you are almost desirous of infection within those groups.”

COVID-19 also poses a particular risk to older people, and shielding the entire elderly population from infection probably wouldn’t be possible. “It’s really, really hard to keep it within those people who are at minimal risk,” Hanage says.

Many elderly people live in multigenerational households or nursing homes, raising their risk of exposure to the novel coronavirus. People in long-term care facilities account for about 40 percent of deaths related to COVID-19 in the United States. Back in February, an outbreak of the disease killed 43 people in a nursing home in Kirkland, Washington. “That was an early warning sign and all of the nursing homes were aware that they might be in trouble,” Vermund says. “And yet we still had astronomical death rates; we still did not succeed in keeping the virus out of the nursing homes.”

Another problem with allowing COVID-19 to spread rampantly is that while the risk of serious illness or death is far lower among young adults or otherwise healthy people, Hanage says, “It’s also not nil.” Researchers also worry that even people with mild cases of COVID-19 may experience lingering health problems from the disease. And allowing COVID-19 to run rampant in young people could mean that the disease becomes so prevalent that elective surgeries and medical appointments must be canceled because the risk of transmission is so great, Hanage says.

There have been several cases where people have been infected with COVID-19 a second time, although the implications for herd immunity—such as how common reinfection might be and how contagious people are during their second bout of COVID-19—are not yet clear.

Regardless, allowing COVID-19 to spread like wildfire is not a viable option. “What we need for herd immunity is a vaccine,” Vermund says. Until one becomes available, we have plenty of ways to minimize the spread of COVID-19, including masks, social distancing, spending time outdoors when possible and improving ventilation indoors, and avoiding large groups.

“Those are classic respiratory disease control measures and that’s what we have to rely on over the next year,” Vermund says.

There are also new advances such as screening tests that can return results within an hour or are inexpensive enough to allow us to track COVID-19 on a much larger scale than has previously been possible in the United States.

“You can minimize exposure [to COVID-19], minimize risk, and equally get a reasonable amount of things back to, not normal, but closer to normal,” Hanage says. “We’re still not in a great place, but there are things that we can do to improve matters and to keep us going through the months ahead.”

When Samsung announced the first Galaxy Z Fold smartphone back in 2019, it was the perfect embodiment of an early adopter device. At $1,980, it was twice as expensive as flagship smartphones, and its unique form factor made it immediately identifiable. It was undoubtedly flashy, but from a usability standpoint, it felt like a Frankenstein’s monster of gadgets. The parts were there—you had a smartphone and a tablet in one device—but the experience didn’t feel totally seamless.

Yesterday, Samsung announced the Galaxy Z Fold2, and in addition to some serious hardware upgrades, the device adds some practical features to make its form factor more useful.

The outside of the device now sports a 6.2-inch screen that takes up the entire front surface, compared to the smaller 4.6-inch screen that felt too miniscule on the original model. That makes it much more satisfying to use without having to flap it open. Opening the device still reveals a 7.6-inch screen, but now Samsung has added a protective layer of glass to the outside of the display, which should make it more durable. Even with the new glass, however, you can still expect to see a fold crease on the screen.

Underneath that crease, Samsung has redesigned the hinge, which now has increased elastic material in it, allowing it to rest in between 75 and 115 degrees of tilt. You can sit the phone open and facing you like a laptop to enable a makeshift two-display setup. So, you could have a video conference happening in the top display while the controls rest in the bottom. You can also turn the phone around and simply watch content on the outer screen without having to prop the phone up to find a comfortable angle. Those in-between orientations make using the device a lot more practical.

The camera upgrades make a lot of sense, too. The main camera array includes three individual modules, including a typical wide-angle, a super-wide angle, and a telephoto lens. Now, you can take a selfie using the main cameras on the outside of the clamshell while using the external screen as a viewfinder. You can also show the feed from the cameras on both inside and outside displays simultaneously.

There are now five total cameras on the Galaxy Z Fold2. There’s a selfie cam on front of the closed device, and another inside to go with the larger screen.

When it comes to apps, Samsung has streamlined some of the multitasking functions that seem natural for this kind of device. You can now save groups of apps to open at the same time in specific multi-window orientations. So, if you typically launch YouTube, Chrome, and Gmail at the same time, you can create a shortcut to throw them all up on the screen simultaneously. Samsung worked directly with Google in order to maximize compatibility with its apps.

Microsoft also got in on the development for Z Fold2, which means Office apps work better together now. For instance, you can keep Excel and PowerPoint open next to each other and drag-and-drop elements between the two.

These aren’t the flashiest aspects of the device, but as Samsung shifts its focus from early adopters to productivity-oriented users, they’re going to be important. The company is now competing against Microsoft and its Surface Duo device, which is firmly grounded in the function-over-fashion mindset.

Only real-world experience with the Z Fold2 will tell if these durability and usability improvements can justify the $2,000 price tag, but—at least on paper—this version seems more ready for the real world than its older sibling.

Whether you’re working or gaming on your computer, efficiency and precision are key, and while your brain may be doing the heavy lifting, your hands play no small part. A new and improved keyboard could make a great gift for those hard-working hands of yours. Modern keyboards are ergonomic, so they ease tension and make typing a smoother and more satisfying experience. Such a small change in your setup could make a huge difference, especially if you’re working at a computer eight or more hours a day. If you’re a gamer, you know that the right keyboard can help you squash the competition, so up your game! Here are some of our favorite new keyboards on the market right now.

This aircraft grade aluminum keyboard is built to last. Made specifically for gamers, it is extremely durable and can handle the intensity of long-term gameplay. It’s also lightweight, unlike other bulky gaming keyboards. The keys have multicolor backlighting that is adjustable, making your game visually stimulating even off-screen. The Corsair K95 can store up to three profiles without external software and has a total of 8MB of settings. You can assign multi-key combos and other complex commands to one of its six dedicated macro keys. It also has Cherry MX Speed RBG mechanical switches to further advance your gameplay. This keyboard is a speed machine with a comfortable wrist pad for sustained comfort.

Leave your wrist and hand pain in the past. A raised, sloped area—where the keys are broken up by the triangular shape—helps create a more desirable, comfortable position for your hands. The lightweight keyboard comes in a stylish two-tone gray with a mélange Alcantara fabric wrist pad. It is Bluetooth compatible, and it screams productivity with low stress. The battery life can last up to 12 months.

This wireless keyboard has concave keys to snugly fit your fingertips, creating an ultra-comfortable typing experience. It connects via bluetooth and can do so to multiple computers at once. With the backlighting on, the keys automatically illuminate based on your finger proximity, offering an aesthetically pleasing and precise experience. A full charge on USB-c lasts up to ten days with backlighting on and up to five months with backlighting off.

This mini keyboard is a secret beast, registering key pressing at the speed of light via light-based actuation. It does so while still responding with satisfying feedback clicks. The Huntsman utilizes the Razer Chroma lighting ecosystem with 16.8 million backlight colors on its matte aluminum keys. These keys are extremely durable and have a smooth texture that’s pleasurable to the fingertip. Complex key commands can be assigned to macro keys with Razer Hypershift, which allows you to switch from one set of controls to another in a single click.

Every pizza lover knows that the final step in getting a great pie is the shape of the slice. There is the classic triangle, a sturdy square, and you may even see some rectangular shapes if you are dealing with a nice flatbread. Each shape promises something filling and fun.

A good slicer is key. How many times of you been let down because the cheese on your carefully chosen slice, slides off and sticks to the one next to it when you pull it out of the box or pan? We want to end your pain and suffering by offering you some options for precise pizza cutters that can cut through even the thickest layer of cheese.

This razor-sharp, stainless steel pizza cutting wheel is a great way to get even slices every time. It can cut through thick, thin, and deep-dish crusts with ease while being gentle on your wrist. This cutter is designed with an ergonomic handle to keep you in control and your fingers out of the way. It’s super easy to use and super easy to clean. With just the touch of a button, the blade will pop out of the wheel so you can clean it thoroughly in the dishwasher. When not in use, this wheel will fit nicely in the included storage base, which reduces clutter and extends the life of the blade.

This 14-inch rocking pizza cutter will give you restaurant quality cut slices. It is guaranteed to keep your toppings in place. Simply place the cutter over your pizza, in the desired direction, and push down while utilizing the natural rocking motion for a smooth slice. This magic maker is practically all blade, but not to worry, it comes with a protective cover for safe handling and a sleekly designed handle so you can get a good grip. The cutter is made from anti-rust stainless steel and can go in the dishwasher. Try it out on other foods, like brownies, cakes, veggies, and more. If you are serving pizza for the masses, Kitchenstar also has a 16-inch version for seamless slices.

A pizza wheel from KitchenAid is a classic way to get great looking slices. It has a simple, straightforward, familiar design for easy use. The wheel is made from rust-resistant, 430 stainless steel that is going to stay sharp longer. The angled handle is comfortable and features a finger guard to protect your hand from any slippage. It’s compact and dishwasher safe so you will have no problem cleaning and storing this pizza cutter. Try this wheel out on your next batch of dessert bars for an unbelievably easy cut.

While pizza scissors may seem unconventional, they are a surprisingly functional way to get your desired slice size. The Scizza from Dreamfarm is particularly great because it has extra-long 12-centimeter blades and an elevated handle so your hands are never in the way as you cut. The Scizza has a nylon base that will evenly slide underneath your pizza as you cut; it won’t scratch any non-stick pans or baking sheets and is heat-resistant up to 400 degrees Fahrenheit. The german, stainless steel blades can be taken apart for sharpening, plus they are dishwasher safe.

For years, Amazon has envisioned deploying drones to deliver packages to customers’ yards. In the company’s plan, an electric aerial vehicle would take off from a distribution center, cruise some 15 miles or less, and deposit whatever small item an American consumer wants faster than they can say, “Alexa, send me Air Jordans, but do it via the air.” (Technically, Amazon aims for the drone deliveries to take half an hour or less.)

In late August, the Federal Aviation Administration gave the company a green light to keep pushing the program forward in the national airspace; read more about the details in this FAA decision document.

Amazon calls the service Prime Air, and it relies on a drone known as the MK27, which Amazon showed off last year. Like many other drones, it employs multiple propellers that allow it to take off and land vertically, but this one pulls off an additional trick. While in cruise flight, it pivots so that the propeller shrouds become wing-like, giving the craft an aerodynamic boost as it flies more like a fixed-wing aircraft than a helicopter. That’s similar to a configuration that a much bigger cargo drone from helicopter-maker Bell uses, which can carry a whopping 70 pounds. But the Amazon concept is rated for cargo that’s lighter than 5 pounds, so it would be bringing items that are more likely to be running shoes than dumbbells.

That may not sound like much weight, but that sub-5-pound weight class actually “represents between 75 and 90 percent of the packages that Amazon delivers today,” Jeff Wilke, an Amazon executive, said last summer.

The intersection of delivery drones, airspace regulation, and a behemoth of a company like Amazon (which is less accustomed to building flying machines than, say, Boeing) is both complex and controversial. But Ryan Wallace, an assistant professor at Embry-Riddle Aeronautical University and expert in drone public policy, welcomes the development. “Many UAS [unmanned aircraft systems] operators, particularly in the commercial space, have been frustrated with the pace, or the momentum, of regulatory change,” he says. “I think this is a very positive indication that the FAA is starting to be responsive to the industry’s push forward.”

He adds that Amazon’s work will help others in the sector. “Honestly, they are blazing trails for the rest of us,” he reflects. “In addition to the FAA’s eye being on Amazon’s success, you have the rest of the industry cheering them on from the sidelines.”

Amazon does not have carte blanche to do whatever it wants with the drone deliveries. The FAA’s exemption decision applies to just one specific drone model, and among other restrictions, states that the company cannot fly at night unless they add lights, can’t fly higher than 400 feet, and can operate “only in sparsely populated areas.” In other words, drone deliveries are likely not coming to densely-packed suburbs anytime soon. They also need to have one pilot in charge of one drone—a one-to-one ratio.

The FAA’s decision document also outlined comments made by more traditional aviation-focused organizations or companies, like the Air Line Pilots Association. That group, according to the FAA, “expressed concerns with Amazon’s proposal to conduct its own internal investigations of accidents and incidents and that the petition for exemption implies the investigations would occur without government coordination.”

In other words, delivery by drone is moving forward, but there is still plenty for companies and regulators to get straight. But for now, the news is a victory for Amazon—or anyone who is excited about a potential future where their orders arrive from the sky.

“This certification is an important step forward for Prime Air and indicates the FAA’s confidence in Amazon’s operating and safety procedures for an autonomous drone delivery service that will one day deliver packages to our customers around the world,” David Carbon, the vice president for Prime Air at Amazon, said in a statement. “We will continue to develop and refine our technology to fully integrate delivery drones into the airspace, and work closely with the FAA and other regulators around the world to realize our vision of 30 minute delivery.”

Taking a bath is a wonderful way to destress after a long day. Whether you just need a quick soak or a luxuriously long float in your tub, you know it’s important to surround yourself with things that make you feel calm and comfortable. A bathtub tray is the perfect way to store your favorite bombs and bubbles or prop up a book and perch your favorite bath time beverage. These trays will really elevate your bathing experience, keeping you carefree and calm in your personal, at-home spa.

This tray has everything, literally. It comes with a candle/cup slot, book/tablet holder with a waterproof cover, phone slot, wineglass holder, and two detachable trays. It’s made of high-quality bamboo which is covered in a thin layer of lacquer to keep it water-resistant. This tray was made to fit tubs of any size; it has extendable sides that when pushed all the way in measure 29.5 inches long but can reach up to 43 inches. These sides are lined with non-slip silicone strips to protect it from sliding so you don’t need to worry about your glass or electronics falling into the warm water. This tray can hold anything and everything you might need for a relaxing soak.

Get ready to unwind with your favorite bath accouterments at your fingertips. This tray has a slot for your phone, a reinforced book prop that folds down when not in use, wine glass holder, and double hooks to hang a washcloth, loofah, or razor. It has slip-resistant arms that extend up to 39.5 inches, and it’s 8.5 inches wide. Choose your favorite finish, grab your favorite candles, and get ready to unwind. If you are looking for something simple and sleek, this tray is a great option.

This bathtub caddy doubles as a portable desk and breakfast tray, making it great for almost all of your lounging needs around the house. Like many of the trays listed here, this model comes with a wine glass holder, smartphone slot, candle/cup holder, book/tablet rest, and anti-slip arms. It also features two extendable/removable trays for accessories, bath products, and more. The tray can reach up to 42.9 inches with sturdy, foldable legs that can extend up to 10. 4 inches, perfect for balancing on the bed or other flat surface. This is a tray that everyone, even the bath naysayers, can enjoy.

If you don’t necessarily need all the bells and whistles for a great bathing experience, then this simple, crisp tray might be the one for you. This acrylic caddy has two sturdy handles and a non-slip bottom. It is a great way to bring your favorite beverage into the bath, rest a candle, or hold some of your best bath products. This tray measures 33 inches wide and 9 inches deep, which will be suitable for most tubs. It’s a stylish way to store your most used salves, salts, and scrubs.

What’s the weirdest thing you learned this week? Well, whatever it is, we promise you’ll have an even weirder answer if you listen to PopSci’s hit podcast. The Weirdest Thing I Learned This Week hits Apple, Anchor, and everywhere else you listen to podcasts every-other Wednesday morning. It’s your new favorite source for the strangest science-adjacent facts, figures, and Wikipedia spirals the editors of Popular Science can muster. If you like the stories in this post, we guarantee you’ll love the show.

While you’re here, don’t forget to snag tickets to our next (virtual) live event, which is happening on September 15!

FACT: Spiders love to live in cars, but maybe not for the reasons you’ve heard

By Sara Chodosh

I don’t know much of anything about cars, but I do know that they’re not supposed to have spiders. So when I first heard the story about how Mazda6 sedans were apparently overrun with yellow sac spiders to the point of requiring a recall of more than 100,000 vehicles, I kind of accepted it at face value. 

Then I realized that I do actually know some things about spiders (a heck of lot more than I know about cars), and it seemed odd that an arachnid would be attracted to the smell of gasoline—the commonly cited reason behind Mazda’s fuel tank issue. Sure, some people love the scent, but why would a spider? As I explain in the episode, the olfactory explanation doesn’t actually pass the sniff test—which led me to wonder why a particular vehicle might experience widespread yellow sac infestations.

The major complicating factor here is that spiders are everywhere. Seriously. You don’t realize how many spiders are in and around your house right now. While the oft-repeated “fact” that you’re never more than three feet away from an arachnid is not technically true, that’s only because the world is such a heterogeneous place—you might be a few hundred feet away from the nearest spider if you’re in a mall parking lot, but there may be multiple critters within a few inches of you if you’re standing in the grass! The main takeaway is that spiders can be really tiny, there are lots of them in the world, and there’s bound to be at least one kind of eight-legged creepy crawler that enjoys living in any given environment—your car included. But don’t freak out: Spiders are generally helpful creatures.

You’ll have to listen to the episode to find out the strange journey I went on to track down the answer. For now, I’ll say that this was a big exercise in how a great story can become so pervasive that it seems true.

FACT: Racism and weather science once collided to kill thousands of people

By Kendra-Pierre Louis, Reporter for the new podcast How to Save a Planet

In September of 1900, a hurricane hit the bustling island city of Galveston, Texas and killed at least 10,000 people. As the deadliest natural disaster in US history, the storm gets plenty of attention—but most people present it as an unavoidable tragedy. No one knew it was coming, lots of people died, and these days we can do better.

But you don’t have to look too closely into the Galveston storm to realize those deaths were, in fact, completely avoidable. The city’s residents could have been told about the hurricane far enough in advance to evacuate, thanks to Cuban Jesuit priest and meteorologist Father Benito Viñes. He and the other priests at his observatory were particularly adept at reading the clouds for storm intensity and trajectory, and he tried to warn Texans about the incoming threat. But the US Weather Bureau had an aggressive policy of squashing Cuban forecasts—which they saw as backwards, unscientific, and liable to incite unnecessary panic.

FACT: The N95 mask was inspired by a bra cup—and the woman who designed it is also behind the greatest snack food ever invented

By Rachel Feltman

I’d like to talk about ribbons, bras, and N95 masks.

Born in Manhattan in 1917 to a pair of poor Jewish immigrants from Russia, Sara Finkelstein was a real 20th-century thinkfluencer right from the start. In her two decades as Decorating Editor for House Beautiful, she helped pioneer such concepts as the “family room” and living with a roommate to split expenses.

But her real impact started in the late 50s, when she set off on her own as a design consultant. Now going as “Sara Little”—she was 4′11″ and had frequently been called “Little Sara” in the early years of her career—she helped dozens of companies design and market products that people would actually find useful. That was more radical at the time than you might think: Up until that point, most mass-market products were designed based on what retailers said they wanted, not based on what consumers said they needed. Her accomplishments are astonishing, and we probably don’t know about most of the products she worked on. A few highlights:

1. She’s responsible for the first successful boxed chocolate cake sold in England, because she figured out that American cake products were flopping due to the differences between “cake” and “pudding.”
2. For Corning, she used materials developed for ballistic missiles to create freezer-to-oven-to-countertop dishes. She <i>also </i>developed the ergonomic lid tops that are so ubiquitous today—allegedly by watching how tigers grasped their prey.
3. She reportedly convinced a cosmetics company to sell matte makeup products after getting very interested in Geisha culture in Japan.
4. She once went to various prisons to interview professional lock-picks to help her design a better lock.
5. She helped create both Bacos, aka bacon bits, and Bugles, aka the greatest snack of all time.

But these days, Sara Little Turnbull (the professional name she adopted upon marrying in her late 40s) is best known for her influence over a now-ubiquitous product: The N95 mask. In this week’s episode, I dive into the myths—and fantastic truths—of her journey from working with gift wrap ribbons to reinventing the face mask. I’m ready to write the TV show about Turnbull’s fabulous career at absolutely any time.

If you like The Weirdest Thing I Learned This Week, please subscribe, rate, and review us on Apple Podcasts. You can also join in the weirdness in our Facebook group and bedeck yourself in Weirdo merchandise from our Threadless shop.

Follow all of PopSci’s COVID-19 coverage here, including breakdowns of the safest swimming options, safest dining options, and a tutorial on safest long-distance travel options.

Since coronavirus cases started to climb back in March, scientists have been struggling to identify drugs and other therapies that can treat COVID-19, the disease caused by the novel virus. Unlike many bacterial invaders that are thwarted by antibiotics, there aren’t many pharmaceuticals that help us beat viral infections. Last week, the FDA issued an emergency use authorization for a treatment called convalescent plasma. The therapy isn’t new—in fact, it was used in the 1918 flu pandemic. Here’s everything you need to know about the treatment, what it does, and how well it works.

What is convalescent plasma?

When your body comes into contact with an infectious microbe (like a bacteria or virus), your immune system generates antibodies to fend off the invader. Those antibodies remain in your bloodstream for some time (it varies by person and infection) even after you’ve recovered to help you fend off future infections with the same microbe. That’s exactly what people’s immune systems do when they come into contact with SARS-CoV-2, the virus that causes COVID-19.

The antibodies rest in the blood’s plasma, which is the liquid material that holds blood cells. Scientists think that antibodies that helped one person fight off COVID-19 could help another person who’s also been infected with the novel coronavirus. So, in a person who successfully fought COVID-19, doctors remove some of their plasma, isolate the antibodies, and inject them into another person who is currently battling the disease.

The theory is that if you give someone with COVID-19 these antibodies—or convalescent plasma—early on in their illness, then those antibodies might start fending off the virus even before the recipient’s own immune system makes custom antibodies. That extra boost, so to speak, could help provide a better outcome for someone that might have had a severe bout of COVID-19.

Which diseases has it worked on?

The use of convalescent plasma has been around for around 100 years and has been used to both prevent and treat various infectious diseases throughout the past century. In fact, doctors and researchers have used the treatment for outbreaks of polio as well as past pandemics, including the 1918 flu. It’s also been used as a treatment for rabies, hepatitis B, measles, Ebola, MERS, and SARS. Because SARS and MERS are both coronaviruses, a few reports showing small amounts of success with convalescent plasma led researchers to try using the therapy in COVID-19 patients.

How well does it work?

Since the start of the pandemic, there have been a number of case reports on the effectiveness of the treatment. Many of them weren’t controlled studies, however, and most times the patients got a number of other treatments—like steroids, antivirals, and other drugs—in addition to the convalescent plasma. So, it’s hard to tell how well the plasma treatment worked on its own from those case reports.

In August, the Mayo Clinic released the results of a study they conducted on convalescent plasma that included more than 35,000 people. It found a small decrease in the death rate in folks who received the treatment, particularly those who received it early in their diagnosis. It also found that people who received transfusions of the plasma within three days of their initial COVID-19 diagnosis had an average death rate of 8.7 percent, whereas those who received the treatment after four days or more had a death rate of 11.9 percent.

Still, the study hasn’t been peer-reviewed, and it didn’t include a placebo group, meaning that there’s no group of COVID-19 positive people who received identical care other than the addition of the plasma treatment to compare to.

Further, each of the patients in the 35,000-person trial also received at least one more form of therapy—an antiviral, antibiotic, or corticosteroids, for example.

In the US, there are now a number of studies investigating how well convalescent plasma works on COVID-19 that do include a placebo and more rigorous testing, but most of them are still ongoing and results are not yet available.

Because of the weakly positive results of the Mayo Clinic trial and the other case reports, scientists around the country, including Anthony Fauci and the head of the National Institutes of Health and, initially tried to get the FDA to hold off on giving the plasma treatment emergency approval. Some researchers think the convalescent plasma case represents in some ways how all treatments for COVID-19 are being studied. “It raises the question of what strength of evidence is necessary to treat during a pandemic,” Harlan Krumholz, director of the Center for Outcomes Research and Evaluation at Yale New Haven Hospital, told STAT.

Is it risky?

Convalescent plasma appears to be safe. Severe adverse events in the first four hours after the transfusion was reported in less than one percent of people who received the treatments. That included at least 72,000 people.

Are there similar, better treatments?

Some scientists and drug companies are working on designing and creating monoclonal antibodies, which are lab-made versions of the same antibodies our immune system naturally produces, that specifically target SARS-CoV-2. They would be infused into a person’s vein in a similar way to the current convalescent plasma. There are some ongoing clinical trials, but no definitive results yet.

Nothing’s more important than staying hydrated when hiking, and an excellent way to do this is with a hydration bladder. These water containers sit in special pockets on most hiking packs, which have an opening for the bladder’s drinking tube so you can sip throughout the day while keeping your hands free for other things. It’s more efficient than a water bottle, and the contents usually last longer, too. Hydration bladders come in many different sizes, so it’s important to judge how much water you’ll need for your hikes when choosing which bladder to bring.

When purchasing a hydration bladder, pay attention to durability, weight, and closure type. You want something that will stand up to the rigors of the great outdoors, but won’t weigh you down. You also want to make sure the opening allows easy access to the inside of the bladder so you can thoroughly clean it.

With a good hydration bladder in your pack, you’ll be ready to get outside without worrying about quenching your thirst.

The Widepac has a three-liter capacity, and is made from a three-layer polyethylene material treated with an antimicrobial agent and Source’s “GrungeGuard” technology to prevent the growth of bacteria. The wide-slide closure makes refilling simple, and the drinking tube can be disconnected from the reservoir by pushing a button at the connecting joint. The helix bite valve, which opens the flow of water by applying pressure, comes with an included cover.

The Platypus Big Zip has a three-liter capacity, and features a switchable tube set-up that can plug into either the bottom or a connection point halfway up the bladder. The zip-top is easy to fill, and the durable plastic reservoir, which features dual-layer construction, uses silver-ion technology to help prevent bacterial growth. The bite valve features a twist lock for additional protection against leaks, but it doesn’t come with a cap to keep out dirt—that needs to be purchased separately.

This two-liter hydration bladder has an easy slide-seal top opening that closes tightly, but also provides wide access for easy filling and cleaning. A rigid backplate makes it easier to insert the bladder into a backpack’s hydration sleeve, even when the pack is fully loaded—but that does add some weight. The bite valve can be locked with a quarter-turn twist to help prevent leaks, and the whole unit is dishwasher safe for easy cleaning.

This hydration bladder, which holds three liters of water, features an easy-open snap closure on the reservoir that makes refilling or cleaning the system a … well, a snap. The large ergonomic handle is easy to grab and go, and a self-sealing bite valve prevents leaks. CamelBak uses its “Hydroguard” technology that inhibits bacterial growth, and the bladder is made from 100 percent BPA-, BPS-, and BPF-free plastic.

If you’re looking to take your workouts to the next level, ankle weights will do the muscle blasting trick. Strap them on while you’re doing strength training routines like leg lifts, donkey kicks and planks, and they’ll put your lower body through the ringer (in a really, really good way).

Burn more calories and firm up your glutes, quads, and hamstrings with these exercise accessories.

Choose between Henkelion’s three weight options (2-, 3-, 5-pound) and five colors (purple, pink, grey, blue, black). You can adjust the size if you want to use them as wrist weights, allowing for a more heavy duty arm workout. Enjoy a lightweight cotton material and a silver reflective strip, perfect for late night outdoor exercise.

A sturdy metal loop holds tight, to make sure that this pair of ankle weights stays put, no matter how strenuous your workout gets. Quickly adjust the weight by adding or subtracting from the five removable pockets, which hold between one to five pounds. The anti-fray design means you won’t have to deal with all the wear and tear that comes with regular use.

Adjust the resistance of these ankle weights by adding or removing the iron rods, which total between three to five pounds. Made from stretchy neoprene material, they fit comfortably around your ankles or wrists (hooray for no more chafing!) You’ll also get a free workout guide and videos, with exercises that are designed around your new weights.

Whether you’re just starting your fitness journey or are already a workout pro, you can easily customize the challenge level of these ankle weights. Choose from a wide variety of weight sizes, ranging from 1-10 pounds total. An adjustable velcro band makes it easy to create the best fit for your body and the durable, light cotton material helps whisk away sweat and moisture.

Modern fitness trackers often try to set themselves apart by adding more advanced hardware and sensors inside. Now, many high-end trackers and smart watches include ECG devices for tracking heart rhythms—one company, Withings, even promises sleep apnea detection in its upcoming wearable.

Amazon, however, has decided to set its new fitness device apart from the rest by relying heavily on AI algorithms and listening to your voice. The $99 device is called Halo and it has a heart rate monitor inside, as well as an accelerometer, temperature sensor, and no screen all. It tracks the typical fitness stuff you’d expect like steps and pulse trends. But, It also has a pair of microphones, which are important for the device’s most interesting—and so far, controversial—feature, called Tone.

When you first set up Halo, it asks you to read a few quotes from classic literature. It uses that information to build a voice profile of how you typically speak. The device will then listen to you as you talk during the day and use an algorithm to give you a positivity score regarding your speech. If it determines that you don’t have enough positivity when you talk, it will give you suggestions about how to cheer up your speech pattern.

Many people already fear that smart assistants like Amazon’s own Alexa are already listening to everything they say, which makes the prospect of strapping a dedicated listening device to your wrist all day seem dubious. Amazon says that the watch will intermittently listen throughout the day, or you can specifically trigger it to listen for up to 30 minutes by pressing the button. There’s a hardware switch to turn off the microphones completely, but that defeats one of the key functions of the device.

Amazon has tried to get out ahead of the obvious security concerns involved with Tone. The company claims that all of the speech processing and analysis happens in the app or on the device itself—it never makes its way to the cloud. Once the processing is done, the recording gets deleted and isn’t saved anywhere. That’s a departure from how Alexa works—you can go and listen to recordings of your Alexa requests right now by logging into your Amazon account.

Even with secure recordings, there’s still the somewhat murky issue of just how the algorithm perceives your speech patterns. Obviously, a person’s speech patterns can change for a variety of reasons, whether it’s their mood or a simple stuffed nose.

Amazon isn’t alone in this department: Grammarly, the online copy editing tool that checks your spelling and grammar as you type, has a similar tone detection service that analyzes the phrases you type and tells you how it perceives your words with a simple emoji. It can rate your typing with qualifiers such as “accusatory,” “formal,” “encouraging,” or “regretful.” Since it’s happening with typing, it’s obviously working on a different level than Amazon’s technology, but it could have a similar effect on guiding how users communicate. The “neutral” rating in Grammarly comes with a straight-faced emoji that looks unimpressed or negative. I have it on right now and it suggests the tone of this post is “concerned,” which isn’t totally inaccurate.

It’s clear that Amazon plans to expand on its Halo brand more in the future. The band costs just $99, but it will likely enjoy the regular cycle of deep price cuts that Amazon typically employs in order to bring people into its infrastructure of services. Right now, you can pre-order a Halo for $65, which includes six months of the Halo subscription (typically $3.99 per month).

Once you’re in the system, Amazon plans to keep users by implementing a health points system, a familiar technique for fitness trackers. You get a base goal of 150 somewhat nebulous points per week. You can earn them by walking, but you can earn more by running. You lose a point for every sedentary hour you spend per day beyond the eight it expects you to spend at your desk. It’s reminiscent of Nike’s Fuel Points from when it made its own fitness tracker.

Voice tone doesn’t factor into your points total, but the features together put a strong emphasis on encouraging users to shape their behavior around the AI-driven suggestions. It’s not uncommon to feel like you’re letting your fitness tracker down when you don’t hit your goals. Now, your tracker can hear the sadness in your voice when you talk about your failure—and it can give you some AI-based tips on how to sound more chipper.