Absolute zero--that’s zero degrees Kelvin, or -459.67 degrees Fahrenheit--is understood by textbook definition to be the absolute coldest anything can be, a temperature threshold at which atoms actually lose all of their kinetic energy and stop moving completely (or at which entropy reaches its lowest value). There can be nothing stiller than completely still, and hence absolute zero is as low-energy as something can go. Right? But researchers have discovered that’s not exactly the case. By messing with the distribution of high- and low-energy atoms within a system, a team of physicists at the University of Munich in Germany has created what it defines as a negative temperature system--one that has a temperature south of absolute zero.
The researchers describe their system in terms of hills and valleys (picture this). At absolute zero, a group of atoms has no energy and is motionless, and thus all atoms are at the bottom of the valley. As the temperature rises above absolute zero that changes, but not all at once--some particles gain a lot of energy, and some gain just a little, so now the atoms have different energies and are spread along the slope of the hill, stretching from valley to hilltop. Physics says the most disordered state of this system occurs when there are an equal number of particles at every point along the slope, and that’s the top of the positive temperature scale--increase the energy any further and the particles would no longer be evenly spread, lowering the system’s entropy (for a more detailed description of all this, click through to New Scientist’s write-up).
The point is, you’re in the positive temperature scale when you have some number of high-energy particles atop the energy hill and some larger number of particles in the valley. So to reach their theoretical negative temperature scale the U. of Munich researchers forced that model to flip, placing more high-energy particles atop the hill than in the valley. Says New Scientist:The resulting thermometer is mind-bending, with a scale that starts at zero, ramps up to plus infinity, then jumps to minus infinity before increasing through the negative numbers until it reaches negative absolute zero, which corresponds to all particles sitting at the top of the energy hill.
Suffice it to say that this isn’t something that tends to occur naturally on Earth. The researchers pushed their way into the negative temperature realm by placing atoms in a vacuum at just above absolute zero with most particles in the low-energy state and then used lasers to push the majority of them up the energy hill into higher-energy states. This inverse energy distribution is, on paper, a negative temperature system.
This is of interest not just because it seems we’ve drilled through temperature’s lower limit, but because negative temperature systems could assist physicists in experimenting with quantum interactions not possible in the positive temperature realm. And going negative is always interesting, especially if you’re into certain cosmological theories that posit that for every particle there is an anti-particle (a positive and a negative). For instance, there’s the universe we can see and then there’s the dark universe, whose dark energy is thought to apply negative pressure on the cosmos. Maybe that mysterious stuff exhibits negative temperature as well.
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It is scientifically postulated that something less can be achieved than being absolutely 'still'; a vacuum of stillness! How interesting! ;)
@robot, a vacuum isn't totally empty, there are things that are called imaginary particles that quantum mechanics say pop in and out of existence in a brief moment of existence. thus a true vacuum isn't totally empty. but basically from what i'm understanding of this article; they are taking atoms that are a fraction of the temperature of absolute zero kelvin and shooting a good portion of them with a laser so that they are energized, not heated, so that their electrons and protons are in a higher energy state, then they cool them down some more? or when they lose that added energy they are below absolute zero?
either way it makes some sense, ice gets colder once you've frozen all the water in it, why can't atoms be the same?
to mars or bust!
Robot, do you just sit on the computer all day waiting for new PopSci articles and then immediately post the first thing to enter your head, no matter how incoherent a thought it is?
ghost,
I understand you have focus on the word vacuum and less on the point of vacuum of stillness. Actually I was just trying to simply state something negative than being perfectly still, which I believe the article is writing about. The topic is interesting and hard to visualize. It is fascinating that some scientist this to be a reality of sorts.
Definitely read the link in the article "New Scientist's write-up" if you want to understand what they are talking about.
I've anticipated this for some time now. They actually did it achieved a temp. even below absolute zero!?! Awesome. This to me sounds like a prelude to negative energy. Which has been scientifically proven already but now can possibly become a more frequent scientific tool. Could this mean monopole magnets in our future with this? Anti-gravity implications perhaps? Time can only tell.
So this may be the start of the process by which stars invert from their core, outward.
Maybe this is the way to beat the Coulomb's limitation. I've had that 'law' in mind for a long time now, and I've always interpreted it as a limitation, not a law. Yeah, I know. Whothehell am I; right? Tungsten, beryllium, bismuth...spheres within spheres around the condensate in proper order..lithium might be another part.
Seems like if we could match, or come close, to the actual numbers of atoms of the condensate with spheres of the right materials in proper order, and then; of course, using beryllium's neutron propagation trait at the right point in the process...
It might be that we don't try to match atom for atom, but rather using the materials as a spherical propagation stream with the approximation as close as possible. Gotta have the materials ready to act as a two way street with only one lane.
Maybe scratch lithium... water-doped carbon for superconductivity...maybe each sphere is half water-doped carbon?
Maybe just one sphere of beryllium and bismuth, and then introduce water-doped carbon in the loose pile configuration that the superconductivity was discovered in...as a ring rather than trying to match that loose configuration state as a sphere...get it to spinning, and then run an electron stream at it in the opposite direction?
Maybe just stop speculating and drop some experiments. The speed of sound was considered deadly at one time. It was broken by a dude in a junk suit last year. Maybe we just can't observe and measure all the shit we talk about, just yet. I work in positive and negative numbers all day. .0001 inches tolerance isn't uncommon. We probably just can't measure accurate enough to cut the margin of error. If you change the definitions of words, and the rules of your experiment(contradictory to measurable, accepted, terms and definitions), MAN, you fly a fart to Mars with a bottle rocket.. Absolute zero should be accepted as "DEAD STOP" in this universe. Anything below that is extra-versal, or so micro-versal that we will have to revisit it's definition later, when we can measure it accurately.
Here is another nice link read in reference to the article with a little longer explanation too.
www.sciencedaily.com/releases/2013/01/130104143516.htm
Send a stream of neutrons around the BEC and pull it into the stream, with the temp lowered as here, maybe buying time, right? If so, couldn't the stream of neutrons that is pulling the BEC be guided into the center? As long as the cooling process is still working? The BEC would then be orbiting and be ready to be smashed.
@ Apoc; A Bose-Einstein Condensate is one of the possible events in the absolute zero temp range. Yeah, we can call these few Kelvins in drop a new absolute zero, but dead stop in this universe is even rarer than that. I don't know if it actually exists at all.
Except in U.S. Government, of course.
Neutrons and electrons and then neutrons again.. (bismuth? 126 neutrons at 100%, 9/2, integer)...with the proper number of neutrons to initiate the sucking of the BEC; then at contact, if you get that aim and timing right hitting it with your beam, you could be shaping a bowling ball by pulling a noodle. Smash flat when shaped, after ramping up your laser and vectoring the BEC noodle into orbit; at which point it recombines.
With what...I was wondering about an extremely well frozen, coated tungsten die set that you'd deliberately crush, but really it seems like it should be alloy. Gotta have a lot of alpha in there to work against-with that gaining beamline while it is spinning up and the whole mess is getting ready for the show.
The laser could then be just the alignment tool, discrete against the quantum approximation of all the mass as it climbs, following the...bismuth? If there were an element that light would either follow around, or shove around an initialized orbit; that may be a good one to start with.
The very high energy laser is safety equipment in this theoretical combustion engine.
The really costly part is that it may very well be cheapest and easiest to build a suitably massive, fast stroke stamping press, and use it to crush the impact chamber of the particle accelerator into a much smaller, gravity well shaped potentialty. Maybe multiple power types to accelerate the press handing off.
I'm thinking the die would have to have a coating of beryllium that is lightly spread on the outside, more concentrated towards the middle, where it's real thick.
We want some kinda grease layer under the beryllium, which I now see as drawn in chain spiral pattern descending on the center well to whatever calculated end profile. Superconducting potential material between it and the tungsten alloy dies.
Try the first compression test with uncharged die set?
It's interesting because negative temperatures interact with negative energy, essentially -#°K an object interacts with or produces negative energy.
I think Absolute Zero is impossible to attain, like absolute stillness. Only for a short while, untill something interacts with it, + or - .
Personal Thought; To that end the same applies to monopole magnets. The very idea of somthing wrenching out all the ions from your body should deter you.
~ and so science fiction was made.
i have a feeling that once we go past 0 kelvin into the negatives time travel will emerge from that study
think about it if everything at 0 kelvin comes to a standstill with no energy. doesn't that mean that once you enter the negatives they will reverse how they normally behaved. just a crazy thought of what popped up in my head
this is an excerp from the Science daily Article
“The inverted Boltzmann distribution is the hallmark of negative absolute temperature; and this is what we have achieved,” says Ulrich Schneider. “Yet the gas is not colder than zero kelvin, but hotter,” as the physicist explains: “It is even hotter than at any positive temperature – the temperature scale simply does not end at infinity, but jumps to negative values instead.”
Note this sentence:
“Yet the gas is not colder than zero kelvin, but hotter,”
According to the Heisenburg Uncertainty Principle, absolute zero can never be reached...let alone temperatures below absolute zero.
What I gather from reading the articel in Science Daily is that the researchers needed a way to describe the new energy distribution seen in the particles. A way to do this is to adjust the temperature scale to fit the results. In this adjusted temperature scale, temperatures that are actually above absolute zero are now counted as being below absolute zero...however, the newly seen partical distribution is accounted for.
I read the article in science daily. My reaction was that this seems like a bogus claim. They reduce a bunch of atoms to near absolute 0, then they add enrgry with a laser. I guess I don't understand how the distribution causes the temprature to be considered "negative" at that point.
@ matsci1 ; The uncertainty principle is that we can't know both the specific location and the speed of an object at the same time. We pollute our own studies.
That doesn't mean something can't reach absolute zero, nor according to this; does it say that it can't go below that.
I do wonder about a couple things with this. It seems to me that this has to be happening quite often in nature. Everything decays. Objects in motion tend to stay in motion. Radiation is released as heat. Space has lots of shadows and lots of water too. This being an observance of evaporative processes, I think there should be a way to see it somewhere.
I wonder if any temp readings of comets have yielded negative temperatures in the past and been dismissed?
This is how it was explained to me that reaching absolute zero would violate the uncertainty principal:
The uncertainity principal states that the uncertainty in a particles position, (Delta)X, multiplied by the uncertainty in its momentum, (Delta)P, will be greater than or equal to Planck´s constant divided by 2pi…
(Delte)X(Delta)P(Greater than or equal to) h/2pi
Momentum is mass times velocity. At absolute zero all motions stops and you can know the particles momentum exactly…it is zero. If the momentum is zero the uncertainty principal has to still be satisfied. However the uncertainty in position can not be large enough to satisify this requirement…zero times infinity is still zero…thus the Uncertainty Principal is violated.
You can get really close to absolute zero…for instance in the Millikelvin range or lower, but not to absolute zero itself.
I was looking at the Daily news artical and the quote “It is even hotter than at any positive temperature – the temperature scale simply does not end at infinity, but jumps to negative values instead.” peaked my interest. Does this mean it exceeds maximum hot? or absolute zero? or does this mean after absolute hot it jumps to negative values?
@ matsci1; No, it doesn't. Generating a BEC doesn't create something that's not moving, because it will want to move right along with the rest of the galaxy and everything else.
So, to explain that they have managed to manipulate the entropy of this system into a high energy, low entropy state they start by claiming to have accomplished the impossible (something infinite being achieved) followed by something illogical (infinitely high magically becoming infinitely low) followed by another impossibility (being infinitely low and then actually getting back to zero) and then pretty well saying "viola, below absolute zero".
I'm calling b#llsh1t.