Geekier light-up card
A geeky card is all well and good, but what about one to demonstrate that your love is electric? This DIY card uses conductive ink to power a light-up robot. Cute and affectionate, the love-bot should earn a glowing review. Difficulty: Three out of five hearts. Dan Bracaglia

90 minutes: the time it takes to make your own light-up Valentine’s Day card using conductive ink

13 billion years: the age of the oldest known star in the universe

14,000 tons: the mass of Fermilab’s unfinished, 500-mile-long neutrino detector, which saw its first particles this week

Detector Block

A worker with one block of Fermilab’s Ash River neutrino detector. The overall detector is made up of 28 such blocks.

73 percent: the alarmingly high injury rate for women’s snowboard cross during the 2010 Winter Games (see how that compares to other events here)

32 feet: the wingspan of Taranis, the UK’s new stealth drone

Taranis In Flight

It’s a stealth drone! There’s probably a human involved in piloting it. Probably.

1958: the year the world’s longest predator-prey study began on an island in Lake Superior

177,147: the number of ways to tie a tie

The Cape Knot

You could tie a tie this way, but it isn’t a Windsor knot, so you’d be incorrect.

$40,000: the money a game designer is hoping to raise via crowdfunding to produce this inventive anti-stealth videogame

Screenshot from “Nothing to Hide”

125.9 million: the number of Americans who play games on their smartphones (you could be gaming for science)

1982: the year of the first use of the smiley face emoticon, which the human brain now understands as a real face

3 micrometers: the length of a gold motor that scientists drove inside a living cell