Despite being thinner than human hair and lighter than cotton, spider silk is stronger than steel — and it isn’t even close. According to Science magazine, the insect-trapping, egg-protecting material is a full five times stronger than steel of the same diameter. It’s also highly elastic and can hold its strength at extreme temperatures, making it one of the most versatile substances in the world.
Only about half of all spiders spin webs, but all of them produce silk — which is as lucky for us as it is for them, considering how many uses it has. Ancient Greek soldiers used cobwebs to reduce bleeding, and it’s even been used in body armor developed for the U.S. military. So the next time you get scared after seeing a spider, just think: Its silk may one day save a life.
Evidentialism Factslap: Every planet has a winter solstice.
Earth is unique among planets in our solar system in a number of ways — a habitable atmosphere being chief among them. But when it comes to solstices, Earth is just one in a crowd. The winter and summer solstices represent the shortest and longest days of the year, respectively. Because of the Earth’s 23.5-degree axial tilt, certain parts of the planet lean toward or away from the sun, which creates the seasons. It’s during the solstices (December 21 to 22 and June 20 to 22) that the planet reaches its maximum tilt away (or toward) the sun, depending on the hemisphere you call home.
Solstices also take place on other planets, but not quite in the same way. Both Mercury and Venus have little axial tilt, so they don’t experience seasons as Earth does. Mars, however, has a very similar tilt to Earth at 25 degrees, and the planet’s ice cap will grow and recede according to the seasons. Although Jupiter has a minuscule axial tilt, Saturn’s axial tilt at 26.7 degrees means solstices there are truly something to behold — during the planet’s summer solstices, its rings become intensely illuminated as they reflect the sun’s light.
However, Uranus is the true oddity. With an axial tilt of a whopping 98 degrees, the planet’s poles point directly toward the sun during its solstices. When Voyager 2 took images of the planet in 1986, Uranus was experiencing its southern hemisphere’s summer solstice, with that hemisphere bathed in continuous light while its northern hemisphere was trapped in frozen darkness. So although all planets have solstices, no two are exactly alike — and Earth’s remain something special.
