Hey, Vsauce. Michael here.And Jake. And Kevin. And we are in Santa Monica, which of course means that the quot;Vquot; in quot;Vsaucequot;will stand for the Roman numeral five, as in five questions from you guys. Our first question comes from quot;@notchquot;. He didn't ask this of me in particular,but I love how nonintuitive the answer is.Assume
an Earth that's perfectly spherical and a rope, stretched around the equator snugly. What would happen if that rope was just,say, six meters longeré Six meters isn't very much, but because of the relationshipbetween a circumference and a radius, six meters of extra rope would allow theentire rope to not fit snugly around the earth,
but one meter above it, all the way around. That's cool, but what if instead of a rope we used something more rigid, like a structure, a bridge and we built the bridge all the way around the Earth. And then, all at once, destroyed its supports. Would it floatéClearly the earth's gravity would pull the structure down,
but down is in the opposite directionfor the other side of the bridge. Well, it turns out such a scenario would be incrediblyunstable. Earth's gravity isn't equal everywhere, and if you follow @tweetsauceyou saw some great graphs showing just how much gravity changes, simply based on the density of rock below. When you factor in the Sun and the Moon,you wind up with a bridge structure that is not gonna stay where it is.If the bridge itself was indestructible, it would start
violently hula hooping around theearth, crushing things. But there's no known material strong enough to do that.Instead, you would wind up with bridge pieces flying everywhere. A sphere around the earth would be a bitmore stable, but a ringé Not so much. The ring, even if spinning, would rapidlybreak apart into smaller pieces. Last week you guys asked me a questionthat I have always wondered. Let's say I was stranded in themountains, waiting for rescuers to arrive,
but it was going to take a while.I had plenty of snow and plenty of water, but I was hungry dying of starvation would it make sense to amputate one of my legs and eat itéI mean,
What Are Eye Boogers
So, Mr. Sandman, I asked you to bring me adream, and you brought me these gross eye boogers. Ok, but, what actually is this goopy junkthat gathers in the corners of my eyes while I'm asleepé You might know it as eye boogers, sleepies,dream dust, sleep sand, or the sleep in your eyes. Scientists actually don't have a standardtechnical term for this crusty eye residue, but some call it gound or rheum.
Which is much less fun to say. Rheum is a term for any thin discharge thatcomes from mucusy parts of your body, like your eyes and nose. The kind that comes from your eyes is madeup of all kinds of junk, like mucus, dead skin cells, oil, dust, and bacteria. This delightful mixture gathers and driesto form a crusty residue in the corners of your eyes after you've been snoozing fora while. But then, why do eye boogers only seem tobuild up when we're sleepingé
Well, it turns out that gound or at leastthe things in it is kind of always there. You just don't know that it's there mostof the time. Your eyeballs need to be kept nice and wetto function, so they're protected under this watery coating called a tear film. A tear film actually has a couple of parts:an inner layer of watery mucus that coats your cornea and keeps your eyes lubricated,and a thin oily layer on top to keep all that moisture inside. So normally when you're awake, any crudthat gets in your eye is washed away by this
tear film whenever you blink. Your eyelids are a lot less active when you'reasleep, though. When you close your eyes for the night â€” oreven just for a nap â€” you stop blinking, which means you're not clearing out allthat debris. So it builds up, along with some of the mucusand oils from your tear film, and collects in the corner of your eye. And, before you know it, you have eye boogersin all of their crusty, cruddy glory. Some gound is dry and crumbly, and some iswet and sticky it all depends on what's
in your tear film. For example, people who have allergies tendto rub their eyes or produce more eye mucus, so there's more gunk floating around, whichmeans goopier eye boogers. Gross, yes. Dangerousé Not usually. But excessive eye boogers can be a sign ofa more serious health problem. People with certain eye conditions, such asoveractive oil glands or blocked tear ducts, can have more eye discharge and residue buildup. And with some infections, like pinkeye, thegunky buildup can get so bad that people can't
open their eyes in the morning! Those are some strong boogers. But don't worry for the vast majorityof people, gound is normal and harmless. Thanks to two of our patreon patrons AbbyBarnum, and a patron known only as â€œMikeyâ€� for asking this question, and thanks toall our patrons, who keep these answers coming. If you'd like to submit a question to beanswered, just go to patreon scishow. And don't forget to go to scishowand subscribe!.