Should You Eat Yourself?

Should You Eat Yourself?

Hey, Vsauce. Michael here.
And Jake. And Kevin. And we are in Santa Monica, which of course means that the “V” in “Vsauce”
will stand for the Roman numeral five, as in five questions from you guys. Our first question comes from “@notch”. He didn’t ask this of me in particular,
but I love how non-intuitive 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 longer? Six meters isn’t very much, but because of the relationship
between a circumference and a radius, six meters of extra rope would allow the
entire 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 float?
Clearly the earth’s gravity would pull the structure down, but down is in the opposite direction
for the other side of the bridge. Well, it turns out such a scenario would be incredibly
unstable. Earth’s gravity isn’t equal everywhere, and if you follow @tweetsauce
you 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 the
earth, 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 bit
more stable, but a ring? Not so much. The ring, even if spinning, would rapidly
break apart into smaller pieces. Last week you guys asked me a question
that I have always wondered. Let’s say I was stranded in the
mountains, 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 it?
I mean, it kinda makes sense, right?! I’d have my entire leg to eat as food,
which would probably fill me up and I would have one less limb that I would need to keep alive. The only problem is that the trauma your
body would endure from the loss of a limb would greatly exceed the benefit you would get
by eating the food. You’re better off keeping that limb on your body, because your body’s process of using
reserves of energy is more efficient than the process of digestion.
So keep the leg on and let it wither away, keeping you alive.
Don’t cut it off and eat it and digest it. How does hair know when to stop growing? It’s a good question, because the hair on my arm, which there’s a lot of, never grows any longer than this. And if I were shave my arm off,
it would grow back and stop right where it is right now. But head hair is different. For instance, my hair – what’s left of it –
would keep growing if I didn’t cut it. But no other animal has that situation.
You don’t see wolves out in the forest saying, wow, look how long my hair is
getting, I better get to the barber shop. So, why do humans have head hair that grows so long, but body hair elsewhere that stops
seemingly right when it’s supposed to. Well, first things first. The hair on your head will not keep growing for ever. Typically around six years of growth is the limit. When hair grows, it is in what is known as its
anagen phase. And for hair on your head that phase can last up to six years. But the anagen phase of hair elsewhere
on your body – eyebrows, eyelashes – is much shorter. Except in cases like this guy, whose
eyebrows grove like head hair and have allowed him to set the world record
for longest eyebrows. Humans probably lost their fur coats,
their thick body hair, because it didn’t really help us hunting
and running around sweating on the savannah. And unlike other animals,
us humans had discovered fire and could make clothing to keep ourselves warm
without needing a built-in fur coat. To be sure, long hair that falls over
your ears and neck can keep you warmer. But leading theories also argue
that long head hair may be our fault. A result of the fact that early humans picked mates that could grow longer hair on their heads. Mates that could do that were probably healthier and in colder climates literally had a built-in hat to keep their body warm. One of the questions I get the most
is about eye floaters. Those little dots or squiggles that you see
in your vision, especially when looking at a bland scene, like the clear blue sky. Eye floaters are made out of little fibrals
that occur in your eye as you age. And you can’t look directly
at them because they’re inside the fluid of your eye. Turning your eye to look
at them simply causes the fluid to move and the floater as well.
But the thing about eye floaters that I love the most is that they are almost always microscopic. You can’t see them with the naked eye, except when they are inside your eye. If you were to pull an eye floater out,
you wouldn’t be able to see it. But in your eye, it’s close enough to the retina to leave a shadow on the retina and
that’s what you see when you see eye floaters. Finally, how much would Wikipedia weight if i printed all the text out and bound it into books?
Well luckily, there’s a Wikipedia article about this very topic. The English-language Wikipedia contains
about two billion three hundred and forty five million words, which, if printed at the density of the
Encyclopedia Britannica, would equal about 1,759 volumes. Which would look like this. Altogether they would weigh about 7,000 pounds. If you’re between the ages of 13 and 18, you may want to check out the Google Science Fair. It’s an amazing competition.
These guys are great. They actually helped make that Earth bridge animation for me. So be sure to check out And I’ll keep checking out Los Angeles.
I’m here with Kevin and Jake from Vsauce2 and 3 for the first time ever. The three of us have never been in one
location simultaneously until now, so be sure you’re subscribed to us, because amazing videos will come soon. And as always, thanks for watching.


  1. Wanna know how you can tell you're watching this in 2019? All the popular comments are along the lines of-

    (me, everyone, nobody, etc): exists, question in the title, etc.
    (Michael, something in the video, etc): or is it?, hold my beer, anything else unoriginal , etc.

  2. 3:35
    In Australia a farmer found a sheep he had lost ages ago, it was roughly the size of a small car and had enough wool on it for 40 jumpers/sweaters

  3. You dont see wolves saying "look how long my hair is i need to get to the barber shop."

    Of course not wolves dont speak!

  4. Not the best idea to eat snow, its cold which in return will lower your core body temperature. Well, if you have a water bottle or other container to fill with snow and heat up with your breath, go for it

  5. 3:58 ur telling me after I'm 6 years old my hair should have stopped growing?? (presuming it started growing when i was born)

  6. the molecules we are made up of were in the air ever since the dinosaurs so when we are buried underground those molecules are becoming trapped in that closed coffin therefore meaning we are running out of air almost every year. One day humans will indeed have to open up coffins to spread the now dirty air which will cause extinction. I have solved the greatest riddle of mankind. But that will happen in a few million years if you ask me. Hummans will go out because of lack of air . I have truly foreseen the future

  7. i saw this on my reccomended and i was like oo 6 hours ago then i see a comment being like when you realise this was made in 2013 and its like :O

  8. The hair on your head comes from a scalp not from skin. Scalp doesn't have the same governor as skin does when the hair is growing. But hope does your skin know when your hair is cut?

  9. you know you can actually survive on an island without food if you eat a part of your finger and wait for it to grow back , it will only grow back if it still has a piece of nail still on , so if you asking about water , apparently my school said you can drink fishes eyeballs 😛 , so you can survive your whole life on a island without food.

  10. 𝗡𝗼𝗯𝗼𝗱𝘆:
    𝗔𝗯𝘀𝗼𝗹𝘂𝘁𝗲𝗹𝘆 𝗡𝗼𝗯𝗼𝗱𝘆:

    𝗩𝘀𝗮𝘂𝗰𝗲: 𝙎𝙝𝙤𝙪𝙡𝙙 𝙮𝙤𝙪 𝙚𝙖𝙩 𝙮𝙤𝙪𝙧𝙨𝙚𝙡𝙛?

  11. Hi i have a hard maths question. In a room are 7 Canadians, 5 Americans, 10 Australians, 5 Chinese and 8 Japanese people. in how many ways can they be arranged at a 15 seat, circular table, so that each country has equal representation, but no two people of one country sit together? Can you please help us

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