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  • Hey, Vsauce, Michael here, and subscribing to Vsauce is a no-brainer. Or is it? I mean,

  • you would need your brain to understand the words that I was speaking, and you would need

  • your brain to decide whether or not you liked what you were hearing. You would also need

  • your brain to move your muscles in just the right way to click the subscribe button. In

  • fact, you need your brain to do a lot of stuff, and, without a brain, well, you can't do much

  • of anything at all. So, literally speaking, is there really such a thing as a "no-brainer?"

  • Let's begin with no-header's...decapitation. It's a macabre subject, I know, but what's

  • the matter? Are you chicken? Ok, good. Because Mike certainly was. In 1945, farmer Lloyd

  • Olsen went out to grab a chicken for supper. He cut the chicken's head off, and it didn't

  • die. Mike The Headless Chicken lived for another 18 months. He toured the country and surprised

  • onlookers, he could walk and perch, and was fed by putting little drops of water or pieces

  • of grain down his throat. But, here's the thing- Mike The Headless Chicken's actions

  • weren't a no-brainer, because even though he didn't have much of what we would call

  • a "head" left, he did have a bit of his brain stem.

  • If we want a clearer no-brainer, we're going to have to look at an even more simple creature,

  • the cockroach. These guys don't even breath through their heads so, without one, they're

  • fine. Instead, they breath through holes all over their bodies. And instead of being controlled

  • by a big, massive brain, they have little bundles of nerves, ganglia, throughout their

  • body, and so, even without any head parts, even when completely decapitated, a cockroach

  • can live for weeks. It can walk around, respond to movement- really, its only problem is that,

  • without its head, it will eventually starve to death.

  • Us humans are not nearly as fortunate. Without a head and brain we die within seconds, if

  • not instantly. But, before you get jealous, keep in mind that with our heads intact, we

  • are capable of some actions that don't necessarily require the brain: reflexes. When you snap

  • your finger, your finger moves at about 20 mph. And a really big sneeze can expel air

  • at nearly 30-40 mph. But nerve impulses- they're really quick. They can clock in at 250 mph,

  • but, sometimes, that's not even fast enough. For instance, if you accidentally put your

  • hand on a hot stove, cells are dying quickly. And 250 mph doesn't cut it, you need to take

  • an action, fast. It's not worth it to tell your brain what's happening right away. And

  • so, instead, your immediate reaction to pull away is mediated by other parts of your nervous

  • system. The same can be said for involuntary and unconscious processes.

  • So, in a way, these unconscious, involuntary, or reflexive behaviors could be considered

  • no-brainers. But, I'm not quite satisfied yet because they still require that your brain

  • be there, keeping you alive. So, what if you weren't alive? Well, in your dead, brainless

  • body, your muscle cells still contain a little bit of energy in the form of a ATP.

  • Backyard Brains, right here on Youtube, demonstrates this with insect parts. This leg is no longer

  • connected to a brain or a body, but energy remains in the cells. And so, researchers

  • can detect electrical signals when the leg is touched, or even simply breathed on.

  • "Whoa, that popping sound you're hearing is the spontaneous discharge rate of the living

  • neurons in the still-living leg."

  • The muscle cells of a human limb would respond in just the same way. But you don't need wires

  • to observe behavior like this. Salt can also do the trick. The introduction of sodium ions

  • can cause a process similar to an action-potential in a living animal. Salt added to these fresh

  • frog legs makes them dance, though not for very long. The cells will eventually run out

  • of energy, or simply decay. But, to be sure, there are many other brief candidates for

  • no-brainers at the moment of death. For instance, muscles relaxing, causing a person to soil

  • themselves. Technically, a no-brainer. But it's a misconception that a corpse continues

  • to grow fingernails and hair; instead, it's actually the skin, itself, shrinking as it

  • dries, making hair and nails appear longer.

  • But, let's take a closer look at these skin cells, because we might be on to a quite satisfactory

  • no-brainer. Your skin cells live on the periphery of your body, and they don't require a constant

  • stream of new nutrients from your blood. And, so, even though you are dead and your brain

  • is no longer calling the shots, your skin cells can continue to live, gathering nutrients

  • through osmosis, and dividing for days. In fact, you can harvest skin cells from a corpse

  • after 24 hours.

  • On a related note: digestion. Sure, a lot of the digestive processes completed by you

  • being alive and having a nervous system that works. But, part of the work is done by bacteria

  • that just happens to live inside your gut. And when your dead or your brain is gone,

  • they'll continue digesting. So, in a way, making poop, at least part of that process,

  • is a no-brainer.

  • But here's the thing, these bacteria that live inside you are foreign bacteria. Are

  • they you? For that matter, what about the skin cells that continue to live after you're

  • dead? Are they you, or are they merely cells that you have made a good home for? We're

  • getting pretty philosophical here because we're basically asking if you are merely your

  • brain, and everything else that goes on when you no longer have one is just other stuff

  • that you aren't doing?

  • You can argue that without a brain your body no longer has your intentions. It no longer

  • does things because you have decided to do them. In other words, a no-brainer may be

  • impossible for you to do because it requires not using you...

  • If you are merely what your brain does and not what your cells do off on their own when

  • the brain is gone then, in a way, being you, being alive, is a yes-brainer.

  • Another great yes-brainer is checking out Vsauce3. You can find some scientific video

  • game analysis, some gamer LÜT, and some pretty cool apps to download. Go check that out and,

  • as always, thanks for watching.

Hey, Vsauce, Michael here, and subscribing to Vsauce is a no-brainer. Or is it? I mean,


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B1 中級

脳がないと何ができないのか? (What Can You Do Without a Brain?)

  • 138 14
    smilehumanbeing に公開 2021 年 01 月 14 日