Placeholder Image

字幕表 動画を再生する

  • Hey, Vsauce Michael here, and today,

  • in honor of Leap Day, I would like to talk about leaps.

  • What's the largest leap a living thing could possibly take?

  • And how does the fact that life can leap

  • possibly give us evidence that you, me, and all of us

  • are actually aliens?

  • Well, in 1903, the Wright Brothers

  • became the first humans to fly

  • in an airplane, and then a mere 66 years later,

  • we were already landing on the moon.

  • Neil Armstrong's giant leap for mankind

  • may have been a small step for him,

  • but let's put these two events in perspective.

  • The Wright Brother's original flight was so brief

  • and low, it could've completely occurred

  • inside the external tank of the space shuttle.

  • What I'm getting at here is that going from the very first airplane

  • to us landing on the moon only took 66 years.

  • But to get from the invention of the motorcycle

  • to the very first successful backflip on a motorcycle

  • didn't take 66 years.

  • No, it took nearly 120.

  • The first successful backflip done on a full sized motorcycle

  • didn't happen until the year 2000,

  • and it was accomplished by Kerry Hart.

  • Now, since then, double backflips and even triple backflips have been done on motorcycles.

  • But according to calculations done by extreme sport physics,

  • no matter how much better riders get,

  • with the current power motorcycles have,

  • you will never be able to do any more than four back flips in one jump.

  • Extreme sports in general are excellent for demonstrating physics

  • for instance, your center of mass.

  • Your center of mass is a point in space

  • where your mass is concentrated.

  • It's where your weight as caused by gravity acts from.

  • Now, humans have a surprisingly high center of gravity,

  • which makes it possible for magicians to do tricks like this one.

  • The concept of a center of mass

  • also explains why a skateboarder can increase his or her speed

  • on an incline just by changing how tall they're standing.

  • It's also the reason you can pump your legs

  • to swing higher in a swing.

  • What you accomplish by pumping your legs on a swing

  • is an elevation of your center of mass above

  • where your body actually is.

  • Now, because gravity acts at that point,

  • you're going to swing back down as if you were

  • higher up than you actually were.

  • So you gain more and more acceleration each time.

  • Geometrically speaking,

  • the center of the lower 48 states

  • is near Lebanon, Kansas.

  • But this is where things get heartwarming.

  • If you were to cut out the lower 48 states

  • and then take that shape and figure out how to balance

  • it perfectly, you would find that the center of mass

  • for the United States is a town in Nebraska called Friend.

  • Back to leaps, here's a question you may have asked yourself

  • while watching certain movies, could a snow boarder

  • escape an oncoming avalanche?

  • Well, in 2007, Popular Science Magazine said no.

  • But technically, you could.

  • Extreme sports physics points out that Galileo showed that when friction and drag are low,

  • gravity accelerates all objects at the same rate.

  • So while it's possible, it wouldn't necessarily be safe.

  • But when are extreme sports ever safe?

  • If you want to get really unsafe, let's go back to Joseph Kittinger.

  • I've covered this guy in lean backs in the past.

  • He's the guy who back in 1960 as part of a government experiment

  • jumped off of a weather balloon 102,000 feet above earth,

  • so high up that you can see the back of space.

  • But within the next few years,

  • Red Bull may have something hidden up their sleeve.

  • It's rumored that Kittinger himself may be advising an upcoming project

  • with Felix Bongardner where Felix will dive

  • not from 102,000 feet up, but 120,000 feet up.

  • The difference here is that Felix will be jumping to earth

  • actually from what we consider space,

  • and during his fall, he will literally

  • break the sound barrier.

  • His body will travel faster than sound.

  • He will become the first human to break the sound barrier

  • with their body.

  • Earth's gravity loves to pull things down towards it.

  • But the gravity we experience here on the surface is just one gravity,

  • one g—it's what causes us to weight what we weigh.

  • But when we accelerate, we experience more than 1g.

  • When the world record for the most air achieved on a snow board occurred,

  • the snowboarder himself experienced four to five g's at the base of the ramp.

  • Meaning that momentarily, his legs each had to support 700 pounds.

  • To put this in perspective, astronauts aboard

  • the space shuttle experience a peak of only 3g's.

  • More than 5g's experienced for an extended period of time

  • can easily be lethal.

  • Enter the euthanasia coaster.

  • It's a roller coaster designed to kill the people who ride it.

  • The first drop accelerates you to more than 200 miles an hour.

  • And these loops are built to provide a constant 10 g experience for one full minute.

  • It's estimated that no human being

  • could even survive past the first two loops. Why?

  • Because 10 g's exerted that way

  • would pull blood away from your brain, starving it of oxygen

  • resulting in brain death.

  • And that's just 10 g's.

  • If you were to ride on a bullet,

  • you would experience a peak g force

  • of 190,000.

  • That means that your body would weigh 190,000 times more

  • than it does stationary on earth.

  • But here's where things get muddy.

  • Japanese researchers have found bacteria

  • that not only survive, but thrive in an ultra centerfuge

  • exerting not 190,000 g's,

  • but more than 400,000.

  • The implications here are mind blowing.

  • We already know that some single celled lifeforms

  • can survive in extreme conditions.

  • Just this morning, I was reading one of Bill Bryson's books

  • about how we have actually found dormant, but viable bacteria

  • trapped inside cameras

  • left for years on the moon.

  • If simple life forms can also survive incredible g-forces,

  • that means that the entire earth was blown up by an asteroid, life as we know it

  • might not be over.

  • There may be simple life forms that could

  • survive, dormant, traveling through space

  • only to land on other planets billions of years in the future.

  • In fact, who's to say that a similar process

  • isn't what brought life here to earth?

  • It sounds crazy, but the entire concept has a name:

  • Panspermia.

  • Let's keep things grounded and stick to earth.

  • Specifically, extreme sports.

  • I had all these leap thoughts lately because I've been working with really cool extreme sport channels

  • new oneshere on YouTube including Ride with Tony Hawk, Ally Sports, and Network A.

  • If you like extreme sports, you should definitely

  • check these out, they've even got special messages just for you.

  • So, have fun, cherish the leap day,

  • and as always, thanks for watching.

Hey, Vsauce Michael here, and today,

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B1 中級

EPIC LEAPS。 (EPIC LEAPS.)

  • 6 0
    林宜悉 に公開 2021 年 01 月 14 日
動画の中の単語