Subtitles section Play video Print subtitles 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 ones—here 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.
B1 leap gravity extreme earth center survive EPIC LEAPS. 7 0 林宜悉 posted on 2020/03/28 More Share Save Report Video vocabulary