字幕表 動画を再生する 英語字幕をプリント Have you ever looked up into the night sky and wondered what it would be like to be an astronaut floating around in the space station? Why are the astronauts floating this weightlessness in space? You can experience the kind of place. Why? Why? They're weightless there. Is there a gravitational force on them? Yeah, but I guess it's gonna be really weak. No, on the astronauts, because I just flit around. It's like they float away. If it wasn't for the walls of the space station because they're outside of Earth's gravitational pull. Oh, I see what you've done here. I see what you've done here. That's clever. Mmm. Because now I want to say that they're outside of Earth's gravitational pull. But I just said that the moon wasn't you got it Well played. Think about this. Space station is on Lee, about 400 kilometers away. So if you're in Sydney, it's about while a little further than the drive to camera. Do you really think that the earth exerts a big gravitational pull on you, but nothing on the astronauts a short distance away? Well, the truth is this The force on the astronauts is almost a cz much as the force on you. So why are they floating while you're stuck here? The answer is the astronauts aren't floating. They're falling on. Not only that, but the space station that they're in is falling as well, eh? So why doesn't the space station come crashing into the earth? Well, the reason is the space station in the astronauts have a huge sideways velocity of nearly 28,000 kilometres per hour. So even though they're falling towards the earth, they're going so fast that as they fall towards the earth, the earth surface curves away from them and therefore they never get any closer. So the space station and the astronauts inside are constantly accelerating towards the earth centre. But they never get any closer. And because both objects are accelerating at the same rate, the astronauts feel weightless.