Is There Gravity In Space?
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? There's weightlessness in space. You can experience the kind of weightlessness.
Why? Why are they weightless though? Is there a gravitational force on them? Yeah, but I guess it's probably really weak. Not on the astronauts, 'cause they just float around. It's like they'd float away if it wasn't for the walls of the space station, right? 'Cause 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. H. 'Cause 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 me, well played.
Think about this: the space station is only about 400 km away. So if you're in Sydney, it's about, well, a little further than the drive to Camra. 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 as 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.
And not only that, but the space station that they're in is falling as well. So why doesn't the space station come crashing into the Earth?
Well, the reason is the space station and the astronauts have a huge sideways velocity of nearly 28,000 km/h. So, even though they're falling towards the Earth, they're going so fast that as they fall towards the Earth, the Earth's 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's center, but they never get any closer. And because both objects are accelerating at the same rate, the astronauts feel weightless. They have this amazing sensation of floating.