When we go into the spaceship, we enter through the kitchen. So the Frog with the one eye shows us her fridge. Because we are sandwich lovers, we ask her to show us how to make a sandwich in space. 

That’s when it’s appropriate to explain that everything ‘floats’ in space. But, It doesn’t really float!

I’ll tell you a secret: things don’t really ”float” in the space station. What’s actually happening is that they in free fall. But everything in the space station is falling at the same time. So it looks like things are floating, but they are really ”falling”, they are in acceleration.

Einstein’s happiest thought is just that! 

When you are in free fall, lack of gravity and acceleration look the same. At that moment, you don’t know if there is no gravity or if everything is accelerated. You can’t tell the difference. And that’s why it’s called the principle of equivalence.