What is “space time” and how does it “bend”?

Question

I’ve heard the term “space time” thrown around, and that gravity “bends space-time” but how does that work?

In: 16

Answer 1

Imagine a large bedsheet, being held up at all four corners. If you drop a marble in the middle, it’s going to make the bedsheet sag, or “bend”, in the middle.

If you drop a baseball, or a bowling ball in the middle, it’ll make the bedsheet sag even more. If you drop the marble in with the bowling ball, it’ll roll right towards the bowling ball, along the fabric of the sheet.

It works similarly with spacetime. Mass bends spacetime in such a way that it attracts things with mass towards each other. The more mass, the more bending, and the more attraction.

Edit: [here’s a literal children’s book about it.](https://old.reddit.com/r/nextfuckinglevel/comments/w4x3ds/books_for_babies_that_are_on_another_fucking_level/)