Re: Why doesn't the earth just fall straight to the sun?

Dear Max,

the analogy between space-time in Einstein's theory of gravity and a stretched rubber sheet is very intuitive and very good. However, every analogy has its shortcomings. And in this case it might be a bit disleading: The Earth has its own dip. This dip stands for the attraction the Earth exerts on small bodies in its vicinity. It is not meant to impede the Earth's movement. The reason that the Earth or any other planet is not falling straight into the sun is that it has a velocity tangential to its orbit. Because of the tangential velocity the Earth tries to escape the sun, but the gravitational pull is just such that Earth neither drops into the sun nor escapes but is captured in an orbit. If the tangential velocity was less, the Earth would spiral into the sun.

I hope this helps,
regards,
Michael