[Klathmon]

I always hated using terms like "orbital velocity" trying to explain things to people who don't know what it means.

The analogy I use is imagine you have a ball on a string. If you spin that ball around your head, so the string is tight, how hard do you think it would be to hit a friend with it? Now how hard would it be to hit yourself with it?

A friend, you just let go! The ball is already spinning and WANTS to go flying out further away. But to hit yourself? You are going to have to first stop the spinning, then pull it toward yourself, or just pull repeatedly on the string harder and harder until it spins faster and faster until it hits you. It's a lot more effort!

It may not make sense at first, but it's easy to forget that earth is spinning around the sun pretty damn fast, and to get near it you need to first stop (or GREATLY reduce) that spin, that orbit, and only then can you start to approach it.

[Sean1708]

> A friend, you just let go!

I'm kind of in two minds about this analogy because on the one hand it does correctly explain why it's difficult to get to the sun from the earth, but on the other hand we don't get to mars by turning the sun's gravity off.

[Klathmon]

That's a fair critique, but most people (that I've spoken to about this anyway) understand that a rocket needs to "push against gravity" to go places, they just forget or don't know that orbital velocity is a thing and what it means (or that you need to cancel that orbital velocity out before you can start using gravity, and that gravity is ultimately pretty weak)

The analogy is meant to try and explain why going toward the sun might be harder, especially when it is so counter-intuitive if you've never thought about it, and it does so by taking some liberties with parts of orbital mechanics that people already instinctively understand.

[Sean1708]

I think on balance it's a definitely a decent analogy, this was just something that jumped out at me as being a possible source of confusion. If this is an analogy that you've used successfully without this confusion coming up then it's probably not too big a deal.

[benj111]

Surely in your analogy you would need a trained hamster sitting on the ball of wool, spinning a ball of cotton, trying to hit you, rather than you trying to hit yourself?

I suspect the analogy might break down before we got anywhere useful though?