Re: is there gravity in space?

Joey -

There is gravity where ever there is matter, where ever there is energy, and in all the space in between. The closer you get to matter (planets, stars, comets, or anything else), the stronger the gravity gets. The farther you get, the weaker it gets, but it never goes away completely. And there are places where the gravity is so small that it would be hard to measure.

Gravity is a field of energy that comes from matter, and the field reaches forever, but may not be noticably felt a great distances.

There are some locations in space where you might feel very little gravity, even though you would be very close to matter...

For example, there are spots that are between the Earth and the Moon where the gravity from the Earth is exactly as strong as the gravity from the Moon and they cancel out. (But you would still feel the gravity from the Sun.)

And here's something interesting... IF you could dig a hole to the center of the Earth, you wouldn't feel ANY of the gravity coming from the Earth! The reason is this: Pretend that you can cut the Earth exactly in half. Each half of the Earth would generate gravity. If you are in the middle, exactly between the two halves, the gravity from one half pulling you one way is exactly as strong as the gravity from the other half pulling you the other way and they cancel out, just like with the Earth and Moon example above!

When you are on the surface of the Earth, all of the Earth is below you pulling down. But if you're at the center of the Earth, there is just as much of the Earth above you as there is below you, so there is just as much gravity above you as below you.

If you found yourself floating as far out in space as you could possibly imagine, there would still be gravity. It might be pulling you so weakly that you may NEVER have felt it before you grew old and died. But it's there... holding the universe together.

Shel

Note added by the moderator:

It all depends on what you mean by gravity. If it is the feeling of "weight," then a free floating astronaut has none, but one in a rocket that is accelerating feels heavy. Similarly, a free-falling bungee jumper feels weightless for a a few seconds, but you and who are standing and supported by the surface of the Earth feel heavy.

Shel is of course right that the attractive force of gravity is pervasive in the universe and impossible to escape.

Marc Herant, astro moderator