# Universal Gravitation in Zero Gravity **URL:** \ **Category:** Factual Questions\ **Created:** [February 18, 2012, 12:55am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207 "2012-02-18T00:55:29Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [February 18, 2012, 12:55am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/1 "2012-02-18T00:55:29Z")
Shuttle scientists observed crystals floating in solution gravtiating together into clusters. It has been used to explain how the planets coallesed from residual matter when our sun was a newborn star. Yet, if Newton’s universal gravitation explains the behavior of these crystals (in zero gravity), then why don’t the astronuats themselves gravitate together, by the same logic??? ---
**Author:** ![Strinka](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/strinka/32/512_2.png) [@Strinka](https://boards.straightdope.com/u/Strinka)\ **Post date:** [February 18, 2012, 1:09am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/2 "2012-02-18T01:09:37Z")
Because the astronauts can move themselves around by other means, by pushing off the walls and such. That’s much stronger than gravity. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [February 18, 2012, 1:10am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/3 "2012-02-18T01:10:13Z")
If there were no other forces at work, they certainly would. However, vibration, air currents, the astronauts’ own muscular movements, etc. all serve to overwhelm the attraction of gravity. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [February 18, 2012, 2:54am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/4 "2012-02-18T02:54:17Z")
I suspect, **Jinx** , that you’re misunderstanding the bit about crystals gravitating together. There’s been much research in growing crystals in microgravity, and how it differs from full gravity, but I doubt they’ve ever had crystals in solution coming together _because of_ gravity. It’s much too small of a force. As pointed out, even the attraction between two astronauts is very very small, and any crystals in solution would have orders of magnitude less mass. ---
**Author:** ![NonrandomPerson](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@NonrandomPerson](https://boards.straightdope.com/u/NonrandomPerson)\ **Post date:** [February 18, 2012, 3:48am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/5 "2012-02-18T03:48:23Z")
Currently it holds that for planet/star formation to start the dust and gas comes together through electromagnetic forces (call it static electricity if you must). This also applies to grains of rice (as tested on the ISS) and tiny crystals. While gravity is there it is just so weak compared to electromagnetism (read: many orders of magnitude weaker). ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 18, 2012, 4:49am UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/6 "2012-02-18T04:49:45Z")
No matter how precise you got, even doing things like doing the experiment in a total vacuum and making the objects as nonstaticky as possible, you still couldn’t observe objects coalescing gravitationally on the Shuttle, because the Shuttle orbits well inside the Earth’s Roche limit. This means that the variations in the Earth’s gravitational field are more significant than the gravitational attraction between the individual particles, and so they’ll tend to be pulled apart, not together. ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [February 18, 2012, 5:00pm UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/7 "2012-02-18T17:00:55Z")
The gravitational attraction didn’t increase in space, you’re attracted to anyone walking by you in exactly the same way to exactly the same degree. You may add to your question why you don’t clump together with the crowds at the mall. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [February 18, 2012, 5:51pm UTC](https://boards.straightdope.com/t/universal-gravitation-in-zero-gravity/613207/8 "2012-02-18T17:51:14Z")
> [@Nanoda](#): > > The gravitational attraction didn’t increase in space, you’re attracted to anyone walking by you in exactly the same way to exactly the same degree. You may add to your question why you don’t clump together with the crowds at the mall. Don’t you? Very often, crowds _do_ clump together. (OK, it is not due to gravity, but still, this is a terrible example.)