Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: harleybarley on 23/07/2008 02:15:05

Title: Is there anything that is unaffected by gravity?
Post by: harleybarley on 23/07/2008 02:15:05

Is there anything in or on our world that is unaffected by gravity?  The only possible things I can think of are thoughts and feelings which may not be directly affected by gravity.


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Title: Re: Is there anything that is unaffected by gravity?
Post by: DoctorBeaver on 23/07/2008 07:41:05

To the best of our knowledge, everything that has material substance is affected by gravity. Thoughts & feelings are the result of electrochemical reactions and have no material substance; hence, they are unaffected by gravity.

However, experiments in space have shown that some chemical reactions proceed differently in zero gravity. Maybe one of our chemistry experts can shed some light on whether the reactions in the brain are likely to be affected.

Title: Re: Is there anything that is unaffected by gravity?
Post by: Andrew K Fletcher on 23/07/2008 09:11:15

Ahem Eth, microgravity, which is not even real microgravity but a resisting of gravity caused by the centrifugal force of travelling around the planet Earth fast enough to prevent the ship from falling back to Earth. So we cannot entertain the thought of life without gravity because even an orbiting object is still subject to the force of gravity.

Title: Is there anything that is unaffected by gravity?
Post by: DoctorBeaver on 23/07/2008 14:00:17

My apologies - microgravity not zero gravity.

Title: Is there anything that is unaffected by gravity?
Post by: Ian Scott on 23/07/2008 17:08:44

I thought we position >90% of the galaxy to be "dark matter" to explain its expansion rate - with gravity I guess but how come I don't see lumps of it on my floor?

If dark matter is so prevalent why isn't it in our houses or footpaths?

Our perhaps gravity is at question - is the formula for attraction less well conceived than it could be? Certainly I don't find "dark matter" to trip over and if so prevalent why specifically not were we live?

Title: Is there anything that is unaffected by gravity?
Post by: lightarrow on 23/07/2008 20:12:30

Quote from: Ian Scott on 23/07/2008 17:08:44

I thought we position >90% of the galaxy to be "dark matter" to explain its expansion rate - with gravity I guess but how come I don't see lumps of it on my floor?

If dark matter is so prevalent why isn't it in our houses or footpaths?

Because its density is so small that its presence doesn't even influence a bit planets' motions in our solar system; in the vast "void" between stars and stars' systems, however, its even tiny but omnipresent density, over immense volumes of space, rules out the conventional mass.

Title: Is there anything that is unaffected by gravity?
Post by: JP on 23/07/2008 20:50:48

In addition, its thought to not interact with other matter through the electromagnetic force.  Since the electromagnetic force is responsible for us seeing and feeling things that are in our paths, it makes sense that this matter might be hard for us to see and feel: i.e. "dark."

Title: Is there anything that is unaffected by gravity?
Post by: Ian Scott on 23/07/2008 21:52:27

Good answers

But is "dark matter" a ghost solution - its is so vacuous and we can't measure it in simple day to day life so therefore its plausible? I don't like untestable and therefore disprovable theories.

I'd like a piece of dark matter as a paper weight but then what would it be - would it need to be larger than a house to test the weight lifting of a fly eg?

If dark matter is here then it is here and around us - if we fail to observe dark matter then we need to try harder.

How do we know if some dark matter lands on my shoulder for example? There must be a lot of it around and obviously we wouldn't know if a piece of dark matter landed on our shoulders!