Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Chris Burgess on 12/04/2009 16:30:01

Title: Does anti-matter curve space in the opposite direction?
Post by: Chris Burgess on 12/04/2009 16:30:01

Chris Burgess  asked the Naked Scientists:
   
Hi Chris,

If matter curves space inward towards itself, does antimatter curve space outward away from itself?

If a gravitational field is an energy field (Kip Thorne says so), then using mass/energy equivalence, can a unit of mass/matter be converted into a unit of contracting gravitational energy/space?

Can antimatter be converted into a unit of expanding gravitational energy/space?

If true is this why we live in an expanding universe where most of the antimatter was converted into units of expanding space?

Thanks,
Chris Burgess

What do you think?

Title: Re: Does anti-matter curve space in the opposite direction?
Post by: Vern on 12/04/2009 17:18:20

All of the theories that enjoy any acceptance have anti-matter and matter reacting the same in a gravity field. There is very little experimental evidence because anti-matter is difficult to contain long enough to get a measurement. Both anti-matter and matter attract gravitationally and when one meets the other, they annihilate, becoming gamma radiation.

As far as I know, there is no theoretical mechanism that would produce anti-gravity.

Quote

Can antimatter be converted into a unit of expanding gravitational
energy/space?

Not by any process that I know about, or can imagine.

Title: Re: Does anti-matter curve space in the opposite direction?
Post by: LeeE on 12/04/2009 19:57:32

Just thought I'd point out that the mutual annihilation of matter/antimatter should produce a gravity wave due to the matter disappearing.

Title: Re: Does anti-matter curve space in the opposite direction?
Post by: AllenG on 12/04/2009 20:30:28

Quote from: LeeE on 12/04/2009 19:57:32

Just thought I'd point out that the mutual annihilation of matter/antimatter should produce a gravity wave due to the matter disappearing.

Would nuclear reactions also produce gravity waves? There is a small loss of matter there.

Title: Re: Does anti-matter curve space in the opposite direction?
Post by: syhprum on 12/04/2009 21:01:36

Any movment of mutualy gravitating bodies results in the generation of gravity waves.
I have read that Jupiter radiates 20 Watts somewhere.

Title: Does anti-matter curve space in the opposite direction?
Post by: Mr. Scientist on 13/04/2009 08:08:32

I would imagine so. An antigravitational object would be like ''opposising the curvature'' which would deflect a antigravitational object away from normal gravitating objects.

Title: Does anti-matter curve space in the opposite direction?
Post by: swansont on 13/04/2009 19:19:09

Quote from: LeeE on 12/04/2009 19:57:32

Just thought I'd point out that the mutual annihilation of matter/antimatter should produce a gravity wave due to the matter disappearing.

Why?  Gravity in GR has an energy density dependence, not a mass dependence.  You should get a reduction because the energy leaves, but not from the annihilation itself (i.e. the change in mass).  IOW, photons contribute to gravity.

Title: Does anti-matter curve space in the opposite direction?
Post by: swansont on 13/04/2009 19:20:20

Quote from: syhprum on 12/04/2009 21:01:36

Any movment of mutualy gravitating bodies results in the generation of gravity waves.
I have read that Jupiter radiates 20 Watts somewhere.

It's the acceleration that causes it, AFAIK.  Not just movement.

Title: Does anti-matter curve space in the opposite direction?
Post by: LeeE on 15/04/2009 00:35:22

Jupiter is accelerating?

Title: Does anti-matter curve space in the opposite direction?
Post by: syhprum on 16/04/2009 21:28:50

This article calculates the gravity wave power radiated by the Earth orbiting the Sun at 313 Watts at 3.17*10^-8 Hz

  http://en.wikipedia.org/wiki/Gravitational_wave

Title: Does anti-matter curve space in the opposite direction?
Post by: yor_on on 18/04/2009 01:45:15

When antimatter and matter meets they disappear. There should be no wave created, as I see it, they are 'negating' each other, and don't 'explode'. on the other hand there should be a gravitational difference as they annihilates as they both follow spacetimes geodesics.

"The only direct experimental result on antimatter and gravity comes from Supernova 1987A. This supernova in the Large Magellanic Cloud emitted both neutrinos and antineutrinos, some of which were eventually detected on Earth. Those neutrinos and antineutrinos took 160,000 years to reach Earth, and while travelling were bent from a "straight line" path by the gravity from our own galaxy. The bending with gravity changed the time needed to reach Earth by about 5 months, yet both the neutrinos and the antineutrinos reached Earth at roughly the same time (within the same 12 second interval). This shows that the neutrinos and antineutrinos "fell" similarly, to a very high level of precision (about 1 part in a million). [4] and [5] provide some background information on this."

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/antimatter_fall.html

Title: Does anti-matter curve space in the opposite direction?
Post by: Obiewahn on 27/04/2009 15:56:07

See http://www.newscientist.com/article/dn16204-does-antimatter-fall-up.html for a current experiment to verify this.

Title: Does anti-matter curve space in the opposite direction?
Post by: yor_on on 23/10/2009 04:27:49

Does that experiment say what I think I read?

That they will create Atoms????

"It will first build highly unstable pairings of electrons and positrons, known as positronium, then excite them with lasers to prevent them annihilating too quickly. Clouds of antiprotons will rip these pairs apart, stealing their positrons to create neutral antihydrogen atoms."

Thanks for that one Obiewahn.

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http://en.wikipedia.org/wiki/Positronium