Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Antimatter hsa antigravity?

Physorg.com has an article in which a scientist suggests that antimatter repels normal matter, and is thus a candidate for the cause of the accelerated expansion of the universe. Gravitationally antimatter would be attractive to other antimatter, and only repulsive to normal matter. His theory is that antimatter is just like real matter, except that it is time reversed. Supposedly this is a result of a combination of General Relativity (GR) and Quantum Mechanics (QM). The large quantities of antimatter required would be in the large voids that have been observed in the universe.

I am going to wait for more information, from another source, before I jump on that band wagon. Not being highly trained I have no good way to actually figure out what is going on there. My main top-of-the-head problem with it is that I would think that the antimatter in the voids would clump together and make antimatter stars and galaxies. We don't see them, after all the lack of stars and galaxies in the voids is why we notice them.

Bill Gill

Hi Bill G
Apparently Anti-matter can be seen- indirectly at least.

In 1978, gamma ray detectors flown on balloons detected a type of gamma ray emerging from space that is known to be emitted when electrons collide with positrons — meaning there was antimatter in space.
Gerry Skinner, an astrophysicist at Goddard Space Flight Center in Greenbelt, Md., stated these gamma rays apparently came from a cloud of antimatter roughly 10,000 light-years across surrounding our galaxy's core. This giant cloud shines brightly with gamma rays, with about the energy of 10,000 suns.
Now, an international research team looking over four years of data from the European Space Agency's International Gamma Ray Astrophysics Laboratory (INTEGRAL) satellite has pinpointed the apparent culprits. Their new findings suggest these positrons originate mainly from stars getting devoured by black holes and neutron stars.
As a Black hole or Neutron star destroys a star, tremendous amounts of radiation are released. Just as electrons and positrons emit the tell-tale gamma rays upon annihilation, so too can gamma rays combine to form electrons and positrons, providing the mechanism for the creation of the antimatter.

The mysterious source of this antimatter has now been discovered — stars getting ripped apart by neutron stars and black holes.

http://www.space.com/scienceastronomy/080111-antimatter-space.html

I'm not really surprised that there are natural sources of antimatter in the universe. We create antiparticles on a regular basis in our colliders, so when you think of the really energetic reactions taking place in and around black holes and white dwarfs and supernovae...................> I can't believe that such large amounts would exist without leaving traces that can be found in our observations.

Bill Gill

Bill said
"I can't believe that such large amounts (of Anti-matter) would exist without leaving traces that can be found in our observations."

I do agree with you absolutely Bill. As you mention in the Physorg.com article, anti-matter should clump gravitationally together with itself, as does normal matter, and only be repulsive to normal matter?

Its the repulsive part that dos'nt quite make sense to me.
I always understood that when anti-matter came in contact with normal matter, there is a 99% release of energy, raw power, with no radio activity. Plus gamma rays .
Is that what the Physorg article means by repulsive? I dont think so.

Gerry Skinner, an astrophysicist at Goddard Space Flight Center in Greenbelt, Md., stated these gamma rays apparently came from a cloud of antimatter roughly 10,000 light-years across surrounding our galaxy's core. This giant cloud shines brightly with gamma rays, with about the energy of 10,000 suns.

Thats a cloud of anti-matter surrounding our galaxy's core...? I am going to speculate here:-

A/ The am-cloud has been collected and is held in place by our galaxys Black Hole? Or
B/ The am-cloud is somehow produced by Black holes themselves, as evidenced by the visual production of Gamma rays coming from most Galaxy centers?

I know that anti-matter is a fact, as CERN can produce tiny amounts of it.
The tiny amount that we have to keep away from our normal matter, if we want to store it.

Now, my thoughts are:- "Produce anti-matter here on Earth, and it annihilates,.....but when its (produced?) within the vicinity of a Black hole, it survives" Very strange.

Bill said
'Well, I think we are talking about 2 different antimatter clouds here'.

Mike Kremer wrote,
Thats Ok Bill, at least we are talking about the same thing ...i.e Antimatter
thats in two different places in the universe

'Your' Anti matter inhabits those great dark large void spaces in the universe.
Voids of vacuum, where there is a far better vacuum than we can produce in a laboratory here on Earth.
That means, less than a dozen atoms of matter per cubic ft of Space.
With probably even less atoms of Anti-matter, than that.
My thinking is...with the ever expanding Universe, your vacuum Voids are growing ever bigger. Making it unlikely that anti-matter here, is going to interact with any other matter, whether positive or negative, in the cold vacuum of space.

Where-as 'My anti matter' is compacted and clumped as a Toroidal cloud around the Black Hole in the center of our Galaxy. With seemingly lots of activity in the form of Gamma rays. my question now is ...so does this cloud become smaller over time?
Or stay pretty constant? How did it get there in the first place? Is it being replenished?. Does the Black Hole play any part in the formation of the anti-matter cloud?
Lots to speculate about here.