Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 01/10/2013 18:30:02

Title: Is dark-matter any relation of anti-matter?
Post by: thedoc on 01/10/2013 18:30:02
Lionel marr  asked the Naked Scientists:
   
I understand there are two big probems: dark matter - what is it and where does it all come from? And anti-matter - what happened to it after the big bang?

As they both seem to make up large parts of the universe is there any way that darkmatter is what happened to anti-matter after the big bang?

Many thanks,
Lionel.


What do you think?
Title: Re: Is dark-matter any relation of anti-matter?
Post by: syhprum on 01/10/2013 20:56:45
I there was an abundance of antimatter in the universe there would be a great deal of gamma radiation at 511 kev due to its annihilation with matter of course this is not seen.
Antimatter reacts with electromagnetic radiation in the same way as normal matter hence it would not be dark !.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 03/10/2013 10:09:53
Most, most interesting syhprum.
What WMAP sees is what there is there. No dark matter because it is not there!  So why pretend the dark force has anything to do with matter?  It can be an electromagnetic or electrostatic force and have no mass at all??  All we need to do is admit there are massless non gravitational forces in space and forget about looking for physical material.
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 04/10/2013 02:26:25
Lionel marr  asked the Naked Scientists:
   
I understand there are two big probems: dark matter - what is it and where does it all come from? And anti-matter - what happened to it after the big bang?

As they both seem to make up large parts of the universe is there any way that darkmatter is what happened to anti-matter after the big bang?

Many thanks,
Lionel.


What do you think?
Dark matter is simply matter which seems to only interact via the gravitational interaction. Antimatter, on the other hand, could have simply annihilated its matter counter part and leaving only matter behind. Mind you that there is no real way to say something like the proton is matter and the antiproton antimatter. It was simply because protons were discovered first. Particles which have the same mass, opposite charge and spin is called its anti-particle. That's about all there is to the difference between the two.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 04/10/2013 11:04:09
Most interesting
If the antiparticle has the opposite charge to the particle touch they will annihilate. But what if we magnetize[spin] them in opposite directions so their north poles face each other and push apart.   
As the electromagnetic force is 10^36G but the weak electrostatic force is only 10^25G this would stop them annihilating, not so?
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: webplodder on 04/10/2013 17:29:50
Lionel marr  asked the Naked Scientists:
   
I understand there are two big probems: dark matter - what is it and where does it all come from? And anti-matter - what happened to it after the big bang?

As they both seem to make up large parts of the universe is there any way that darkmatter is what happened to anti-matter after the big bang?

Many thanks,
Lionel.




What do you think?

I suppose that as anti-matter originated from the same 'primordial egg' as ordinary matter the two might be just two different sides of the same coin. After all, we only have to look at the way life has evolved on earth over many millions of years to see that what was originally very similar has diversified into many forms. The same may be true of matter and anti-matter.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 05/10/2013 02:24:58
Most interesting
If the antiparticle has the opposite charge to the particle touch they will annihilate. But what if we magnetize[spin] them in opposite directions so their north poles face each other and push apart.   
As the electromagnetic force is 10^36G but the weak electrostatic force is only 10^25G this would stop them annihilating, not so?
CliveS

Don't think of them as annihilating when they touch since that's not very meaningful in quantum speak. Think of it as them annihlating when their wave functions have significant over lap.

If they were to actually touch the interaction electric energy would be infinite. Bill wouldn't like that. Lol!
Title: Re: Is dark-matter any relation of anti-matter?
Post by: evan_au on 05/10/2013 02:42:25
Antimatter is easy to detect. Dark matter has (so far) eluded all attempts to detect it. So they are not the same thing.

There is a hypothesis mentioned by Nobel laureate Richard Feynman that a positron may be an electron going backwards in time. This seems to fit the mathematical equations, but of course, we can't reverse time at will, so we can't actually test this. The same theory applies to other antiparticles too.
Some have speculated that all the antimatter went back in time, but of course, we can't test this either...
See: http://physics.stackexchange.com/questions/391/is-anti-matter-matter-going-backwards-in-time
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 05/10/2013 03:59:33
Antimatter is easy to detect. Dark matter has (so far) eluded all attempts to detect it. So they are not the same thing.

There is a hypothesis mentioned by Nobel laureate Richard Feynman that a positron may be an electron going backwards in time. This seems to fit the mathematical equations, but of course, we can't reverse time at will, so we can't actually test this. The same theory applies to other antiparticles too.
Some have speculated that all the antimatter went back in time, but of course, we can't test this either...
See: http://physics.stackexchange.com/questions/391/is-anti-matter-matter-going-backwards-in-time

Anit-matter pseudo molecules have been created and they don't appear to go back in time. The creation process was a time positive event.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 05/10/2013 04:13:50
Quote from: evan_au
There is a hypothesis mentioned by Nobel laureate Richard Feynman that a positron may be an electron going backwards in time. This seems to fit the mathematical equations, but of course, we can't reverse time at will, so we can't actually test this. The same theory applies to other antiparticles too.
I fully agree, i.e. it's not meant to be taken literally. It is meant to be taken as something that has the same mathematical form and as evan said, since there is no way to verify that its true you have to take it with a grain of salt.

I did a bit of searching and came to find out that actually, the idea was John Wheeler's idea, but Feynman popularized it.  I'm told that he probably meant it as a cocktail party joke.  It is discussed (in that spirit) on page 65-66 of Introduction to Elementary Particles, 2nd Edition by David J. Griffiths.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 05/10/2013 06:15:35
Quote from: jeffreyH
Anit-matter pseudo molecules have been created and they don't appear to go back in time. The creation process was a time positive event.
Why do you refer to them as "pseudo" molecules? I see no reason to refer to them as such, they're just "molecules," plain and simple. That concept can only be applied to sinlge particles, not systems of particles like atoms or molecules.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 06/10/2013 09:52:35
Quote from: jeffreyH
Anit-matter pseudo molecules have been created and they don't appear to go back in time. The creation process was a time positive event.
Why do you refer to them as "pseudo" molecules? I see no reason to refer to them as such, they're just "molecules," plain and simple. That concept can only be applied to sinlge particles, not systems of particles like atoms or molecules.

They are not stable and exist in an artificially created environment. They also are not composed of the same arrangement of particles as matter. Since we are forcing them into existence I assume they would not arise naturally in physical terms.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: syhprum on 06/10/2013 21:50:35
Although a very small quantity of anti Hydrogen atoms have been created I do not think that there has been any evidence of the more common form of molecular Hydrogen forming 
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 07/10/2013 13:13:28
Pmb,  you speak of wave function. Have you ever thought of what shape the molecules that are interacting have? From electric point of view any charge with a sharp edge would invite interaction first which may be the reason that quantum are in set energy sizes. More to do with 3D of nucleus position within the shaped volume enclosure, rather than orbits?
Clive S
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 07/10/2013 16:52:16
Pmb,  you speak of wave function. Have you ever thought of what shape the molecules that are interacting have?
On that level (atomic, molecular, etc.) the only meaning that can be given to "shape" is the wave function. That means that the shape of the object is the shape of the probability distribution.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 08/10/2013 10:04:27
So why would you think that a molecule would be a sphere? It could be any shape and more importantly the electron shells that surround it need to fit together without gaps, particularly if it is a liquid.
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 08/10/2013 10:26:03
So why would you think that a molecule would be a sphere? It could be any shape and more importantly the electron shells that surround it need to fit together without gaps, particularly if it is a liquid.
CliveS

A picture tells a thousand words.

http://www.newscientist.com/article/dn11272-microscope-discerns-atoms-of-different-elements.html#.UlPO_9K-pmM
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 08/10/2013 10:33:17
So why would you think that a molecule would be a sphere? It could be any shape and more importantly the electron shells that surround it need to fit together without gaps, particularly if it is a liquid.
CliveS

A picture tells a thousand words.

http://www.newscientist.com/article/dn11272-microscope-discerns-atoms-of-different-elements.html#.UlPO_9K-pmM

That is merely a repesentation of an atom, nothing more. And in physical reality they're not sphere's by any sense of the term.

That photo appears to be from a tunneling electron microscope which works on the principle of quantum tunneling. The representation is that of the tunnel current which reflects a probability distribution. What you're seeing is a spherical symmetric probability distribution.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 08/10/2013 15:20:54
So why would you think that a molecule would be a sphere? It could be any shape and more importantly the electron shells that surround it need to fit together without gaps, particularly if it is a liquid.
CliveS

A picture tells a thousand words.

http://www.newscientist.com/article/dn11272-microscope-discerns-atoms-of-different-elements.html#.UlPO_9K-pmM

That is merely a repesentation of an atom, nothing more. And in physical reality they're not sphere's by any sense of the term.

That photo appears to be from a tunneling electron microscope which works on the principle of quantum tunneling. The representation is that of the tunnel current which reflects a probability distribution. What you're seeing is a spherical symmetric probability distribution.

There are other images showing the wave properties.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 08/10/2013 15:24:18
Quote from: jeffreyH
There are other images showing the wave properties.
And would you care to share the location of those images with the rest of the class? :)
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 08/10/2013 16:27:06
Quote from: jeffreyH
There are other images showing the wave properties.
And would you care to share the location of those images with the rest of the class? :)

http://panda3.phys.unm.edu/nmcpp/gold/phys330_s06/
http://spiff.rit.edu/classes/phys314/lectures/stm/stm.html
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 08/10/2013 16:33:59
Quote from: jeffreyH
There are other images showing the wave properties.
And would you care to share the location of those images with the rest of the class? :)

http://panda3.phys.unm.edu/nmcpp/gold/phys330_s06/
http://spiff.rit.edu/classes/phys314/lectures/stm/stm.html
Now carefully read and examine what the explanation by the images say of what the image is. Is this consistent with what you believe the pictures really represent?
Title: Re: Is dark-matter any relation of anti-matter?
Post by: jeffreyH on 08/10/2013 16:38:34
Quote from: jeffreyH
There are other images showing the wave properties.
And would you care to share the location of those images with the rest of the class? :)

http://panda3.phys.unm.edu/nmcpp/gold/phys330_s06/
http://spiff.rit.edu/classes/phys314/lectures/stm/stm.html
Now carefully read and examine what the explanation by the images say of what the image is. Is this consistent with what you believe the pictures really represent?

I have no idea but it looks interesting.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 10/10/2013 09:42:21
The problem is that you need to think new physics; this requires first priority be given to the electromagnetic balancing forces inside the molecules electron enclosure and then the 3D geometry of the charged magnetized particles. To only consider energy balance or wave function interaction is insufficient
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Pmb on 13/10/2013 08:27:43
The problem is that you need to think new physics; this requires first priority be given to the electromagnetic balancing forces inside the molecules electron enclosure and then the 3D geometry of the charged magnetized particles. To only consider energy balance or wave function interaction is insufficient
CliveS
Who did you mean when you said "you"? Are you speaking in general or did you have something to say to a particular person?
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 14/10/2013 16:00:17
I am speaking generally.  WMAP proved that CDM model does not balance the universe.  We need an additional force of 5G to pull the solar system together.  But because we have been taught that gravity is the only force out there, it has to be assumed that there is extra invisible dark matter in space [which our instruments indicate isn't there] 
Instead, why not consider whether that force could be an electro-magnetic?
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: yor_on on 14/10/2013 17:11:16
Can you link to it Acsinuk?
It sounds interesting, but it you have a EM force co-acting it should be measurable, shouldn't it?
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 18/10/2013 17:15:23
You would think so but I am not so sure!  We know that the solar wind is mostly ionized proton molecules.  Now if they are ionized that means they are being pulled outwards electrically towards our planet and pushed away from the sun by presumably a DC voltage.  But we cant measure that voltage without a really sensitive instrument because the voltage field around the metal spacecraft shorts itself out.   Another thing, we can measure the electrons a little but which way are they flowing?  If the positive ions are moving one way the electrons are sure to be moving in the opposite direction towards the sun.
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 01/11/2013 17:01:32
Yor-on
I think I answered the question incorrectly by talking about electrostatics.  From the magnetic point of view the main flux back to the sun will be at the centre of the north and south poles. Our magnetic field is just the leakage flux really.
How to measure the main field may be possible above the poles but not by satellites orbiting elsewhere or at the lagrange points
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: Ethos_ on 03/11/2013 16:06:41
IMHO,...........Dark matter may only be similar to anti-matter in that, they both are gravitationally active. While the verdict is still out, I suspect that Dark matter is gravitationally observed because it exists extra dimensionally. That idea means that; While we can observe the gravitational interactions, we can't see any of the electromagnetic radiation. We may be seeing evidence here for the existence of a parallel universe or, more likely, evidence for string theory.
Title: Re: Is dark-matter any relation of anti-matter?
Post by: acsinuk on 05/11/2013 17:15:35
Yes, dark matter appears to be gravitational because it has an extra force that is needed to balance the CDM model.  But it is the force that balances the CDM model not the presence of dark matter.  I accept that both matter and anti-matter are attracted together by gravity.
CliveS
Title: Re: Is dark-matter any relation of anti-matter?
Post by: spartaman64 on 15/11/2013 03:14:23
I there was an abundance of antimatter in the universe there would be a great deal of gamma radiation at 511 kev due to its annihilation with matter of course this is not seen.
Antimatter reacts with electromagnetic radiation in the same way as normal matter hence it would not be dark !.
If there was an abundance of antimatter we would be dead.