Negative Matter

[Harold Squared]

Curious about negative matter as opposed to the antimatter first postulated by Dirac and later confirmed by the discovery of antiparticles, thanks in advance for your gracious contributions.

[Mordred]

There is no negative matter.

[Strange]

 

However the big difference, arguably the biggest difference, between anti-matter and negative matter is that negative matter doesn’t exist.

http://www.askamathematician.com/2012/02/q-whats-the-difference-between-anti-matter-and-negative-matter/

 

There is also (hypothetically speaking) mirror matter: http://en.wikipedia.org/wiki/Mirror_matter

[studiot]

Look up the term effective mass in solid state physics.

 

This can be positve or negative as in the case of the Hall effect for certain substances.

 

Also

 

https://www.google.co.uk/search?q=negative+effective+mass&hl=en-GB&gbv=2&oq=&gs_l=

Edited January 29, 2015 by studiot

[ajb]

The more common term is exotic matter, it would have negative energy. Such things are sometimes considered in general relativity as they allow, for example wormholes to be supported. Within general relativity such exotic situations are not ruled out, one has to add essentially by hand further conditions on the matter to be considered 'physical'. There conditions come under the generic name of 'energy conditions' and there are several of them. You need such things as general relativity by itself will allow any kind of matter distribution. Loosely, these conditions say in one form or another that we do not have negative energy particles.

 

Moreover, no such particles have yet been seen.

 

However, the situation is more interesting in semi-classical gravity where you consider quantum fields on a curved background. Again. loosely it is difficult to construct classical field theories that does not obey these energy conditions, but it is just as difficult to construct a quantum field theory that does obey these energy conditions! Again, I will say that I have been very loose here, but you can make more precise statements here.

[MigL]

Negative energy or negative mass is an 'accounting' trick, possibly without a 'real' consequence.

 

Two virtual particles pop into existence at the event horizon of a black hole. One falls iside the event horizon. Its partner flies off and becomes real ( hawking radiation ).

The other particle is the 'interesting' one. It falls into the black hole, yet the black hole loses mass !

 

This is termed 'exotic' matter, and it has the property of 'negative' mass/energy.

Whether this has an actual physical meaning is debatable.

[Mordred]

Negative energy or negative mass is an 'accounting' trick, possibly without a 'real' consequence.

 

Two virtual particles pop into existence at the event horizon of a black hole. One falls iside the event horizon. Its partner flies off and becomes real ( hawking radiation ).

The other particle is the 'interesting' one. It falls into the black hole, yet the black hole loses mass !

 

This is termed 'exotic' matter, and it has the property of 'negative' mass/energy.

Whether this has an actual physical meaning is debatable.

Good example the antimatter particle that falls in annihilated with tma matter particle already in the BH resulting in loss of mass. So I would say it has physical meaning, but the term negative matter is misleading of that process

[MigL]

Ah, but classically there is no matter left inside the BH for the virtual particle to annihilate with.

[Mordred]

Ah, but classically there is no matter left inside the BH for the virtual particle to annihilate with.

Yet there is still an infinite density mass lol. Gotta love BHs they can give ya a headache at times. Lol

[studiot]

 

MigL

Negative energy or negative mass is an 'accounting' trick, possibly without a 'real' consequence.

 

I respectfully suggest you go and measure some Hall voltages before you make such sweeping pronouncements.

 

You do not need to be near a black hole or other exotic body to do this, nor do you need exotic substances, copper, gold, magnesium and aluminium will suffice.

I await your results and explanation with interest.

[MigL]

Off the top of my head ( 3rd yr semiconductor physics and 4th yr solid state physics were a looong time ago ), the effective mass is the 'apparent' mass that a particle seems to have as it makes its way through a crystal lattice. This effective mass being 'heavier' for denser or more tightly bound crystals.

So what I dimly remember jives with what I said.

 

I expect you'll now set me straight.