The antimatter tag has no wiki summary.
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Is anti-matter matter going backwards in time?
Or: can it be proved that anti-matter definitely is nót matter going backwards in time?
From wikipedia:
[There is considerable speculation as to why the observable universe is apparently almost ...
3
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3answers
661 views
Why would Antimatter behave differently via Gravity?
Confinement of antihydrogen might help provide a future answer. http://arxiv.org/abs/1104.4982
7
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3answers
603 views
What actually happens when an anti-matter projectile collides with matter?
I'm trying to understand what would really happen when large quantities (e.g., 10g) of anti-matter collide with matter. The normal response is that they'd annihilate each other and generate an ...
7
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3answers
843 views
Does a particle annihilate only with its antiparticle? If yes, why?
Or to put the question another way - what is the result of a proton-positron collision, or an up quark-charm antiquark collision, etc.? As far as I know, annihilation happens only between particles of ...
2
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4answers
3k views
What is pure energy in matter antimatter annihilation?
I used to read the term "pure energy" in the context of matter antimatter annihilation,
are them photons? is it other form of heat, are particles with mass ?
What does it refer to?
thanks
9
votes
1answer
716 views
How would we tell antimatter galaxies apart?
Given that antimatter galaxies are theoretically possible,
how would they be distinguishable from regular matter galaxies?
That is, antimatter is equal in atomic weight and all properties, except for ...
6
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4answers
1k views
Spontaneous pair production?
So I've been looking into particle-antiparticle pair production from a gamma ray and don't understand one thing.
Let's say I have a 1,1 MeV photon and it hits a nucleus - electron-positron pair with ...
4
votes
2answers
508 views
Do particles and anti-particles attract each other?
Do particles and anti-particles attract each other?
From the very basic understanding that they are created out of nothing mutually and collide to annihilate each other seems to indicate this happens ...
2
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2answers
444 views
What happens if we put together a proton and an antineutron?
A hydrogen nucleus consists of a single proton.
A 2-hydrogen (deuterium) nucleus consists of a proton and a neutron.
A tritium nucleus consists of a proton and two neutrons.
This makes me wonder how ...
7
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3answers
449 views
What was missing in Dirac's argument to come up with the modern interpretation of the positron?
When Dirac found his equation for the electron $(-i\gamma^\mu\partial_\mu+m)\psi=0$ he famously discovered that it had negative energy solutions. In order to solve the problem of the stability of the ...
6
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4answers
352 views
Matter-Antimatter Asymmetry in Experiments?
As I hope is obvious to everyone reading this, the universe contains more matter than antimatter, presumably because of some slight asymmetry in the amounts of the two generated during the Big Bang. ...
2
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3answers
592 views
Particle antiparticle annihilation-do they have to be of the same type?
I read that a particle will meet its antiparticle and annihilate to generate a photon. Is it important for the pairs to be of the same type? What will happen when for example a neutron meets an ...
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2answers
210 views
Antimatter bomb
I stumbled upon this wikipedia article on antimatter weaponry.
Being greatly appalled by the sad fact that large sums of money are being wasted on this, I could not stop myself from thinking for a ...
4
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2answers
216 views
Baryon asymmetry
Baryon asymmetry refers to the observation that apparently there is matter in the Universe but not much antimatter. We don't see galaxies made of antimatter or observe gamma rays that would be ...
3
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2answers
207 views
Can different species of particles annihilate with other species
Obviously electrons annihilate with positrons, but can a muon annihilate with an positron, or can an anti-taon cancel with a muon? similarly for quarks of different species, e.g. u and anti-strange.
...
1
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2answers
116 views
Matter - Antimatter Reactory Practicality
With current technology, would the energy released by a matter-antimatter annihilation be more than the energy needed to created the antimatter in the first place? Would it be worth it? Just curious, ...
14
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4answers
610 views
What is anti-matter?
Matter-- I guess I know what it is ;) somehow, at least intuitively. So, I can feel it in terms of the weight when picking something up. It may be explained by gravity which is itself is defined by ...
12
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3answers
702 views
No hair theorem for black holes and the baryon number
The no hair theorem says that a black hole can be characterized by a small number of parameters that are visible from distance - mass, angular momentum and electric charge.
For me it is puzzling why ...
9
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2answers
1k views
Do anti-photons exist?
I know what anti-matter is and how when it collides with matter both are annihilated. However, what about anti-photons? Are there such things as anti-photons?
I initially thought the idea ...
4
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2answers
335 views
the causality and the anti-particles
How can I quantitatively and qualitatively understand the fact that there is a relevence between the existence of anti-particles and the causality?
14
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1answer
422 views
In general what will holding an anti-hydrogen atom for more than a 1/10th of second allow scientists to discover?
In general what will holding an anti-hydrogen atom for more than a 1/10th of second allow scientists to discover?
Specifically, given that they can hold one for <1/10th of a second, what would ...
10
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5answers
676 views
Anti-Matter Black Holes
Assuming for a second that there were a pocket of anti matter somewhere sufficiently large to form all the type of object we can see forming from normal matter - then one of these objects would be a ...
5
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1answer
124 views
How fast is the matter and antimatter reaction compared to nuclear chain reaction?
What I mean is, the nuclear chain reactions take microseconds for every generation and that is the reason that nuclear weapons exist. Because in nuclear reactors the reaction rate is much slower thus ...
1
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3answers
437 views
Anti-matter repelled by gravity - is it a serious hypothesis? [duplicate]
Possible Duplicate:
Why would Antimatter behave differently via Gravity?
Regarding the following statement in this article:
Most important of these is whether ordinary gravity attracts ...
-3
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3answers
565 views
Andromeda is made of antimatter. Am I wrong? Why?
Andromeda is made of antimatter. Am I wrong? Why?
Of course I do not know that Andromeda is made of antimatter.
_but____ I do not know that Andromeda is made of matter.
Does anybody know what is ...
7
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5answers
853 views
Why Negative Energy States are Bad
The argument is often given that the early attempts of constructing a relativistic theory of quantum mechanics must not have gotten everything right because they led to the necessity of negative ...
6
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4answers
862 views
If an anti-matter singularity and a normal matter singularity, of equal masses, collided would we (outside the event horizon) see an explosion?
If an anti-matter singularity and a normal matter singularity, of equal masses, collided would we (outside the event horizon) see an explosion?
4
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2answers
389 views
Is nature symmetric between particles and antiparticles?
Is nature symmetric with respect to presence of particles? Do we have an antiparticle for every particle thought of? Are there any proven examples where we don't have an antiparticle? And what about ...
3
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2answers
314 views
Creation of particle anti-particle pairs
I was reading some QFT notes and there is one point that I don't understand, they are justifying why we need QFT saying that the number of particles is not preserved once we consider special ...
2
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0answers
146 views
What makes *electric* charge special (wrt. CPT theorem)?
I'm wondering why the 'C' in CPT - charge conjugation - refers specifically to electric charge. Of course you could say that C is just defined as $e^+ \leftrightarrow e^-$... but there has to be ...
1
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2answers
336 views
Schrödinger's equation, time reversal, negative energy and antimatter
You know how there are no antiparticles for the Schrödinger equation, I've been pushing around the equation and have found a solution that seems to indicate there are - I've probably missed something ...
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2answers
1k views
What would happen after the collision matter and the anti-matter [duplicate]
Possible Duplicate:
What actually happens when an anti-matter projectile collides with matter?
Suppose 1 kg of a stray meteorite anti-matter moves to the earth.
What would happen after ...
-1
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1answer
124 views
How to guarantee that a kilogram of antimatter will quickly annihilate another kilogram of matter?
What I mean is, suppose we could somehow get a kilogram of matter and contain it safely. Now lets say we want to make a bomb using this kilogram, now, we have two ways, either store another kilogram ...
