What is known about radiation produced by anti-matter?
Would the atomic spectra be similar?
Would an anti-matter body emit thermal radiation as a blackbody?
Established Member
What is known about radiation produced by anti-matter?
Would the atomic spectra be similar?
Would an anti-matter body emit thermal radiation as a blackbody?
Order of Kilopi
Photons are their own antiparticles, and the atomic and molecular energy levels will be the same in antimatter and matter: so the spectra should be identical.
Grant Hutchison
Established Member
1) Not all that much.
2) Yes, it would have the same spectra.
3) Yes, anti-matter obeys thermodynamics just fine.
Make note that superconductors do not absorb radiation the same way as normal conductors. There is one example of differing radiation properties. They come close to normal conductors once the frequency gets above the microwave range.
Established Member
Has this all been verified in experiments? I could'nt find any on the web.Originally Posted by alainprice
Order of Kilopi
If I am not mistaken, these identical characteristics of antimatter are predicted by the theory which is derived from what we are able to test in atom-smasher experiments. We can make antiprotons in the laboratory, and positrons occur naturally, but assembling them into a sample of antihydrogen and exciting it to produce an emission spectrum would be a beastly job. Any contact with ordinary matter means annihilation into a flash of gamma radiation.
Once again, don't take my words as gospel without running them past fellow BAUTers who are better informed than I.
Established Member
The properties of superconductors are fairly well known. Those of anti-matter radiation have not been properly tested.
Note my answer to the question:"What is known about radiation produced by anti-matter?" is - "Not all that much".
Grant gave the most concise answer, in that photons do not care whether matter is normal or anti, since the photons can do both. We do know the mass and charge of anti-matter very well. Therefore, there is no reason to think they would act differently under the known forces.
edit: you may want to research laser cooling of antihydrogen. I think the Lyman-alpha line can be used to cool it, so that's proof that it reacts to radiationt the same way. Although it is radiation absorbed and not emitted. One of the biggest problems in producing antihydrogen is that the techniques used result in high termperature particles which are nearly impossible to contain. They annihilate before they can be tested upon.
Order of Kilopi
This e-mail from the person at CERN responsible for the website dealing
with low-energy antihydrogen is relevant:
Subject: Re: ATHENA antihydrogen and gravity
From: "Lars Varming Jorgensen" <lars.varming.jorgensen@cern.ch>
Date: Fri, April 3, 2009 2:27 am
To: jroot@freemars.org
Hi Jeff,
No, the acceleration of antihydrogen in a gravitational field has not yet
been measured....and it is still some years off. This is because this is a
very hard experiments that we are presently not capable of doing. The
two experiments presently working on antihydrogen, ALPHA and ATRAP,
are working hard towards trapping the anti-atoms, which is the next big
goal. We hope this will happen this year, but might eventually take longer.
It is of course hard to predict when major breakthroughs will happen in
basic research. After the anti-atoms have been trapped the first
experiments will be spectroscopy and not gravity. That is because we
only need to trap them in our neutral traps to do spectroscopy, while to
do gravity measurements we need to cool them down further, probably
by up to a factor of 1000.
ASACUSA, another experiment working with anti-protons, will now also
start doing anti-hydrogen experiments. Their main goal is another type
of spectroscopy called hyperfine splitting. A forth experiment, AEGIS,
has just been approved to do experiments and their main aim is a gravity
experiment that is slightly less strenuous, but also probably less accurate.
Still, it should give us a first idea of how antimatter behaves in a
gravitational field. AEGIS is scheduled to take their first beam in 2011
and even if they were to be ready by then, it would still take several
more years of experiments before they would expect a result.
So the conclusion is that we are unlikely to know much more about
this until somewhere around 2015.
* * * *
I, personally, am not yet convinced that the photon is its own antiparticle.
-- Jeff, in Minneapolis
http://www.FreeMars.org/jeff/
"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"
"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves
Member
Any chance of quasars having an anti-matter black hole for a core and a normal matter galaxy around it, since they are so far away, might explain why we don't seem to be able to find much around these parts. Blazing away brightly with normal radiation, no way to tell if the hole in a galactic core is a normal or mirror matter core?
Perhaps there are mirror matter black hole floating around still , annihilating a star or planet here and there, flash, gamma ray burst.
If an anti matter black hole was on the loose in our universe, wouldn't it be getting eroded each time it had a normal matter contact event.
Would it not also then, eventually get so small that it would explode back into non black hole material, due to it having surpassed its own event horizon in size?
Order of Kilopi
A black hole formed from antimatter would be indistinguishable from one formed from normal matter. Any annihilation that occurs below the event horizon will produce radiation that's just as trapped as the matter and antimatter that produced it. The mass-energy of a black hole will increase, regardless of whether you drop matter or antimatter into it.
If you're suggesting that the missing antimatter is in the form of black holes, you'll have to come up with some reason for antimatter to collapse into black holes to such a greater degree than normal matter...and even those supermassive black holes are only a fraction of the mass of the galaxies around them, so you've still got a lot of antimatter to account for.
It would not get smaller, and it makes no sense to speak of a black hole "surpassing its own event horizon in size".
Member
Soo, hmm. ??
I thought the mass annihilation was equal on both sides.
if an electron and an anti electron (same mass) have the contact, flash gone. gamma rays. (and bits, I suspect perhaps)
if the kilo of normal matter is smacked into the kilo of mirror matter, (same mass), flash, gone, gamma rays.
What would you think of black hole collisions,
Collisions with equal mass (is this even possible?)
total annihilation of both into gamma rays.
If one mirror matter black hole is superior in mass to another normal matter black hole it will absorb how much of the original normal matter black hole and how much of the mass of the original normal matter black hole would be converted into gamma rays?
If the mass of the two combined black holes is of course going to be superior again, are the two of their constituents going to remain behind a curtain of event horizon, invisible from view in constant turmoil with each other for ever.
Would they not eventually convert themselves completely into gamma rays with no mass, there fore the remaining mass of the total is below event horizon mass? A sudden instantaneous welcome back to the universe.
Of the remainder of the total mass of the two before collision.
And the stored up gammas rays.
Boom.
About the quasars.
I was thinking of the good pic of the quasar that reveals that they appear to have normal galaxies around them. We have have a black hole at our galaxies core, why is a quasar galaxies core so brilliantly dazzling.
Order of Kilopi
Gamma rays have energy equivalent to the annihilated mass. The black hole doesn't care if its mass-energy comes from matter, antimatter, photons, or any combination thereof: it all ends up in a spot of exotic physics very close to the mathematical singularity at the centre of the black hole. Whether or not matter and antimatter annihilate on the way to the singularity makes no difference to the mass of the black hole.
The energetic processes that run quasars come from outside the event horizon of the black hole. The energy released during accretion to such massive objects is huge, and a lot of it escapes before it crosses the event horizon.
Grant Hutchison
Member
Sorry, this is the bit I still don't understand.
Say a normal matter star of 5 solar masses whacks into some mirror matter black hole of however big a mass of stuff you need for one of these babies.
Does or does not the event cause 5 solar masses of mirror matter to convert to massless gamma rays,
which are trapped within the event horizon forever to bounce, due to the fact that nearby, there is a mass of material which is of such mass that there is an event horizon creating a black hole.
That same mass having just been reduce by 5 solar masses, the gamma rays are at the moment still trapped, but if this keeps happening, the mass is getting eaten at and at the same time, it is storing up a big kablooey hello, of gamma rays.
??
Yes, No?
Member
Ok, thanks for that, so, once an event horizon has formed.
Radiation as we know it, as far as the black hole is concerned, regardless of its normal/mirror matter status, is really equivalent to mass or to be considered as such. Under those circumstances.
But radiation as we know it, and interact with has no measurable mass.
Is that it?
Order of Kilopi
It doesn't. The antimatter passes straight through the event horizon, and ends up very quickly at the singularity, where the physics is so exotic that the difference between matter and antimatter is essentially trivial. There is just a very, very small and dense knot of mass-energy in there, at a level of physics that we don't yet understand. And space-time is so distorted in its vicinity that nothing can leave, not even gamma rays.
We can't measure it because the quantities of energy involved are so small. But a box of photons weighs more (by a tiny amount) than a box containing no photons, because of the energy of the photons. Likewise, a charged battery weighs more than an uncharged battery, and hot water weighs more than cold water.
Grant Hutchison
Order of Kilopi
Photons have no rest mass, but they always travel at c...they are never at rest. They do have energy, and since energy and mass are equivalent, photons trapped within a black hole will contribute to its gravity. The gamma radiation from 1 kg of matter and 1 kg of antimatter annihilating has a gravitational effect identical to that of 2 kg of matter, 2 kg of antimatter, or the original 1 kg of each.
In any case, as Grant notes, there isn't necessarily any matter or antimatter within the black hole for whatever you drop in to annihilate. What's there is probably closer to what matter and antimatter both initially formed from.
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