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Does Antimatter Fall Up Or Down?
KentuckyFC writes "There are enough loopholes in the general theory of relativity to allow antimatter to fall up rather than down in a gravitational field. We've never been able to make enough of the stuff to do the experiment. But at the European particle physics laboratory at CERN, where scientists have been refining the technique for making antihydrogen, researchers are designing an experiment called AEGIS that will finally settle the matter. The idea is simple — fire a beam of antihydrogen atoms and watch which way they fall — but the details are fiendish (abstract). The answer should help solve a number of important conundrums such as why there is so little antimatter in our part of the universe and what the value of the cosmological constant is."
Or will it settle (or unsettle) the anti-matter?
It's a cool experiment, but it's news once you get the result, not "a few years" before.
Unless they're trying to drum up interest for funding...
Forget thrust, drag, lift and weight. Airplanes fly because of money.
I guess it depends on the existence of gravitons. Does the universe really bend or is that just a description of the gravitational force, or is gravitons exerting the force, and in that case does anti-gravitons exists, and what happens when gravitons collide with anti-matter?
According to GR, gravity is the curvature of Space-Time. As the anti-matter moves through space it has to follow this curvature. If it does not, that means GR is wrong (which may be the case, but I doubt this experiment will disprove GR).
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Professor: And the microwave radiation, combined with the gravitons and graviolis from the supernova, blasted us through time itself.
It doesn't-matter.
+1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
I wish the results were that antimatter falls upwards. If that were true, while it would have no practical use in the near future, it would be a hole in physics that our far descendants could exploit.
I'm probably wrong & welcome being corrected, but I can't shake this thought.
I'm under the impression Electromagnetic fields & Gravitational fields function similarly or the same.
I'm thinking of a field situated like the simultanious implosion of a uranium or plutonium bomb, with these antimatter things trapped in the center.
What if on one point of the field the magnetic strength was weakened, perhaps by touching it with another magnetic field, while on the oppisite end the strength was increased. Shouldn't the antimatter head toward the stronger field point if it were going to rise due to gravity instead of fall ?
Wanna fight ? Bend over, stick your head up your ass, and fight for air.
And is too far away to see properly as it repels other matter so dissipates into a fine particulate spray. A fine candidate for being the missing "Dark Matter" An interesting theory - we'll just have to wait and see I guess.
'Don't worry' said the trees when they saw the axe coming, 'The handle is one of us.'
it had mass just like anything else, and is therefore affected by gravity just like any other particle with mass.
Wouldn't "falling up" mean that antimatter has negative mass ? And if so, how does this comply with energy/mass conservation laws ?
... why should antimatter be any different? In fact every particle with mass yet measured behaves the same way in gravity. I can't see any reason why antimatter should be any different.
my relativity teacher told his class, is a function of time: At first, it was non-zero, then people said it was zero, then it might be non-zero after all.
Swedish plasma phys. PhD student; MSc EE; knows maths, programming, electronics; finance interest; seeks opportunities
So anti-matter falls up in gravity field and Guiness bubbles sink in a gravity field what happens when you mix the two?
But how does this help explain why our area of space has so little anti-matter? If this was true then it would mean we are at the bottom of the universe, as opposed to what; or is the current thinking that anti-matter is not effected by gravity and this experiment would provide that it is?
Particle and antiparticle must have
* the same mass
* the same spin state * opposite electric charges
http://en.wikipedia.org/wiki/Antiparticle
Sigger than your average
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What like http://xkcd.com/417/ ?
I wank in the shower.
since it has a mass, and it's mass is not negative (source: wikipedia), it should fall down, right?
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Well you could centrifuge it to enhance the effect, but I wonder if that would answer the wrong question?
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What makes you think the downfalling case would be any better? If it falls down, then it will annihilate with whatever it falls into. If it falls up, then it won't be around anymore. Either way, it's not going to stick around for long.
If antimatter "falls up" imagine this:
In a reasonable empty space exist two particles, one of matter, the other from antimatter. They are of equal mass. They are causing gravity on each other. The antimatter runs away and the matter follows. And with INCREASING SPEED !? OOPS.. There must something wrong here...
Maybe the matter does not pull antimatter and antimatter does not push matter ?
Maybe they both pull each other after all.
Antimatter falls strange.
Real Daleks don't climb stairs - they level the building.
solve a number of important conundrums such as why there is so little antimatter in our part of the universe
Eek, no, leave it where the hell it is!
Ok, maybe one George Bush sized piece...
I think the problem is likely that you can only build up a large amount of antiprotons and positrons. As soon as you start making hydrogen, you can't trap it anymore and it falls out.
I think the reason you can't measure the hydrogen is because there's not enough. It falls out before you can get enough to tell what its velocity is. Keep in mind that hydrogen is very light and won't fall downwards because of gravity. Instead, you have to measure the curvature of its path to try to see which way it's accelerating. I'm guessing we hit another problem here, which is the Heisenberg uncertainty principle. If you just have one or two particles, you can't really tell which way they are headed. I think the idea behind this experiment is to create a stream of particles so that you have enough of them to really measure where they are going.
Of course, I could be completely wrong about all that, too.
Only in British imperial units. And in four hundred years, it will inflate to 47 due to spacetime expansion.
Ezekiel 23:20
Surely antimatter can only exist for as long as it doesn't hit matter and since matter exists everywhere (even in the (near) vacuum of space) then that's an extremely short time period (milliseconds? if that).
This would mean they wouldn't exist much anywhere in the universe, never mind just "our" part.
Just occoured to me: Are they claiming that the laws of physics could be different in "our" part of the universe?
Perhaps someone with a little more knowledge on this topic could explain.
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Secondly, anti-matter is already used outside of particle physics, e.g. see http://en.wikipedia.org/wiki/Positron_emission_tomography. From these experiments it is abolutely clear, that the positrons have the same mass as electrons. After all, two photons are emmitted in the annihilation process, each have an energy equivalent to the mass of an electron. This can only be explained through the fact, that the positron has the same (positive) mass as an electron. Otherwise energy/mass conservation would be violated.
Furthermore, negative mass would also imply, that anti-matter would be accelerated in the opposite direction with respect to the acceleration force. This would imply many strange phenomena, and in the end, also violate the energy conservation law.
Oh, wait a minute. This means, that even negative mass would fall down, as it is repelled by the earth, but it reacts to the repulsion by an acceleration towards earth....
Just a few technical details to sort out, first :-)
...and, of course, if your antimatter-powered airship crashes, the phrase "Oh, the Humanity!" is going to be even more applicable. Maybe without the "the".
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So with Hydrogen being lighter then air, does this mean anti-hydrogen will fall to the ground?
As I rememeber, this has already been tested by drifting positrons down the length of the SLAC accelerator tube and measuring the beam deflection due to gravity (at least 20+ years ago).
Yes, anti-matter does fall down just like matter.
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Isn't a negative mass density also necessary to create stable wormholes ? As far as I remember, wormholes are possible
So, if antimatter falls up, we're one step (of, um, billions, probably) closer to creating artificial wormholes.
Did it really take 65 physicists to decide that the best way to test gravitational effects was a particle beam deflection? I suppose simplicity is nice, but I honestly expected something more complicated with that many collaborators...
It falls sideways, just to screw with those smarmy scientists.
The possibility that antimatter might fall "up" is news to me.
Do you really think that scientists should work away in their own little worlds and only pop their heads up and bother us regular folk when they have an answer?
Personally I think the questions are often interesting in themselves.
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There are enough loopholes in the general theory of relativity to allow antimatter to fall up rather than down in a gravitational field.
Uh, no there are not. Gravity (or geometry, same thing in the theory) depends on mass energy in General Relativity. Stuff (with mass energy) follows the metric (the local geodesic). Even photons (which are their own anti-particles) follow the geodesic - and that has certainly been tested. Equivalence principle tests also show that different sorts of nuclear matter (including neutrons) individually follow the geodesic. Anti-matter certainly has mass energy, and (with matter) can be converted to photons and is no different in the theory. In other words "there is only one type of geodesics and there are no antigeodesics for antimatter."
The original article talks about "flavors" of General Relativity. Ain't so such beasties. Period. If you go to the real original article, you find a proposal for a 1% test of the equivalence principle for antimatter, and no such claims of flavors. Now, the equivalence principle has been tested to better than parts per trillion, and part of the mass energy in ordinary matter is made up of antimatter (in virtual particle pairs), so (based on the experimental evidence) I would claim that this test will be negative and is not actually that interesting as new physics. (The articles say that these older tests are "model dependent," but they are not model dependent enough to matter for this.)
That doesn't mean that this shouldn't be done (everything should be tested in physics, and different tests are always useful), but the prediction of General Relativity is clear : if anti-matter has anti-gravity, then General Relativity is wrong. The experimental evidence is also clear : this isn't going to be accurate enough to matter. Will make for some good public relations, though.
I always assumed this was the reason for the accelerating expansion of the universe. If anti-matter fell down, then we'd be seeing a deceleration in the expansion.
FOXTROT UNIFORM CHARLIE KILO
I am not a physicist, but my instinct is that if it proves true that antimatter falls up, then it means that there would be such a thing as antigravity. A large mass of anti-matter (say, a planet, or at least anything big enough to have an appreciable gravity field), will he held together by it's own antigravity, and antimatter objects will fall towards it; while normal matter would be pushed away.
My guess is that this experiment will prove false, meaning that antimatter will fall just like normal matter, but it is an interesting hypothesis. I'll be interested in seeing the results.
Intelligent responses welcome, flames will be met with marshmallows.
Somewhat silly questions regarding anti-matter - just in case someone knows the answers:
What happens if anti-hydrogen hits anti-helium? Do you end up eith energy + hydrogen (ie, does it anihilate 1 proton and one electron from the helium, leaving the rest), or does it fail to react?
Does anti-matter only react to its opposite particle? I.e. does an anti-proton react to an electron? Somewhat related, does anti-matter anihilate on contact with other stuff, like neutrinos or photons?
And is the only anti-matter anti-protons and positrons? I.e. is there an anti-photon, anti-quark etc.?
We do not live in the 21st century. We live in the 20 second century.
Quote:
The idea is to fire a beam of antihydogen atoms at a target and see how much they are deflected by gravity.
That's easier said than done. Creating a beam of this stuff turns out to be remarkably tricky. The problem is that it's easy enough to trap antiprotons and positrons in electromagnetic fields. It's even fairly straightforwad to put them together so that they form antihydrogen. The problem is that antihydrogen is neutral and simply falls out of the trap. So some way has to be found to collect and trap these antiatoms.
---
Uh - can somebody explain to me why they need a beam and don`t just take a look if the antihydrogen falls out on the bottom or the top of the trap?
"we are all atheists about most of the gods that societies have ever believed in. Some of us just go one god further."
If I had mod points, I'd mod you up. I could've sworn I'd read something similar.
And bonus points to whoever finds the actual study paper on it.
Women must be made of antimatter. Why else would they levitate away from me?
It's not science. Even doing a nice bunch of calculations and saying "Well this shows that anti-matter should do this," is not science, or at least not the important part. Science is testing beliefs by experiment. So regardless of what we think anti-matter will do, and regardless of how sure we think we are, we still need to test it. That's how science works. You come up with an idea, you test it. If the test falsifies it, you come up with a different idea and test it. If the test supports it, you come up with more tests to try and falsify it.
Through this process, we come to understand the natural world, and come to be fairly certain that our understanding is correct. Math and theoretical work is great, but actually testing those theories is what makes science what it is.
So even if we are 99.999999% certain that our calculations are solid and anti-matter does something, we still need to test it. There are plenty of things that we've been certain about that, when we tested it, turned out not to be the case.
Except that the anti-particles would have negative mass -- we'd be looking for more dark matter, not less.
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Rule of Slashdot #0: You and people like you are not representative of the larger population. - A.C.
When wood burns, oxygen is not added - it is actually the Phlogiston that disappears!
..Just like Soylent Green is made of people!
Phlogiston is antimatter!
(gasp!)
(More info at Wikipaedia, for the historically challenged..)
File not found. Fake it(Y/N)? _
Back {mumble} years ago, I asked my high-school physics teacher this same question. "Do matter and antimatter attract or repel each other by gravitation?" After he firmly put down the ranks of kids who thought antimatter was something made-up for Star Trek, he said he didn't know... And then he spent the rest of the period researching it in the texts that he had. And concluded that he still didn't know.
Then he assigned the question to me as a research problem. D'oh! In that pre-Internet era I went through the subject in the school and local libraries and found that... I didn't know. I'm glad we were right!
Chelloveck
I give up on debugging. From now on, SIGSEGV is a feature.
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So the probability of obtaining funds drops dramatically.
(Although they may try to sell it to military as an exotic weapon, as another
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It's really really dumb, but when I was much smaller than now I had this theory that matter and antimatter worked like magnetism where opposites attract. Matter would move away from matter, antimatter would move away from antimatter, and matter would attract antimatter. So why would the earth then have gravity? Because there would be antimatter in the core! But why would the moon circle around the earth then? It would need to contain no antimatter. But then why can people walk on the moon? For that it would have to have an antimatter core too. And why would the sun attract the earth? So the conclusion then was that my theory was stupid. So I shouldn't have posted it here, but hey, this article made me remember that weird theory I had back then I wanted to share it.
Physics would truly be weird if this was true that anti-matter might fall up. First of all, there is no evidense that anti-matter is anywhere near that weird. It is just a form of energy, just as matter is a form of energy. Though some people do not understand that basic notion. When you combine matter with anti-matter you get energy. In terms of energy, adding matter and anti-matter is similar to adding 1 + 1 and getting 2. Not adding 1 and minus 1 and getting 0. That is a very important difference, and that is part of the reason that the notion that anti-matter might 'fall up' is just not credible. But that is not the reason for my post... The following comments were posted this week on a related blog that helps put some of the conversation surrounding the Large Hadron Collider Safety controversy in perspective I think. From a June 2008 blog by Martin Meenagh Quote: âoeBy what means can an Hawaii Court, even if it is a federal one, assert any authority over a facility outside the USA?â I am not a lawyer, but the case has world wide implications, some court must take jurisdiction. Quote: âoegoing to do anything but make Europeans and Canadians determined to go ahead anywayâ A few very credible scientists believe that CERN is basing their theory of safety on at least one flawed assumption. If the following reasonable and plausible assumptions prove to be correct, then the uncomfortable truth is that the probability of destruction of Earth is actually closer to 100%, though only mother nature currently knows for certain due to our limited understanding of the physics involved. A. LHC Creates black holes as CERN Predicted (1 per second) [1] B. Micro Black holes do not evaporate as LSAG accepts is plausible. [2] C. One or more micro black holes are captured by Earthâ(TM)s gravity as LSAG accepts as plausible. [3] D. Micro Black holes grow exponentially as Dr. Otto E. Rosslerâ(TM)s paper predicts and calculates. [4] If the reasonable and plausible assumptions above prove correct, and Europeans and Canadians are determined to go ahead anyway, then that would be an unfortunate situation. The entire world is in this together after all! Quote: âoeThere is a world issue here. In libel, in risk assessment, and in extradition casesâ Yes, there are also potentially issues with respect to freedom of speech, corporate deception, and mis-representation of facts designed to confuse or mislead the public as to risks involved. The lawsuit also alleges on page 15 of AFFIDAVIT OF LUIS SANCHO IN SUPPORT OF TRO AND PRELIMINARY INJUNCTION: [5] Quote: âoeCERN has neither asked mankind to validate these experiments, nor has it been open and clear about those risks to the public. On the contrary it has systematically hidden evidence, and hence it is, in my opinion and hopefully that of this Court, liable of criminal negligence and occultation of proofs, as it carries about what amounts to a potential global genocide.â Quote: âoeWould you have any links that you could send any readers and myself to as a short cut?â I would suggest LHCDefense.org for the legal focus. Sincerely, JTankers Administrator, LHCFacts.org References: [1] http://doc.cern.ch/yellowrep/2003/2003-001/p1.pdf [2] http://xxx.lanl.gov/abs/gr-qc/0304042 [3] http://lhc2008.web.cern.ch/LHC2008/documents/LSAG.pdf [4] http://www.wissensnavigator.com/documents/OTTOROESSLERMINIBLACKHOLE.pdf [5] http://www.lhcfacts.org/?cat=9
http://en.wikipedia.org/wiki/Gravitational_interaction_of_antimatter
Gravity's Rainbow?
So like, they can*t make enough antimatter to make like an anti-piano and throw it out the window and see where it goes ?? :) Ohhhh they should make some Anti-Carries!!! That would be really fun to float in the air!! But would I go into space???? omgosh!
Carrie -The Christmas Angel
which is what this 'flying up' seems to imply - instead of attraction there is repulsion,
Then wouldnt all the antimatter be out at the edges of the universe?
Darwin Hawking Blackmore
But doesnt it get you a tad nervous that we are making this "anti-*" stuff here on earth and shooting it up to see which way it falls?
How does anti-hydrogen work on life thingies? Does it have the potential for a destructive chain reaction? Are the cientists not part of the global-universal conspiracy against america?
NO SIG
They missed one option. What if antimatter is not affected by gravity? I'll put my money on falling down.
Anti-protons and positrons are anti-matter and are produced very easily in particle accelerators. Why not test gravity on them before testing it on an anti-hidrogen, which is simply a bound state of an anti-electron and an anti-proton? This isn't experimental physics, this is demagogy.
Do they have a asston of antimatter in them? Could they be filled with antimatter that is being "pushed" away by the gravity of the black hole???
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You could walk around the office shining ("darking"?) your ant-flash-light into people's eyes and freaking them out as the world does dark.
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Antineutron consists of 2 anti-down and 1 anti-up quarks.
U+F8FF
"... what the value of the cosmological constant is."
Duh... 42. Now we just have to figure out the cosmological question.
So lets say it does fall up ... Does this mean that anti-matter is actually repelled by gravity? On a larger scale, wouldn't this cause anti-matter to be repelled by large clusters of matter (galaxies)?
This leads to another question, would anti-matter exert some sort of anti-gravity, in turn repelling normal matter? The mind boggles, especially since I left the boundaries of college physics when I started writing.
That it doesn't fall at all? Up, or down? That antimatter doesn't interact gravitationally with normal matter in any way. but only with other antimatter?
File under 'M' for 'Manic ranting'
Up, Down or not at all? What about a direction orthogonal to the direction of gravity for normal matter?
If we continue to accept that gravity is a distortion of space-time, up-falling antimatter must also move through time in the opposite direction to matter.
And maybe that explains why there is a relative scarcity of antimatter here-and-now. Antimatter would tend to collect in the past, in the spaces between gravity wells, while matter would tend to collect in the future, inside gravity wells.
I'm looking forward to some experimental answers.
Sorry, this is all silly.
"Anti-matter" is not the opposite of matter. It is matter with opposite charge or other opposite properties. Mass has no opposite. It is there, or it isn't. (Or it is and then it isn't and then it is and then it isn't, on the level of quantum fluctuations of the gravitational field.)
And no, a hole isn't "anti-matter". It's merely a void in the surrounding matter. It rises because of a principle known as "buoyancy" which is really the gross action of the matter surrounding it causing pressure differentials as a function of distance from the CM. As long as the surrounding matter can flow, it can fill any displacement of the void, and the mass will tend to move down rather than up, and the void will therefore appear to tend to move up rather than down.
And no, hot-air balloons don't rise because of the heat, they rise because they make the air in the balloon less dense than the air outside the balloon. How they do it is not relevant. A rigid balloon and a vacuum pump would work, too.
Anything with mass will follow the pull of gravitiy, but does anti-matter have mass in the same measue that matter does?
Also, what is "fall?" Hot air rises and cool air falls - but cool air is really the absence of hot air.
There's a big difference between a belief that something is most likely true, and an experiment that removes all doubt.
Tell that to the physicists.
There are many beliefs that physicists stick to about the real world without experiment because the consequences for long-cherieshed of those beliefs not being true would be too awful.
As a number of other physicists have pointed out here, anti-matter has mass and falls like everything else that has mass.
If it does not, then far more is wrong in physics than some minor law, or backwater part of relativity. We have been able to very successfully predict the existence and many properties of anti-matter. If gravity does not act on anti-matter normally, it would mean some fundamental understanding quantum mechanics is wrong, and we may not have an explanation for why anti-matter even exists.
A very high payoff if they get an unexpected result, but very, very unlikely. If I were doing this experiment, I would doubt my own abilities first if I didn't get the result everyone else expected. A hard thing to put yourself up against.
Are they? Ever seen evidence of one? Gravitons are a purely theoretical construction and, worse of all, one that does not work. While you can construct a quantum field theory of gravity it does not work to arbitrary energies. You have to impose a cut-off threshold and since there is no valid reason for doing so the theory is broken...hence all the theoretical activity trying to reconcile GR and Quantum mechanics.
The gravitational field as a scalar field surperposed on a flat space-time is just another way of describing gravitation
You mean a vector field since gravity has direction, rather than the Tensor field of GR.
I think that after the Big Bang, all the anti-matter went the other way. The other way in time. To see the anti-matter universe, you would have to travel back in time to the Big Bang, and then keep going past the BB even earlier. Then you would be in the anti-matter universe, but of course, going the wrong way. In other words, the anti-matter universe is sorta like driving in England. Everybody is going the wrong way, and on the wrong side. My wife has a habit of asking me "what is the matter?" I found that answering her "Energy" is highly satisfying.
The really neat thing about science is that if you do the experiment the answer is only partly relevant because you'll probably learn something else that is equally cool along the way...
(Someone actually speaking real physics...wow...)
Actually, hasn't the anti-matter "falling up" been considered before? I.e. if it fell "up" -- that would
mean it's repelled by matter? I.e. could explain universe expansion? But I thought that'd been ruled out as a possibility....If it were true, would anti-matter attract other particles of anti-matter?
Isn't matter and antimatter (as we define them), simply a different mix of quarks? And don't each of
the quarks have theoretical weights -- none of them are negative -- isn't it just the charge that's different
on antimatter (though a guess an anti-neutron would still sum to zero on charge?)...b
Theres some talk about anti matter in the military but from research i have done on anti matter its just another ATOMIC BOMB (but way stronger something like 4 magnitudes stronger in energy nuclear energy, ill check my sources for that) I still might except this idea of "Falling up."
Besides the MAGENTIC fields, we most also consider the red shift
But absolutely, not relatively, as had earlier been pointed out.
.
- aqk
F U
I've always wonder about this but I'm not a PHD. Antimatter on a Feynman diagram looks like matter moving backwards through time. In support of this, I think, entropy in a closed system of antimatter would work backwards. Tend towards order. Anyone know if this is BS or not? Is this a worthy experiment?
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