Timeline for Why would Antimatter behave differently via Gravity?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 10, 2016 at 18:40 | comment | added | Sentry | The experiment in the article you linked did not test the influence of gravity on antimatter. Though there are no details, it seems like it just tested the equality of the strong force for matter and antimatter, which is a completely different question. Second, I did not say that antimatter gravity was repulsive. This case can indeed be considered excluded. The interesting question is if the strength is equal, or if it differs by a small amount. And this has not been conclusively tested, so there is still a good justification for the above experiment | |
| Sep 27, 2016 at 10:30 | comment | added | Luboš Motl | The effect of gravity on antimatter has been tested many times. If you want some really specific, naive experiments, check e.g. zmescience.com/science/physics/… - But even without these experiments, it's spectacularly obvious that gravity is equally attractive for antiparticles. Each normal object contains some admixture of antimatter, too - which depends on the material etc. (virtual antiquarks etc.). If there were a repulsion, it would be easier to see violations of the equivalence principle. | |
| Sep 25, 2016 at 23:12 | comment | added | Sentry | I believe there is a strong justification for tests of the gravitational interaction of antimatter. You speak of "experimentally established, known laws of physics", but strictly speaking in most cases they have only been tested with matter, not with antimatter. For example, there is not even a test of the equivalence principle with antimatter. So in the end, there is still a possibility that matter and antimatter behave differently. Antimatter gravity probably can't be repulsive, but the force of gravity could differ by a few percent from matter gravity. | |
| May 4, 2011 at 2:44 | comment | added | dmckee --- ex-moderator kitten | Unless I've missed something I don't buy your argument about the nucleon sea. Every $\bar{u}$ is paired with a $u$, every $\bar{d}$ with a $d$... . If we assume some (bizzar!) theory that support anti-matter anti-gravity those contributions cancel out. Not that I expect a surprise here. I know the PIs on at least one proposed experimental test and they expect antimatter to be gravitational attracted to matter. But it remains an important untested prediction. Interesting stuff is rarely found in the well tested parts of theories, but rather when in obscure corners. Dot the i's cross the t's. | |
| May 2, 2011 at 18:11 | comment | added | anna v | There is an ancient greek proverb : "many despise money, nobody despises glory". It was spoken of generals in the colonial wars of the time. | |
| May 2, 2011 at 17:28 | comment | added | Luboš Motl | I see, Anna, but the Nobel prize also comes with some funding, doesn't it? :-) | |
| May 2, 2011 at 17:24 | comment | added | anna v | I think you are being unfair about the funding. It is more the Nobel effect than anything else. There are still experimentalists going for the unexpected so as to make a big splash and that is why they pursue funding for such experiments. In addition your certainty of experimentally established laws of physics has not filtered down to experimentalists, who tend to be measuring limits and pushing them as far as possible.. | |
| May 2, 2011 at 15:46 | vote | accept | Michael Luciuk | ||
| May 2, 2011 at 14:25 | history | answered | Luboš Motl | CC BY-SA 3.0 |