4 ms·
I am nothing short of _astounded_ that we don't know if anti-matter "falls up".
by ordinary 15y ago
I am nothing short of _astounded_ that we don't know if anti-matter "falls up".
- sp332 15y agoI've never heard anyone argue that it would react any differently to gravity than normal matter. After all, the only difference is the electrical charge of the particles. They have the same mass.
- smosher 15y agoI think the "falling up" argument comes from the conception that antimatter is the time-reverse of matter.
- delinka 15y agoOr perhaps must be affected by antigravity the way matter is by gravity. Assuming antigravity exists. Whether that's correct at all I don't know, but that's the logic being used.
- machrider 15y agoOf course, regular old hydrogen "falls up", being lighter than air. :) I guess if gravity is truly reversed for antihydrogen, it would fall up even faster. But I highly doubt it's actually gravitationally repulsive.
- smosher 15y agoThe simple solution is to let it fall in a vacuum, which seems to be what they're doing in this case.
- lloeki 15y agoSo if it "reacts the opposite" to gravity, what does that mean? I would see no reason for Newton's law to not hold true around our scale, so repelling means F=Gm1m2/r^2 which only makes sense if one of the masses is actually negative. Just the thought of it looks like fun.
- icegreentea 15y agoWell, the point of science is that we don't know until we observe it. So it shouldn't be that astounding since we've had a ridiculously hard time getting large amounts of neutral antimatter (everything before was charged, so EM affects overwhelmed gravitational). The consensus seems to be that antimatter will behave 'normally'. but we haven't seen it yet. Also, it turns out that certain frameworks where anti-matter is repelled by matter gravity doesn't violate anything else that hasn't already been violated (for example, CP and CPT symmetry have already be observed to be broken). And thus the uncertainty.
- Jach 15y agoHold on, where are you getting the CPT-symmetry violation from? This paper http://arxiv.org/abs/0801.0287v4 http://arxiv.org/abs/0801.0287v4 has a collection of experimental results hinting at that but the conclusion does not as yet seem to be very strong.
- deleted 15y ago[deleted]
- monochromatic 15y agoI thought this was a settled question, but I guess it's never been tested... so it's just consensus opinion, not verified fact. I am also surprised.