This is super exciting. One day when I'm wealthier than God I'm going to donate some money to the guys who are trying to find him.
Antihydrogen Trapped For 1000 Seconds
81–90 of 109 posts
Re: Antihydrogen Trapped For 1000 Seconds
#82Earlier quoted context omitted.
Is there any conceivable way to make such a system fail-safe?
Nothing is fail-safe.
I think you misunderstand what the term means. For example, the control rods in some nuclear reactor designs are held up out of the core by electromagnets. Thus even in the event of complete power failure, the rods fall naturally, stopping the reaction. Since failure results in a safe state, this is referred to as a "fail-safe" system.
By contrast, if you were holding a lump of antimatter contained by an electromagnetic field, a power failure would result is the antimatter escaping confinement and annihilating with your body, releasing an unimaginably large amount of energy nearly instantly. This is what you might call a "fail-deadly" system, because a failure results in a decidedly unsafe state.
Re: Antihydrogen Trapped For 1000 Seconds
#83Earlier quoted context omitted.
I'm with you on this one. If antimatter was just backwards everything then there'd be large conspicuous clusters of the stuff all over the cosmos because ordinary matter would be repelling it instead of annihilating it. While there does seem to be a lot of dark matter out there, if it were actually antimatter and had opposite gravity to normal matter one would imagine there would be a huge discrepancy between cosmolo…
We know two things about dark matter: - It doesn't interact electromagnetically. - It does interact gravitationally and produces extra gravitational attraction beyond the electromagnetically interacting matter we know about. - It is dispersed throughout galaxies. The first property rules out baryonic antimatter as dark matter, since that would interact electromagnetically. The last two properties rule out anything th…
>We know two things about dark matter:
while we don't know whether it exists at all. Whatever phenomena are explained by DM are also easy explained by molecular hydrogen (i.e H2) which is almost not detectable. [The hydrogen we know about in the space is atomic - H, and there should be orders of magnitude more of molecular one than atomic when you have atomic at such interstellar space conditions]
Re: Antihydrogen Trapped For 1000 Seconds
#84By the way, there's something I've been wondering about for a long time. I read somewhere that there are no antiphotons and antimatter emits light just the same as normal matter. So, I assume that there's no way to tell whether a photon was emitted by antimatter or by matter. Therefore, how do we know distant galaxies aren't made of antimatter ? Maybe there's an obvious answer, but as far as I know, the only thing we…
I think the way that is usually phrased is that "photons are their own antiparticles".
Rgd "anti matter galaxies", we do detect particle cosmic rays on earth that originate from outer space (outside the solar system), though I don't know either whether they might originate from as far as other galaxies.
However, gravity is weak compared to the other forces, so galaxies can be expected to eject fast moving matter in addition to radiation (just like our sun).
So, given my meagre understanding of physics, I wouldn't expect to have seen anti-matter galaxies without also seeing gamma radiation fields spanning the space between a matter and an antimatter galaxy as particles annihilate each other.
Re: Antihydrogen Trapped For 1000 Seconds
#85Earlier quoted context omitted.
Seriously, matter moving backwards in time? This is amazing. I never had a reason to learn more about antimatter until now. Thanks .
I think people may be overselling this a bit. It is true that antimatter bears certain resemblances to matter traveling "backwards in time" when the math is examined, but the mental images conjured up by a plain-English reading of that phrase are almost entirely wrong. It's not like you tap the antimatter and the motion goes backward in time. I hate using metaphors, but it's somewhat more like you have a guy walking…
I don't fully understand your analogy. How exactly is that situation "backwards in time" if it still is moving forwards? Where could I find more info on this?
Re: Antihydrogen Trapped For 1000 Seconds
#86$100 says antimatter is also attracted by gravity. Anything else would be too cool for school.
It is actually great that they're doing this experiment 'cos if it turned out in a way that contradicted theory (which I think says "antimatter falls") then we might have to re-examine a whole lot of things!
For example, if antimatter rises, there ought to be a statistical preference for black holes to emit antimatter.
One of the posters on that site said CPT violation would be another great thing to check. Hell yeah!
Re: Antihydrogen Trapped For 1000 Seconds
#87So who is bootstrapping the first startup right now to make hoverboards?
Assuming 1kg of antimatter can be used to hover 1kg of matter and that your hoverboard could carry 80kg, should it's containment fail, it would detonate with the force of 3.4 gigatons of tnt. That's roughly equivalent with the entire present nuclear arsenal of the united states, and would cause 3rd degree burns out of direct thermal radiation over 300 kilometers away. So, umm, no .
Antimatter is definitely ridiculously dangerous stuff in macro quantities.
Though strictly speaking, from a bomb-building point of view, it would be very difficult to design a weapon where matter-antimatter mixing happened more or less completely and simultaneously. Otherwise you "merely" have a series of uncontrolled multi-megatonne explosions in an increasingly large area, instead of a single multi-gigatonne explosion.
Re: Antihydrogen Trapped For 1000 Seconds
#88Earlier quoted context omitted.
> I kind of hope that's not how they go about achieving this Don't worry. The design is impractical anyway - regulating the "anti-mass" would be extremely difficult. Just when you got it balanced, the kid would drink a glass of water and the board would sink into the ground. Due caution would indeed be advisable when selling these gadgets, though. A matter-antimatter collision of 50kg would be equivalent to about 2.1…
So you're saying that this has fantastic military applications? Interesting...
The military don't like antimatter weapons because they are fail-dangerous. They require active stabilisation.
If a nuke fails, nothing happens. If antimatter containment fails, your entire arsenal of antimatter weapons go up at once.
For a similar reason, nitroglycerin is strangely unpopular for both civilian and military purposes.
Re: Antihydrogen Trapped For 1000 Seconds
#89Earlier quoted context omitted.
I think the "falling up" argument comes from the conception that antimatter is the time-reverse of matter.
Of 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.
The simple solution is to let it fall in a vacuum, which seems to be what they're doing in this case.
Re: Antihydrogen Trapped For 1000 Seconds
#90Earlier quoted context omitted.
I think people may be overselling this a bit. It is true that antimatter bears certain resemblances to matter traveling "backwards in time" when the math is examined, but the mental images conjured up by a plain-English reading of that phrase are almost entirely wrong. It's not like you tap the antimatter and the motion goes backward in time. I hate using metaphors, but it's somewhat more like you have a guy walking…
I don't fully understand your analogy. How exactly is that situation "backwards in time" if it still is moving forwards? Where could I find more info on this?
Actually, it sounds like you got it perfectly. There is legitimately a way in which he's going "backwards", it's just not the way you would naturally think of if I just told you he's going "backwards". The backwards-through-time thing is one way of reading the math, but it doesn't mean what you think if you just read what the English says. Antimatter is way less interesting than "backwards in time" can make it sound. It's interesting, but not "kill your grandfather before your father is born" sort of interesting, just "fun particle physics" interesting.