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Antihydrogen Trapped For 1000 Seconds

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Re: Antihydrogen Trapped For 1000 Seconds

#21

Post by mikle »

Dn_Ab wrote: post #17
SeveredCross wrote: post #11

Earlier quoted context omitted.

Possibly with something like http://en.wikipedia.org/wiki/Laser_cooling , where you're not actually striking it with matter, but only with photons, though I don't know if photons react with antimatter (I presume not, but I am not a particle physicist).

Antimatter is just matter moving backwards in time, so it interacts with photons (which by the way, is its own antiparticle). This is one line of reasoning which strongly suggests antimatter should fall down not up in a gravitionational field. although iirc Dark matter is something does not interact with light.

Seriously, matter moving backwards in time? This is amazing. I never had a reason to learn more about antimatter until now. Thanks .

Re: Antihydrogen Trapped For 1000 Seconds

#22

Post by SeveredCross »

sp332 wrote: post #15
SeveredCross wrote: post #11

Earlier quoted context omitted.

Possibly with something like http://en.wikipedia.org/wiki/Laser_cooling , where you're not actually striking it with matter, but only with photons, though I don't know if photons react with antimatter (I presume not, but I am not a particle physicist).

Of course they interact with photons. Photons are how electric and magnetic fields are propagated. So if they can be contained by an electromagnetic trap, they interact with photons.

I think I should've been more specific—I know that the two interact, but I wasn't sure if they /react/. That is, would collision between photons and antimatter produce the same sort of decay as matter-antimatter collision. Some research suggests that it indeed would.

Re: Antihydrogen Trapped For 1000 Seconds

#23

Post by viraptor »

gecko wrote: post #14
dadro wrote: post #13

If it is proven that that anti-matter is repelled by gravity does that mean hover-boards will become a reality in our lifetimes? What are some of the potential practical applications?

Given that antimatter explodes violently when put into contact with regular matter, I kind of hope that's not how they go about achieving this. A kid who forgets to recharge his board, allowing the magnetic fields to collapse, could do a considerable amount of damage.

Not saying that it's as feasible as normal engine, but when you ride a bike you pretty much fill it with matter that explodes violently when ignited. Then you ignite small parts of it to make the bike move...

We may still see some normal devices which use antimatter in one way or another.

Re: Antihydrogen Trapped For 1000 Seconds

#24

Post by Dn_Ab »

jxcole wrote: post #18
dadro wrote: post #13

If it is proven that that anti-matter is repelled by gravity does that mean hover-boards will become a reality in our lifetimes? What are some of the potential practical applications?

No. I am not a physicist, but my understanding is that certain devices that have been proposed for use in space manipulation devices (e.g. wormholes, alcubierre drive), require either a form of matter that has reverse gravity or thousands of times the available energy of the known universe. http://en.wikipedia.org/wiki/Worm_hole#Traversable_wormholes http://en.wikipedia.org/wiki/Alcubierre_drive

Antimatter is not going to help you there. You need exotic matter of the negative mass kind. which are not thought to exist.

Re: Antihydrogen Trapped For 1000 Seconds

#25

Post by jerf »

mikle wrote: post #21
Dn_Ab wrote: post #17

Earlier quoted context omitted.

Antimatter is just matter moving backwards in time, so it interacts with photons (which by the way, is its own antiparticle). This is one line of reasoning which strongly suggests antimatter should fall down not up in a gravitionational field. although iirc Dark matter is something does not interact with light.

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 forward on the road, but if you hit him violently enough he'll end up turned around, walking back-first but in the same direction. Yeah, he's walking backwards through time! ime! ime! ime! but it's not like you can actually send messages backwards or anything; give him a message and he's still walking in the positive-time direction. There's a lot of cancellation of the negative term that goes on and he's still dancing to the tune of the same arrow-of-time as the rest of us.

I'm pretty pessimistic that antimatter will be repulsed by gravity, because you would suddenly have a term that would have to appear for the potential energy of the now-flipped gravity field. It makes much more sense for it to be affected normally. It's an interesting question that we might as well look at, on the off chance that the science will be wrong (which is when it advances, after all), but I wouldn't hold your breath.

Re: Antihydrogen Trapped For 1000 Seconds

#26

Post by zoul »

Dn_Ab wrote: post #17
SeveredCross wrote: post #11

Earlier quoted context omitted.

Possibly with something like http://en.wikipedia.org/wiki/Laser_cooling , where you're not actually striking it with matter, but only with photons, though I don't know if photons react with antimatter (I presume not, but I am not a particle physicist).

Antimatter is just matter moving backwards in time, so it interacts with photons (which by the way, is its own antiparticle). This is one line of reasoning which strongly suggests antimatter should fall down not up in a gravitionational field. although iirc Dark matter is something does not interact with light.

> Antimatter is just matter moving backwards in time

That could finally put an end to the chicken-egg problem. There was an anti-matter chicken in the first egg and it had moved back in time to lay its own egg after it hatched!

Re: Antihydrogen Trapped For 1000 Seconds

#28

Post by HelloBeautiful »

Dn_Ab wrote: post #24
jxcole wrote: post #18

Earlier quoted context omitted.

No. I am not a physicist, but my understanding is that certain devices that have been proposed for use in space manipulation devices (e.g. wormholes, alcubierre drive), require either a form of matter that has reverse gravity or thousands of times the available energy of the known universe. http://en.wikipedia.org/wiki/Worm_hole#Traversable_wormholes http://en.wikipedia.org/wiki/Alcubierre_drive

Antimatter is not going to help you there. You need exotic matter of the negative mass kind. which are not thought to exist.

>> which are not thought to exist

which have been observed a few times in colliders

Re: Antihydrogen Trapped For 1000 Seconds

#29

Post by Dn_Ab »

mikle wrote: post #21
Dn_Ab wrote: post #17

Earlier quoted context omitted.

Antimatter is just matter moving backwards in time, so it interacts with photons (which by the way, is its own antiparticle). This is one line of reasoning which strongly suggests antimatter should fall down not up in a gravitionational field. although iirc Dark matter is something does not interact with light.

Seriously, matter moving backwards in time? This is amazing. I never had a reason to learn more about antimatter until now. Thanks .

Well, in the same manner that a cow is spherical. :) I use it to motivate that antimatter is not so different from matter and not this exotic thing.

Re: Antihydrogen Trapped For 1000 Seconds

#30

Post by btilly »

HelloBeautiful wrote: post #28
Dn_Ab wrote: post #24

Earlier quoted context omitted.

Antimatter is not going to help you there. You need exotic matter of the negative mass kind. which are not thought to exist.

>> which are not thought to exist which have been observed a few times in colliders

Citation needed. Matter with negative mass would be big news.
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