Antihydrogen Trapped For 1000 Seconds • Hacker News Board

Re: Antihydrogen Trapped For 1000 Seconds

#41

Post by BoppreH » Mon, May 02, 2011, 3:47 PM UTC

SeveredCross wrote: post #22

sp332 wrote: post #15

Earlier quoted context omitted.

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.

If they can be trapped using photons for this long, I guess they don't react?

Re: Antihydrogen Trapped For 1000 Seconds

#42

Post by kijinbear » Mon, May 02, 2011, 3:47 PM UTC

jwuphysics wrote: post #31

Femur wrote: post #10

Earlier quoted context omitted.

>>"The long term storage of significant amounts of antihydrogen should soon settle the question of whether antimatter falls up or down." Would this mean that if I am "holding onto" a chunk of antimatter heaver than myself I will fall up into space?

If you were holding onto a chunk of antimatter you would probably be missing a hand.

Not if you're holding onto it using a magnetic field, or any other method that doesn't involve direct contact.

Re: Antihydrogen Trapped For 1000 Seconds

#43

Post by delinka » Mon, May 02, 2011, 3:50 PM UTC

smosher wrote: post #19

sp332 wrote: post #16

Earlier quoted context omitted.

I'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.

I think the "falling up" argument comes from the conception that antimatter is the time-reverse of matter.

Or 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.

Re: Antihydrogen Trapped For 1000 Seconds

#44

Post by amalcon » Mon, May 02, 2011, 3:53 PM UTC

pavel_lishin wrote: post #35

enko wrote: post #34

Earlier 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…

> The design is impractical anyway Nah, you just need a miniature collider inside the board, manufacturing more anti-matter as necessary. And obviously, it would be powered by annihilating matter/antimatter together, via a small Mr. Fusion at the back.

They could just use a compressed-air ballast tank. That would certainly be simpler than a miniature collider, and the explosion risk isn't that bad compared to the rest of the device.

Re: Antihydrogen Trapped For 1000 Seconds

#45

Post by Jach » Mon, May 02, 2011, 3:56 PM UTC

icegreentea wrote: post #37

ordinary wrote: post #7

I am nothing short of _astounded_ that we don't know if anti-matter "falls up".

Well, 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 i…

Hold on, where are you getting the CPT-symmetry violation from? This paper 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.

Re: Antihydrogen Trapped For 1000 Seconds

#46

Post by Jach » Mon, May 02, 2011, 3:59 PM UTC

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 .

Go read Feynman's QED.

Re: Antihydrogen Trapped For 1000 Seconds

#47

Post by enko » Mon, May 02, 2011, 4:03 PM UTC

amalcon wrote: post #44

pavel_lishin wrote: post #35

Earlier quoted context omitted.

> The design is impractical anyway Nah, you just need a miniature collider inside the board, manufacturing more anti-matter as necessary. And obviously, it would be powered by annihilating matter/antimatter together, via a small Mr. Fusion at the back.

They could just use a compressed-air ballast tank. That would certainly be simpler than a miniature collider, and the explosion risk isn't that bad compared to the rest of the device.

That is a good solution. You should patent it! METHOD FOR DYNAMICALLY REGULATING BALLAST MASS ON ANTI-GRAVITY FLOATATION TRANSPORT DEVICE

Re: Antihydrogen Trapped For 1000 Seconds

#48

Post by [deleted] » Mon, May 02, 2011, 4:06 PM UTC

Jach wrote: post #45

icegreentea wrote: post #37

Earlier quoted context omitted.

Well, 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 i…

Hold on, where are you getting the CPT-symmetry violation from? This paper 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]

Re: Antihydrogen Trapped For 1000 Seconds

#49

Post by enko » Mon, May 02, 2011, 4:09 PM UTC

StavrosK wrote: post #39

enko wrote: post #34

Earlier 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...

So .. you don't read much sci-fi, do you?

Re: Antihydrogen Trapped For 1000 Seconds

#50

Post by Dn_Ab » Mon, May 02, 2011, 4:10 PM UTC

Someone wrote: post #40

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.

I do not understand: - I think all photons fall down in a gravitational field. - you claim photons are their own antiparticle. Hence, antiphotons fall down in a gravitational field. How then would antimatter fall upwards ~because~ it is the antiparticle of matter? Am I wrong in 'knowing' that all light bends the same under gravity?

Best as I can tell I don't think we disagree. You are saying that antimatter should react the same way with respect to gravity as matter does right? Then I agree. I do not think antimatter will be found to fall up or be repelled.