Anti-matter

[YunyunCitrus]

sorry if it's in the wrong spot, but I'm not sure where it goes.

 

So I've read that scientists have found and isolated anti-matter, and want to do experiments on it. I haven't found any articles about experiments and stuff, so I'm just wondering what do scientist know about anti-matter, and what are they still trying to find out?

[mathematic]

The simplest particle of antimatter is the positron, used in hospitals (PET scanner).

[alpha2cen]

what are they still trying to find out?

 

They have done researches about anti-matter storage method, anti- matter molecule making, anti-matter property measurement and anti-matter usage, etc..

Edited August 2, 2012 by alpha2cen

[swansont]

There is an experiment (ATRAP; there also used to be ATHENA) testing anti-Hydrogen to see if all the properties are as expected. While making anti-protons and positrons is relatively easy, they tend not to stay around long and some tests are hard to do on charged particles.

[Widdekind]

 

From a "Feynmann perspective", perceiving anti-particles as (normal) particles, propagating backwards in time (anti-time-wards), pairwise processes resemble Compton scattering, of electrons, off of hard (high energy) photons:

 

1. Pair annihilation resembles an incident electron, scattering off of an intense radiation field, and being "deflected backwards in time"
2. Pair creation (as perceived in forward-time frames) resembles an anti-time-wards propagating electron, scattering off of an intense radiation field, and being "re-deflected forwards in time"

Pairwise processes seemingly resemble Compton scattering, wherein the interactions are intense enough, to "boot particles back the other way through time". Normal particles are propagating, through the fabric of space time, from the "beginning of time" (Big Bang) towards the "end of time" (Big Crunch); anti-particles are normal particles, propagating through the fabric of space time, "the other way", from "the end of time" (BC) towards "the beginning of time" (BB), from a "Feynmann perspective", as herein understood & defined.

 

Space-time "doesn't care" which way particles propagate (BB-->BC, BC-->BB); our "arrow of time" seemingly simply reflects the fact, that the preponderance of particles, in our space-time fabric, are all propagating through space-time, in the same timely direction (BB-->BC). Inexpertly, that asymmetry seems to deny the possibility, that all particles & antiparticles are the same exact particle, zig-zagging forwards and backwards through time. For, were that the case, there ought to be as many particles as anti-particles -- the one particle would have to be propagating forwards in time as often as backwards in time. Even if so, qualitatively, the "Feynmann perspective" seemingly implies that pairwise processes can be analogized to Compton scatterings (?).

 

Please ponder a black hole, surrounded by an intense >MeV radiation field. Electrons falling towards the BH from afar could be considered, as successively "deflecting backwards in time", and then "re-deflecting forwards in time", off of that radiation field. Viewed from a large-scale perspective, such electrons would fall towards the BH, forwards through time; and then simply plunge straight into the BH, along a space-like axis, as they (on closer inspection) "rattled back-and-forth through time" down towards the BH:

 

................|

...._______|

../.............|

/...............|

|................|

|................|

e^-............BH

[Widdekind]

On second thought, i doubt that anti-particles (perceived to be) propagating forwards in time are completely like particles propagating backwards in time. For, the EM fields (say) of an anti-electron would still propagate away from the positron, at light-speed; the virtual photons of EM interactions between the positron and other charges would occur in forward time. As such, a normal electron, propagating backwards in time, could "tell" that it was a positron propagating backwards in time; because particles in its vicinity would (from its time-reversed perspective) respond to what it would perceive to be its future positions & speeds. Again, particles could tell, by probing their EM fields, whether they were propagating forwards in time (in the same time sense as their fields' virtual photons), or backwards in time (vice versa). So, perhaps the "Feynmann perspective" was only a poignant comparison, not meant to be completely accurate.