Exotic Matter
Scott DeWar
Prof. Emeritus-Supernatural Events/Countermeasure
I am aware of the electron / anti electron [or positron IIRC] production from previous discussion, more notably PET scanners used in cancer cell observation on the molecular level. I was once told I do not want a pet scan. In the last year I have had it explained WHY I don't want one. More specifically, the gamma ray produced when the mater and anti matter introduce them selves.
Scott DeWar
Prof. Emeritus-Supernatural Events/Countermeasure
Yeah, I understand. Mine has been coming out bubbling and steaming.
tomBitonti
Adventurer
An idea, musing about this: If I setup a double slit experiment and put a reflector on the outward side that causes the washes from the slits to cross, then send through individual photons or electrons, will these sometimes reflect off themselves?
Since a single interaction can't conserve momentum, does that mean this particular reflection can't happen?
Edit: Trying to answer this myself on my drive in to work: One line of reasoning: Particles arriving from the left or the right are distinguishable events, meaning, normal probabilities should be used, not amplitudes. A particle crossing from the left is exclusive with a particle crossing from the right. No self collisions are possible. Second line of reasoning: If particles always reflect exactly, then a reflection would be indistinguishable from a non-reflection. There is no noticeable result (except the reflection is indistinguishable from a non-reflection, so some considerations of amplitudes with this). Third line of reasoning: If a scattering interaction can occur (not just a reflection) and amplitudes must considered, then a bizarre result seems possible, where the electron or photon can (very rarely) scoot off in a random direction.
Thx!
TomB
Last edited:
freyar
Extradimensional Explorer
As in PET scans, the positrons (anti-electrons) we'd normally encounter are produced as a product of nuclear decay; large particle accelerator experiments also produce them a lot, though not necessarily from photon-photon interactions. The electron/positron annihilation into 2 gamma rays is precisely the reverse process of two photons hitting each other to form an electron/positron pair.
I agree with you and your medical professional that you don't want a PET scan if you don't medically need one. Compared to an X-ray, you get a high dose of radiation from them. But I do think it's worth noting that the scary estimates of how likely that dose of radiation is to cause a future medical problem, like cancer, are based on extrapolation from extremely high doses of radiation (like people who were exposed to nuclear accidents, etc). There's no direct evidence that PET or CT scans cause cancers --- in fact, one study I saw on the BBC news page a while back concluded that CT scans don't increase the risk of cancer at all. So, while I think best medical practice is to avoid unnecessary testing and unnecessary risks, I wouldn't be scared of getting a PET scan if the doctors think it would be helpful for treatment.
freyar
Extradimensional Explorer
If I understand what you want to set up, the mirror will change the interference pattern from the double slit experiment, but that's normal quantum mechanical interference, not due to the photon "hitting" itself in the sense I was talking about. Scattering really requires two different particles.
Yah. Consider that, in the standard double-slit experiment, the particle goes through *both* slits, which is what sets up the interference pattern in the first place. It is, in effect, already interacting with itself.
tomBitonti
Adventurer
I was thinking about a device like the Stern-Gerlach (?sp) device used by Feynman in his lecture notes. If that can be used to split a particle stream then to recombine the streams to test quantum effects, then in a similar fashion the device could be used, not to split and merge the stream, but instead to split and then cause the branches to cross.
Thx!
TomB
In a quantum mechanical sense, that's what the double-slit experiment already does.
Similar Threads
