If antimatter is 'time-reversed', and time began at the Big Bang, is antimatter on the other side of T-zero?

Question

Where is all the missing antimatter? Instead of doing a dance and positing near total mutual annihilation after formation of both leading to today's matter universe, could time reversal really mean something here, and the antimatter produced be moving in the reverse direction? Number lines in one dimension can extend both before and after zero point. Spatial dimensions extend on both sides of any reference point one defines- why not time? And in a spacetime closed universe these two ends will meet- so time too? If so, then antimatter will be coming at us from the 'future' which is also before the past. What little we see today in cosmic rays may be partially all that's left after future annihilations, which will have eaten the bulk of all matter and antimatter (but not today).

Of course this scenario requires a little fuzziness about the time between the Bang and matter formation. Unless there was some sort of linkage through the singularity to the other side, now lost.

Thoughts?

If antimatter is coming at us from the future, then the further ahead we go, the greater its 'flux' will be, though most of it will never get this far into the past, since it would have annihilated matter in our future. The implication would be that there will be less matter in the future, and relatively more antimatter flux, until its 50:50 and then there will be more antimatter till the end of time (from our perspective, which is the beginning of time from the antimatter perspective). As for causality, it should be time reversed for antimatter, too, shouldn't it? We don't see any large structures in the universe made of antimatter so it would be hard to test, and individual atoms may not do here?

Some of the odd particle properties (such as parity violations) may have to do with time reversal? Or lack of antimatter neutrinos?

Answer 1

Antimatter is just an atom with the proton and electron charges reversed - that's it's DEFINITION. The kind of matter you are talking about wouldn't be called antimatter, it'd be called something else. I don't see how atoms made up of positively charged electrons and negatively charged protons would have any effect on time. You are positing that in an anti-matter universe time moves in reverse. What does that mean? That effects precede causes when all matter is made of atoms with reversed polarity sub-atomic particles. Sounds kinda weak.

Antimatter (the above definition of it) can, and has been created in the particle accelerators. It DOES annihilate when it comes into contact matter. This isn't theory. PET scans use anti-electrons (called positrons) for imaging (see here http://science.howstuffworks.com/nuclear-medicine.htm). Positrons don't travel backward in time, they are converted to energy.


[edit - in response to additional information]
First. Parity violations have nothing to do specifically with antimatter - although the effect has been observed in electron-positron annihilation's, it has more to do with weak nuclear interactions.

Second. The reason we don't see large antimatter structures is due to the tendency for matter and antimatter to spontaneously convert to energy in the form of gamma rays. If a large part of the universe were being consumed in matter-antimatter annihilation's, the amount of background gamma radiation would be huge - we'd notice it.

Third. I don't know what you mean by 'time-reversal'. A time-line is just a way of refering to a series of events or objects in motion. If there is a type of matter that moves in 'reverse' time, but maintains causality rules, I don't see how you could distinguish that (except mathematically) from our own observable universe. When most people talk about backwards time travel they are talking about moving their current selves to a point in space-time that USED to exist - before some event took place.

Answer 2

I think that is an absolutely brilliant thought. The great Nobel prize winning physicist Richard Feynman has elucidated that an electron traveling east is totally equivalent to a positron traveling west, and it is as if time is in reversal for the two particles. The fact is, nobody knows why the universe consists only of matter and no anti-matter. How do we know this is true for the whole universe? We don't, but we get a good sampling of all the matter in the universe by studying the makeup of cosmic rays, which are essentially all matter, and no anti-matter, and they arrive from all parts of the universe. If all of the antimatter ceated in the big bang went off in the opposite direction in time, then that would explain its total absence in our universe. What a brilliant thought!!

Answer 3

This isn't quite the case, as the sign of mass is also flipped with time reversal. Let us call a particle's antimassive counterpart its contraparticle, which has its own anticontraparticle of opposite charge but equal negative mass.

A contra-electron would be an electron moving backwards through time, and would appear to us to have negative mass and positive charge. This positive charge would attract normal electrons. From the contra-electron's point of view, it is the electron that has positive mass and negative charge. Therefore, it is also attracted to the electron.

However, since the contra-electron is moving backward through time, and its timeline shows it is closer to the electron's current position in the future than in the past, it will appear to us as moving farther away from the electron's position. The electron in turn will appear to be moving toward the contra-electron because its arrow of time is in the same direction as ours. The end result is an electron chasing its contraparticle.

This seems like perpetual motion, but remember that the contraelectron has opposite mass, so the net momentum is zero. This also holds for electron-anticontraelectron interactions, except now the electron is the one being chased.

As for contraparticle-anticontraparticle interactions, they appear repulsive, while identical contraparticles appear to attract.

Answer 4

Just 6 days ago (7/17/2006)I wrote Kaku and 4 days ago to Turner on this very idea. Here's an excerpt from my "gedankenexperiment":

"... I think the anti-matter is in a "serial" (not parallel) universe. The reason I call it "serial" is because it exists before the big bang and continues to move farther back in time (before Big Bang) as we move forward in our own time. This idea is mostly base on Feynman diagrams that have anti-particle moving backward in time. (Something like a quark and anti-quark absorbing a gluon creating an electron and positron pair headed off in different temporal directions.) Could an entire anti-universe be moving backward in time relative to us? (While they seem to themselves to be moving forward in their own anti-time frame?)

What existed at the time of the Big Bang (there was no time before)? Could it have been Energy (quarks, anti-quarks and gluons) joining to make matter and anti-matter? If so could the anti-matter have shot off into the past, traveling backwards in time (our reference) "before" the Big Bang and leaving our "forward" moving universe mostly devoid of anti-matter?
[Anti-matter(-time) <- (Big Bang) -> (+time)Matter] In this case, like a line graph, time Zero IS the Big Bang. Time moves toward infinity both left and right simultaneously. (It would be interesting to plot this in Minkowski space-time.)

Like Eta Carinae (but in 4 dimensions or more), could the symmetrical explosion of energy fronts of matter and anti-matter split-apart an unstable, but timeless nothing that existed before the Big Bang? The thought of this kind of physical symmetry is irresistible.

I would be interested if anyone is pursuing this course of study or if it has already been rejected because it's not as crazy as, say, the Copenhagen Interpretation? "

Answer 5

It seems to me that anti-matter moving backward in time would create matter and anti-matter out of pure energy. This does not happen, so I suppose time moves in the same general direction for all particles from our point of view (excluding tachyons and a few others).

Answer 6

..I like sandwiches.