Unbreak my heart

So the big bang (supposedly) happened, and the universe blossomed. For a long time, or what we can safely refer to now as “normally”, is that the universe went into expansion in the three dimensions. When time turned out to be a dimension too, it was logical that it was expanding, in other words we are traveling one way through time. Do the other ultra-minuscule space dimensions expand too? I donno, but if it is true, the detection of Kaluza-Klein particles would become progressively difficult, outstripping the growth of technology at CERN. Someone should pay attention to this. Anyway, so basically we are on a one way ticket through time, but some theorists say that gravity will eventually overcome the insane expansion, resulting in a big crunch where the universe contracts. This means that the space dimensions will begin to shrink too (Kaluza-Klein particle detection will be easier then, if CERN waits long enough ;) - alternatively, they can wait longer, long enough for them to be undiscovered) and probably time – which will then run backwards. Politicians will contest like hell after they win, our culture will continually improve, we’ll all keep growing younger and best of all, excreta will crawl back in, get undigested and uningested (which is different from unvommiting).


Now comes the crazy-enough-to-be-true part: Imagine localized areas of the cosmos in which this has already happened. Marcus Chown explores this possibility in his book, the universe next door, a replica of the article can be found here.
Now dead, defunct galaxies living out in backward time would explain dark matter, but this theory says that backward time areas and forward time areas can co-exist. Got me thinking…


So there is a thought experiment. Imagine a balloon tied to a weight. The weight does not fall because of the balloon which does not rise because of the weight. Imagine the tension on the string becomes so much that it breaks, the balloon falls, the weight rises. In backward time, the balloon falls, the weight rises, the string unbreaks and the tension decreases. Now here comes the part where backward time and forward time co-exist. The balloon is from forward time, the weight from backward time. What happens?



A computer simulation, might give the answer:



The balloon-weight on the left is in forward time, on the right is in backward time, and the center one is one element from each, the balloon from forward and the weight from backward.








Around midway:







And the end:







This does not seem to make sense. The weight should only rise if it meets tension in the end, but the balloon is allowed to rise without being released in the first sense. Gravity should not let the weight stay in the air, but it should rise because it falls, and that is probably why it rose, but it wouldn’t fall if the string didn’t break. In short, there is no final condition for the balloon to rise, and stay there. What happens before/after is not open for contemplation.



Is it impossible for time running in two directions to exist then?



Racked my brains for other thought experiments at this point of forward time. Two pendulums in different time directions bumping into each other and going back would make perfect sense from either and both perspectives, a handshake is unimaginable one would have already met the other… so two time directions looked like they could not exist together at all, and it would result in a matter – anti-matter type explosion.



Apparently, not really. Two Ford Thunderbirds, pitted against each other.







One catch… the blue one is in backward time, the red one in forward.






















So the blue one has crashed because it had grazed the red one, the red one will crash because it will graze the blue one. No problem, nothing wrong with this scenario. Totally possible. In backward time, the blue Thunderbird gets uncrashed, (ungrazes) a passing red Thunderbird, and (un)goes on its (un?)happy backward way. The red Thunderbird hits a blue Thunderbird and crashes. Therefore, it is perfectly possible, in this case for two objects in backward and forward times to co-exist.



Not as simple as that though – what about a head on collision? So are forward time-backward time interactions possible only to a very limited degree? Imagine, the blue car facing the other direction. A grazing crash is still imaginable. Increase the amount of contact… only possible as long as each car does not restrict the direction of travel of the other car.