Missing Matter, Parallel Universes?

Phoghat writes "Could mirror universes or parallel worlds account for dark matter — the 'missing' matter in the Universe? In what seems to be mixing of science and science fiction, a new paper by a team of theoretical physicists hypothesizes the existence of mirror particles as a possible candidate for dark matter. An anomaly observed in the behavior of ordinary particles that appear to oscillate in and out of existence could be from a 'hypothetical parallel world consisting of mirror particles,' says a press release from Springer. 'Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other.'"

Now all we have to account for

[overshoot]

... is the observations that dark matter not only doesn't interrupt with electronic matter (except gravitationally) but also doesn't interact with itself.

Re:My own theory

[Anonymous Coward]

When cosmologists talk about parallel universes, they have a very precise meaning, not Star Trek kinda parallel universes. In this case, a parallel universe is a plane of spacetime that is an actual distance away (through one of the higher dimensions in, for instance, M theory). Some particles that aren't attached firmly to our plane can travel between them (gravity is thought to be weak because of this). So if a cosmologist says that a parallel universe might be the cause of some effect, they *probably* have an idea for a mechanism, not just "They're like us, but they all have goatees!" These ideas are very difficult to test at the moment, so most of the work is theoretical, but they're not unfalsifiable in principle. This is why we do things like build bigger and bigger particle accelerators; it lets us create the conditions needed to test some of these crazier ideas.

Re:Not parallel universes

[huckamania]

So, limiting the discussion to dark matter and dark energy, which are still open to debate, it would be nice to have a score card of what is in and out.

WIMPs are out.
Mirror matter in and out, apparently.
String theory, in then out then in but not nearly as cool as it was the first time.

My theory is that fundamentally the big bang theory is mis-understood. The universe, as we know it, is currently under construction and subject to change. Not on human time scales, but if we wind back the clock and play it forward, the universe has been getting weirder. Look at the growth of the periodic table since the beginning of the Universe, the birth of protostars and galaxies, etc. I don't see why it isn't capable of continuing to increase in weirdness.

This begs the question of how is the Universe getting weirder. This is where the big bang theory draws dragons and warns of impending doom. I like to think of it as if two water droplets were coming together. One is red, one is blue. When they mix, they create a Purple center. Our Universe is the purple part. From inside the purple part, you can't see the red and blue Universes and it would appear, if you wound back the clock, as if the Purple Universe appeared out of nowhere and it would also appear as if the Purple Universe was not only growing, but the growth would be accelerating. This doesn't break the big bang theory and doesn't break any other known theories. It does remove the need to explain expansion and other observations.

Is that any stranger than mirror matter or string theory?