lots of problems with the dark matter idea. Along with the multiple universe concept, these ideas are sort of like religion - ways to fill in the unknowns that sound more reasonable and sellable than "DUH". Problem is we have only the materials that we can detect and work with, that we call "real", to use to build a machine to detect something that we cannot detect and may not exist, or may be unmeasurable for some other reason, like the problems in the Michaelson Morely experiment. That is - the dimensionality of the Universe contracts in the direction of motion.
ho hum
how about warm left over particles?
Do you know the biggest question of all? Why are all of each kind of particle absolutely identical. I mean the rules of universal distribution say that when the fertilizer hits the fan, 1) it is never evenly distributed, and 2) the pieces are never the same size. So if everything did suddenly pop out as they say "void of form" and condensed, why did they all condense into identical pieces? Whay do all electrons and protons weigh the same (have the same mass), the same spin, etc etc as every other trillion trillion trillion of them no matter how old they are or how far they've traveled? Why aren't some chunks larger?
Jim