java physics

Physics of the early Universe is at the boundary of astronomy and philosophy since we do not currently have a complete theory that unifies all the fundamental forces of Nature at the moment of Creation. In addition, there is no possibility of linking observation or experimentation of early Universe physics to our theories (i.e. its not possible to `build' another Universe). Our theories are rejected or accepted based on simplicity and aesthetic grounds, plus there power of prediction to later times, rather than an appeal to empirical results. This is a very difference way of doing science from previous centuries of research.

The current observations and estimates of dark matter is that 20% of dark matter is probably in the form of massive neutrinos, even though that mass is uncertain. The another 5% to 10% is in the form of stellar remnants and low mass, brown dwarfs. The rest of dark matter is called CDM (cold dark matter) of unknown origin, but probably cold and heavy. The combination of all these mixtures only makes 20 to 30% the amount mass necessary to close the Universe. Thus, the Universe appears to be open, i.e. Ω_M is 0.3.