gluons present didn't form into individual protons and neutrons, but remained in a quark-gluon plasma. The early Universe was full of matter and radiation, and was so hot and dense that the quarks and. But what if we go all the way back to the earliest times of all: to the very first moments of the Big Bang? If entropy has always increased, does that mean that the Big Bang’s entropy was zero? That’s what Vratislav Houdek wants to know, asking: If you look at the Universe today and compare it to the Universe at any earlier point in time, you’ll find that the entropy has always risen and continues to rise, with no exceptions, throughout all of our cosmic history.
This is true not only of a closed system within our Universe, but of the entire Universe itself. One of the most inviolable laws in the Universe is the second law of thermodynamics: that in any physical system, where nothing is exchanged with the outside environment, entropy always increases. In fact, the entropy was finite and quite large, with the entropy density being even higher than it is today. has always increased from any moment to the next, but that doesn't mean that the Big Bang began with zero entropy. Looking back a variety of distances corresponds to a variety of times since the Big Bang.
