Is there more than one way to build a universe?
The Big Bang is a theory of the formation of the universe and matter at the highest possible state of energy and density, then explaining how an infinitesimal and finite speck of concentrated everything becomes redistributed across the infinite and trackless void we call all of space and time.
In that theory, our impossible speck also happens to contain all of that space and time, so said redistribution involves space expanding faster than light to cross the necessary distance in the needed time to make room for the infant universe, later slowing down before speeding up again to produce matter and build the first stars.
It’s fair to say some of the concepts that arise in understanding the process of the Big Bang are counter intuitive and somewhat difficult to understand. It involves a few holes which can’t yet be explained and a few loose ends that stubbornly won’t go away. Yet still it remains our best scientific description of the beginning of the universe as we understand it.
Still the challenge of that theory, as with any theory of such scale worth it’s salt would be, is to to figure out how to take all of that and work it out so we end up with the universe we see around us. It is no easy task to be sure and science has been diligently been working on achieving this end for more than a century now and have made some suprising and remarkable discoveries along the way, but it hasn’t been completely proven yet.
Recent observations from LIGO as well as others point to the relative abundance, even arguable ubiquity, of black holes both large and small throughout the universe, even in orbit around each other, and that’s a problem for the Big Bang.
At least in part because it is in essence the theory of a black hole made out of space time exploding and forming the universe, but in the resulting early chaotic universe black holes are not easy to come by and even harder to form. To do that you need stars, big ones, in order to break enough of the rules involving the physical laws of matter to get it into a configuration where in can collapse it down enough to form a black hole.
One of the theoretical consequences of the Big Bang is dark energy, which is responsible for causing the expansion of space. What it is or how it works is not well understood yet in that context. Another other is matter, which is responsible for giving us mass which gives rise to gravity.
One form of that matter is called dark matter, and it is impossible to observe directly because it doesn’t interact with light. It is not only known to exist because of it’s gravitational footprint, combined with dark energy in the Big Bang model it comprises more than 90 percent of the energy and matter of the universe itself. Everything we can see is but the smallest fraction of what’s out there.
The early universe with it’s hot clouds of diffuse nearly pure gas is a wonderful place to make huge hot stars, which subsequently makes it difficult to create direct collapses into black holes. Not impossible of course, just harder to do in that environment. Thing is it’s fairly clear by this point that galaxies need black holes to form, they all have a big one right in the middle, and there is clear symmetry between a galaxy and it’s center in almost every case.
Given that giant, super mass and intermediate black holes have all been observed and evidence continues to mount that black holes may have formed so big and so early in the history of the universe they lack mechanism or explanation, a question began to rise in the back of my mind.
What about a universe that formed from the other end of the spectrum?
What would the universe look like if matter and all of space starts off cold instead of hot? What if matter gained mass at the lowest possible energy state and density rather than the highest as proposed in the big bang and what would the consequences of that look like?
We never really talk about it, and since all of science is busy trying to prove the Big Bang and all other avenues of study or interest in that context is considered a waste of time it’s easy to understand why. In truth I never hear any real or practical discussion on what the universe would look like from a cold Baryo-genesis, so let’s consider it for a moment.
As a thought experiment one of the first things that grabs my attention is that cold Baryo-genesis gives rise to kinds of both dark energy and dark matter as a natural consequence in the forms of thermal spatial expansion and a stunning range of black hole formations from billions of solar masses to sub stellar.
All of this would happen before the first stars.
When you place hydrogen or helium in their lowest possible energy states they form a superfluid rather than a gas, and super fluids have extraordinary properties including almost no viscosity. This makes them ideal for collapsing down directly into black holes before atomizing into gas and forming nebula which could collapse into stars.
In the Big Bang the universe is cooling down and currently has gone from infinitely hot to about four degrees above absolute zero and is still cooling. In cold Baryo-genesis the universe is getting warmer. That warming it fractions of a degree above absolute zero would allow ambient matter to become superfluid nebula which form and collapse directly into super massive black holes with hot quasars that throw heat energy and hot matter back into the galactic medium.
This process of collapse would occur again and again, producing ever smaller singularities, until the fluid becomes too diffuse and the nebula too small to smash down into black holes and they atomize into the gas from which are born the first stars.
Expansion of spacetime could be viewed as a thermal property in a warming universe, just like everything else in that universe that we know of does, that we have to engineer in anticipation of, rather than as an unknown energy property in a cooling one.
If you’ve ever seen expansion joints on a bridge or wondered why they cut lines into a sidewalk it’s because matter expands when you heat it, it would make sense if space also expanding when it got warmer. The universe is full of stars and is making new ones all the time meaning like it or not there is more heat being added to the universe every day.
Another notable consequence of a cold baryo-genesis is black holes still remain a candidate for the gravitational effect of dark matter even though the idea has been highly constrained to those around a few Jupiter masses or so. Bigger or smaller than that and there would be effects on distant light which have not been observed.
It should be said that because black holes have been so highly constrained they have fallen out of favor as the reason for the dark matter effect. The current favorite are WIMPs, which are a neutrino like theoretical particle 30 times the size of a proton which doesn’t interact with light and has never been observed despite years of careful experiments. This means black holes are still a possible explanation for dark matter.
Another effect of cold Baryo-genesis would be that many of the earliest stars would form in environments already polluted with metals from quasars and black hole formations, meaning they might form metal poor, but few if any stars could ever form completely metal free and would likely never be observable from our frame.
Taken a step further the warming universe would leave a fingerprint on the universe itself just like the Big Bang, a cosmic background at every wavelength.
The idea of cold Baryo-genesis is not intended as a challenge to the Big Bang, it is simply meant provide context from another frame of reference. To look at the question from a different point of view if only for the purpose of conversation.
If our answer to a question, to any question, is provably correct, all other answers to it should be provably wrong. If one of those answer lines up well with our rules and ends up with our observable universe, we should look at it and talk about it. If for no other reason than it would make for a fascinating discussion on the mechanics of how a universe can build…well, a universe, much like our own.
Exactly like our own really.