Fundamental problems in Cosmology - Dark Matter

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Dark Matter

The universe looks very different now. It’s a lot bigger. Our universe is only a tiny part of the cosmos.  

What is in this Cosmos?

We can't see what's out there. We will detect it if we look for it. The gravitational pull we call Dark Energy must come from some very massive stuff. What is this “stuff”?

Oddly the clue may lie within black holes. All of our stars and galaxies will eventually end up in a black hole. It will take time. But that is the fate of all baryonic matter.

Actually I prefer to call it Light Matter. Baryon comes from the Greek meaning heavy. As we will see this is a particularly bad choice.

I call it Light Matter for 2 reasons.

1. It produces the light/radiation in our universe. Unlike Dark Matter.
2. It is many orders of magnitude less dense than the core of black holes and Dark Matter.

So we have Light Matter which we can see but is less than 5% of the observable universe and Dark Matter which is a about 24%.

All Light Matter is going to end up in black holes. It's not a quick process. Black holes do not vacuum up everything around them, but it is a 1 way process. Our universe is very young in cosmic terms 14 billion years is nothing compared to the eons stretching before us. Stars will last for up to 100 trillion years and in 10^33 black holes will dominate the universe. We will come back to the timeline of the cosmos later.

Even Dark Matter will end up in the ever increasing mass of black holes. It takes longer because it doesn't lose energy by producing EM radiation in the accretion disk. It will lose energy, however, and hence momentum through gravitational waves as it spins round the black hole.

So everything we know in our universe is going to end up in black holes. If there is anything out there in the cosmos, it's black holes. Black holes are the future. Black holes are the basic stuff of the cosmos.

I know it's just a speculative theory, but no new particles, forces or dimensions and definitely no creative mathematics have been created or destroyed in the production of this theory.

Using a favourite phrase of mine - the “most probable solution” -  the cosmos is made up of black holes. The Light Matter of our universe is by comparison merely a firework show.

Before delving further into Dark Matter we should get a clearer picture of black holes.

So what is a black hole?

Well it's not a singularity. That is not a real thing. It's a mathematical construction.

What is inside a black hole? Most of the theory and all of the observation is about the event horizon. What about the core? What happens inside? The usual answer is “we can never see what’s inside a black hole etc.” We need to ask the question though. The core of black holes is where it all happens. The event horizon is but the veil of gravity.

The closest we can get to seeing that core is to look at neutron stars. The little brothers of stellar mass black holes. We see a change of state under the massive force of gravity as a neutron star is born. They have densities of 1017 kg/m3(the Earth has a density of around 5×103 kg/m3 and even white dwarfs have densities over a million times less) meaning that a teaspoon of neutron star material would weigh around a billion tonnes.

What further change of state will occur when a stellar mass black hole forms? Now scale that up to supermassive black holes. What about those cosmic scale black holes which will form with masses of galaxy clusters? When all the standard forces have been quashed and only gravity remains, what what kind of matter remains. The secrets of Dark Matter may lie within the cores of such black holes. For now I will refer to the mass within black holes as Black Matter. Extremely dense and where once again, gravity is king.

The timeline of the cosmos

Cosmic matter must have existed before the Big Bang.

Now I don't want to argue against the accepted standard that time began with the Big Bang. That's time as we measure it in our universe. Without baryonic (Light) matter and radiation, time - seconds, years, light years, etc, has no meaning. But all that matter out there in the cosmos must have existed before the Big Bang. If the cosmos exists, it was there before the Big Bang.

The Cosmic Cycle

So how did our universe begin?

Now this is much more dangerous ground. It is all very well coming up with a theory about Dark Energy. In 40 years nobody has come up with the answer, and my theory is at least as good as any of the others around. However, the Big Bang is a well regarded part of the standard model. And so it should be. As we go back in time and the universe gets smaller and smaller, the Big Bang theory explains and has predicted so much.

The problem is the first few moments. How did it actually begin? All the theories start out with nothing. Nothing existed, or could exist before the Big Bang.

So to get round this problem some very creative solutions have been proposed. I’m tempted to draw parallels with the creation story of the bible, but no.

How about the matter/antimatter problem. It's a bit of a fudge to say there must have been some quantum imbalance. But if you're starting from nothing it is difficult to explain.

Then we have the doubling trick. How to get from a tiny amount of matter created by the antimatter imbalance. Easy. As any gambler knows, you can't lose if you can just keep doubling. 100 should do it! And then stop? It really is most unlikely.

If I'm right about Dark Energy and the size and age of the cosmos then, once again it's simple. We don't need “vacuum energy” and we don't need to worry about the matter/antimatter imbalance and the rest. Matter and energy are conserved because the Big Bang really was a big bang.

If the cosmos was full of cosmic scale black holes, black matter, then it is most probable that our universe was created from one of those.

I know that elegant simplicity is not everything, but this is both elegant and simple. Everything we see and know is going to end up in a black hole. Everything we see and know came from one.

The rest of the Big Bang theory remains intact. But now we have a ‘real’ explanation how it started.

Dark Matter

At last.

So Dark Energy is cosmic gravity. The cosmos is massive and much older than our universe. Our universe, our Big Bang, came from a cosmic scale black hole

There is risk of course that only using real things in the universe and following the “most probable” course could take us to a bridge too far. But here we go!

One of the many things that cannot be explained by the standard model is - where did Dark Matter come from? Was there Dark Antimatter? Did Dark Matter exist before the Big Bang? There is very little written in the places I am allowed to go, Google, Wikipedia etc. But then as we have absolutely no idea what it is, it’s even more difficult to say where it came from.

Well, in the absence of any other ‘creative’ suggestions, here we go.

As proposed, everything in our universe came from a cosmic scale black hole. So the Dark Matter in our universe came from that event.  They were created at the same time from the same place. If Light and Dark Matter were entirely different things created in different ways, different parts of the cosmos, at different times, they would be, well, more different. They occupy the same part of the cosmos. They both create gravitational force and are affected by gravity. The relative amounts of both Light and Dark matter are in the same orders of magnitude.

In the beginning -

Not very long ago, only about 14 billion years ago, a cosmic scale black hole became unstable. Perhaps the enormous gravitational forces at the centre of this beast resulted in a change of state. Maybe even turning mass into pure energy. Possibly two of these giants created a binary collision. The energy of that explosion created the temperatures and matter of our universe. The rest is the Big Bang theory - hydrogen, helium, CMB, formation of stars and galaxies, etc. No need though for Inflation Theory, no matter/antimatter problem, no reason to create mass from energy of the vacuum, no need for ‘expansion’ of space, no horizon problem either. We will come back to these later.

The Big Bang reversed the process described earlier when we imagined what was really going on in a black hole. Odd isn’t it. There are two things physicists won’t talk about. What happens in a black hole and how it all started. Two sides of the same coin. The ‘Cosmic Cycle’. Dark becomes Light and Light becomes Dark. Let's not get philosophical. Let's stick to describing what really happens in the universe.

Hydrogen forms into stars. Stars, depending on size, collapse into black holes, neutron stars or just burn out. The atoms collapse to neutrons and neutrons collapse into what I call black matter, whatever that is, the stuff in the core of black holes.

When a massive black hole explodes this process is reversed. Light and Black Matter explodes out creating our universe. Light Matter is an energised form of Black Matter. Apparently not all matter is energised to the Light form, only about 15%, probably from the core where the forces of gravity were strongest.

Now it's easy to see how supermassive black holes formed so early after the Big Bang.

The latest lensing measurements suggest that black holes can make up no more than 40% of Dark Matter. If so then Black Matter may be sufficiently stable to exist in less than stellar mass scale. It has no atomic structure so no ability to produce light, EM forces, nor strong or weak nuclear forces. It is the extremely dense and stable stuff of the cosmos. My guess is that we won't find it in the many detectors on earth. It's not a new and tiny particle. It's in dense clumps out there. Not sufficiently big to form gravitational event horizons and therefore very small. Too small to create measurable lensing events. The universe is a big dark place. It's easy to hide dark stuff, Black Matter.

Now let's turn to some of the other “creative” bits of the Standard Model. What really happens in the cosmos.