DARK MATTER, WHAT IS IT?

It is called Dark Matter because so far nobody has given it an identity.

INTRODUCTION

The presence of Dark Matter has been established through multiple astronomical observations. Specifically, something helped put galaxies together and is currently holding them together. The something that is holding all of the universe’s galaxies together also bends light that is coming from behind the galaxies. When all of the observed information is put together and evaluated, the most likely conclusion is that there is some type of matter around galaxies that gravitationally interacts with the galaxies while at the same time interacting with the expanding space of the universe.

The problem is that whatever this matter, or mass, may be it cannot be seen. That is, other than gravitationally this mass/matter does not interact with anything else in the universe or anything else that is known about within the universe. Hence the name, Dark Matter.

So we know that this Dark Matter is here in our universe, but we know nothing else about it. This is a bad position to be in because it severely restricts how we can move forward with understanding the basic workings of our universe. But all is not lost. We can evaluate what we do know, or think we might know, as well as the lack of results from current dark matter experiments to see what conclusions, or hypothesis, we can make about Dark Matter. This is the purpose of this paper.

DISCUSSION

This paper is the 4th paper in the series looking at dark matter. The first,

Dark Matter: a Galactic Dyson Sphere, https://medium.com/@philofysks/dark-matter-a-galactic-dyson-sphere-3a88908c959e

Is a discussion about what dark matter is doing with galaxies in the universe.

The second paper, Dark Matter, It Has Been Here Since the Beginning, https://medium.com/@philofysks/dark-matter-its-been-here-since-the-beginning-2788b4327021

Is a discussion about how all current evidence indicates that dark matter has been around since the time of the big bang.

Dark Matter: What Is It’s Purpose, https://medium.com/@philofysks/dark-matter-what-is-its-purpose-622c4ea1fd8e

Is a discussion about what dark matter does with galaxies in the universe and how it interacts with the universe.

These three prior papers are are building blocks to this paper in trying to use what has been concluded so far, along with other clues as to what dark matter may, or may not be.

Even Nothing Tells Us Something

Although the first indications of dark matter were discovered in 1933, it wasn’t until the around the mid-eighties that dark matter was “accepted” by the science community. One of the first experiments to try in gather information about dark matter was in 1986. So for about the last 36 years large and complex detectors have been built and experiments undertaken in order to find a possible dark matter candidate particle.

It is important to note that despite the fact that there is nothing known about what dark matter actually is, the experiments and detectors are looking for a dark matter particle. This is known because there are hundreds of written research papers and other forms of science communications that have theories about what kind of particle dark matter has to be. Additionally, the Standard Model of Particles is one of today’s most celebrated discoveries so it would appear that particles is form that the scientific community has decided upon as to what dark matter must be.

So far no experiment or detector has been able to find a dark matter particle. Maybe dark matter has some form other than a particle. This means that a dark matter particle, as we think of particles, simply doesn’t exist. Additionally, at the particle level gravity is virtually too weak to detect. In essence when all possible things and information are considered this lack of a particle discovery is telling us that the odds are we are not going to detect any dark matter particles, if they even exist.

THE NEXT CONCLUSIONS

In the first of the previous papers listed above it was shown that the dark matter halo around galaxies was acting as a barrier between the stable space of the galaxies and the expanding space of universe. The second paper listed showed that dark matter had to be around since the beginning stages of the universe, and that it must have assisted in the first clumping of normal matter. From the early relationship of dark matter with the first clumping of normal matter, and to later times in the universe with the collisions of galaxies we can conclude that dark matter must be transmissive to normal matter.

Currently astronomy has discovered multiple instances of past and present galactic collisions. Photographs of these collisions show the robbing and/or exchange of stars, dust and matter between the colliding galaxies. These galactic collisions can only occur if the dark matter allows the normal matter of the galaxies to pass through it.

The above conclusion regarding the transmissibility of normal matter through dark matter in the galactic collisions can be extrapolated back to the first clumping of matter. That is the dark matter in the early universe also had to let the first particles of normal matter pass through so that the normal matter could clump together to form the first stars and galaxies.

So through galactic collisions and the early clumping of matter we can conclude that dark matter has to have the property of transmissibility with respect to normal matter.

Looking at galactic collisions provides us with another property of dark matter, it can interact and combine with itself.

Recent observation in astronomy has shown us the existence of diffuse galaxies. These galaxies are dwarf galaxies in that they are small with a minimal amount of stars, and they do not have a dark matter halo. Although these galaxies have half the number of stars as our Milky Way galaxy they are about the same size as the Milky Way galaxy. In other words, the stars of these galaxies are completely spread out. The conclusion here is that the lack of the dark matter halo has exposed these stars to the expanding space of the universe so the stars of diffuse galaxies are being spread apart with the expanding space of the universe.

There is an additional conclusion associated with these dwarf, diffuse, dark matter free galaxies. The dwarf diffuse galaxies have no dust or other diffuse star forming matter within them. The theory is that diffuse galaxies are the remnants of a collision with a larger galaxy and that in this collision all of the star forming matter and galactic dust was stripped out of the diffuse galaxy and pulled into the larger galaxy. Similarly, the indications are the larger galaxy also stripped away the dark matter from the diffuse dwarf galaxy.

Since the diffuse galaxy lost its dark matter to the other, larger galaxy involved in the collision this shows that dark matter can also be stripped away and then combine with the dark matter in the larger galaxy. Just like normal matter can be stripped out of the diffuse galaxy.

There is another question associated with galactic collisions and the combining of dark matter. Galaxy collision have been occurring within our universe pretty much since the beginning of galaxy formation. In so many of these collisions the galaxies move apart and each maintains some amount of it’s dark matter halo. In other cases the galaxies combine and the dark matter halo transforms into a halo for the combined galaxies. This leads to so many follow up questions; how does the dark matter know what to do when galaxies collide?

Through current observations of galaxy collisions it is possible to show three cases as to what dark matter does:

1. It separates itself into halos around both colliding galaxies
2. It becomes a halo around one of the galaxies, leaving the other galaxy unprotected from the expanding space of the universe.
3. It combines and forms a single halo around both of the colliding galaxies.

NOTE: The stripping, exchanging and combining of dark matter from one galaxy into the other in a collision provides another area for additional discussion, research and hypothesis regarding how dark matter works in our universe.

GOING BACK TO THE BEGINNING

The above conclusions on what dark matter does in galactic collisions are looking at how dark matter is currently working within our universe after the formation of galaxies. But what about the early universe and the formation of galaxies?

It is known that in the early stages of the universe there had to be the formation of clumps of normal matter that would ultimately grow into stars and galaxies. One of the goals has to be to try and understand and/or try and determine how dark matter was working with the early normal matter in order to form normal matter clumps.

With respect to the early universe and the original clumping of matter, the space of the universe was much smaller than it today since the universe has been expanding since the very beginning. This means that it would not be possible for dark matter to start out at the size necessary to form a galactic halo. To the contrary, dark matter itself had to have formed as part of the big bang and formed at the same time as normal matter. One of the possible inferences here is that dark matter would start combining into small halo shapes that would grow as the universe expanded. These early halo shapes would be small enough and would start pulling normal matter in thus allowing it to start forming matter clumps.

As the dark matter halo continues to grow with the expanding universe, it pulls in more and more normal matter resulting in enough matter to form the first planets. The universe continues to grow, so do the dark matter halos thus allowing even more matter to accumulate and start clumping inside the protected space of the dark matter halo. Ultimately the halos reach galactic size with enough normal matter inside to start forming galaxies.

Thinking Outside Of The Box

The general question now is how is it the early dark matter halos grew? Maybe it was through clumping just like the early normal matter.

As was previously stated, the early universe was expanding. The expansion of the early space of the universe will move particles of all kinds further and further apart. This will have an adverse effect on the initial required clumping of any kind of matter. Clumping dark matter can provide a catalysts that limits the effect of the expanding universe space on normal matter. Additionally, it is known that dark matter makes up about 85% of the total matter in the universe while normal matter makes up the remaining 15%. Due to the gravitational interaction between dark matter and normal matter the high amount of dark matter would assist in the clumping of both normal and dark matter.

In order for dark matter to create stable space and protect normal matter from the expanding space so it may start clumping it has to form some type of halo enclosure around the normal matter. So, what it the most simplest way to create a halo, or a hollow sphere, for normal matter? Start out that way. What if dark matter actually starts our as some type of hollow sphere?

As the dark matter starts to clump the size of the hollow sphere within the dark matter also grows thus resulting in a larger halo with a larger open center. This would account for the ability to accept increasing amounts of matter. Current galactic collisions have shown us that dark matter does combine with itself. As for the hollow sphere, this is not that much of a stretch to consider as forming in the early part of the universe. Just look at normal matter.

With out going into details, it is known that normal matter is also a basically a hollow sphere of some sort. Protons and neutrons are both made up of three up and down quarks. However, the combined rest mass of these three quarks is only about 1% of the mass of the proton and neutron. The other 99% of the mass is unknown; however, there are various theories. This means that there is a very large mass difference between the mass of a proton or neutron and the quarks that make up these two particles. In other words, there is a “hole” and all of the protons and neutrons that make up of the matter in the universe.

If normal matter can have a “hole” in it why can’t dark matter?

CONCLUSIONS

As stated earlier in this paper a dark matter particle has not been found. The lack of any finding of a dark matter particle is strong evidence that one does not exist in the manner that physics current understands and identifies particles. Furthermore, if all of the facts are considered, it is not hard to understand that dark matter is in all likelihood not a particle as science currently understands particles. In order to start to understand what dark matter may be, acceptance of the fact that the universe is fascinating and wonderous essential. That is, look outside of the box a what dark matter could be, and all that it does.

It is known that the universe has been expanding since its beginning. It is also known that the distribution of matter/particles, was also smooth throughout the early universe. This means that as the universe expands the amount of matter in any given region becomes less dense. Additionally, at the particle level we know that gravity is barely measurable making it an incredibly weak attractive force. As the matter/particle density in the universe goes down with the expansion of the space of the universe it becomes harder for the matter/particles to clump to start forming stars and galaxies. This would include any particles of dark matter. This is where the higher density of dark matter and its halo shaped construction comes in. Its density gives it a high chance of clumping which allows it to create a non-expanding protected space. This in turn allows normal matter to join in with dark matter. And, as the dark matter halo grows, more matter is brought into the halo. This gives the halo enclosed matter an opportunity to clump and form the first stars and galaxies.

Currently it is not possible to say that dark matter comes in a halo or hollow sphere construction as it basic shape as was put forth as part of this paper. The fact of the matter is that virtually nothing is known about dark matter. So, this fact also means that it is not possible to say that a basic halo shape construction for dark matter does not exist.

Imagination is where new discoveries will be found. It is time to move beyond comfortability of the small amount of physics that is known in today’s universe.

Written By Steve Guderian 9–4–22