Why would large quantities of dark matter not stick together ?

In summary, the conversation discusses the properties and behavior of dark matter and how it differs from regular matter. The speaker suggests that instead of positing new objects with complex properties, it may be more logical to modify the rules of gravity to explain dark matter. However, the strange behavior of gravity and the discovery of dark matter continue to challenge our understanding of the universe.
  • #1
mikenovice
1
0
Does dark matter form orbits around stars ? Why would dark matter and "regular" matter, say, a dust belt not mingle and stick together?

Just with black holes, with d.matter we are positing new objects with complex properties instead of simply admitting imperfection in gravity. Since it is difficult to show how gravity is mediated (as opposed to showing its effects, which are clear)...to me, Occham's razor is best applied by modifying gravity rules locally instead of inventing new substances.
Of course, it is inelegant to make exceptions to gravity, which works well. On the other hand, gravity is so strange as to be suspicious: something leaves a mass at lightspeed, collides with other objects: the effect of this collision is to suck the object against the direction of the impact, and it does not weaken from use, and penetrates any type of element ?

While gravity generally applies, it is so strange that one should be willing to think about exceptions.
 
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  • #2
The problem is that Dark Matter is known to exist. Every time we develope some new isntrument with greater sensitivity, we see new things that we could not see before. Untill that moment, those things were Dark Matter.
...gravity is so strange as to be suspicious: something leaves a mass at lightspeed, collides with other objects: the effect of this collision is to suck the object against the direction of the impact, and it does not weaken from use, and penetrates any type of element...
Since the development of GR, this is not the way gravity has been understood to function. It is not a form of radiated energy, but a geometric condition of spacetime.
 
  • #3
mikenovice said:
Does dark matter form orbits around stars ? Why would dark matter and "regular" matter, say, a dust belt not mingle and stick together?

Just with black holes, with d.matter we are positing new objects with complex properties instead of simply admitting imperfection in gravity. Since it is difficult to show how gravity is mediated (as opposed to showing its effects, which are clear)...to me, Occham's razor is best applied by modifying gravity rules locally instead of inventing new substances.
Of course, it is inelegant to make exceptions to gravity, which works well. On the other hand, gravity is so strange as to be suspicious: something leaves a mass at lightspeed, collides with other objects: the effect of this collision is to suck the object against the direction of the impact, and it does not weaken from use, and penetrates any type of element ?

While gravity generally applies, it is so strange that one should be willing to think about exceptions.

LURCH said:
The problem is that Dark Matter is known to exist. Every time we develope some new isntrument with greater sensitivity, we see new things that we could not see before. Untill that moment, those things were Dark Matter.

Since the development of GR, this is not the way gravity has been understood to function. It is not a form of radiated energy, but a geometric condition of spacetime.

dark matter is not dark because scientists have seen dark matter and will see dark matter.
 
  • #4
Dark matter, as conventionally defined, does not compact like ordinary matter. The particles simply pass through each other. They interact as weakly with one another as they do with ordinary matter.
 

1. Why is dark matter considered to be "invisible"?

Dark matter is considered to be "invisible" because it does not interact with electromagnetic radiation, such as light. This means that it cannot be seen with traditional telescopes or other instruments that rely on detecting light.

2. How do we know that dark matter exists if we cannot see it?

Scientists have been able to observe the effects of dark matter on the motion of stars and galaxies. The gravitational pull of dark matter is what keeps these objects from flying apart, and can be measured through various astronomical observations and simulations.

3. Why wouldn't large quantities of dark matter stick together?

Dark matter particles do not interact with each other, making it difficult for them to clump together. Additionally, dark matter is thought to be spread out evenly throughout the universe, so there may not be enough particles in one area to form a large cluster.

4. Can dark matter be created or destroyed?

It is currently believed that dark matter cannot be created or destroyed. It is a fundamental component of our universe and has been present since the early stages of the universe's formation.

5. How does dark matter affect our understanding of the universe?

Dark matter plays a crucial role in the formation and evolution of the universe. Its gravitational pull helps shape the large-scale structure of the universe, and without it, galaxies and other structures would not be able to form. Understanding dark matter is essential for developing a complete understanding of the universe and its history.

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