A rudementary question on dark matter

In summary, dark matter is a form of invisible matter in the universe that has a much greater mass than the visible matter, such as stars and galaxies. It does not emit any electromagnetic radiation and can only be detected through its gravitational effects on ordinary matter. Its existence and location can be inferred through gravitational lensing, but it remains a challenging concept to study.
  • #1
hms.tech
247
0
I think that there is mass associated with all dark matter in the universe and this mass is much greater than the total mass of the stars in a particular galaxy.

Now, if I were to classify the mass into two categories :
1. visible
2. invisible

How would I carry that out ?

Is dark matter invisible mass or would it be counted as visible mass ?
 
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  • #2
let me rephrase that, is dark matter visible to the eye ?

Does it emit e.m radiation in the visible region of the spectrum ?
 
  • #3
hms.tech said:
let me rephrase that, is dark matter visible to the eye ?

Does it emit e.m radiation in the visible region of the spectrum ?

"dark matter" does not emit radiation in the visible region or any other region of the EM spectrum...otherwise we would be able to detect it, and not just theorize its existence. the best evidence of the existence of dark matter is indirect - that is, we can't detect dark matter directly, but we can see its effects on ordinary matter. take spiral galaxies for instance - surely their inner regions orbit their respective galactic centers faster than their outer regions...and yet the outer regions still appear to orbit their respective galactic centers much faster than their detectable masses suggest. and so some scientists theorize that there is a substantial amount of "dark matter" in those outer regions (that cannot be seen by any ordinary means of detection) that provide the additional gravity necessary to account for the faster-than-predicted orbits of the outer regions of spiral galaxies about their respective galactic centers.

so your hypothesis that there is mass associated w/ dark matter is in line w/ dark matter theory, b/c even though it does not radiate anywhere in the EM spectrum, its gravitational effects can be detected.
 
  • #4
The existence and location of dark matter can be inferred by gravitational lensing. It is one of the best ways we have to locate it but even then it's not easy. I do remember a team of astronomers created a map of the dark matter, if I find it ill link it. However dark matter is still classified as invisible matter in your question. Visible matter are things like planets, stars, galaxies, etc. Dark matter is its own form of matter and does have mass and it is predicted to be much larger than the mass of what we can see.
 
  • #5


I would like to clarify that the concept of dark matter is still a subject of ongoing research and there is no definitive answer to your question at this time. However, based on current understanding and evidence, dark matter is considered to be invisible mass. This means that it does not interact with light or other forms of electromagnetic radiation, making it difficult to detect using traditional observational methods. Therefore, it would not be counted as visible mass.

To classify mass into visible and invisible categories, we would need to consider the different properties and characteristics of matter. Visible mass refers to the matter that can be directly observed through its interaction with light, such as stars, planets, and other celestial objects. On the other hand, invisible mass, also known as dark matter, is inferred through its gravitational effects on visible matter.

To accurately carry out this classification, we would need to use various observational and theoretical techniques, such as measuring the rotation curves of galaxies, studying the dynamics of galaxy clusters, and looking for distortions in the light from distant galaxies. These methods can help us identify the presence and distribution of dark matter in the universe.

Overall, dark matter is considered to be invisible mass, and it would not be counted as visible mass in the classification process. However, further research and advancements in technology may provide us with a better understanding of dark matter and its properties in the future.
 

FAQ 1: What is dark matter?

Dark matter is a type of matter that is hypothesized to exist in the universe, but cannot be seen or detected by any of the known methods. It is believed to make up about 85% of the total matter in the universe.

FAQ 2: How do we know that dark matter exists?

Dark matter was first hypothesized in the 1930s to explain discrepancies in the observed rotation of galaxies. Since then, various observations and experiments, such as gravitational lensing and the cosmic microwave background, have provided evidence for the existence of dark matter.

FAQ 3: What is the difference between dark matter and regular matter?

Dark matter and regular matter are fundamentally different in that dark matter does not interact with light or other forms of electromagnetic radiation, making it invisible to our telescopes. It also does not interact with regular matter through the strong or electromagnetic forces, only through gravity.

FAQ 4: What is the current understanding of the nature of dark matter?

The exact nature of dark matter is still unknown and is currently a subject of ongoing research. Some theories suggest that it could be made up of particles, such as WIMPs (weakly interacting massive particles), while others propose alternative theories of gravity to explain its effects.

FAQ 5: What are the implications of dark matter for the universe?

Dark matter plays a crucial role in the structure and evolution of the universe. Its gravitational effects are necessary to explain the formation and rotation of galaxies. Understanding dark matter is also essential for our understanding of the universe's ultimate fate and the expansion of the universe.

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