Is Dark Matter a Cop-Out in Cosmology?

[chuchulainn]

I have no quantitative understanding of current cosmology, so go easy.

The intent of this post is to promote civil debate, not critisize current science.

So basically, I look at astrophysicists and I think of them as saying "oh, because there are observations we don't understand, there MUST be a mysterious, magical substance leading to these behaviors". IE, I'm thinking that dark matter/energy is a cop out. To my understanding, with our current technology, this theory isn't really even falsifiable.

Now, can someone with more knowledge than me (that's basically everyone on this forum), correct me if I am wrong?

 

[twofish-quant]

So basically, I look at astrophysicists and I think of them as saying "oh, because there are observations we don't understand, there MUST be a mysterious, magical substance leading to these behaviors". IE, I'm thinking that dark matter/energy is a cop out. To my understanding, with our current technology, this theory isn't really even falsifiable.

It is quite falsifiable. Saying that "oh it's just dark matter" and then stopping would be a cop out, but people aren't doing that. What people are doing is to say, "things seem to work out nicely if we assume that there is this much dark matter, composed of this type of substance, which reacts this way with matter, and doesn't react in this other way."

A lot of what people are doing is to use process of elimination. Let's assume that the dark matter is made up of light particles. Well, if it were made up of light particles then it would smear out large scale structure of the galaxies. Well, let's suppose, it's made up of protons and neutrons, in that case the galaxies aren't clumpy enough. Repeat for about ten years, and you come up with very good ideas for what it is and what it isn't. Well, let's suppose there is no dark matter and our understanding of gravity is wrong, then things clump in the wrong way. Let's suppose dark matter is made of black holes. Then if you look at distant stars, you should see a flicker if one of them passes in front of a star. We looked. We don't see that. Scratch that from the list.

One reason dark matter is getting a lot more firm, is that it's no longer quite as dark as it was before. If you have clumps of dark matter, then you ought to see it distort the light of distant quasars, and we've gotten to the point that no only do we see these distortions, we can use them to map out where the dark matter is and isn't.

Saying it's some mysterious magical substance that we can't understand would be bad. But what people are doing is to try to figure out what that substance is, and once you make some educated guesses, you then have some idea where to point your telescope and what to look for,

 

[twofish-quant]

Also, I think it's the situation that either dark matter/dark energy exists *or* there is something really basic about gravity that we are getting wrong. If you could add one mystery term to gravity and get dark matter, then people would go with that, but no one has gotten that to work.

It so happens that you can get dark energy to work nicely by adding one term to the gravity equation, so that's one thing that people are looking at, but right not observations haven't ruled out other things.

It's also possible that we are just basically misinterpreting what we see, but as time passes and we have more and better observations, that becomes less and less likely.

 

[chuchulainn]

Thank you for clearing that up for me :)

 

[sardar]

I can understand where your skepticism about dark matter comes from. It is a concept that is still not fully understood and cannot be directly observed or measured. However, it is important to remember that science is a constantly evolving field and our understanding of the universe is constantly expanding.

Dark matter is not a cop-out in cosmology. It is a well-supported theory that is based on extensive observations and calculations. The existence of dark matter is necessary to explain the behavior of galaxies and the structure of the universe. Without dark matter, our current understanding of cosmology would not make sense.

While it is true that we currently do not have the technology to directly observe dark matter, scientists are continuously working on new methods and technologies to detect it. In fact, there have been recent advancements in this area, such as the detection of gravitational waves, which provide further evidence for the existence of dark matter.

It is also important to note that the concept of dark matter is not a new one. It has been proposed and studied by scientists for decades, and its existence has been supported by numerous independent studies and observations.

In summary, dark matter is a crucial part of our current understanding of cosmology and is not a cop-out. As scientists, we must continue to question and explore this concept, but it is important to do so with an open mind and a willingness to accept new evidence and theories.