Is there really dark matter?

[Frank1985]

It hasn`t been proved to exist, as far as I know. But, if there`s no dark matter to bend, and we can`t travel faster than the speed of light, can we ever see aliens?

 

[promytius]

Since so many more people believe in dark matter than believe in aliens, I don't see the connection.
No "proof" of either, yet one is part and parcel of modern physics, and the other is still fictionalized.

 

[Valeriy Tarasov]

We don't know why peripheral stars in spiral galaxies have constant velocity (by the way in early universe it is not observed phenomena) - speculate about dark matter, particles which are not detected. Atomic nuclei cannot be explain for proton/neutrons composition - speculate about strong force, quarks which don't exist as all other particles. It looks as both cases are nothing more than speculations.

 

[Catastrophe]

What I do not like about dark matter (although I can see why it might have been introduced) is that it has no comparative components of "ordinary" matter. That is, it is nothing but a label for an unknown?

Or am I missing something? Are we really in touch with only 5% of thr Universe? - or is 5% far too high an estimate anyway?

Cat

 

[Valeriy Tarasov]

That is, it is nothing but a label for an unknown?

Yes, IMHO.

 

[Helio]

What I do not like about dark matter (although I can see why it might have been introduced) is that it has no comparative components of "ordinary" matter. That is, it is nothing but a label for an unknown?

I think it is a label for a discovered phenomena. There have been consistent observations (indirect) of its presence around all sizes of galaxies, and clusters. The Bullet Cluster adds to the evidence with its more unique dynamics.

But, to your point, it is an unknown as to what sort of particle this might be, assuming it is a particle.

Thus, until the particle is found for it, "Dark Matter" should be taken as a label for both the known (gravity-like phenomena) and the unknown (particle?).