What hold galaxies together?

@ Will: Yes I see what I did

However, a force and an acceleration are completely different things.

 

Thanks for the props, gonzo. It means a lot coming from you.

 

Dark matter is simply matter that we do not have the capability to observe. We have a very good handle on gravity and how it affects the formation and movement of structures in the universe so we can deduce that what we observe is caused by a form matter that we cannot see. There is no other force we know of that can explain the observations, therefore dark(unobservable) matter.

By invoking SVT are you saying that the motion of galactic matter through the universe is somehow inducing some kind of effect like we would see as if it were moving through a fluid?

 

He can't be saying that, because SVT isn't a legitimate fluid-dynamic theory

 

https://www.google.com/amp/s/scitec...sicists-favor-of-a-new-theory-of-gravity/amp/

If one were to look at more familiar examples of such behavior, such as the rotation of depressed weather systems, we might have to revisit the horrifying idea of the Ether. What if the rotation of disk galaxies was caused by a sort of Coriolis Effect? Maybe the whole universe is rotating, causing collective particles of matter that move towards each other, like air mass into a depression in the atmosphere, to begin rotating until their motion towards each other is balanced by their centripetal effect.

 

I once postulated that a black hole could cease to be a black hole if you imparted enough spin so that the matter within were to spread out into a thin enough disc.

You hit on something very interesting. Perhaps the universe is spinning so fast that it is expanding due to centripetal forces and dark energy doesn't exist. We are just simply unable to observe the spin due to our position within the universe. Edit: I guess that wouldn't make sense though since the universe seems to be expanding uniformly in all directions.

I love the idea of the ether, it would certainly help explain a great many things. Not much evidence for it though, as far as I'm aware.

 

The idea that we can see anything like the edges of the Universe from where we are, that the observed uniform expansion isn't just localized to a few hundred, or even a few hundred million galaxies out of uncountable numbers, presents me with a definition of "Universe" that is in complete contrast to what I understood the word to mean.

Gonzo says,

Yes, acceleration and force are different, but in my physics classes, acceleration was always caused by and evidence of a force being applied. Here again is a challenge to the definitions I have come to know and understand.

However, in the case of an acceleration, a rotation or angular momentum creates the frame of reference for a centripetal force. Centripetal force causes a constant acceleration and in a friction free framework, there is no need to apply any new energy to create a force and experience a constance acceleration. Only the static centripetal force can exist without adding more energy to create a force to accelerate a mass. Is this what is meant by curved space-time creating a sense of gravitational attraction without the application of a force?

 

I hate to wade in on a totally non-topic, as this is a boat forum not an astrophysics forum - go there if you wish to debate such matters..not a boating forum!
But..it appears I shall... despite my best efforts to stay of these non-related forum topics.

But that link is nonsense.....if you understood what dark matter is, you'l see why it is utter pockycock.

When astronomers viewed galaxies through telescopes and measured their characteristics they saw they have a classical spiral shape.
But what they observed didn't make sense. Because in any spiral as the centre rotates the farther and farther away you are from said centre of rotation these regions will move at a different rate to those very close to the centre. Just like the difference between the Earth's rotation around the sun and that of say Neptune. It takes much longer to perform one orbit.

But when astronomers made observations of these galaxies they noticed that those outer edges regions moved at the same rate as those much closer to the centre - as they are "fixed" together somehow. This is impossible..it cannot do that..but it did and every other galaxy they measured since they noticed this behaviour, did the same....huh..what's going on?

They reasoned the only conclusion to this is that there must be more mass, much more, as this would explain the constant rate of rotation.
But they couldn't "see" or detect anything....so they came up with the term "dark matter".

That's it in a nut shell.

 

If I, or anyone, understood what dark matter is, it wouldn’t be called Dark Matter!!!!
My theory may be poppycock, but I think it might stand as long as it’s not disproven or a better one is presented. I know they are thinking about a strange, but unidentified type of neutrino, but the jury is still out.

 

It is understood by scientists ... they just don't understand why. But thyey know more of what it is, than what is is not.
Dark...simply means they cannot "see it"...when looking through a telescope, hence the mystery.

Can't prove a negative....it is poppycock. Simply repeating the same mantra does not alter this fact.
Facts which seem to be severely lacking in this thread.. where opines are subverted as fact!

 

All they “know” is that it has to exist to explain the clumping of galaxies. That’s about all the C19 scientists “knew” about Ether. It had to exist in order to transmit light.

 

And that explains your poppycock nonsense - which is not referenced by any of the world's scientists - how??

 

I agree.
But you can disprove a theory. The Michelson Morley experiment disproved Ether. Darwin disproved creationism. Einstein disproved the relativity of light speed.
My theory may indeed be poppycock, but disproving it won’t require proving a negative.

 

Not..'may'....it is poppycock. I see no scientific references to your statements to support your argument ergo, what is it?...just an opine, and nothing else.
So why keep peddling the same mantra over and over again?
Just a waste of band width.

 

You sound angry.
No, it’s not an opinion, it’s more than that. It’s a theory based on an argument.
It may not be true. But why not attack the argument instead of trying to dismiss it by assertion (“it’s poppycock”)

Not “over and over again”. Just once.