Questions about the structure of dark matter

[untilthecern]

If we assume that dark matter interacts with mass, according to Einstein's general theory of relativity, the presence of mass will bend the fabric of space-time and thus dark matter into curves. So, can we suggest that this matter, which occupies a large majority of space, behaves like a very dense liquid? Because if we think of the space-time index as three-dimensional, it would appear as if planets were sinking in this liquid. Accordingly, wouldn't it also possess the properties of gases? Couldn't we propose a statement such as: ‘If the entire universe is constantly expanding and this gas occupies its volume, a distance will arise between celestial bodies, and this distance will increase logarithmically as the observer's distance increases’?

 

[Nugatory]

If we assume that dark matter interacts with mass,

There’s no “if” here, dark matter is defined to be the stuff we haven’t seen yet that is interacting with the mass we have seen. It differs from ordinary matter only in that we haven’t seen it yet; in particular it has mass and behaves gravitationally just like any other matter.

according to Einstein's general theory of relativity, the presence of mass will bend the fabric of space-time

Please please try to forget that you ever heard that phrase “fabric of space-time”. It is a metaphor, not an accurate description of the theory, and pretty much inevitably leads to misunderstanding. For example

…and this bends dark matter into curves.

That is not what is going on.
To see what is going on, you might try the video below (by our member @A.T.) which shows how gravitational attraction is the result of initially parallel lines in curved spacetime meeting. Similarly, the overall expansion of the universe is the result of initially parallel lines diverging, analogous to how two people walking towards the equator on initially parallel straight paths will find the distance between them increasing.


If you are really serious about this stuff you will want to learn relativity for real. Taylor and Wheeler’s “Spacetime Physics” is free online and what I first learned from in my last year of high school.

 

[Ibix]

Please please try to forget that you ever heard that phrase “fabric of space-time”. It is a metaphor, not an accurate description of the theory, and pretty much inevitably leads to misunderstanding.

I'd go as far as to say forget any popsci you've read around relativity and cosmology. Far too much of it varies between "broadly illustrative", "correct but only in narrow circumstances", and "just plain wrong".

 

[untilthecern]

There’s no “if” here, dark matter is defined to be the stuff we haven’t seen yet that is interacting with the mass we have seen. It differs from ordinary matter only in that we haven’t seen it yet; in particular it has mass and behaves gravitationally just like any other matter.Please please try to forget that you ever heard that phrase “fabric of space-time”. It is a metaphor, not an accurate description of the theory, and pretty much inevitably leads to misunderstanding. For exampleThat is not what is going on.
To see what is going on, you might try the video below (by our member @A.T.) which shows how gravitational attraction is the result of initially parallel lines in curved spacetime meeting. Similarly, the overall expansion of the universe is the result of initially parallel lines diverging, analogous to how two people walking towards the equator on initially parallel straight paths will find the distance between them increasing.


If you are really serious about this stuff you will want to learn relativity for real. Taylor and Wheeler’s “Spacetime Physics” is free online and what I first learned from in my last year of high school.

I'll check the course you mentioned, thanks

 

[untilthecern]

So we can't assume the thing like that. got it