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DontPanic
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Has Dark matter really been proven? And if, so what does this mean for the future of our understanding of physics?
DontPanic said:Has Dark matter really been proven?
The data fall precisely where predicted a priori by the modified Newtonian dynamics (MOND). The scatter in the BTFR is attributable entirely to observational uncertainty. This is consistent with the action of a single effective force law but poses a serious fine-tuning problem for LCDM.
Robin said:The assumption that the action of gravity is scale dependant seems to be a fudge. But then one could argue dark matter is a fudge. I can't help thinking if the action of gravity is scale dependant then the incredibly accurate measurements made by astronomers would reveal this when comparing for example the orbital behaviour of our moon or mercury to that of pluto.
Robin said:The assumption that the action of gravity is scale dependant seems to be a fudge. But then one could argue dark matter is a fudge.
DontPanic said:Has Dark matter really been proven? And if, so what does this mean for the future of our understanding of physics?
Ameter said:3) Our model of the structure of space itself is wrong.
cristo said:What do you mean by this?
Ameter said:If we think of space in four dimensions, we model it as a 3-dimensional (flat) plane relative to the fourth dimension. GR has shown that gravity can be modeled as an indentation in this plane, where the indentation is proportional to the mass of the object. However, this indentation is negligible at great distances, and so our model is essentially still a plane.
cristo said:GR tells us that space-time is curved, not just that the 3 spatial dimensions are curved. You seem to be describing an analogy which is often used to help describe the notion of curvature (i.e. the bowling ball on trampoline analogy). Of course, there exist spacetimes which are not asymptotically flat.
Ameter said:Simple answer: no
Long answer: Observations of galactic rotation tell us that one of three things is true:
1) More mass exists inside a galaxy than we can observe
or
2) We do not understand gravity completely.
or
3) Our model of the structure of space itself is wrong.
We don't know which is true. Many (most?) astronomers believe 1) is the most likely explanation. I personally believe that the answer is a combination of 2) and 3), but couldn't support that with anything physical (yet)
Vanadium 50 said:Neutrinos are dark, and matter, but they can't be dark matter - they are traveling too fast to have the right properties.
Decimator said:Do I misunderstand something about dark matter? Dark matter is essentially noninteractive matter, is it not? We have an example of that, neutrinos. They only interact via gravity and the weak force. Note that I do not think that neutrinos are the majority of dark matter mass, just that they're an example of dark matter.
Please tell me if I'm wrong. I like being told I'm wrong, it let's me learn things.
Dark matter is a type of matter that cannot be seen or detected through electromagnetic radiation, but its presence is inferred through its gravitational effects on visible matter. It is thought to make up about 85% of the total matter in the universe.
The existence of dark matter was first proposed in the 1930s by Swiss astronomer Fritz Zwicky, who noticed that the visible matter in the Coma galaxy cluster could not account for the high speeds of its member galaxies. Later, in the 1970s, Vera Rubin and Kent Ford provided further evidence for the existence of dark matter through their observations of galaxy rotation curves.
Aside from the initial observations of galaxy rotation curves and gravitational lensing, other pieces of evidence for dark matter include the large-scale structure of the universe, the cosmic microwave background, and the distribution of galaxies and galaxy clusters. Additionally, numerous experiments, such as the Large Hadron Collider, have failed to detect any dark matter particles, further supporting its existence.
There is currently no definitive proof of dark matter's existence. However, the overwhelming amount of evidence from various observations and experiments strongly suggests that it is a real phenomenon. Scientists continue to study and search for dark matter particles and ways to directly detect them in order to provide more concrete proof.
If dark matter is proven to exist, it would greatly impact our understanding of the universe and the laws of physics. It could potentially help explain the missing mass problem in galaxies and provide insight into the nature of gravity. Additionally, it could have practical applications in technology, such as in the development of new energy sources.