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Frabjous
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We do not seem to have any unexplained orbital/gravitational anomalies within the solar system. What does that imply for the local dark matter distribution?
If I understand correctly, we ”observe” dark matter in galactic clusters and filaments. Does this imply that some kind of weak clumping is going on? Or is it something else?Ibix said:Dark matter doesn't clump the way normal matter does,
The difference between dark matter and regular matter is that dark matter doesn't interact with electromagnetism - hence its darkness. When two bits of normal matter collide, what's actually happening is that their electromagnetic fields interact - if you push against a wall the electrons of your skin surface repel those of the wall. And it's that collision process that leads to matter clumping into spinning gas clouds, as the bits of gas collide and lose energy as heat. Dark matter doesn't collide, so where bits of matter would collide, lose energy, and eventually form a solar system, bits of dark matter just carry on about their days.Frabjous said:If I understand correctly, we ”observe” dark matter in galactic clusters and filaments. Does this imply that some kind of weak clumping is going on? Or is it something else?
Delightful.anorlunda said:That is described in the paper, The Potato Radius: a Lower Minimum Size for Dwarf Planets you might have fun reading it.
I was describing truly collisionless dark matter, but you can allow very very small cross sections for collision. Exactly how big is a topic of active debate, as far as I know.Frabjous said:Apologies for making this look like 20 Questions.
Do we believe that the electromagnetic interaction is zero or is it very small; i.e., below current levels of detectability?
I can't give a citation but I remember reading (here on PF I believe) that the total mass of dark matter within out solar system is comparable to that of a very modest sized asteroid but it is diffuse, so it has no effective effect on any orbits or anything.Frabjous said:We do not seem to have any unexplained orbital/gravitational anomalies within the solar system. What does that imply for the local dark matter distribution?
That's correct, but let's emphasize that the solar system is not just a small scale model of the galaxy. And that most of the galaxy's dark matter it outside the range of the visible matter. This artist's impression depicts that (except that the artist had to make the dark mater look visible to depict it.) Depicting invisible stuff with pictures is hard.phinds said:I can't give a citation but I remember reading (here on PF I believe) that the total mass of dark matter within out solar system is comparable to that of a very modest sized asteroid but it is diffuse, so it has no effective effect on any orbits or anything.
BillyDoster said:Interesting information! Always interested in astronomy! Black matter is amazing! There is so much more to discover in this and other universes!
I don't think this is a very good question. Do we know anything? Do we know that energy is conserved? Or that the violation is too small to measure? Do we know that electric charge is conserved? Or just that the violation is too small to measure? Do we know that reindeer don't fly? Or just that every one we see can't (or won't).Frabjous said:zero or is it very smal
Local dark matter distribution refers to the concentration and arrangement of dark matter particles in our immediate cosmic neighborhood. Dark matter is an invisible and mysterious substance that makes up about 85% of the total matter in the universe.
The local dark matter distribution is measured through various methods, including gravitational lensing, galaxy rotation curves, and simulations. These techniques allow scientists to indirectly observe the effects of dark matter on visible matter and map out its distribution.
Understanding the local dark matter distribution is crucial for understanding the overall structure and evolution of the universe. It also helps us to better understand the formation of galaxies and the role of dark matter in shaping the large-scale structure of the universe.
No, the local dark matter distribution is not the same everywhere in the universe. It is believed to vary depending on the location and environment, as well as the distribution of visible matter. However, the exact distribution is still a topic of ongoing research and debate among scientists.
The local dark matter distribution does not have any direct impact on our daily lives as it does not interact with ordinary matter. However, its presence and distribution play a crucial role in the formation and evolution of galaxies, which are essential for the existence of life in the universe.