“A cosmic mystery of immense proportions, once seemingly on the verge of solution, has deepened and left astronomers and astrophysicists more baffled than ever. The crux … is that the vast majority of the mass of the universe seems to be missing.” –William J. Broad
When Fritz Zwicky first calculated what the mass of a galaxy cluster needed to be to keep its galaxies moving at the observed speeds and compared it with the masses due to the starlight he saw, there was a huge discrepancy. The amount of gravity in the Universe, when compared to the amount of visible matter, didn’t match.
Image credit: Adam Block / Mount Lemmon SkyCenter / University of Arizona.
Adding up all the known sources of normal matter didn’t quite get us there, either: only one-sixth of the matter can be made of protons, neutrons and electrons. The other 83% or so must be some form of dark matter, which is yet undiscovered. Well, except for around 1% of it, which we actually know must be in the form of neutrinos.
Image credit: Hitoshi Murayama of http://ift.tt/KHJkt0.
Come find out about it — including how much there is and how we know — on today’s Throwback Thursday.
from ScienceBlogs http://ift.tt/1OgF7ui
“A cosmic mystery of immense proportions, once seemingly on the verge of solution, has deepened and left astronomers and astrophysicists more baffled than ever. The crux … is that the vast majority of the mass of the universe seems to be missing.” –William J. Broad
When Fritz Zwicky first calculated what the mass of a galaxy cluster needed to be to keep its galaxies moving at the observed speeds and compared it with the masses due to the starlight he saw, there was a huge discrepancy. The amount of gravity in the Universe, when compared to the amount of visible matter, didn’t match.
Image credit: Adam Block / Mount Lemmon SkyCenter / University of Arizona.
Adding up all the known sources of normal matter didn’t quite get us there, either: only one-sixth of the matter can be made of protons, neutrons and electrons. The other 83% or so must be some form of dark matter, which is yet undiscovered. Well, except for around 1% of it, which we actually know must be in the form of neutrinos.
Image credit: Hitoshi Murayama of http://ift.tt/KHJkt0.
Come find out about it — including how much there is and how we know — on today’s Throwback Thursday.
from ScienceBlogs http://ift.tt/1OgF7ui
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