“A dwarf standing on the shoulders of a giant may see farther than a giant himself.” -Robert Burton
Both the internal motions of individual galaxies and the wholesale motions of galaxies within clusters require much more mass than normal matter — protons, neutrons and electrons — can account for: about five times as much. Because this can’t be any of the Standard Model particles, and it can’t interact either electromagnetically or with the nuclear forces, we refer to it as dark matter.
Image credit: Wikimedia Commons user Stefania.deluca.
But oddly enough, the smallest galaxies exhibit dozens or even hundreds of times as much dark matter as normal matter, a puzzle which only makes sense if you consider the incredible violence of star birth and death.
Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration.
Come find out all the details of how we know this and why this is expected on Forbes!
from ScienceBlogs http://ift.tt/1OGhIRR
“A dwarf standing on the shoulders of a giant may see farther than a giant himself.” -Robert Burton
Both the internal motions of individual galaxies and the wholesale motions of galaxies within clusters require much more mass than normal matter — protons, neutrons and electrons — can account for: about five times as much. Because this can’t be any of the Standard Model particles, and it can’t interact either electromagnetically or with the nuclear forces, we refer to it as dark matter.
Image credit: Wikimedia Commons user Stefania.deluca.
But oddly enough, the smallest galaxies exhibit dozens or even hundreds of times as much dark matter as normal matter, a puzzle which only makes sense if you consider the incredible violence of star birth and death.
Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration.
Come find out all the details of how we know this and why this is expected on Forbes!
from ScienceBlogs http://ift.tt/1OGhIRR
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