The Physics Classroom
Is there a "hole" in the universe?
The Eridanus Void. This area shows almost no signs of cosmic matter, meaning no stars, planets, solar systems or clouds of cosmic dust. Researchers couldn't even find dark matter, which is invisible but measurable by its gravitational pull. There were also no signs of black holes that might have gobbled up the matter once present in the region.
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The cosmic rays depicted here can be described as high energy particles like protons or other sub-atomic particles. These particles can come from our Sun (Solar cosmic rays) or other places like supernova explosions or neutron stars and black holes (Galactic cosmic rays). Galactic rays are higher energy than solar rays but Extragalactic cosmic rays, which come from quasars/blazars or the black holes in the center of galaxies, are even higher energy.