(PhysOrg.com) -- Suppose at some point the universe ceases to expand, and instead begins collapsing in on itself (as in the “Big Crunch” scenario), and eventually becomes a supermassive black hole.

Dark matter, predicted to account for most of the universe's mass, remains highly elusive. Physicists have been searching for various particles that could be promising dark matter candidates, such as ...

Figure showing that the dark matter waves (in red) drive the ionosphere's plasma to produce photons (in green) which propagate down (to the left) to the Earth's surface. Credit: Physical Review ...