In addition to formation by supernovae and neutron star mergers, it should be possible for black holes to form via direct collapse. Simulations such as the one shown here demonstrate that, under the right conditions, black holes of any mass could form in the very early stages of the Universe. However, there must be something novel at play, or this process will not occur until after the first stars have formed. (Credit: Aaron Smith/TACC/UT-Austin)
Known as primordial black holes, they could thoroughly change our Universe’s history. But the evidence is strongly against them.
Whenever we think about the Universe, it’s fun to imagine what else might be out there beyond the limits of what we’ve discovered so far. But as vast as our…
