3 ms·

Or unless you manufacture or discover a low–mass black hole

• jfengel 5y ago
  That's right. If we could create one in a supercollider, it would would be so small that it would be hot enough to evaporate instantly. There might also be a range of primordial black holes formed directly out of pre-CMBR energy. They'd have to be small enough to be hotter than the CMBR, but not so hot that they'd already have evaporated in the last 14 billion years. That's a relatively narrow range, all things considered, but if primordial black holes exist at all then they could exist at any range.