Comment Comment by GolDDranks My understanding is that they can't be _ultramicroscopic_, but they can be quite small. According to the Wikipedia:> A primordial black hole with an initial mass of around 10^12 kg would be completing its evaporation todayAnd according to this:https://www.omnicalculator.com/physics/schwarzschild-radiusMass: 10e12 kg → Schwarzschild radius of 1.5e-14 m which is smaller than a hydrogen atom (5.3e−11 m).I wonder what would be the mass that'd keep a black hole in thermal equilibrium with the current background radiation...(Edit. whoops, minus sign in a wrong place made the calculations haywire, fixed now.) parent GolDDranks 1 year ago
> A primordial black hole with an initial mass of around 10^12 kg would be completing its evaporation today
And according to this:
https://www.omnicalculator.com/physics/schwarzschild-radius
Mass: 10e12 kg → Schwarzschild radius of 1.5e-14 m which is smaller than a hydrogen atom (5.3e−11 m).
I wonder what would be the mass that'd keep a black hole in thermal equilibrium with the current background radiation...
(Edit. whoops, minus sign in a wrong place made the calculations haywire, fixed now.)