So, when I said I'll leave the question of the time it takes for the trillion-ton, atom-sized black hole to consume the Earth for another time...?
Yeah, it's about a billion
years. Lol, I thought it would take a long time, but not THAT long. The Eddington Limit really ...er... limits it, as it can only start out eating about a kilogram per second, and it pretty much stays that way until near the end.
The actual solution for how the black hole grows with time is an exponential of the form
For this case, plotting the Earth's remaining mass over time gives a curve like this, where the y-axis is in kilograms and the x-axis is time in millions of years.
Making the black hole more massive doesn't change the timescale a whole lot. Even if we made the black hole the same mass as Earth, it still takes about 30 million years to truly consume Earth, though at least it has a more steady effect:
Now I'm starting to think Dark Matter really isn't made up of primordial multi-ton microscopic black holes.
There could be some primordial microscopic black holes out there, and actually there are some researchers following the idea that it could explain much of the dark matter. If so they must have a particular distribution of masses to be consistent with observations (or lack thereof). I think more astronomers are in the "new fundamental particle" mode, but either way the models can only benefit from more data at this point.