How can a singularity be used to prevent the formation of the Moon?

[Noisy Rhysling]

I have a race that is famous for going over the top with solutions to problems. Their garbage trucks dump the waste directly into their sun. Entire cities move around the globe to keep the sun at "high noon" ... so they don't have to light the streets at night. "Can openers" have self-contained nuclear reactors. And so on.

Now, they have decided that humans are a danger to them, because our solutions are simpler and more efficient. They have therefore decided to rid themselves of this danger. True to form they have built a time machine and are going back to the time when Earth was impacted by Theia and will use a singularity to keep the Moon from forming. See? Simple.

My problem is I don't know if they'll need more than one singularity. They fussy, they just want Earth with no moon. So do they need something to keep Earth on the right orbit while the singularity pulls the debris away from a Terrestrial orbit? More than one? Orbital mechanics is Rich Purnell's field, not mine. Thoughts, suggestions, mud pies?

 

[mfb]

What do you mean by singularity? A black hole?

Dropping a small black hole (a few trillion tons or something like that should be sufficient) into the Moon or anything that is going to form the Moon is sufficient to have the whole Moon become a black hole. The impact on Earth? Negligible. A bit more asteroid impacts. Life would still form. The black hole would have nearly the same mass and therefore the same gravitational influence as the Moon.

 

[Noisy Rhysling]

What do you mean by singularity? A black hole?

Dropping a small black hole (a few trillion tons or something like that should be sufficient) into the Moon or anything that is going to form the Moon is sufficient to have the whole Moon become a black hole. The impact on Earth? Negligible. A bit more asteroid impacts. Life would still form. The black hole would have nearly the same mass and therefore the same gravitational influence as the Moon.

However, life as we know it wouldn't have existed without the tides to stir up the oceans.

And the black hole was to keep the debris from coalescing in a single body, as I said in the OP.

 

[mfb]

However, life as we know it wouldn't have existed without the tides to stir up the oceans.

We don't know that.

A black hole moon of the same mass would produce tides just like the regular moon. If introduced early enough, it can probably lead to a significantly lower mass, as it can kick things out of Earth orbit (by close fly-bys, which would lead to an impact with a regular moon).Unrelated: A society that finds the most impractical solution for everything won't be able to work. Someone has to build the nuclear reactor for the can opener, for example. How much effort is that?

 

[Noisy Rhysling]

We don't know that.

A black hole moon of the same mass would produce tides just like the regular moon. If introduced early enough, it can probably lead to a significantly lower mass, as it can kick things out of Earth orbit (by close fly-bys, which would lead to an impact with a regular moon).Unrelated: A society that finds the most impractical solution for everything won't be able to work. Someone has to build the nuclear reactor for the can opener, for example. How much effort is that?

Okay, I'm lost. When did I say they'd replace the moon with a black hole?

 

[mfb]

You said "adding a singularity". What does that mean? I assumed you mean a black hole.

 

[Noisy Rhysling]

You said "adding a singularity". What does that mean? I assumed you mean a black hole.

The singularity was to keep the Moon from coalescing and helping to create the conditions for life on Earth as I understand it. The singularity would suck up all the material that didn't leave Earth orbit after the impact.

 

[mfb]

A singularity is a mathematical concept. "Putting a singularity there" without further definition makes as much sense as "putting a 5 there".
A black hole would reduce the mass that finally orbits Earth, but it would not completely get rid of an orbiting object.

You can let them push Moon out of the way by other means if you want to get rid of it. Or push the object that collided with Earth out of the way, avoiding the impact completely.

and helping to create the conditions for life on Earth as I understand it

This is a highly speculative idea. The tides might have contributed, but we don't know. A publication saying "this could be like that" does not mean that's how it happened.

 

[Noisy Rhysling]

A singularity is a mathematical concept. "Putting a singularity there" without further definition makes as much sense as "putting a 5 there".
A black hole would reduce the mass that finally orbits Earth, but it would not completely get rid of an orbiting object.

You can let them push Moon out of the way by other means if you want to get rid of it. Or push the object that collided with Earth out of the way, avoiding the impact completely.This is a highly speculative idea. The tides might have contributed, but we don't know. A publication saying "this could be like that" does not mean that's how it happened.

Well, if anybody sues me for using the concept in a story I'll be able to say that you warned me.

And the point is to keep the Moon from forming at all.