David Kipping

You take a previous great man's idea and you just sort of maybe slightly tweak it and improve it.

That's how I see the Hello Drive.

And I just suggested, why not replace those out for black holes?

which is certainly very common.

And rather than flying your ship into that hell hole of a blender system, you just stand back and you fire a laser beam.

Now, because black holes have such intense gravitational fields, they can bend light into complete 180s.

They can actually become mirrors.

So the sun bends light by maybe a fraction of a degree through gravitational lensing, but a compact object like a black hole can do a full 180.

In fact, obviously, if you went too close, if you put the laser beam too close, the black hole would just fall into it and never come back out.

So you just kind of push it out, push it out, push it out until you get to a point where it's just skirting the event horizon, and then that laser beam skirts around and it comes back.

Now, the laser beam is doing a gravitational slingshot,

But light photons can't speed up unlike the spaceship case.

So instead of speeding up, the way they steal energy is they increase their frequency.

So they become higher energy photon packets, essentially, and they get blue shifted.

So that you send maybe a red laser beam that comes back blue, it's got more energy in it.

And because photons carry momentum, which is somewhat unintuitive in everyday experience, but they do, that's how solar sails work.

They carry momentum, they push things.

You can even use them as laser tweezers and things to pick things up.

Because they push, it comes back with more momentum than it left.

So you get an acceleration force from this.