David Kipping

I'll talk about the halo drive in a moment, but the halo drive is useful for a civilization which is a bit more advanced than us that has spread across the stars and is looking for a cheap highway system to get across the galaxy.

For that first step, just to context that, the halo drive requires a black hole.

So that's why you're not going to be able to do this on the Earth right now.

But there are lots of black holes in the Milky Way, so that's the good news.

So we'll come to that in a moment.

But if you're trying to travel to Alpha Centauri without a black hole, then there are some ideas out there.

There was a Project Daedalus and Project Icarus that were two projects that the

British Interplanetary Society conjured up on sort of a 20-30 year time scale and they asked themselves if we took existing and speculatively but realistic attempts at future technology that are emerging over the next few decades how far could we push into the travel system and they settled on

fusion drives in that.

So if we had the ability to essentially either detonate, you can always imagine nuclear fission or nuclear fusion bombs going off behind the spacecraft and propelling it that way, or having some kind of successful nuclear fusion reaction, which obviously we haven't really demonstrated yet as a propulsion system, then you could achieve something like 10% the speed of light in those systems.

But these are

huge spacecrafts.

And I think you need a huge spacecraft if you're going to take people along.

The conversation recently has actually switched.

And that idea seems a little bit antiquated now.

And most of us have kind of given up on the idea of people physically, biologically.

stepping on board the spacecraft.

And maybe we'll be sending something that's more like a microprobe that maybe just weighs a gram or two.

And that's much easier to accelerate.

You could push that with a laser system to very high speed, get it to maybe 20% the speed of light.