When it comes to space travel, the ultimate fuel isn't something we mine or refine.

It's something that annihilates everything it touches.

But if we can harness it and use it safely, antimatter could be the key to reaching the stars.

So why does antimatter keep showing up whenever we talk about near-light-speed starships?

The appeal is simple. Most rockets are about throwing mass away fast. Antimatter is about turning

mass into the ultimate rocket exhaust, particles moving at or near the speed limit of the universe.

That's why it shows up in every

near-light-speed starship discussion, ride along things like laser-sales and kuglitz black holes,

is one of the few options where math even allows you to play in that league. And you've heard

the usual version, matter touches antimatter, they vanish in a flash of gamma rays, and you ride that light

like a torch drive.

The treble is, that's the clean and simple version that I think leaves out a lot.

For starters, real annihilation doesn't give you one neat exhaust boom of convenient photons

to reflect out the back, gives you a whole grab bag, pions, muons, neutrinos, gamma rays.

Basically, whatever the particle zoo can cough up given the energy in the circumstances.

Some of those products are great for proportion because they can be reflected or they're

charged you can push them out the back with magnets. Others, like neutrinos, are the opposite.

With known physics, they're almost useless as a propellant, because they fly through everything and refuse to be steered. But that same ghost-through-matter-trick is also what would make them amazing. If you ever had clock tech, they could reflect or calumate them. You could have a near-light-speed exhaust you can't melt your engine

on, and you can stand behind the rocket plume unscathed. We don't have that, so for now,

photons are the best game in town, and preferably the lower energy ones.

We'll discuss that later, but we should start by clarifying why high-energy photons

are an awesome propellants.

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