This is not a practical thought for now or what I’m working on currently, but here’s a thought about the future of space-warfare that came to mind:

Imagine being on a ship, boarding another (or having yours boarded by an enemy), and you needing to defend yourself. I’ve written before that, to protect the hulls of ships, martial arts is likely to evolve into something reflecting ancient times.

The armor we’d use would likely be a more advanced version of what I’m designing now. Rifles would be higher-powered, if used at all, because if there’s a tear in the hull of any given ship…that threatens the lives of all involved in the raid: both the defenders and the assailants.

So, that means, futuristic swords and sabers are likely to make some form of a comeback…with the martial art to wield it properly.

But, here’s a thought: deflecting bullets with swords.

Science fiction? I don’t think so.

Bullets are made of varying metals. Metals are subject to the forces of electromagnetism.

With something like a portable nano-particle battery like what physicists like Dr. Michio Kaku talked about (which already exist, but aren’t in their mass-market form), why couldn’t you have magnetically charged swords?
The biggest reason why most people think you can’t deflect a bullet with a sword is because of the speed of the bullet versus human seeing and reflex abilities. Real, existing, modern Japanese swordsmen like Isao Machii can deflect low-level projectiles with his katana, that’s he’s passed many scientific tests on live camera to prove.
Though, he’s spent his entire life training to gain that skill. It would be unrealistic to expect the average or special operations space soldier to develop that level of skill in the time it takes to go through their varying phases of military boot camp.

…but what if you could reverse the equation? Instead of trying to solve the abstract problem from the LHS, why not solve it from the RHS?

Instead of having the sword go to the bullet, why not have the bullet go to the sword with a nano-particle charged blade using a controlled and limited magnetic field that the soldier could use AI-supported visual aids (like Google Glass) to calculate the trajectory of the bullet based on how the barrel of the enemy’s gun is pointing?
That’s actually really easy to calculate, even by hand: it’s just standard trigonometry and calculus. The margin of error produced by the instant calculation with quantum computing would be mitigated by the magnetic field generated by the sword; you wouldn’t need perfect accuracy with the sword; you’d only need to be within a certain range of the bullet as it gets closer to you.

Then, the sword would essentially suck the bullet from the air.

The only real hurdles at that point would be the force of pressure on the swordsman’s joints and bones. The sword may catch the bullet, but the force of the bullet hitting the sword could break the arm of the swordsman without some kind of bone-supporting extension to their armor.

That can be done, though.

…then, when you’re done, turn off the sword: the bullets you deflected will drop to the ground.