Designing a realistic Force Field

So far my ideas include a heat shield and a device which curves spacetime to make bullets miss you. Any thoughts/comments/ideas?

edited 5th Oct '14 6:50:16 PM by KSPAM

How's the heat shield going to stop anything?

By vaporizing incoming projectiles, obviously

How would you avoid the searing heat from causing dangerous burns to the wearer of the force field?

And this is why I brought this here. I don't know.

The first device could work...in vacuum. There's no heat transfer via convection, all you need to worry about is radiated heat, and that is manageable if your projector is set properly. In an atmosphere what you'd get when you turn it on isn't a shield...it's an explosion. The thermal energy would cause a nuke-style shockwave of rapidly expanding air, which would rather comprehensively ruin the day of everybody in the general vicinity.

The second device has a limitation that would realistically plague many, many such shield devices across countless settings:

You'd be blind while using it.

The light you need to see with would travel the same curved path around you as whatever you're trying to deflect.

Man you know how hot you need to make a shield in order to vaporize something?

Like really damn hot. Like all you're gonna be doing is turning bullets into molten splashes of metal. Which are arguably much worse for your face.

So far, the closest thing we have to shield technology is reactive armour. I suspect that realistic force field technology would be further advancements in reactive shields. You might want to look into utility fog as a potential future active protection system.

Is a personal force field anywhere near plausible for hard sci-fi or is that a no-go?

It can be done, but it's not easy. It would probably be easier (for personnel) to design some high-tech armour that has a similar level of protection.

Looks like my best option is the space-bending field, since the Precursors who built this technology (as well as many other inventions which would later help sentient life colonize the local superclusters) had already mastered the manipulation of local spacetime to the point where they could alter the flow of time and space with some effort and crush entire planets into micro-singularities. I'll just have to remember to acknowledge that while the field is active, the user is basically in an invisible sensory deprivation tank (although sound could get in if strategic blind spots were put in the field for sending and receiving transmissions).

You could go for the Floating Armor design. Just grab some armored plates and magnetically suspend them were they're needed. You can use iron or any ferromagnetic substance at lower power settings or just about anything at higher settings. Phlebotinum is a common choice.

I would say that this falls at about a "3.0" on the Mohs Scale Of Science Fiction Hardness

Active protection systems. Specifically hard-kill systems. Some of them like the Iron Curtain project are named after (fictional) force field generators.

Would an active focused sound projection system work in atmosphere? Where you have two speakers, and they're both aimed at a certain focal point where a bullet will be, and very high-decibel sound is burst to collide with that bullet to wreck up its trajectory. Setting aside the question of a power source, of course, and assuming that tracking bullet trajectory isn't a problem.

As a bonus, this could be used to fly, as it could also vibrate air resistance down to zero in the direction you're trying to go or simply fly through vibration alone.

So is that an option?

No, well, technically yes but by that point you'd need high explosives since any physical object would shake it'self apart attempting to cause that much noise. Focusing in multiple sources doesn't work because the sound waves don't sync up perfectly.Also, at a certain point of agitation, the air stops carrying sound properly.

I'm not sure where you're going with the thrust idea since sound is a push and a pull, a moment of high pressure followed by a moment of low pressure.

Hm. How about this then? A system capable of generating the decibels to do all that (at worryingly close range) would also be able to generate thrust through air pressure manipulation, with an effect similar to a pulse jet engine.

Putting that aside, what about this: the exact mechanism is like the current theory about the cause of thunder - thermal expansion resulting from plasma, which probably can't stop a physical projectile (though it will ruin a missile's guidance computer) - and boils down to at least two big-ass full-bore lightning generators somewhere on the source's frame or physical presence.

If NASA is to be believed, dumping that much power into an engine will produce thrust. (And if XKCD is to be believed, dumping that much power into anything should result in movement.)

(It'd clearly need an unrealistically high-output power source, of course.)

I've toyed with the idea of using a type of shielding in my Sci-Fi story which generates a... magnetic? Something to that effect... field around the armor. Projectiles would be slowed considerably, not stopped; a suit of body armor would provide protection for that.

Too much strain on the shield and the generator would overheat, though. Make things fair.