You know what they say, the best offense is a good defense, and with the Energized Particle Shield 9000 (patent pending) you will have the ultimate defense possible! The EPS units can be scaled up or down to fit your needs. Personal protection? Try our handy belt or backpack mounted units, only 1-5 lbs and capable of stopping anything from bullets to fists! Need a bit more power? There are vehicle and even spaceship mounted versions that can obliterate those pesky fighter ships on contact. Ship models also have the optional tractor beam feature! Don’t compromise, the EPS 9000 is the very best on the market, order today!

So as you can see from the sales pitch above, I have a shielding technology that is quite versatile. My most scientific explanation I can come up with is that it uses charged particles suspended in an electric field. When an object enters the field, it immediately compresses and reaches high temperatures while allowing powerful electric currents to flow between the field and the foreign object. So something like bullets are destroyed or deflected, and something soft like a fist is severely burnt. They protect against objects with less mass better, so a bullet is easier to defend against than say, a truck. The versions mounted on spaceships are strong enough that if smaller ships contact them, the extreme heat and electric current can destroy them. So the question is, what is the best method for creating this charged particle field? I’ve considered electric and magnetic fields, along with using plasmas, so am I missing something? Assume that power generation and waste heat are not an issue (I have a decent workaround for it).

  • $\begingroup$ Given how many things are stopped by this, how do you get enough oxygen through to breathe? $\endgroup$
    – Cort Ammon
    Jan 22, 2018 at 21:32
  • $\begingroup$ The shields don’t affect slow moving objects like the wind, otherwise they would hinder the wearer’s movement. $\endgroup$
    – Nick
    Jan 22, 2018 at 22:04
  • $\begingroup$ The average speed for a molecule of air is on the order of 1000mph. ( I ask because when it comes to shield plausibility, this is one of the most famous challenges to overcome) $\endgroup$
    – Cort Ammon
    Jan 22, 2018 at 22:15
  • $\begingroup$ True. I had envisioned a shield that works mostly by deflection, so the tiny air molecule with negligible inertia would get though, while a bullet would be deflected off of its path. $\endgroup$
    – Nick
    Jan 22, 2018 at 22:22
  • $\begingroup$ water balloons, the latest thing in shield-piercing technology. (steam your enemy to death) $\endgroup$
    – Jasen
    Jan 23, 2018 at 11:22

1 Answer 1


This is not plausible

As written, this is not plausible from a scientific standpoint. The most obvious flaw is that if you attempt to destroy a bullet with heat as a way to prevent it from hitting you, it will not dissipate the mass or the kinetic energy of the bullet, so you end it being hit by a very hot vapor from the vaporized bullet. This is probably worse then just being hit by the bullet.

The only plausible energy shields with current understanding of science are highly specific.

I have yet to see any scientific explanation in fiction for a general purpose energy shield. You can plausibly create some very specific ones - something to detonate mortars or other explosives at a distance so they don't reach their intended targets for instance, but those target a very narrow threat range.

For world building purposes, you are almost certainly fine hand-waving it

Very hard-sf is likely to encounter issues with any type of general energy shield, as mentioned above. But if you step into just slightly softer-sf energy shields are a remarkably common trope and you will likely get little concern from simply hand-waving the matter and giving it any properties you want, even in SF that is relatively hard in most other areas.

If you want to provide some explanation that is somewhat plausible scientifically, you are best off reaching for totally undiscovered physics to do it. A shield that takes advantage of the properties of a tightly coiled fifth dimension and relies on new advances in string theory sounds scientific and doesn't exactly violate known science so much as step around it for instance.

  • $\begingroup$ I was thinking that I would have to be a little inventive with some physics, but I wanted to make sure that I wasn’t just overlooking a simple answer. $\endgroup$
    – Nick
    Jan 22, 2018 at 17:45

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