What Would Be The Effects Of a Scifi Pressor Ray Beam Gun?

[Spacescifi]

Scenario: You have a scifi pressor ray gun. What that means is you have a laser pistol that shoots out a laser beam with concussive force... because it violently repels all mass it hits. When fired the gun has no recoil, since the laser beam only becomes repulsive after it leaves the gun's dark yet transparent repulsor lens. The repulsor lens changes the normal laser beam passing through it into a white colored pressor laser beam. Like real laser beams you won't see it from the sides unless in a dense fog, at night, or if fired underwater. Also the repulsor lens only converts light into pressor rays that are fired from behind it... you could shine a flashlight into the front of the lens all you wanted and it would do nothing.

How strong is the concussive force of the pressor beam? Like a fired bullet from a handgun, or nonstop fired bullets if you pull the trigger and hold it (which will drain the gun's powerbank faster).

Main Questions: What sound would it make when fired in the air? My guess is that if fired in pulses it would make a loud cracking sound equivalent to lightning, not because it is heating up the air (because the pressor laser beam delivers concussive damage and is not a hot laser) but because it is displacing all the air from the laser beam's path by repelling it. If the trigger is pulled and held then I would expect a constant booming sound as air is constantly blown away from the path of the pressor beam as it diffuses through the air. With enough range the pressor laser beam spreads out to be less lethal and more of a conical stiff breeze at the farthest range of the beam where it is weaker.

What visual and other effects would the pressor beam have underwater? I already know the beam would be white and would spread out with distance, but what visual effects would it have on the water if any? Would it cause air bubbles or shockwaves? And yeah... any fish unfortunate to cross the path of  a nearby fired continous pressor beam will quickly become a cloud of red mist, besides being bisected if it cannot get out the way fast enough.

Bonus: The same technology is used for rocket propulsion powered by pressor rays, just don't make a laser. Instead shine light out a repulsor lens fitted down the throat of a mirror coated nozzle, which transfers momentum from the reflection of the repulsive rays, thus creating thrust in the opposite direction. Momentum transfer would occur even if the nozzle were non-reflective, but a reflective nozzle increases thrust virtually for free so it is preferred.

So yeah... the scifi repulsor lens is key, since without it all you have is ordinary light (which has very, very, weak repulsive force) and lasers.

Concluding Comments/Questions: What are your thoughts? Did I get the sound effects right? What would the underwater visual effects be like?

 

[Terwin]

Either you have:

a) a flashlight that applies less pressure than direct sunlight on a white piece of paper

or

b) you have the main component of a perpetual motion machine

 

In either case, you have not really given enough information about your magi-tech tool to answer any of your questions.

If anything, I would expect your force-gun to have a range of perhaps a couple cm under water as it uses all of its force to push against the water in question(which would then pull you along with the generated flow)

Even in air, I would expect the range to be less than a meter, as it pushes against the air(which has mass, and is thus a valid target by your description), so in-short you have a very high-tech fan/propeller blade that breaks the 3rd law of motion(action/reaction), making it much less useful for providing propulsion(unless you are blowing air into a sail).

[Spacescifi]

9 hours ago, Terwin said:

Either you have:

a) a flashlight that applies less pressure than direct sunlight on a white piece of paper

or

b) you have the main component of a perpetual motion machine

 

In either case, you have not really given enough information about your magi-tech tool to answer any of your questions.

If anything, I would expect your force-gun to have a range of perhaps a couple cm under water as it uses all of its force to push against the water in question(which would then pull you along with the generated flow)

Even in air, I would expect the range to be less than a meter, as it pushes against the air(which has mass, and is thus a valid target by your description), so in-short you have a very high-tech fan/propeller blade that breaks the 3rd law of motion(action/reaction), making it much less useful for providing propulsion(unless you are blowing air into a sail).

 

I see, so I should retcon the gun as having recoil after it is fired.

At first my reasoning was not to have recoil as it would push directly on back against the glass repulsor lens... and I thought since it is firing bullet level concussive force... that may break the glass.

Would it? Granted I could just as easily craft workarounds so the glass won't break, but even bullet proof glass only lasts so long before breaking.

So lenses would likely need to be thick enough that they don't crack under the recoil pressure. And I imagine even then you may have a limited number of shots before you would have to replace the lens because it cracks.

 

As for range, it woukd be farther than suggest, given that it projects concussive force into a narrow beam that requires distance to spread out and therefore weaken. It would spread at the sams rate as a normal laser beam.

So for example, let's say the pressor laser gun has a lens of 9mm (millimeters).

You won't have to worry about bullet drop (no bullets), but with enough range (more than you suggest) you would have to worry about beam spread. Given the fact that you can shine a laser beam from wall to wall inside a large factory or warehouse and the spot size is still small, I would say it is still lethal for a few hundred meters at least.

Once the spot size becomes significantly larger than the lens then instead of piercing targets you would only be pushing them.

 

Edited Tuesday at 12:48 AM by Spacescifi