Imagining realistic energy weapons

[Trantor]

Realistic energy weapon - how about microwaves? I remember reading a story about operation black buck, and a side comment of one of the maintenance staff was that they used the onboard radar of the vulcans to hunt down their dinner. A rabbit was dead in less than a second, a deer "needed" a few seconds.
So against soft targets a microwavedevice could be suitable.

[Mjolnir]

Microwaves could be rather easily turned into an antipersonnel weapon, but one I doubt would ever see much use. Eyes and testicles are relatively vulnerable to heat damage by absorbed microwaves, and you could expect a large number of blind and sterile casualties instead of reliable "clean kills". This would probably be considered "superfluous injury or unnecessary suffering", and if it's not already banned, probably soon would be under something similar to the Protocol on Blinding Laser Weapons. They're also fairly easy to block, a simple wire mesh of sufficiently fine pitch will reflect them. (think of microwave oven windows)

That, and the enemy may just develop wearable rectenna mesh and use your microwave beams to recharge their lasers and railguns.

[Trantor]

Eyes and testicles are relatively vulnerable to heat damage by absorbed microwaves, and you could expect a large number of blind and sterile casualties instead of reliable "clean kills".

Even better, injured persons bind way more resources behind enemy lines than dead ones.

This would probably be considered "superfluous injury or unnecessary suffering", and if it's not already banned, probably soon would be under something similar to the Protocol on Blinding Laser Weapons.

In a total war nobody would care.

They're also fairly easy to block, a simple wire mesh of sufficiently fine pitch will reflect them. (think of microwave oven windows)

There´s a point.
MV-weapons would be more of a "terror-weapon" against soft targets.

That, and the enemy may just develop wearable rectenna mesh and use your microwave beams to recharge their lasers and railguns.

Hm. So the gunners should be instructed to look for other targets...

[anticarrot]

The power pack doesn't have to be too dangerous. Flywheel energy density is determined by the strength of the material. Use nano tubes and you can beat energy density of conventional battery technology by an order of magnitude or two. Optomistically you could get it almost as high as petrol. Getting power out woudl be easy - but currently the *other* big limit on flywheel batteries is getting the motors to reliably spin at sufficiently high RPM.

It's all up to how you define 'realistic'. It is definately realistic to expect major technological breakthroughs, but is it realistic to expect specific breakthroughs?

Another aspect is how often and how desirable is it for a single human to only have a laser to solve any given problem? Soldiers today carry many weapons. So do cops. Both have extensive support networks. Any technology tends to work best when combined with many others. If you really want a 'laser rifle' that can blow up a tank, the most realistic option is a rifle that ranges the target, takes a geotagged picture of it, and sends this information to a artillery officer sysop, who then says, "Yes, that's a T72" and presses the 'strike authorised' button, and obliterates the target with a 155mm guided artillery shell a minute after the trigger is pulled. And that laser weapon would almost certainly be a small coke can cylinder sitting on top of a more conventional rifle.

Here are some sample laser weapons in descending order of realism (YMMV):
*Aiming lasers - very hand portable. Significantly smaller and lighter than the guns they attach to.
*Blinding lasers - very hand portable. Can easily be a rifle accessory. Unfortunately currently very illegial in every country that can build one.
*Nausia lasers - use specific light pulses to disorient target. They do work, but only on a portion of the population. Caount as reduced lethality because some can have a bad reaction.
*Target designation lasers - Can be hand portable. Soldiers do not usually use the weapons that need these.
*Ranging lasers - Somewhat hand portable, but this is difficult to determin as they're often only used on weapons that are heavy in and of themselves.
*Digital target designation lasers - currently a two handed or tripod device. Soldiers do not usually use the weapons that need these.
*Low power Thermal lasers - Currently used in Israel to 'poke' IEDs. Possibly convertable to a single use 10kg '100 yard poking stick'.
(All of the above are actual military equipment. Realistically, as laser diode, optics, and hardened IC technology increaases, most of the above will shrink to smaller size.)
(Getting onto the unrealistic options)
*Comm laser. 1kW laser and small newtonian telescope. Backpack portable. Essentially uninterceptable communication between a soldier on the ground and a GEO satellite.
*High performance blinding lasers - In the 1kw+ range you and your 30 friends can use these as 'laser flak' to defend yourself against guided bombs and missiles.
*Mid power Thermal lasers - Crew served 20kg+ weapons plugged into portable generator or support vehicle. Beyond 50kW they have some marginal use in combat engineering and against some soft targets. Beyond 100kW they are effective against most soft targets, and could score mobility kills on tanks by spotwielding things that shouldn't be.
*Slow Sniper laser - Another 20kg+ crew served weapon. Dumps 1000j of energy into human skin in a tiny fraction of a second, which basically blows a small hole in them.
All of the above in smaller forms.
(and the impossibilities)
The Amazing Dissapearing Man laser - This would amount to a projectable suicide vest. It would not be bystander friendly.

[bunnyboy]

Blinding lasers - Unfortunately currently very illegial in every country that can build one.

Unfortunately? Why do you need one? No, it is bad weapon.

You don't wan't give it to idiots, because they play dare with mirrors.
You don't wan't give it to conscripteds, because they use it to get easily home. (no more shooting themselves to leg)
You don't wan't give it to protester, who will use it on your leaders and workers. (bulletproofing makes nothing if there are windows)
You don't wan't give it to criminals, who use it create mayhem in their sinister plots or to get away. (just shoot the driver)
You don't want use it on cities, because there are lot of reflective surfaces.
You don't wan't use it on present of water or rain, same reason.
You don't wan't to pay 50 years of pension to victims of accidents.
You don't wan't to pay war reparations, if you lose.
You don't wan't blind beggars on your streets, if you win.

Ps. There are lot of laserdevices strong enough. Couple of years ago in Finland one hockeyplayer get accidentally blinded, when some childs used laserpointer to mark their favourites.

[Tamren]

How much of a muzzle flash do lasers usually have? Beam weapons in general are usually depicted with a cone shaped "flash" emitting from the barrel where the emerging beam inexplicably gets thicker momentarily. Is this just artistic license or does it actually happen? For light to spill out in a "bloom" effect a laser emitter would have to have a lot of unfocused light that doesn't join the beam. So that would probably indicate a poorly designed system.

Most of the examples I can find online are pictures of high powered laser pointers. And its hard to tell if its a characteristic of the beam or something to do with the camera used to take the picture. The mortar point defence laser linked earlier certainly doesn't have one. (visible to the naked eye at least).

[Aygar]

How much of a muzzle flash do lasers usually have? Beam weapons in general are usually depicted with a cone shaped "flash" emitting from the barrel where the emerging beam inexplicably gets thicker momentarily.

A laser in a average enviroment will not have a gun like muzzle flash. If the there are particulates in the air these will cause some backscatter but this will not be muzzle flash like. If the beam is powerful enough then as the beam gets closer to its focal point it may start ionizing the air around it which will be visible but that would not be near the emitter.

--Aygar

[Aygar]

Tamren

See also
http://www.projectrho.com/rocket/sidear ... php#Lasers
and
http://panoptesv.com/SciFi/LaserDeathRay/DeathRay.html

These websites have good information on the behavior of lasers

[osmium]

@ anti-carrot

Do you know what happens when a flywheel fails? I would not call it "not too dangerous" Either the flywheel gets loose, you waste a lot of weight containing it in the first place, or you generate a ton of heat as all of that stored energy (as well as the energy you spent getting the wheel up to speed) is converted to heat. A lot of the new carbon fiber etc high strength materials flywheels are not these miraculous energy storage technology, they have advantages and disadvantages. The difficulty in any energy storage method is getting the energy back into the form you desire, some methods have better (others worse) conversion back to the form of energy you want.

Chemical lasers are nice because the direct byproduct you're looking for is generated and you can just dump the spent reactants (getting rid of the waste heat generated). Batteries are a natural, but with fly wheels or gravitational potential storage systems (towers full of weights and pulleys) you've gotta get that mechanical potential back to something you can use to drive a laser or something. They're certainly great for any mechanical system, but you'd really need to look at the numbers for the specific energy weapon in question to see how they actually stack up vs batteries because it's not just energy storage density, but more like usable energy density because it you lose 50% of that stored energy in conversion...

-O

[Siber]

I recall hearing about flywheel storage where the flywheel is a very long tightly wound ribbon, so when it fails it shreds itself and is relatively easy to contain.[citation needed] I suppose that'd cause a lot of waste heat, but any man portable weapon system could be dropped pretty easily. Seems like the conversion from spinning things to electrical power is something we've rather refined, in every power turbine we've ever built, too...

[Mjolnir]

The ribbon version Siber mentioned and other composite flywheels disintegrate into hot particles rather than producing high-momentum shrapnel. With modern low-rotor-mass very-high-RPM flywheels, the big problem with a failure is dealing with the angular momentum (which can be done using two counterrotating flywheels arranged so that failure of just one is unlikely), and getting them in a usefully sized package. A portable version would need gimbaling so precession forces aren't a problem, which adds to the bulk. In any case, anything capable of releasing large amounts of stored energy in a short pulse on demand is potentially going to do so when sufficiently mistreated...even chemical-propellant bullets.

Flywheels have major advantages for energy weapons, though: high energy density, high efficiency, high charge rate, and given the right design, very high discharge rate. A variation known as a compulsator is used in railguns and other applications needing high energy pulses. Batteries just can't achieve the needed power density and have high losses, and capacitors have low energy density (which indirectly limits the power density at large energies, due to the physical size of the capacitors and the lengths of connecting conductors). For stationary and vehicle-mounted applications, they're a pretty obvious choice.

[Voitan]

http://www.wired.com/dangerroom/2011/02 ... -a-record/

Currently, the free-electron laser project produces the most-powerful beam in the world, able to cut through 20 feet of steel per second. If it gets up to its ultimate goal, of generating a megawatt’s worth of laser power, it’ll be able to burn through 2,000 feet of steel per second. Just add electrons.

We will defeat our enemies by drilling through the planet to hit em on the otherside of the world. Clearly.

[Imbrooge]

Wouldn't the size of a beam weapon weilded by a person be, at the minimum, the size of an antipersonal weapon (like an M-60) or am I being too generous and it would have to be bigger?

I don't really know much about beam weapons but thats just what i'm extrapolating based on what i've skimmed through this thread and would like to confirm it. Presumibly the powersource is ambiguous but is definantly the main reason why I assume it would be so big for something a person would weild.

[Karst45]

We will defeat our enemies by drilling through the planet to hit em on the otherside of the world. Clearly.

i wonder what would happen if you were to drill through the planet with a laser. Would it only melt the rock and stop when it hit the magma? Would it continue to the core and be stopped here or would it continue all the way to the other side. I also wonder what problem that could cause for each situation.

[osmium]

It's just a matter of energy output. What would actually happen would depend heavily on the makeup of the planet and how quickly you can put energy into the target. If it just makes the surface molten and allows said liquid to flow back into the path of the beam you'd have to melt the whole planet. I'm not sure you can physically generate enough power to actually punch through a planet, asteroid sure, big asteroid maybe. You'd be much much better off spending that energy accelerating a 2km wide asteroid at said planet and letting that impact glass the surface of much of the planet and cause the sun to be blocked by the resulting dust storm.

-O

[discord]

and with sufficient velocity would crack the mantle of a tectonically active planet, which would be all kinds of bad....

[bunnyboy]

If you try drill through planet with laser, this will happen.

First laser will turn the air into plasma like big straith lightning. When the laser hit on the surface, earth/stone/existing materia turns to gas, expanding explosively. The hot gas get on way the laser. When the hole goes deeper, there are more plasma on way, which will melt the edge of hole. Also when deeper, to hole will turns to plasmageysir, when high pressure of hot gas try come out of hole.


But if you wan't to continue, you will heat the atmosphere until there are no life on planet, then melt the continent, then melt the planet, then create small star.
And if you still continue "drilling" it will only blow away matter until the gravitation is weak enough to have a hole on to cloud.

[Imbrooge]

2bunnyboy: That is overkill.

In general I realised you could make a laser look like a typical camera, or a flashlight. I am uneasy around cameras enough as it is, the idea that some guy asking to take your picture could actually be pointing a deadly weapon at you and you'd be none the wiser is a whole new can of worms to me.

Even a big flashlight but thats probably more on the remain inconspicious until you reach your target kind of thing.

[bunnyboy]

2bunnyboy: That is overkill.

Yes it is. But any weaker laser makes only a "lava pot" and keeps it steaming.
So no hole through earth. It could work with potato shaped asteroids, when gravity is weak enough to squirt melted & evaporated materia away (in your direction).

In general I realised you could make a laser look like a typical camera, or a flashlight. I am uneasy around cameras enough as it is, the idea that some guy asking to take your picture could actually be pointing a deadly weapon at you and you'd be none the wiser is a whole new can of worms to me.

You don't like this.

[AviLam]

2bunnyboy: That is overkill.

In general I realised you could make a laser look like a typical camera, or a flashlight. I am uneasy around cameras enough as it is, the idea that some guy asking to take your picture could actually be pointing a deadly weapon at you and you'd be none the wiser is a whole new can of worms to me.

Even a big flashlight but thats probably more on the remain inconspicious until you reach your target kind of thing.

Yaap it is. But any gradual laser system device makes only a "lava pot" and keeps it very hot.
So no starting through globe. It could execute with spud established asteroids, when intensity is inadequate enough to implement demolished & vanished materia away.