# Could laser (or other energy-bolt-shooting) guns ever practically replace regular guns with bullets?

This question is about the technical plausibility that, instead of guns with bullets, cops would be using hand guns that emit a bolt of laser beam (or some other energy beam).

Considering issues such as energy needs, risk of eye damage from laser beams, and that (at least some laser frequencies) can ricochet toward the shooter if the target hides behind a mirror, would energy weapons ever be a viable alternative in the hands of law enforcement?

What obstacles would need to be overcome for energy weapons to be able to make all guns with bullets obsolete?

• Are there any situations in which a laser gun would cause eye damage and a regular gun wouldn't? – octern Dec 12 '14 at 6:09
• Some interesting thoughts on the matter: projectrho.com/public_html/rocket/sidearmenergy.php – Adam Davis Dec 12 '14 at 14:08
• One situation where a laser energy weapon would have definite advantage over traditional bullet, I think, would be for extreme range sniper. With laser sniper, you don't need to worry about wind, gravity, or travel time, and a very powerful laser weapon is likely to be much more silent than a very long range bullet, making a sniper much harder to detect. This could give a laser sniper a much longer range and easier to train for. – Lie Ryan Dec 12 '14 at 14:11
• @octern: there are circumstances where an off-the-shelf laser pointer, never mind some laser weapon, can cause (minor) eye-damage and a handgun wouldn't. Specifically when you're out of range of the handgun ;-) More generally, if a laser weapon generates stray reflections (or for that matter refractions) then they'll presumably behave rather differently from projectile ricochets and fragments. Basically, a cop discharging a handgun responsibly can't blind someone a mile away (well, maybe in some circumstances like really tall cliffs). Laser weapons that might be a bigger risk. – Steve Jessop Dec 12 '14 at 14:30
• ... and one could speculate certain kinds of specially-designed surface that reflect enough energy not to melt immediately, and cause such reflections either in all directions or intentionally in a small cone back the way they came from, like a high-vis jacket or cat's eyes. "Go ahead cop, shoot me, it'll blind you and everyone in this shopping mall". – Steve Jessop Dec 12 '14 at 14:36

With foreseeable technology, not really. There are few exceptions. A near lightspeed weapon is really convenient for shooting down small fast moving objects such as missiles, drones, artillery shells, and, in the future, maybe in the bullets. An energy weapon might make it easier to control collateral damage; critical structures could be practically immune and even humans might have very limited risks of lethal damage. Police already use tasers. And energy weapons, sonic and microwave, have been developed for crowd control purposes.

But as a general replacement for guns? The basic issue is that if you are at a relatively close range, relying on humans reflexes for aiming, and need to reliably stop someone, guns are a relatively efficient way to do it. Being mature, simple, cheap, and reliable technology doesn't hurt either.

First point is energy storage. On a gun this is the propellant and the energy is transformed from chemical to kinetic in a very simple and relatively efficient manner. The relatively efficient here means that there are ways to do it more efficiently, but no one bothers since the way it is done is cheap and safe and, in practice, good enough.

For energy weapons this is lots more difficult. There are chemical lasers, but they are really not as convenient as the propellants used in guns. Available batteries have issues of their own as well. And it gets worse. The process of turning the energy into energy weapon is always more complex than with a gun. While this doesn't necessarily make energy weapons less efficient, it does make them more sensitive to wear and tear. And the inverse of collateral damage being easier to control is that practical energy weapons weapons impart their energy to the surface while bullets generally penetrate. This means that if you actually want to stop someone, a gun with a safety bullet will need much less energy to do it.

The end result is that for a given amount of stopping people guns will need much less space to store the energy, can do so reliably for long periods of time (guns are mostly NOT used, but need to work when you need them), and are simple and reliable. Guns would also be much smaller and cheaper than an energy weapon with the same stopping power as the mechanism of operation is simpler. This would be a major factor when arming large numbers of people on a limited budget. Especially when you intend a low rate of actual usage, so that the possible benefits of energy weapons are less important.

• "Police already use ... energy weapons". This made me smile. – PyRulez Aug 9 '15 at 4:05
• Police already use tasers and energy weapons, sonic and microwave microwave Um. No. what-if.xkcd.com/87 Please read about microwave weaponry first. – Nefer007 Oct 29 '15 at 23:23
• @Nefer007 You probably misunderstood what weapons for crowd control means. The fact that it is unlikely for the weapon to hit targets with enough energy to cause real damage is actually a huge positive in such applications. Also it seems the sentence is bit unclear, probably should edit, I did not actually say the police use energy weapons (which at this time might be true or untrue), just that such weapons have been developed for crowd control purposes, which is a fact. Yeah, I'll do the edit. Why not? Thanks for bringing this to my attention. – Ville Niemi Oct 30 '15 at 5:14
• There's one exception that really only makes sense for police. It ought to be possible to create a wireless tazer. A laser can create a straight line ionisation track through the air to the target who would then be zapped with electricity in the usual way. Advantages: speed of light and possibly cannot be defeated with motorcycle leathers or similar. Disadvantage: high power lasers can blind. Current tech: not portable. – nigel222 Dec 16 '15 at 19:38
• @nigel222 Yes, I know about electrolasers, but they actually would fall into the same exception as tasers and crowd control weapons that is already in the answer. For the purposes of this question using wires or using conductive plasma is a difference without distinction. – Ville Niemi Dec 17 '15 at 10:46

To make guns obsolete you would have to match or surpass the advantages of guns

Rate of fire. The amount of energy bolts fired per second must match or surpass guns.

Stopping Power

Stopping power is the ability of a firearm or other weapon to cause a penetrating ballistic injury to a target (human or animal) enough to incapacitate the target. This contrasts with lethality in that stopping power pertains only to a weapon's ability to incapacitate quickly, regardless of whether death ultimately occurs. Some theories of stopping power involve concepts such as "momentum transfer" and "hydrostatic shock" [...]

[...] "Manstopper." Officially known as the Mk III cartridge, these were made to suit the British Webley .455 service revolver in the early 20th century. The ammunition used a 220-grain (14 g) cylindrical bullet with hemispherical depressions at both ends. The front acted as a hollow point deforming on impact while the base opened to seal the round in the barrel. It was introduced in 1898 for use against "savage foes", but fell quickly from favour due to concerns of breaching the Hague Convention's international laws on military ammunition

Hydrostatic Shock

Hydrostatic shock or hydraulic shock is a term which describes the observation that a penetrating projectile can produce remote wounding and incapacitating effects in living targets through a hydraulic effect in their liquid-filled tissues, in addition to local effects in tissue caused by direct impact. There is scientific evidence that hydrostatic shock can produce remote neural damage and produce incapacitation more quickly than blood loss effects.

Also you might also want to consider that we have different guns for different purposes for example.

12-gauge pump action shotguns for close-quarters fighting. Used in a variety of roles in civilian, law enforcement, and military applications.

• As a person with many years of firearms experience in combat, it should be noted that "stopping power" is largely a myth. It is like trying to measure aesthetics, which is why the linked Wikipedia article uses a lot of quotes. – L0j1k Dec 13 '14 at 8:02
• The main advantage of a (hand)gun is its small size / weight. Apart from that, long guns (rifles & shotguns) seem to me to have the edge in any other area. – JDelage Dec 13 '14 at 22:29

Highly doubtful.

First of all, "bolt" and "laser" are different things. A "bolt" would be something like a bolt of plasma whereas "laser" is a beam of light. Particle beam weapons would be another alternative for something "laser like".

Particle beams presently require a synchrotron or cyclotron which has approximately the size of a sports field (for a beam strong enough to penetrate 30cm of body tissue, and an effective range of a few meters outside vacuum).

A "blaster bolt" type of weapon that fires a plasma bolt is almost as hazardous to the wielder as to the target (and to anyone standing nearby). It would require a massive chamber able to withstand considerable heat and pressure, and a powerful coilgun-like mechanism to fire the bolt. Building a coilgun mechanism that isn't the size of a war ship alone is a challenge. The bolt would be damaging to the weapon wielder's eyes and everybody close by, interfere with surveillance cameras (intense infrared emission), and might damage/ignite nearby objects even when not missing the target.
For being a "manstopper" or lethal, the bolt would have to be massive, too. Otherwise it will result in an angry opponent with a severe burn, but certainly able to fight on.

A "laser beam" weapon is somewhat unsuitable as gun insofar as it concentrates its energy on a very small area. Unless the energy is in the megawatt range (try and fit that into a pistol), you will need to point at the same spot for several seconds to heat up the tissue enough to disable/kill a person. Not that this isn't possible, but it's no improvement over a conventional gun. Let's hope the target isn't moving.
Assuming you are able to fit a megawatt (or gigawatt) laser and its power source into a gun, or into a gun and a backpack if you will, it does not make sense to fire shots any more. It makes more sense to have a continuous beam that cuts anything it passes through to pieces (including your opponent, but also bystanders and environment). Note that the Bad Guys would have that kind of weapon, too, and it is much more suitable for them than for the Good Guys.

It's not so much that these imaginary weapons wouldn't be able to injure or kill a person (or don't have "stopping power", boiling someone's brain, cauterizing the mediastinum, or cutting off an arm certainly stops a person very quickly), but they just aren't very useful or have significant advantages over a conventional gun -- despite their ridiculously high technological demands.

The only imaginable advantage over a conventional gun would be the fact that you cannot dodge a laser beam. Assuming robotics evolve far enough so you have autonomous combat droids, they might eventually be able to dodge bullets. Dodging a laser beam isn't possible since at the time you see it (if it passes through a scattering medium and if it's in the visible spectrum at all) you have already been hit.

• To be fair, if we speculate a 1ns laser pulse weapon, then the beam would be 3cm long and then I think can reasonably be referred to as a "bolt". Not sure what the current state of the art is for how much energy can be put into such a pulse. I'd guess that for a hand-held device, approximately "none" ;-) – Steve Jessop Dec 12 '14 at 14:39
• @SteveJessop: Fair enough, though given "nanosecond" exposure, we would need to push that laser's power somewhere into the terawatt range (at least?) to do anything "useful" related to injuring/maiming/killing. Even assuming a power efficiency of 99% (rather than the ca. 20% that we have today) that gun would need a cooler as tall as a building :-D – Damon Dec 12 '14 at 14:49
• Actually, you can 'dodge' a laser. If the spot hits you, move sideways and the firer has to pan with you to keep you under fire. This will be almost impossible from a distance. – Oldcat Dec 12 '14 at 17:33
• +1. In my own answer I was overly sensitive of the technology almost certainly improving in the future and simply repeated some variations of "needs more space" or "needs more energy" where-ever necessary without even explaining properly. But in retrospect, the scale of the issue really needs to be mentioned for proper understanding. Re what you were discussing with @SteveJessop, pulse power and thermal design power are separate things and TDP is what the cooler size is dependent on. We'd just have to limit pulse rate. – Ville Niemi Dec 12 '14 at 17:49
• @Oldcat: so in the same sense that you can dodge a bullet: when the nose of it contacts you, simply move aside in less time than the bullet takes to kill you ;-) All that's left to decide is how long the hypothetical weapon takes to kill and whether you can move faster than that. – Steve Jessop Dec 12 '14 at 18:09

I would imagine the real issue to be a question of non-lethality.

In the case of police officers and law enforcement, this is quite obvious, if the weapon is cost-effective and as capable as a gun, and non-lethal, than I don't see why we would continue to use conventional firearms (for law enforcement in any case; criminals and soldiers are another matter)

Assuming the OP was talking about guns that John Q. Taxpayer can carry, weapons which can neutralize a target without killing him, would certainly change the political views on gun legislation and control and this alone could spur replacement.

• I agree entirely. Take Star Trek for example, while phasers do have the capability to 'disintegrate' someone, most shots tend to appear to be working on the neural level - stunning or killing via the nervous system. Tasers already exist that work with similar principles. – NPSF3000 Dec 12 '14 at 23:26

What obstacles would need to be overcome for energy weapons to be able to make all guns with bullets obsolete?

• size,
• weight,
• capital cost,
• target speed and
• international law.

The LaWS cannon took \$40m to develop

But the 30-kilowatt LaWS is a long way from replacing Phalanx, for the moment, although it does share the older system's targeting radar.

all the targets it blew up were traveling in straight lines and moving relatively slowly,

For the moment the LaWS will be used for close-in targets, although under the terms of the Geneva Convention it can't be used against humans directly.

[ref 1]

The primary factors that have inhibited the transition of the technology into deployed systems are size and weight. Generally, the conceptual designs of laser weapons that are scaled for combat effectiveness are too large to be appealing to users; conversely, weapons that are sized for platform convenience generally lack convincing lethality

[ref 2]

Not cost of munitions.

At less than a dollar per shot, there's no question about the value LaWS [laser weapon system] provides

[ref 1]

"No, it's your turn to carry it!"

References:

• Slight correction: it can't be used to deliberately blind humans. It's perfectly fine under international law to use a laser to blow people up. – Mark Dec 12 '14 at 12:09
• @Mark true. Your laser toting battleship, soldier or policewoman is also required to "take all feasible precautions to avoid the incidence of permanent blindness to unenhanced vision." while blowing people up. In practice it might mean you have to be hesitant about blowing someone up if there might be civilians 5 miles behind them. – RedGrittyBrick Dec 12 '14 at 16:42

There are two big reason energy weapons might get adopted assuming their performance can be brought reasonably close to guns, these are:

1. No need for ammunition. Assuming they can hold charge for a good while or even better be recharged in the field then you remove a lot of weight and logistics requirements.

2. Space safety - in sci-fi settings directed energy weapons can be designed that do not penetrate the hulls of ships but still take out their targets. (Although this doesn't explain why people don't build body armour out of the material used for ship hulls). It also reduces the risks of ricochets in confined spaces considerably.

Energy weapons that exceed the performance of our guns would not need those advantages to be adopted anyway. If energy weapons were developed able to penetrate body armour for example then they would render both body armour and bullets obsolete.

• "this doesn't explain why people don't build body armour out of the material used for ship hulls" -- well, I can build body armour out of material that would stop a cop's handgun, but it would be fairly obvious and a bit unwieldy and they wouldn't let me walk into a bank wearing it! – Steve Jessop Dec 12 '14 at 14:42

"Batteries don't deliver energy that fast. Almost nothing non-destructive, actually, delivers energy that fast."

Batteries don't (yet) but capacitors do and we have some pretty energy dense power generation equipment out there.

If you're talking about something "man-portable" then yeah, you're going to need some sort of development(s) in energy generation. But capacitors can store and release significant amounts of energy in short order (that's why they're particularly dangerous.)

Honestly, there are some benefits to laser weapons (line of sight, speed, etc) but kinetic weapons are still developing.

Just look at the Navy's rail-gun program and all the benefits that will entail; no need for explosives to launch projectiles is HUGE! No more wasted space, no more powder magazine detonations from enemy fire, no more projectile explosions, significantly more energy transfer, longer range, faster cycle time.

I wouldn't discount kinetic energy weapons (like guns) until we have some major breakthroughs in room-temperature superconductors and some kind of ultra-compact power generation equipment. Not saying it won't happen, science has proven time and again to advance and defeat "insurmountable" problems, just that it'll be a while...

Yes, it is possible and it will happen as soon as some criteria is met: - Reliability - All firearms are simple. They are purpose built to be as simple as possible, less things to go wrong. - Cost/effectiveness - There is no point in making a rifle that does all the same things as an AK or an AR, but costs 500 times more. - There ware attempts at energy weapons, some even working(hell the US navy just used the first ever laser cannon a few days ago) during the 80's. Japan is said to have made a energy weapon in 1944, but it is lost. These weapons ware set aside for a reason, it was not their time yet, but it is very close.

• "There is no point in making a rifle that does all the same things as an AK or an AR, but costs 500 times more" -- why am I suddenly reminded of the SA80? – Steve Jessop Dec 12 '14 at 14:46

A laser is pretty much negated as a weapon in the rain, or mist, or dust, or fog - the beam will be scattered. This makes guns superior unless you have an environment where this doesn't occur, such as space.

The function of a gun is to deliver a large amount of energy into a target at a distance.

It turns out that using a one-time chemical reaction to impart kinetic energy into a metal slug is a really effective way to do that, in a relatively compact, lightweight package.

So for any "sci-fi" weapon, be it railgun, laser, or plasma blaster, you've got to determine where the energy is coming from. Batteries don't deliver energy that fast. Almost nothing non-destructive, actually, delivers energy that fast.

• That's how a gun works, but I'd argue that it is not the function of a gun. – NPSF3000 Dec 12 '14 at 23:27