Remember that the speed of light is defined as 3x10^8 m/s in a vacuum . The speed of the energy weapon 'projectile' would depend on the resistance of the environment its travelling in. My layman's knowledge tells me the same idea applies to electicity flowing in wires, though I'm not completely sure. A conduit with less resistance lets electricity flow more efficiently (i.e. without loss, or with reduced loss over distance), but I'm not sure about speed. Call Arania!

ohh,
I should have said 'in space' as that is a vacuum..

Tho it does beg the question of energy weapons and their use in atmosphere..

They were afraid to test the h-bomb at fisrt as it was considered possible that it could set off a chain reaction with the hydrogen in our atmosphere .. thereby instantly incinerating the eintire planet...

Harrier

Seems reasonable, since light travels at the same speed, light weapons would too.

Oooh! people know me!

Anyway, onto the topic.

Energy weapons in the purest sense of the word are actually impossible to concieve. It is not actually possible to create (Let alone manipulate) energy in a pure form, there are various forms of energy, bue no actual 'pure' form of energy.

The most accurate actual interpretation of an energy weapon is that of an energy beam weapon, which in practice is actually a highly focussed and incredibly potent laser weapon (The 'Annihilator' energy beam emplacement in the game 'total annihilation' is a very good example of this).

However, in recent times, the name 'energy weapon' has since degenerated into the category of anything that uses an electrically-based power source to power the weapon (Technically putting tazers under that moniker). Particle accelerators, laser cannons, plasma cannons and similar other exotic and high-power devices that produce rather extensive destruction.

Most science-fiction perpetuations of energy weapons fall under 2 categories-

Photon-based:
Usually energy beam weapons, these are merely high-powered lasers, typically using a photon energy frequency in the visible range to impart energy directly to the target object over minimum surface area, acusing highly potent localised damage. These are direct-fire weapons, and are limited (At least in a vacuum environment) only by the cannons ability to coherently focus the beam. Unlike popular belief, the beam is not visible, and travels at the speed of light (Since the beam is actually composed of light). In an atmosphere, however, the beam is visible, producing a glowing plasma trail due to the superheating of the air in the path of the beam. this adversely afects accuracy, as the plasma scatters the photon stream

Plasma-Based:
Another high-power method of imparting energy by superheating matter to a state whereby electrons are seperated from thier nuclei. The projectile is limited only by the accelerator mechanism, although high-velocity plasma 'beams' usually fall under the 'particle accelerator' category. The pulse is completely visible, and travels under light speed. range in an atmosphere is limited, as the plasma cools very quickly.


Assuming for a moment that it is possible to create a energy weapon that is composed of pure energy, physics assumes that it would travel at the velocity c unless the projectile had mass.

Hope that helps.

wow i think i understand that, lol are u like a physics teacher or something?

lasers are the least likely weapon, it turns out
see this page:
http://www.projectrho.com/rocket/rocket3x.html
(*javascript navigation)

everything you need to know about sci-fi futurist spaceships, weapons, detectors, engines etc - all with solid math to back up the points explained - in a lot of instances its a real reality check - such as 'stealth' in space when using energized reaction mass is nonexistant, since just the radiation emitted will give you away - not to mention that gravitational sensors will spot your mass

we all need a reality check on engagement ranges - they are never anything like star trek or any movie/show/game really, where you can see the enemy with unaided 20/40 sight, although they typically say 'intensify magnification' when we cut to the external shot of the engagement we can see that ships are within single-digit hull's-lengths, eg close enough to scrape the paint

a phaser would be accurate, according to the site's math, to 100,000-200,000 kilometers
a photon torpedo, which is unguided(?) would not be accurate in the least

more likely than phasers are just radiation weapons, X-ray and gamma-ray lasers and bomb-pumped lasers(more likely,er - simple). these would necessitate carrying extraordinary shielding, or they would kill any living thing in the ship- a plus when it comes to capturing alien technology, however if directed at a drone/AI driven ship it wouldn't have immediate effects and would leave you vulnerable

when it comes to kinetic weapons you've got planet-busting asteroids, railguns and coilguns - rail guns actually use Lorentz force(which is demonstrated in cheesy sci-fi and science classes with two 'bunny ear' configured antenae conducting a moving arc) but with the high energies involved a considerable breakthrough in material science is necessary to make them reusable. coilguns use coils to accelerate a magnetic material - this is often confused with a railgun, but its not - there are no rails! coilguns have their own problems, namely the rugged construction of the entire thing which must endure enormous strain as it struggles to accelerate a relatively small projectile to sub-light speeds, and the current surging through the very precisely built coils has to be switched, and switching mechanisms for that kind of current are huge clunky things.

also, a point for kinetic weapons; remember that the closer it is to C the more energy it will release on impact, so if kinetic weapons are fast enough they will be devastating within their limited range

planet busting asteroids are frightening, because they require space-superiority to counter and they could potentially sterilize a planet with no radiation, making them perfect for scouring a planet clean of life and coming back later to colonize it

homing missiles are definitely a gray area, it would really depend on their performance and the countermeasures the enemy might use - eg shoot it down, drop decoys etc

Edited by - Cold_Void on 7/28/2006 3:38:23 AM

Been reading some Honor Harrington novels, Cold? I agree with you and David Weber - he's got the most realistic space-warfare. Star Trek and Wars worth crap in their physics. Visible lasers, close range engagements, sounds in space, etc etc.

@realm: No, i just read far too many books for my age

Just a little side issue on shields, the star wars Episode 2 cross-sections book plots the victory-class star destroyers shield capabilities at somewhere in the range of 7*10^22 Watts. By comparison, the asteroid that wiped out the dinosaurs had an impact energy of 3.34*10^23 Joules, just 1 order of magnitude above the shield's capabilities. They are flinging aroudn weapons that can DEPLETE these shield systems in a few shots. gives a very sobering insight as to how powerful those lasers and blasters are meant to be (And indeed, what would happen in a stray blast just happened to hit an inhabited planet...)

I agree totally with the range issue. with a decent sensor system and targetting systems, one could easily engage other ships over interplanetary distances (Ignoring the impact delay of course. youd have to wait a few seconds to see if the shot connects)

However, most weapons (And technologies) in sci-fi operate on principles that just plain dont exist yet! . The points outlined in that document are based completely upon our current knowledge of physics and spacetime (See the sections on 'Alien Technology' for a better idea). We could very well create other weapons that are completely viable.

Oh, and on the laser issue, i said 'basically high-powered lasers'. To actually create a energy beam weapon would require knowledge on how to directly interact with photon particles, a way to slow them down, and then release them coherently, WITHOUT the use of a medium (Such as a lens or a LASER chamber, which do not have nearly the power output we need)

Oh, BTW, interesting little tidbit: accorindg to some of the star wars supplements, they all apparently wield either ion cannons or plasma cannons, not lasers. they are just called lasers.

And yes, i know that i am a complete dork to know all of this

edit- interesting little thing on space combat Here.

BTW, could everyone please kick anyone that says that mechas and giant robots in space are viable? I have been plagued by the unscience of that idea

Edited by - Arania - PFY on 7/28/2006 6:29:43 AM

just out of curiosity who cares?

I mean the idea of these things is to ENTERTAIN not to be realistic.

PS @ arania how old r u?

ahha yeah you got me - i just read the Shiva Option a month ago FF

science (and its fiction) aren't dorky, they're just over most people's heads

och - no wonder hezbollah has been so hasty to use their rockets - says in the article its capable of downing the katyusha rocket they've been using, and that field models are expected by '07

That'd have pertinant applications in Israel right now. Your conclusion may be right. Or, they're clearing out all their old rockets so they can update their launch systems to Windows Vista in the winter... At the rate they're going, with the alleged news figures, they can keep up their sustained fire of what... 750 a week for about another three months... just in time for the advance shipments.

corect me if I'm wrong, but hasn't the problem with proposed and experimental laser weapons always been one of trageting and maintaining a lock on the target for long enough for said laser weapon to do it's work? Whilst a ballistic projectile is in principle a straightforward thing to calculate the trajectory of, something that's moving around, alters course and trajectory, or breaks up into smaller parts is naturally going to be much harder not only to hit in the first place but to maintain tracking on? This was of course the issue with the much-vaunted Patriot missiles during Desrt Storm, all they hit if they hit anything were the booster stages and not the warheads.

and for all that, the laser weapons could most likely be disabled by EMP, or even more likely, knocked out by a GLA rebel with an RPG-7 or a Toyota full of explosives.

but all this is based on the premise that laser weapons represent a genuine defence against a credible threat. In reality which so often gets ignored in the coo-ing over shiny technology, Hexbollah or anyone else's crappy old 1960's vintage ex-Soviet rockets aren't a credible threat, but a potent political weapon. They haven't killed or even injured that many people, but they've created an atmosphere of terror, and in consequence the justification for counter-action. If anything, a few suicide bombers strapped up with explosives can do more damage than weeks of rocket barrages. So, Uncle Taw thinks, why spend all that money and effort on fancy Star wars kit that actually isnt really going to protect anyone all that much?

and I seem to recall, although again I'm happy to be corrected if I'm wrong, that the Anti Ballistic Missile Treaty of 1972 has not been revoked, thus, if so, making laser defence systems illegal under international law, and thus subject to destruction by the appropriate authorities. Bit like state-sanctioned torture and imprisonment without trial and invasion of a sovereign state. Not that I'm pointing any fingers or anything.

oh yeah, one other point; a laser's pretty dam useless if the thing it's hitting is reflective and non-conductive of heat. All you have to do is cover your rocket in silvered asbestos and what good's the ber -laser then? about as much use as a pocket torch, i.e. none. I think I'm right on that point?