Originally by: Calathea Sata

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Edited by: Calathea Sata on 26/05/2011 21:38:28

Originally by: Ghoest

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Im fairly certain railguns would have recoil. They impart directed kinetic energy you would get an opposite direction force.

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Hahahahahahaha.

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Originally by: Calathea Sata

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Edited by: Calathea Sata on 27/05/2011 11:27:02

Originally by: Culerrta McNab

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Originally by: Calathea Sata

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Accord to that article: Pulsing lasers which fire for very short amount of time (30 nanoseconds) might have a kick similar to a .22.

But the beam lasers in EVE are no where as "pulsey" as that... it's a slowwwwww stream of energy (the laser beams last at least HALF A SECOND) so they shouldn't have any recoil.

TLDR: Beam lasers shouldn't have recoil. Pulse lasers might have.

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You're going on the assumption that the lasers in EVE have the stopping power of a .22, which is clearly not the case. Otherwise fleet fights would take aaaaaaaaaaages.

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My bad, shouldn't have mentioned the .22.

The calculations were done using the assumption "Laser power = Gun firing a bullet". It should scale up and down just fine.

edited to explain: a laser with the power of a gun will have a recoil like a gun. A laser with the power of a cannon will have the recoil of a cannon.

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Originally by: Calathea Sata

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Originally by: Ghoest

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While it is true that a rapidly pulseing laser could have recoil, it is false that a a laser with energy like given gun will in turn have recoil comparable to that gun.

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Depends on the laser firing time. Hence the difference between beam lasers (a slow long-lasting stream of energy) and pulse lasers (a burst in a very small time).

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Originally by: Shiera Kuni

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So you're telling me that you believe a metal slug travelling along a magnetic rail track, not creating a backblow as standard cased ammo does, would cause recoil? The only way I can see it causing recoil is if it produced enough shock after leaving the barrel to push it back.

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Originally by: MotherMoon

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[
So the real question is, if yo took a rail gun, and put it in space. Like 100% in space, not tied down to ANYTHING. Would the rail gun and the slug both move in separate directions at full speed since there is no gravity to give any of the objects weight?

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Originally by: Fearless M0F0

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I guess OP missed physics lab where they show you photons have mass , but then that lab was in college so

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Originally by: Illwill Bill

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<lolrp>
The turrets don't "fire" a laser; they use an extremely high-energy laser to accellerate and focus electron plasma in a tight beam that can be projected onto a target. The recoil isn't from the laser, but from the plasma emission.
</lolrp>

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Originally by: Akita T

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stuff

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Originally by: Akita T

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I said "least" recoil. That doesn't mean "negligible" recoil.
Also, if you want to go by my actual calculations, use those already posted on page #4 : Linkage
Or, to put it ever so slightly differently : if you have a railgun slug and a laser beam dealing roughly the same amount of damage (but through different mechanics), the recoil would be of comparable magnitudes for both.

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Originally by: Akita T

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Originally by: Ghoest

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This would only be the case is the majority of the damage done by the laser was impulse damage itself had to be high enough to compare to the projectile weapons.

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In the case of a laser, the entire energy is electromagnetic energy, which causes mostly thermal damage (and maybe some radiation damage, but mostly just thermal). Just point and heat.
In the case of a rail slug, the entire energy is kinetic energy, which causes a mix of kinetic, thermal and explosive damage which depends on the slug properties.

For a rail slug impact, some of the "stored" kinetic energy transforms into heat on impact, which superheats the slug, potentially causing it to at least partially vaporize and literally explode, with some of the pieces becoming shrapnel, other becoming an expanding cloud of superheated material.
If the target is "too soft", the slug can just pass through it without losing too much energy, leaving a small hole from end to end, not managing to heat up enough to fragment, let alone explode.
If the target is "too hard", the slug could simply fully vaporize (or at least shatter into very small pieces), and if the target also has a layered armor, each successive layer will further fragment and/or vaporize more of the slug pieces, causing it to not deal much damage.
There's a "sweet spot" where the target is neither too hard nor too soft, and the slug manages to pass though the outer layers of armor before disintegrating too much, fragmenting/vaporizing inside the target or at most slightly damaging the layered armor on the other end. This "sweet spot" depends on the slug form, slug material and slug speed, all of which you can vary depending on the internal structure of the target.

The ideal damage dealt is roughly proportional to the total energy E of whatever is hitting (be it laser or railgun slug).
So if you want a railgun slug to deal the same order of magnitude of damage as the laser beam, the kinetic energy of the slug needs to be roughly the same order of magnitude as the electromagnetic energy of the laser beam (and also hit the sweet spot for the rail slug).

The impulse of a laser beam of total energy E is E/c (where c is the speed of light in a vacuum), and it's the same impulse acting on the turret "backwards" to shoot the beam or forwards on the target when hitting it. Obviously, that impulse is negligible compared to the size of the ship and it's NOT what causes the damage. The energy itself, dissipating into heat, that's what causing the damage on the target.

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Originally by: Traejun DiSanctis

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The term "fire" - with respect to the launching of a projectile - was coined because of the actual mechanics of early to modern firearms.......

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Originally by: Akita T

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Originally by: NinjaSpud

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Interesting theory, Akita, but here's my problem with that:
You're ideas sound good until I put them on paper, I didn't see the anomaly until I tried to cross reference the Coefficient of Friction with the recoil...*HEAD VIOLENTLY EXPLODES*

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Ah, come on, it's basic physics.

Impulse is speed difference time mass. I=Dv*m
Speed difference is acceleration multiplied by time that acceleration is applied. Dv=a*t
Acceleration is total force applied divided by mass. a=F/m
Total force is the sum of all forces acting on the object - in this case, the object is a firing assembly, and there are two big sets of forces acting on it in opposite directions : the recoil force (from propelling something forward, be it an explosively fired projectile, a stream of particles, a beam of photons) and the counter-recoil force (initially static then dynamic friction with any bearings or similar limiting/guidance devices and a constantly increasing resistance from the spring assemblies which dampen the recoil the farther away from the initial position it goes).

What we know is the most likely value for the total impulse imparted on the firing assembly by the firing of stuff.
What we don't know is the time in which that impulse is being discharged, nor the mass of the firing assembly, which means we don't have a clue as to the force being applied on the firing assembly. We also don't know how high or low any frictional forces inside the recoiling firing assembly might be, be it initially or afterwards. We don't even know the elasticity coefficient of the springs for the counter-recoil mechanism which brings the firing assembly back in position after the shot.
Even if we make educated guesses regarding the time of the shot and the mass of the recoiling firing assembly, and even if we neglect any friction forces, we still don't know how rigid the springs are, which means we can't know for sure how much distance does the barrel recoil, and depending on that, it could recoil like crazy or it could barely budge.

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Originally by: Akita T

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Edited by: Akita T on 01/06/2011 18:33:54

Originally by: Ghoest

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No gun with a spring is going to be with out a damper. And chances are there wont be a spring. More probable is either a pneumatic type, or even magnetic, system to reset the gun.

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It doesn't really matter what device it uses for the "spring action", the equivalent mechanical device is some form of spring either way.
The important thing is that the "spring-like device(s)" acts with a certain force in the opposite direction.

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Originally by: Soden Rah

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Han solo's original blaster (A WW2 Luger with bits stuck on)...

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