open All Channels
seplocked EVE General Discussion
blankseplocked So...the new lasers have recoil?
 
This thread is older than 90 days and has been locked due to inactivity.


 
Pages: first : previous : 1 2 3 [4] 5 6 7 8 9 ... : last (10)

Author Topic

Abrazzar
Posted - 2011.05.27 15:11:00 - [91]
 

I still prefer my piezo-electric-sponge capacitor hypothesis over all the other attempts at explanation.

Kimiko Tojima
Amarr
Posted - 2011.05.27 15:18:00 - [92]
 

The "Space Defence Initiative" program (SDI) of the eighties included a project about x-ray laser satellites whose laser needed a high energy flash created by a small nuclear device.
Small.Nuclear.Device. <-- There's all the recoil you ever needed. Laughing


Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 15:18:00 - [93]
 

Edited by: Akita T on 27/05/2011 15:26:16
Originally by: Astroka
I am a little put off by the fact that the new laser turrets show recoil when they fire.

Originally by: Shiera Kuni
Actually, if you think about it any magnetic delivery system *I.E. Railguns* wouldn't have recoil either. There are no moving parts save for the ammunition.

Newton wants to have a word with you about the laws of motion, in particular rule number three.
You ALWAYS have recoil when you "shoot" something, be it a chunk of matter, a stream of particles or even a beam of photons.
The only issue is HOW MUCH recoil, and WHERE/HOW that recoil is being dampened/counteracted.
It would very much depend on the mass of the turret assembly and the impulse force of what's being "shot".

Ever heard of solar sails ? Or, better said, LIGHT sails ? How do you think they work ?
Obviously, recoil for a beam of photons is noticeably smaller than recoil for accelerating a slug (orders of magnitude smaller, actually), but there's still some recoil.
Indeed, even an ultralight laser turret firing an extremely strong laser beam should not visibly recoil, but, meh, artistic license and all that jazz.

Shiera Kuni
Repurposed Armaments
Posted - 2011.05.27 15:19:00 - [94]
 

Originally by: NinjaSpud
You're correct, newton states that every action has an equal and opposite reaction. You're only mistake is the word "recoil"

Recoil from a gun is caused by the explosion of the powder, not the bullet traveling along the barrel. Guns still kick when there's a blank inside. When it detonates, the energy from the explosion needs an exit, it finds the path of least resistance and exits out the barrel, pushing the bullet along with it.

Again, with the equal and opposite reaction thing, you get a massive force leaving out the end of the barrel -----> and as a result, it pushes the bullet but also propels the gun in the opposite direction <-----

The amount of energy lost when you fire a bullet is staggering.

Railguns on the other hand, have no explosion, therefore have no recoil. I'm not saying they don't produce kinetic energy, but I am saying that the kinetic energy is conserved in the projectile until impact. The result is the projectile has way more kinetic energy, more because the energy is conserved, or focused in the projectile and does not release until impact.


True story here, my uncle was in the army in the late 80's. he had top secret clearance (computer nerd for spec ops) and one day, they went to a 'new weapons demo'. the army was testing one of its first rail guns.

They took an aluminum casing (non magnetic material) about 500MM. If I remember, that's the size of a football...American not European. In the very center of that casing, was a single steel BB (magnetic material), the same kind you shot birds with as a child.

The loaded this casing into a rail gun, and shot it at an old tank, 5 miles away. He said the gun didn't make a single noise or movement. the only noise they heard was the 500MM casing breaking the sound barrier.

when they inspected the tank, it had a perfect football sized hole clean threw it.

kewl **** eh?



Thank you! I knew I wasn't crazy.


Originally by: Ghoest
Your lack of perception or vision has no bearing on physics.


I'm currently searching my braille keyboard for an appropriate retort.

Virtue Maulerant
Posted - 2011.05.27 15:19:00 - [95]
 

Originally by: Destination SkillQueue
Edited by: Destination SkillQueue on 27/05/2011 15:17:45
Originally by: Virtue Maulerant
The new turrets including what you like to call "recoil" are great. Who gives a **** about physics and realism.


Nerds care and most of them propably care just because they like arguing about it.

Quote:
Railguns on the other hand, have no explosion, therefore have no recoil.


Also because people keep posting stupid **** like this.


Agreed

Riedle
Minmatar
Paradox Collective
Posted - 2011.05.27 15:28:00 - [96]
 

the amount of ignorance in this thread makes me recoil in horrer.

Vaerah Vahrokha
Minmatar
Vahrokh Consulting
Posted - 2011.05.27 15:38:00 - [97]
 

It's a game and it looks cool. So HTFU and enjoy a cool effect for once.





Also, ITT where people split hairs about physics, in a game where ships physics make them slow down like submarines and they steer like a car.

NinjaSpud
Posted - 2011.05.27 15:38:00 - [98]
 

Originally by: NinjaSpud


You're correct, newton states that every action has an equal and opposite reaction. You're only mistake is the word "recoil"

Recoil from a gun is caused by the explosion of the powder, not the bullet traveling along the barrel. Guns still kick when there's a blank inside. When it detonates, the energy from the explosion needs an exit, it finds the path of least resistance and exits out the barrel, pushing the bullet along with it.

Again, with the equal and opposite reaction thing, you get a massive force leaving out the end of the barrel -----> and as a result, it pushes the bullet but also propels the gun in the opposite direction <-----

The amount of energy lost when you fire a bullet is staggering.

Railguns on the other hand, have no explosion, therefore have no recoil. I'm not saying they don't produce kinetic energy (they produce a **** load), but I am saying that the kinetic energy is conserved in the projectile instead of wasted in the explosion. The result is the projectile has way more kinetic energy then a bullet, more because the energy is conserved (or focused in the projectile) and does not release until impact.


True story here, my uncle was in the army in the late 80's. he had top secret clearance (computer nerd for spec ops) and one day, they went to a 'new weapons demo'. the army was testing one of its first rail guns.

They took an aluminum casing (non magnetic material) about 500MM. If I remember, that's the size of a football...American not European. In the very center of that casing, was a single steel BB (magnetic material), the same kind you shot birds with as a child.

The loaded this casing into a rail gun, and shot it at an old tank, 5 miles away. He said the gun didn't make a single noise or movement. the only noise they heard was the 500MM casing breaking the sound barrier.

when they inspected the tank, it had a perfect football sized hole clean threw it.

kewl **** eh?.

Edits:sloppy grammer




So, I'm not to proud to admit it. I wanted to verify my theories so I googled rail guns.

I'll admit, I wasn't 100% correct. While its true, the railgun has no explosive recoil, there is a strong push from the magnetic fields on the rails of the guns. When the magnet is activated or 'fired' there is incredible pressure put on the rails while they support opposing magnetic fields. Wither or not this force would show itself as a 'kick' is completely based on the design of the gun.

TBH, now that I think of it, a railgun changes the momentum of their projectile as a result of the emission of a photon or particle (magnets)....which is actually the scientific definition of recoil.

So, it is a different form of recoil, but recoil after all. My mistake, and as an act of atonement, I will go up to my boss and kick him in the knee. If he laughs about it, I'll keep my job. If not, justice will be served and I'll get fired.

Wait, wasn't this thread about lasers recoil?


stoicfaux
Gallente
Posted - 2011.05.27 15:40:00 - [99]
 

Originally by: Shiera Kuni

Thank you! I knew I wasn't crazy.



Unfortunately, the downside to not being considered "crazy" is that people will think you're simply "stupid" or just "evil"...


Simetraz
Posted - 2011.05.27 15:40:00 - [100]
 

Edited by: Simetraz on 27/05/2011 15:41:24
Newton's third law.

Recoil is an example of that law in action.
With gravity for the most part being zero in space you would actually want any gun to recoil.
Keep in mind with no gravity a lot of motions and reactions you take for granted change radically when there is no gravity to influence them.

I was going to say "So just get over it and enjoy the game."
Then I remembered Trekies and whole physic's debate that went on about Ring World.

So with that in mind I think I am going to be the one that moves on from this thread and just enjoys the game Smile







Mr Kidd
Posted - 2011.05.27 15:42:00 - [101]
 

Originally by: CCP Spitfire
Good question, actually. I'll check with the storyline team and get back to you; meanwhile a quick search (but please do not take it as an "official" answer) suggests that sci-fi laser weapons may indeed have recoil according to the conventional laws of physics.




In support of recoil: http://en.wikipedia.org/wiki/Laser_propulsion

Mara Rinn
Posted - 2011.05.27 15:44:00 - [102]
 

I didn't see any significant recoil on the ship in the title scene. The bright ball of over-saturated-camera-sensor does cover up a lot of the turret, so it might look like the turret is recoiling, but I didn't see any other movement. Looks right to me.

Jacob Holland
Gallente
Weyland-Vulcan Industries
Posted - 2011.05.27 15:45:00 - [103]
 

Originally by: NinjaSpud
<Snip>Recoil from a gun is caused by the explosion of the powder, not the bullet traveling along the barrel. Guns still kick when there's a blank inside.

The recoil of a blank is due to the mass of hot gasses produced by the detonation accelerating.
When a conventional cartridge is fired a mass of black powder/cordite/whatever propellant is being used is ignited to release chemical energy, this energy is converted into kinetic energy in the movement of the atoms in the gas (heat energy) and directed by the chamber, transfering some of its kinetic energy to the projectile.
If the Projectile and the gasses from a conventional cartridge are accelerated to the same velocity in the same time as an identical mass of railgun projectile then the recoil force will be identical, the only difference is where it is experienced.

Conventional firearms do waste a considerable amount of energy, the entire report of the weapon is wasted energy, the heat built up from friction between the projectile and the barrel and the heat build up from the conversion of chemical energy into kinetic.
Railguns theoretically waste less, friction between the rails and the projectile, heat in the movement of electrons in every electrical component and so forth but while the wasted energy will generate forces those forces are not recoil.

Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 15:55:00 - [104]
 

Originally by: Jacob Holland
Railguns theoretically waste less, friction between the rails and the projectile, heat in the movement of electrons in every electrical component and so forth but while the wasted energy will generate forces those forces are not recoil.

"Recoil" is the backwards motion of the shooting device.

If ANY forces need to be applied to whatever it is you're shooting to shoot it (and Newton's second law of motion says you have to), then you'll also have some forces equal in magnitude but opposite in direction (Newton's third law of motion) pushing the gun back.
Any force that pushes the gun back causes recoil, and you ALWAYS have recoil or otherwise you're not shooting anything.

HOW that recoil is compensated and where, that's a completely different story.

Jacob Holland
Gallente
Weyland-Vulcan Industries
Posted - 2011.05.27 16:13:00 - [105]
 

Edited by: Jacob Holland on 27/05/2011 16:12:52
Just re-read the bit you've quoted Akita Very Happy

The forces generated by convection from a hot barrel are not recoil, the reaction force generated by accelerating a mass from the barrel/rail of your weapon is.

You're correct in almost every particular... except the arguement you're arguing against Very Happy

Jaari Val'Dara
Caldari
Deep Space Nomads Corp
Posted - 2011.05.27 16:20:00 - [106]
 

Photons might not have a huge kinetic energy each, but solar sails is a real possibility. So I would assume that if the laser was strong enough, there might be some recoil.

Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 16:21:00 - [107]
 

Sorry, it sounded almost as if you were trying to say railguns have no recoil, and since you didn't specifically mention those forces that do contribute to the recoil, I merely clarified.
In retrospect, your position looks much clearer now (and still correct, of course), but the extra clarification doesn't hurt Razz

Keylah
Caldari
Posted - 2011.05.27 16:27:00 - [108]
 

Nice work CCP with turrets :)

As for the recoil issue, several of the energy weapons in game are listed as Particle streamers or Tachyon weapons.
That implies that they are in fact particle beam cannons/projectors in which case they are launching actual mass.
If that's indeed the case, they would have recoil.
From what I have read and seen in game, I believe the laser is just a carrier beam creating a tunnel to the target
for a particle blast.
Which makes sense since it would take staggering amounts of energy to project a simple x-ray laser beam over distance and
still have it be lethal to the ships in eve.

-K

Tippia
Caldari
Sunshine and Lollipops
Posted - 2011.05.27 16:41:00 - [109]
 

Originally by: Mara Rinn
I didn't see any significant recoil on the ship in the title scene. The bright ball of over-saturated-camera-sensor does cover up a lot of the turret, so it might look like the turret is recoiling, but I didn't see any other movement. Looks right to me.
If you load up Duality and watch the animation, it's quite easy to spot the three segments of the barrel and how they telescope into each other as the gun fires. The back stays in position the barrel does the absorption.

Tsadkiel
Posted - 2011.05.27 16:55:00 - [110]
 

Originally by: Lost Greybeard
Edited by: Lost Greybeard on 27/05/2011 05:32:10
Originally by: Calathea Sata
I agree with OP, laser turrets shouldn't have any recoil simply because they shouldn't. I guess common sense isn't a requirement when CCP hires people.


Depends on your energy load. Despite not having mass, photons do have momentum (hbar*k, i.e. h/wavelength). 500nm is around what the average of the spectrum is (assuming it falls into the visible), so that's 1.32 e-27 N/photon.

Number of photons can likewise be derived from energy consumption. Grabbing a random laser i see a cost of 4.76 e9 J, again assuming 500nm the energy per photon is 3.97 e-19 J/photon. So something on the order of 1.2e28 photons emitted. Given their momentum individually, conservation principles state that a force of about 10N will be exerted on your laser turret in the opposite direction.

This of course assumes optimum efficiency, but still, if the parts of the laser are some ultra-light future material that's a non-trivial quantity of force. So even ignoring the "it's probably a mechanical reset rather than real recoil" aspect, a recoil animation could theoretically be justified.

//Sorry if my arithmetic is off. It's late.

(EDIT: oh, ****, I think I just out-nerded a forum thread about internet spaceships. I mean "hurr, durr, laser no recoil, what mean ug by 'momentum'?")


Lost Greybeard, thank you. I am a grad student in physics and you just saved me from having to make a lengthy response (I suffer from someone-is-wrong-on-the-internet syndrome)

Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 17:07:00 - [111]
 

Originally by: Jaari Val'Dara
Photons might not have a huge kinetic energy each, but solar sails is a real possibility. So I would assume that if the laser was strong enough, there might be some recoil.

Let's assume a battleship laser turret photon stream of total energy around that of the maximum possible kinetic energy of a battleship railgun.

First, try to guess what that likely kinetic energy of a BS railgun projectile would be. We know that at a minimum, railgun projectiles go 250km in less than 1 second (max lock range and server tick), but let's ramp that up to 1000 km in 0.1 seconds just to be sure. That's 10000km/sec, or roughly 3.3% of the speed of light.

We already know that a 100g round of antimatter ammo (0.1 kg is the stated ammo weight in-game) doesn't deal much more damage than a 100g round of lead (only about 50% more), so we can assume the antimatter ammo is actually mostly antimatter support with just a bit of antimatter in it.
The kinetic energy of 100g of any matter accelerated to 3.33% of the speed of light is around 5*10^15 joules (or, a little under ONE MEGATON of TNT's worth of blast energy), while the most likely actual damage of 100g of antimatter at no speed might be in the order of 90*10^15 joules (so roughly 18 times higher, more precisely, around 21.5 megatons of TNT), which basically means that there's VERY ROUGHLY 10% antimatter in an Antimatter L round (when compared to everything else)... still, that puts us in the very rough ballpark of energies involved - a megaton's worth per shot.

The impulse of a photon is equal to its energy divided by the speed of light, so 5*10^15 joules worth of photons shot in a beam would actually have a total impulse of 16,678,204 meter*kilogram/second.
Since all large turrets have the HIGHLY UNFORTUNATE mass of merely 1 kilogram, that would leave you with a very, VERY fast backwards moving turret, to the order of 16678+ km/second !

Let's ramp down the energies here, and say we "only" have the railgun projectiles moving at 250km/s, and the actual projectiles would have only 50 grams as opposed to 100 grams, that's still 3,125,000,000 joules (or, roughly, little under a ton of TNT).
The corresponding laser energy impulse would be 10.4 meter*kilogram/second, which should still be visible on a 1kg firing assembly (around 37.5 km/hour maximum backwards speed).


So... yeah... depending on how you look at it, firing a laser in EVE might very well cause visible turret recoil.

stoicfaux
Gallente
Posted - 2011.05.27 17:14:00 - [112]
 

Edited by: stoicfaux on 27/05/2011 17:20:03
Originally by: Lost Greybeard
[Given their momentum individually, conservation principles state that a force of about 10N will be exerted on your laser turret in the opposite direction.


10N is the ability to move (accelerate) a 10kg object 1 meter (or a 1kg object 10 meters) every second.

The Eve database shows that laser turrets (even XL turrets) have a whopping mass of 2kg (1kg for the turret, 1kg for the crystal,) then yes, Eve laser turrets should have recoil.

Eve turrets are also probably made of paper and should snap off when fired, assuming they don't burn up first.


Thank goodness for Atomic Rocket, which goes into the science behind "real" and scifi spaceships and combat.


edit: And going by the timestamp of Akita's post above, it took me over seven minutes to create this post. Getting old sucks.


Kate Rygel
Posted - 2011.05.27 17:23:00 - [113]
 

Edited by: Kate Rygel on 27/05/2011 17:32:18
Why is anyone even trying to apply real physics to this game when there is next to zero real physics in this universe?

hell, no object in Eve even orbits anything and you all think that Newton or Einstein even existed in this universe or that their theories and laws apply somehow?

FeralShadow
NME1
Posted - 2011.05.27 17:25:00 - [114]
 

This is why I like this game.
The average populace appears to have the knowledge base of an individual with a bachelors degree at the very least. I highly doubt you'd ever find these kinds of discussions on the WoW boards, and while there are the trolls and the flamers and what-not, it's way better than other communities.

stoicfaux
Gallente
Posted - 2011.05.27 17:34:00 - [115]
 

Originally by: Kate Rygel
Why is anyone even trying to apply real physics to this game when there is next to zero real physics in this universe?


Mental ************. The social aspects, meta-gaming, and theory-fu of a game can be more fun than the actual game.


Originally by: FeralShadow
This is why I like this game.
The average populace appears to have the knowledge base of an individual with a bachelors degree at the very least. I highly doubt you'd ever find these kinds of discussions on the WoW boards, and while there are the trolls and the flamers and what-not, it's way better than other communities.


Careful. The WoW community has a lot of heavy theory crafting to the point of having combat simulators, and has lots of programming resources given the plethora of Add-ins available.




Sirinda
Posted - 2011.05.27 17:34:00 - [116]
 

Originally by: Shiera Kuni
Actually, if you think about it any magnetic delivery system *I.E. Railguns* wouldn't have recoil either. There are no moving parts save for the ammunition.

nb4flame: I've actually been working on several railgun designs in the past couple of months.



Proof you have absolutely no clue what Sir Isaac Newton meant when he stated that each action does have an equal and opposite reaction.

For instance, take any muzzle-loader cannon. No moving parts except for the projectile. And still the cannon jumped back several meters with every shot.

I'll give you a hint: Railguns are KEWs. Kinetic Energy Weapons. Which means they impart recoil on the delivery system they're fired from. Recoil you have to absorb somehow.

For instance, with a recoil dampening mechanism, you can even use the equal and opposite reaction force to reload your gun. Isn't that sweet?


Of course, lasers don't have recoil. That is, they actually do produce infinitesimally small recoil, since even photons have a certain mass, but that is of no consequence, except maybe to physicists.

Maybe the Eve graphics designers meant for those moving parts to be coolant sleeves that cover the optical assemblies to better cool them, maybe? I'm talking out of my arse here, since I'll have to rewatch the turret preview.

Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 17:42:00 - [117]
 

Originally by: Sirinda
Of course, lasers don't have recoil. That is, they actually do produce infinitesimally small recoil, since even photons have a certain mass, but that is of no consequence, except maybe to physicists.

If you ramp up the energies high enough, that recoil becomes quite noticeable. See my post above Wink

Sirinda
Posted - 2011.05.27 17:49:00 - [118]
 

Originally by: Akita T
Originally by: Sirinda
Of course, lasers don't have recoil. That is, they actually do produce infinitesimally small recoil, since even photons have a certain mass, but that is of no consequence, except maybe to physicists.

If you ramp up the energies high enough, that recoil becomes quite noticeable. See my post above Wink


Yeah. I just finished skimming the rest of the thread.

Push enough energy into a laser, and eventually it will develop noticeable recoil. Use that to pump coolant through the barrel sleeve, and you're home free. I thought that explanation would be pretty straightforward.


Also, I stand corrected on my previous assumption that photons have mass. They don't, apparently.

Akita T
Caldari Navy Volunteer Task Force
Posted - 2011.05.27 17:51:00 - [119]
 

They don't have REST mass, but they have impulse, so they sort of almost behave as if they had mass in collisions.

Hesperius
Posted - 2011.05.27 17:52:00 - [120]
 

It isn't recoil: it is venting of the coolant so the components don't overheat and cause damage to the optics.


Pages: first : previous : 1 2 3 [4] 5 6 7 8 9 ... : last (10)

This thread is older than 90 days and has been locked due to inactivity.


 


The new forums are live

Please adjust your bookmarks to https://forums.eveonline.com

These forums are archived and read-only