Turbolaser effects in atmosphere.

[Vympel]

I remember Mike made the following observation several years ago:-

Nuclear weapons produce a fireball and shockwave because the intense radiation from the blast heats up the surrounding atmosphere to many times the core temperature of the Sun. This takes place because the radiation is not penetrative enough; the isotherm around the bomb from the initial heating is essentially opaque to X-rays. The superheated volume then proceeds to expand at a hypersonic rate, thus both radiating the air in front of it and superheating it through hydrodynamic effects, thus creating what we know as the rapidly growing nuclear fireball.

In the case of a random energy release whose products are fairly well known (such as a matter/antimatter blast), you should see identical effects. But one could theorize that an exotic-radiation beam which was designed to punch through extremely hardened armour and/or shields would not produce such effects because it would be too penetrative. Ironically enough, this would actually make it less effective against unshielded targets; an overly penetrative weapon will actually do less damage to a soft target (as AP bullets demonstrate). In fact, as an extreme example, a neutrino gun would punch through anything, but it would do no noticeable damage (if I could build such a gun and shoot you, you probably wouldn't even notice).

Just something to keep in mind.

It just occured to me that, if we take Clone Wars visuals to be authoritative, you could say this has been proven.

Observe, the Malevolence being bombarded in TCW:-



And Aayla Secura's ship being bombarded:-



Difference? None.

[Illuminatus Primus]

The problem comes when you have the turbolaser hit something that surely can and does absorb its energy; that superheated armor presumably should disintegrate/fail imperfectly and release heat into the atmosphere. Any substance which is subject to air resistance if exploded will deposit KE into the atmosphere by friction. Or the hot remnants will lose absorbed energy to conduction. If a 100 GT turbolaser hits an armored ship and it explodes, and even 1% of that energy is not absorbed perfectly into driving the phase transitions of the ship's structural make-up, than you'll have a gigaton of energy lost to the environment. If this happens in relatively short time frame in a small area, you should still have nuclear-esque effects.

[Count Chocula]

I'm going to reference fan fiction, which may be a cardinal sin, but Eleventh Century Remnant apparently put a LOT of thought into this in his Hull No. 721 fanfic. One of the combat sequences involved starfighter attacks on a terrestrial station, with a frigate and mobile armor involved. With kiloton blaster shots and missiles flying around, and surface bombardment from space, the story had basically every window in the city out, massive structural damage, and horrendous local weather disturbances from orbital bombardments. Going to IP's point, once a blaster or turbolaser bolt hits a target, that target would likely radiate tremendous heat.

Clone ARC-170s firing on a Jedi starfighter, most likely, do not release enough heat in the on-screen viewing area to show any significant environmental effects, but the blaster misses probably fucked up whatever they hit downrange.

[Vympel]

The problem comes when you have the turbolaser hit something that surely can and does absorb its energy; that superheated armor presumably should disintegrate/fail imperfectly and release heat into the atmosphere. Any substance which is subject to air resistance if exploded will deposit KE into the atmosphere by friction. Or the hot remnants will lose absorbed energy to conduction. If a 100 GT turbolaser hits an armored ship and it explodes, and even 1% of that energy is not absorbed perfectly into driving the phase transitions of the ship's structural make-up, than you'll have a gigaton of energy lost to the environment. If this happens in relatively short time frame in a small area, you should still have nuclear-esque effects.

True, but then, warship armor is super-dispersive, as we know. In fact, none of the shots we saw that hit the Venator's hull in the latest episode caused any damage to the hull at all.

[Eleventh Century Remnant]

Damn' computer ate two replies already-

I'm not particularly comfortable about being quoted as some kind of authority; I hope I know my limitations, and one of them is that I'm an interested amateur at most when it comes to physics. I was just trying to follow what I understood as the best current theory, with a few guesses of my own that hopefully added up to some kind of sense. (That specific scene was a semi-conscious tip of the hat to E.E 'Doc' Smith, anyway- and most of the damage was done by proton torpedoes, which are pretty surely some form of explosive.)

On the point at hand, is there really no effect along the beam path? What happens when the bolt hits the ship can be explained as interaction with armour and shielding, what happens when the bolt hits normal un-exotic matter, even air, would seem to be a better test of how exotic the weapon is, involving one fewer variable at least. There are more than enough mentions of planetary bombardments to suggest a fairly strong interaction.

[Ender]

I posted a thread about this with a calculator in it this summer, do not forget to take into account the time frame. Explosions typically release 90% of their energy in the first nanosecond, with the remaining 10% over the course of a second. This gives rise to the effects we see. If the time frame of energy input is more along the lines of, say, 1/100th of a second you aren't going to see much of a blast.

[Illuminatus Primus]

The problem comes when you have the turbolaser hit something that surely can and does absorb its energy; that superheated armor presumably should disintegrate/fail imperfectly and release heat into the atmosphere. Any substance which is subject to air resistance if exploded will deposit KE into the atmosphere by friction. Or the hot remnants will lose absorbed energy to conduction. If a 100 GT turbolaser hits an armored ship and it explodes, and even 1% of that energy is not absorbed perfectly into driving the phase transitions of the ship's structural make-up, than you'll have a gigaton of energy lost to the environment. If this happens in relatively short time frame in a small area, you should still have nuclear-esque effects.

True, but then, warship armor is super-dispersive, as we know. In fact, none of the shots we saw that hit the Venator's hull in the latest episode caused any damage to the hull at all.

What do you think dispersive means? It re-radiates the energy as waste heat and light. Same problem.

[Illuminatus Primus]

I posted a thread about this with a calculator in it this summer, do not forget to take into account the time frame. Explosions typically release 90% of their energy in the first nanosecond, with the remaining 10% over the course of a second. This gives rise to the effects we see. If the time frame of energy input is more along the lines of, say, 1/100th of a second you aren't going to see much of a blast.

That just means the intensity of the environmental effects will be less than nuclear. A kiloton released over a hundred times as long as a nuke won't be irrelevant or conventional in environmental in scale. Especially because we're talking about much more than a kiloton in many cases.

[Vympel]

What do you think dispersive means? It re-radiates the energy as waste heat and light. Same problem.

Well, firstly, they'd be dispersed over the entire area of the hull, second, they wouldn't re-radiate as waste heat/ light, not if linked to the ship's neutrino radiators. This has been discussed before in this old thread.

[Illuminatus Primus]

Well yeah, active systems could mitigate considerably.

[Darth Wong]

Take three postulates:

1) Hull material with extremely high specific heat
2) Hull material with thermal superconductivity
3) Weapon particles which produce almost no interaction with atmosphere

Given those three postulates, you could predict that a sufficiently massive hull would absorb energy inputs that would normally be sufficient to cause a huge nuclear fireball. Reflected particles would not interact with the atmosphere, and absorption/re-emission would depend on the object's temperature increase. Add active systems and that helps further.

Unfortunately, we're forced to assume unrealistically extreme thermophysical characteristics for our materials, but that's pretty much unavoidable for a civilization which builds maneuverable moon-sized warships.

[Illuminatus Primus]

That's a good point, Mike. We don't see them shredding the scenery, but SW's masonry builds miles-high, city-bloc-area skyscrapers as frequently as humdrum 4-storey buildings in Brooklyn and they're used to traffic control and transportation control where the exhaust from smugglers' hot rods would be a mass extinction event on Earth. They are routinely used to managing extremely high energies, and its available off-the-shelf for mundane and extremely common civilian applications. Luke was from a poor farmer's family and he had a suborbital racer.

[Ender]

I posted a thread about this with a calculator in it this summer, do not forget to take into account the time frame. Explosions typically release 90% of their energy in the first nanosecond, with the remaining 10% over the course of a second. This gives rise to the effects we see. If the time frame of energy input is more along the lines of, say, 1/100th of a second you aren't going to see much of a blast.

That just means the intensity of the environmental effects will be less than nuclear. A kiloton released over a hundred times as long as a nuke won't be irrelevant or conventional in environmental in scale. Especially because we're talking about much more than a kiloton in many cases.

Seeing as how the complaint is that the explosions are less than what you would see from a comparative explosive, and my explanation addresses the complaint, does that matter?

[Ender]

Take three postulates:

1) Hull material with extremely high specific heat
2) Hull material with thermal superconductivity
3) Weapon particles which produce almost no interaction with atmosphere

Given those three postulates, you could predict that a sufficiently massive hull would absorb energy inputs that would normally be sufficient to cause a huge nuclear fireball. Reflected particles would not interact with the atmosphere, and absorption/re-emission would depend on the object's temperature increase. Add active systems and that helps further.

Unfortunately, we're forced to assume unrealistically extreme thermophysical characteristics for our materials, but that's pretty much unavoidable for a civilization which builds maneuverable moon-sized warships.

Both this point and the mechanics of an explosions easily explain the objection here. I know you put together a "Destruction" page a while back explaining the mechanics. If I recall correctly, it was complete, but just not linked from the main site. Am I not finding the link now, or am I misremembering?

[Sky Captain]

Yeah this is what often bugs me in sci fi - weapons supposedly orders of magnitude more powerful than anything we have in real life when used against targets flying inside atmosphere or on the ground produces effect worth few tons of TNT at most.

[Teleros]

I don't think it ever was linked from the main site Ender, but here it is for those who don't have the link: SDN Destruction page.