Effects of a one-ton bomb.

[Khas 12,158]

Useful for determining yields in ground combat in sci-fi. This is what 4 gigajoules does:

[Vince 520]

Nice, though the only franchise i have found where such examples are really applicable is 40K (i use them on some pages) I'll add to the list.

 

11 tons of explosive (assuming tnt) ~46 gigajoules. This one is comparable to bomber payloads in 40K, or the output from meltas - though their thermal transfer flamer type weapons, not bombs. Hand held phasers, when disintegrating large amounts of soft material like rock, would require a DET thermal weapon of this magnitude to recreate its effects, testament to their effectiveness.

 

50 tons of TNT or 209 gigajoules

 

100 tons of TNT or 418 gigajoules

 

Some kilotons / terajoules - this is the sorta magnitude we might expect from Titanic weaponry in 40K, such as volcano cannons, or the weapons from the heaviest vehicles in star wars, like juggernauts or ATAT's. In both cases, they are DET thermal energy weapons rather than bombs however, but similar magnitude.

 

Famous one hundred teraton dinosaur killer - this is similar to what a Venator might dedicate to guns each second, or half what a ISD does; star destroyers in the Eu can extinguish all life without leaving survivors, despite the speed at which they can escape. This asteroid only wipes most life within months, rather than all life in moments.

 

The effects of a petaton range asteroid collision. This one is comparable in magnitude to the power generated in a super star destroyers reactor each second, or similar to the Eclipse superlaser in destructiveness. Also, to melt the crust of Terra in one hour using the bang table, would require a couple petatons per second. So t would require a fleet using DET weapons to inject a couple petatons -or similar magnitude to this asteroid- every second to recreate the effects of a fleet bombardment in star trek.

Edited October 17, 2012 by Vince

[Vince 520]

Perhaps ill edit in examples in the future, with sci fi weapons comparable magnitude to the events.

Edited October 17, 2012 by Vince

[Khas 12,158]

Going by what we see in the movies, I have some doubts about SW ground combat vehicles having KT-level firepower. Titans for 40K, however, probably do have that amount of firepower.

[Vince 520]

The evidence and indirect evidence for that magnitude in the films is three fold.

The fireball diameter with maximum firepower would be kilotons, im talking the first explosion, not the latter bigger one that comes from the reactor. There are two you see, one probably from the weapons, and a latter one from the reactor.

 

Also, heavy vehicles can shake of ordinary tank guns, which can yield up to hundreds of gigajoules... you would need kilotons to down something like an ATAT. Ordinary vehicles require tens or hundreds of gigajoules to kill each other, because triple digit megajoule blaster weapons cause nothing more than trivial surface damage - equating to indirect evidence.

 

Then there are shots that cause tremors throughout the mountain and base...

Wikipedia wrote: "Noticeable shaking of indoor items, rattling noises. Many to everyone feel it with slight to strong intensity. Slightly felt outside. Generally causes none to slight damage. Moderate, heavy, major, or significant damage unlikely. Some falling of objects."

This is a richter scale 4 - 4.9 earth quake. I think energy weapons would be very much less effective at recreating tremors like this when compared to actual earth quakes, bombs or kinetic impacts. Earth quakes of this scale peak at about half a kiloton max. but energy weapons are massless, its going to take many times greater energy to shake the mountain using the AT AT's guns. But at a lower limit you could say, hundreds of tons. Probably kilotons here too.

 

And I agree, I have extracts that heavily imply kilotons for 40K titans.

[Khas 12,158]

Echo Base looked more like it was in a cavern than a mountain. Not to mention that it was made of ice, not rock.

[Vince 520]

The shield generator was said to be over seventeen kilometers distant when they fired in upon it in the film; from that distance it has been scaled in the past to be ~1.8 kilometer long structure. I have yet to see another movie where a vehicles beam weapon can destroy a metal structure of this size, or create a 2Km fireball in diameter. So yields aside, these represent unforgivably powerful weapons.

http://bbs.stardestroyer.net/viewtopic.php?t=10360

with scalings and math, straight to the point. Theres a minimum amount of energy needed to create a fireball.

 

These effects all represent a lot of firepower

In the base we saw people stumbling into walls, objects falling from the ceiling, and corridors being destroyed. All from the tremors created by laser impacts. This base does appear to be underground. These are the effects you might expect from a 4.1 to 4.9 earth quake. To cause that with the AT AT's pulses represents a lot of energy. THe juggernauts weapons are also said to focus nuclear level heat into one small spot - raising to one hundred or more million degrees.

 

The anti-tank turrets on the LAAT' only yield 300 gigajoules and these weapons and ones like it on tanks are no use against AT ATS, there you need there the heaviest artillery. So it makes sense that the heaviest guns, like those of the ATAT and other large vehicles be many times more powerful than those on much smaller and less powerful vehicles. I'd think an ATAT has firepower enough to threaten another AT AT after all.

 

Its worth pointing out that this generator would be considered a cruiser in starship terms. If it were significantly armored, *a lot* of firepower would be required to penetrate its hull. Considering its role and strategic importance it might just well be armoured. The armoured skin of combat vehicles are around an order of magnitude more resilient to thermal weapons than conventional steels, because of their negation of blaster fire. The fireball scaling estimates on the old post produced a 260 kilotons lower limit required to create a fireball 2 kilometers in diameter.

 

Finally, its guns are of similar scale to those of starfighters.

 

All in all i think theres a pretty strong case for hundreds or thousands of terajoules here. And, if you extrapolate from the ICS, they should at least be single digit terajoules per shot. If you can disprove all of that, then i'll move the At At down a video.

 

40K and manga mechs aside, I cannot think of anything that could sit down and exchange firepower with one of these and come out on top.

[Khas 12,158]

Where do you get 17 kilometers from? I can't remember any distance being stated in the movie.

[scvn2812 504]

Those videos serve as a potent reminder of just how vastly more powerful even "low end" science fiction is. If you have casual surface to orbit travel, then the economics and energy densities of your civilization are such that if their destructive power is in proportion to their propulsion (or greater, as it is now) then it stands to reason that even Firefly ought to be able to put some very nasty weapons into the hands of its troops and mounted to its vehicles. Consider that Serenity does two Space Shuttle mission equivalents a trip and makes interplanetary flights and it costs so little that hauling cows equals profit. To do this in any kind of practical time is going to involve probably an order of magnitude greater energy density than we have since Serenity appears to be more cargo hold than fuel tank and space flight in general would need to be a literal million (if not greater) times cheaper.

 

The math of low end scifi taken to its logical conclusions is pretty sick. Honestly, feeling insecure about being a Star Trek fan is like complaining that you got stuck being Batman in a game of Justice League. Sure there are faster, stronger characters with heat vision but he's a billionaire ninja with a never ending supply of increasingly absurd but conveniently useful gadgets on his belt who can out fight just about any non-super and many supers in hand to hand. I happen to like Batman, powers or no powers.

[Vince 520]

Before they fire a gunner states distance, dosnt explicitly state "kilometers" but given the distances involved, and the fact that everywhere else in books and such they often use SI units, it is the most likely unit.

 

Agreed on low end sci fi's possess do a *lot* of power. I mean, Star Treks primary source of fuel is anti-matter, that something is not easy to create. And they have it in abundance.

[Brian Young 11,994]

Excellent topic, Khas. In case I've never told you, you are a pretty cool dude to have around.

Anyway, we know the distance was 17.28 kilometers, because that is what the gunner told General Veers, and it jives with the height of an AT-AT, assuming Hoth is the size of Earth.

As far as weapons in Star Wars, most of the time they use beam weapons, which have a completely different effect than explosives. Explosives spread their energy in all directions, beam weapons cause thermal damage (melting, vaporizing) to a single point. So any lateral effects from these beams prove extremely high yield.

Of course, you are right about the missiles used by gunships and wheel droids. They obviously are conventional explosives, shaped charge or no. The only counterpoint I can offer is when they also took down a starship (aim right above the fuel cells) with two of them, blowing the ship in half. It is likely that took a higher yield and was a shaped charge. But most of the shots, yes, you make a valid point.

[Vince 520]

Though, the Essential Atlas gives a diameter of 7,200Km to Hoth. Maybe this is contradictory the ordinary gravity in the film. I wouldn't like to say. 17Km should be far beyond the horizon of a planet that small. Maybe it was down to ideal terrain.

[Vympel 10]

Echo Base looked more like it was in a cavern than a mountain. Not to mention that it was made of ice, not rock.

 

No, Echo Base was clearly under a rock mountain/hill whatever you want to call it. We can see the rock that makes up the mountain in external shots of the base.

 

 

AT-AT's must have powerful cannons to cause damage to the interior of that base - as is clearly implied by the film with the base being rocked by explosions, and character testimony: "I heard the command centre had been hit!".

[Brian Young 11,994]

Good point. We also see the concussion inside the base at times. From a beam weapon, gosh...

[Khas 12,158]

Eh, it has been a while since I've seen TESB. It's not like I have time to watch all the movies whenever I feel like it.

 

But still, shouldn't we have seen a massive explosion on the side of the mountain, or at least, the aftereffects of one?

[Tyralak 12,068]

Good point. We also see the concussion inside the base at times. From a beam weapon, gosh...

 

However, you're making the assumption that the concussion was caused by the impact of the beam weapon. Perfect example of the logical fallacy cum hoc ergo propter hoc. The concussion could have been caused by a number of things, not the least of which is avalanches caused by beam strikes on ice. It could be something as simple as footsteps from AT-ATs who were coming too close. They ARE rather big and heavy, after all.

[Tyralak 12,068]

Though, the Essential Atlas gives a diameter of 7,200Km to Hoth. Maybe this is contradictory the ordinary gravity in the film. I wouldn't like to say. 17Km should be far beyond the horizon of a planet that small. Maybe it was down to ideal terrain.

 

The normal gravity could also be due to the moon being incredibly dense.

[Khas 12,158]

Let's consider what the other effects would be if this was a kiloton-level weapon.

 

Considering it only takes 10 gigajoules to vaporize 3 tons of rock, and that corresponds to 2.5 tons of explosive force, if the AT-AT's blasts really were in the kiloton range, they would impart a fuckton of energy onto the side of that mountain. Even if it was only one kiloton, that's still enough energy to completely vaporize 1200 tons of rock. We should also have seen high-energy steam released from when the ice was vaporized by the blast. You can't just take the shaking of a base in a mountain and claim "OMG KILOTONS!1111". We'd see nasty side-effects as steam and rock vapors, not to mention the incredible aerial shockwave caused by the release of such heat. Because contrary to what many people think beam weapons do, that energy is going to be released upon impact. Even if it's a plasma weapon, as plasma is a state of matter, and therefore, when in motion, has kinetic energy. So, when a plasma bolt hits something, it's going to release both the kinetic energy of it's motion, and its thermal energy.

 

Oh, and as for the shaking in Echo Base, I was once in a magnitude 5.8 earthquake. It lasted longer and was more severe than that.

[Tyralak 12,068]

Let's consider what the other effects would be if this was a kiloton-level weapon.

 

Considering it only takes 10 gigajoules to vaporize 3 tons of rock, and that corresponds to 2.5 tons of explosive force, if the AT-AT's blasts really were in the kiloton range, they would impart a fuckton of energy onto the side of that mountain. Even if it was only one kiloton, that's still enough energy to completely vaporize 1200 tons of rock. We should also have seen high-energy steam released from when the ice was vaporized by the blast. You can't just take the shaking of a base in a mountain and claim "OMG KILOTONS!1111". We'd see nasty side-effects as steam and rock vapors, not to mention the incredible aerial shockwave caused by the release of such heat. Because contrary to what many people think beam weapons do, that energy is going to be released upon impact. Even if it's a plasma weapon, as plasma is a state of matter, and therefore, when in motion, has kinetic energy. So, when a plasma bolt hits something, it's going to release both the kinetic energy of it's motion, and its thermal energy.

 

Oh, and as for the shaking in Echo Base, I was once in a magnitude 5.8 earthquake. It lasted longer and was more severe than that.

 

Exactly, Khas. We can't theorize these titanic yields and ignore the complete lack of effects supporting them.

[Captain Seafort 17]

We can't theorize these titanic yields and ignore the complete lack of effects supporting them.

 

What lack of effects? There was a km-wide fireball. As for the rest, the obvious conclusion is that they're a lot weaker - the 130kt shot was when Veers ordered maximum power to take out the generator.

[Vince 520]

I agree Khas, not tht they lack KT weaponry, but that they wernt firing those blasts at the mountain. If they had, then they should have destroyed the base. The generator however, we see the multi-kilometer fireball, this is upon initial impact. THEN the generator goes of with a mushroom cloud and a *larger* fireball. Plus, if we accept ordinary tanks discharge tens/hundreds of gigajoules, and cannot damage AT AT's, but AT AT's can, it make sense that their up to an order of magnitude more powerful. Like the logical extrapolation from blaster weapons to tank weapons.

 

I know thats not what i originally said, but thinking about it, it wouldn't make sense. They do after all want prisoners.

[Vympel 10]

However, you're making the assumption that the concussion was caused by the impact of the beam weapon. Perfect example of the logical fallacy cum hoc ergo propter hoc. The concussion could have been caused by a number of things, not the least of which is avalanches caused by beam strikes on ice. It could be something as simple as footsteps from AT-ATs who were coming too close. They ARE rather big and heavy, after all.

 

If it was the mere footsteps of AT-ATs then it should be a steady rocking that doesn't stop, not to mention it should be getting worse as it gets closer. The impacts are intermittent. For that reason alone it doesn't work, and it still doesn't explain Han saying the command centre had been hit. The only reasonable explanation is that they're being struck by weapons fire. The only reasonable source of that weapons fire is AT-ATs.

 

EDIT: the novel:

 

THE Rebel command center, its walls and ceiling still shaking and cracking under the force of the battle on the surface, was attempting to operate amid the destruction. Pipes, torn apart by the blasting, belched sprays of scalding steam. The white floors were littered with broken pieces of machinery and chunks of ice were scattered everywhere. Except for the distant rumblings of laser fire, the command center was forebodingly quiet.

 

There were still Rebel personnel on duty, including Princess Leia, who watched the images on the few still-functioning console screens. She wanted to be certain that the last of the transport ships had slipped past the Imperial armada and were approaching their rendezvous point in space.

 

Han Solo rushed into the command center, dodging great sections of the ice ceiling that came plunging down at him. One great chunk was followed by an avalanche of ice that poured onto the floor near the entrance to the chamber. Undaunted, Han hurried to the control board where Leia stood beside See Threepio.

 

'I heard the command center was hit.' Han appeared concerned. 'Are you all right?'

 

The princess nodded. She was surprised to see him there where the danger was severest.

 

'Come on,' he urged before she could reply. 'You've got to get to your ship.'

 

As for seeing the effects of what hit the base - we never directly saw the base get hit in the first place. So there's no contradictory visuals. Note this does not mean I think they were firing KT beams at the base or whatever, I'm just pointing out an instance that clearly points to pretty powerful weapons generally speaking.