More on photon torpedos: planetary assault

[seanrobertson]

I've heard a good bit of rhetoric from people who insist photon torpedos
must yield well into the gigaton range based on the results or expected
results of planetary assaults.

The first example is something that's routinely pulled out by people
who don't understand the physics involved: "Skin of Evil." The appearance of a fireball on Armus' planet is used as evidence that a photorp is "500 megatons minimum." (Funny, when I watched the episode, I heard
no mention of any no. of torpedos, but it's naturally assumed that
only one was fired.)

This has been beat to death elsewhere, but I'm interested to know
the specifics such that we might archive the counterargument, if not
at I Want YOU! then perhaps at Wayne Poe's website. I'm particularly interested in knowing why it's futile to try and judge an explosion's
yield based on that fleeting fireball; we can all speculate that the
shuttlecraft targetted by the torpedo contained a lot of AM (actually
doubtful), thus contributing to the blast, but hard facts about the fallacious
500 MT conclusion would be better.

The second instance involves dialogue, from DS9's fifth season premiere
"Apocalypse Rising." Damar claims that a full spread of photorps
would "destroy Gowron, his command center, and everything else within
a few hundred kilometers."

I have no problem believing that, especially given that the torpedos
could be fired such that their detonations wouldn't immediately overlap,
thus covering more area. However, I've tried and tried to find information at the Nuclear Weapons FAQ to determine something useful about
this expectation, and I've failed.

Assuming 3-4 torpedos, whatever kind of detonations would be most
useful in killing lots of Klingons, etc., and further assuming that
"a few hundred kilometers" means...I dunno, say, 200-300?, what
would these weapons yield? I don't even know where to begin, truly...
are we talking a few hundred SQUARE kilometers, an area that extends
100-150 km in every direction from ground zero, or what?

Btw, O'Brien shit on the plan in the end, saying that Gowron's CC had
shields that could withstand a dozen photorps. To my knowledge, that's
the strongest, largest theatre shield ever mentioned for a ground-based
installation in "modern" Trek.

[Kamakazie Sith]

The first example is something that's routinely pulled out by people
who don't understand the physics involved: "Skin of Evil." The appearance of a fireball on Armus' planet is used as evidence that a photorp is "500 megatons minimum." (Funny, when I watched the episode, I heard
no mention of any no. of torpedos, but it's naturally assumed that
only one was fired.)

IIRC, visuals agree with only one torpedo being used.

[greenmm]

well, assuming 100% efficiency (ie. 65 MT explosion), you end up with each torpedo creating a crater 1.59 km in diameter, with a so-called TDR (Total Destruction Radius) of about 11 km. Granted, that TDR is based on current civilian contruction technogies, so it's probably not going to be as damaging to stronger materials. However, a nuclear fireball would normally reach out to about 3.7 km, so it's probably safe to say that just about anything not heavily shielded within 3 km of the impact point is either toasty or in little pieces.

Now, the only problem is, I don't know if the torps would be that efficient. So, for safety's sake, let's say they're only working at 10% efficiency. That gives you a 0.74 km diameter crater, and an effective TDR of about 1.5 km.

Assuming maximum dispersion (ie. each TDR from each torpedo only barely touches another torpedo's TDR), then, you get a rough square about 6 km on a side that's either toasty or nicely rubbled. Not to mention that you'll have lower-level overpressure waves heading out about 14 km from each impact point, so the overall area affected would be more on the order of a 56x56 km area.

Depending, then, on how hardened the target area was, you might be able to do that with 64 to 144 torpedoes on maximum dispersion, with the target area resembling a close-range shotgun blast from orbit; potentially less should the torpedoes function at a higher efficiency.

[greenmm]

The first example is something that's routinely pulled out by people
who don't understand the physics involved: "Skin of Evil." The appearance of a fireball on Armus' planet is used as evidence that a photorp is "500 megatons minimum." (Funny, when I watched the episode, I heard
no mention of any no. of torpedos, but it's naturally assumed that
only one was fired.)

IIRC, visuals agree with only one torpedo being used.

Hmmm, talk about a really powerful torpedo, then...

Was there something special about this planet, its atmosphere, or the torpedo itself, though? Or perhaps something about the target it was aimed at that could explain the larger explosion?

[Kamakazie Sith]

The first example is something that's routinely pulled out by people
who don't understand the physics involved: "Skin of Evil." The appearance of a fireball on Armus' planet is used as evidence that a photorp is "500 megatons minimum." (Funny, when I watched the episode, I heard
no mention of any no. of torpedos, but it's naturally assumed that
only one was fired.)

IIRC, visuals agree with only one torpedo being used.

Hmmm, talk about a really powerful torpedo, then...

Was there something special about this planet, its atmosphere, or the torpedo itself, though? Or perhaps something about the target it was aimed at that could explain the larger explosion?

It was fired at a shuttle, so Armus(?sp?) couldn't get off world. Thus the shuttles fuels probably added to the explosion, but to what degree is unknown.

[greenmm]

warp shuttle or standard shuttle?

If a warp-capable shuttle, then it probably would add in the antimatter from its warp core and power system to the explosion...

[seanrobertson]

IIRC, visuals agree with only one torpedo being used.

Hmmm, talk about a really powerful torpedo, then...

Was there something special about this planet, its atmosphere, or the torpedo itself, though? Or perhaps something about the target it was aimed at that could explain the larger explosion?

It was fired at a shuttle, so Armus(?sp?) couldn't get off world. Thus the shuttles fuels probably added to the explosion, but to what degree is unknown.

IMO, not much. We see a Runabout explode in a planet's atmosphere
in one of the "Final Chapter" DS9 episodes, when Worf and Ezri Dax
are stranded on a planet/captured by the Breen. The explosion
indicated that the amount of fuel carried on even a hyped-up shuttle
like a Runabout is pretty small.

However, I reiterate: the explosion in "Skin of Evil" could well have
been caused by a *much* lower yield weapon. Even if it did involve
one torpedo (I don't remember the visuals of a torpedo being
fired), it needn't be a half-gigaton blast. I only wish I could explain
why this is the case...

[Kamakazie Sith]

warp shuttle or standard shuttle?

If a warp-capable shuttle, then it probably would add in the antimatter from its warp core and power system to the explosion...

IIRC the type of shuttle was never stated.

[Alyeska]

warp shuttle or standard shuttle?

If a warp-capable shuttle, then it probably would add in the antimatter from its warp core and power system to the explosion...

IIRC the type of shuttle was never stated.

Agreed, however if you look at the crash site the warp engines looked an awful lot like the E-Ds engines, and that would corespond with this shuttle.

http://www.ex-astris-scientia.org/scans ... /type7.jpg

[Kamakazie Sith]

warp shuttle or standard shuttle?

If a warp-capable shuttle, then it probably would add in the antimatter from its warp core and power system to the explosion...

IIRC the type of shuttle was never stated.

Agreed, however if you look at the crash site the warp engines looked an awful lot like the E-Ds engines, and that would corespond with this shuttle.

http://www.ex-astris-scientia.org/scans ... /type7.jpg

It looked a little too small for it to be that shuttle....IMO.

[Darth Wong]

The first example is something that's routinely pulled out by people who don't understand the physics involved: "Skin of Evil." The appearance of a fireball on Armus' planet is used as evidence that a photorp is "500 megatons minimum." (Funny, when I watched the episode, I heard no mention of any no. of torpedos, but it's naturally assumed that only one was fired.)

Doesn't the name "Armus" remind you of "Arminius?" I see the connection now! Arminius is the fucking SKIN OF EVIL!!!!!

This has been beat to death elsewhere, but I'm interested to know
the specifics such that we might archive the counterargument, if not
at I Want YOU! then perhaps at Wayne Poe's website. I'm particularly interested in knowing why it's futile to try and judge an explosion's
yield based on that fleeting fireball; we can all speculate that the
shuttlecraft targetted by the torpedo contained a lot of AM (actually
doubtful), thus contributing to the blast, but hard facts about the fallacious
500 MT conclusion would be better.

It takes time to dissipate energy. The more energy, the more time. A 1 megaton blast creates a fireball that glows intensely for more than 20 seconds. A gigaton-class explosion at ground-level atmosphere would probably produce a fireball that lasts for several minutes.

However, the fireball in SOE dissipated in less than one second. This indicates kT-level yield at most. There is simply no way to deposit that much energy into an atmosphere and have it dissipate that quickly.

The second instance involves dialogue, from DS9's fifth season premiere "Apocalypse Rising." Damar claims that a full spread of photorps
would "destroy Gowron, his command center, and everything else within
a few hundred kilometers."

Speculative character dialogue.

I have no problem believing that, especially given that the torpedos
could be fired such that their detonations wouldn't immediately overlap,
thus covering more area. However, I've tried and tried to find information at the Nuclear Weapons FAQ to determine something useful about
this expectation, and I've failed.

It depends on what he means by "destroyed".

Assuming 3-4 torpedos, whatever kind of detonations would be most useful in killing lots of Klingons, etc., and further assuming that
"a few hundred kilometers" means...I dunno, say, 200-300?, what
would these weapons yield? I don't even know where to begin, truly...
are we talking a few hundred SQUARE kilometers, an area that extends
100-150 km in every direction from ground zero, or what?

This is the problem with speculative character dialogue. If we take all speculative character dialogue literally, it would only take 1000 Imperial ships to reduce Alderaan to a meteor shower. I remind you of all the times that the meagre 6000 MT arsenal of the world's two Cold War superpowers was said to be capable of "destroying the world several times over" in real life.

Btw, O'Brien shit on the plan in the end, saying that Gowron's CC had shields that could withstand a dozen photorps. To my knowledge, that's the strongest, largest theatre shield ever mentioned for a ground-based installation in "modern" Trek.

If a photorp was gigaton-class, sub-surface detonations outside the shield would EASILY destroy the facility through seismic shock. If their only goal was to destroy rather than capture, there would be no reason not to do this (unless, of course, their torps aren't that powerful).

[seanrobertson]

Doesn't the name "Armus" remind you of "Arminius?" I see the connection now! Arminius is the fucking SKIN OF EVIL!!!!!

Yeah, wow. It's been awhile since I've seen that name!

It takes time to dissipate energy. The more energy, the more time. A 1 megaton blast creates a fireball that glows intensely for more than 20 seconds. A gigaton-class explosion at ground-level atmosphere would probably produce a fireball that lasts for several minutes.

However, the fireball in SOE dissipated in less than one second. This indicates kT-level yield at most. There is simply no way to deposit that much energy into an atmosphere and have it dissipate that quickly.

Great--exactly what I was looking for.

Speculative character dialogue.

It depends on what he means by "destroyed".

I imagine so. It's impossible to tell from what he said, of course, though the goal was to eliminate Gowron (or his purported changeling doppelganger). If accurate, "[destroy him and]...everything else within a few hundred kilometers" would seem to indicate structural damage, knocking down buildings and the like.

This is the problem with speculative character dialogue. If we take all speculative character dialogue literally, it would only take 1000 Imperial ships to reduce Alderaan to a meteor shower. I remind you of all the times that the meagre 6000 MT arsenal of the world's two Cold War superpowers was said to be capable of "destroying the world several times over" in real life.

That's certainly true. My ultimate aim was to show
that both this episode's dialogue and "SoE" needn't
stand in opposition to the FX--or at least
to find out if Damar had to be exaggerating, etc.
I'd like to think that he knows what photorps should be
capable of against an otherwise unshielded target, though,
and if there is some way to make good on his plan with
the sorts of rational/purely canon yields discussed here.
What would the most conservative route be? Air detonations
killing everything within a few hundred *square* km, with a
kind of tri-point North-SW-SE spread? If nothing else, the
hard-line "torpedos are gigatons" Trekkies could have a figure
consistent with observed effects, which could help drive one
more nail into this whole insistence of theirs on turning to
dialogue when things get rocky I'm not out to persecute Trek
fanatics--hell, I'm one of those twelve people still hoping Nemesis will
be good, LOL--but it'd be nice to at least burn a few hands on that desperation stove. One example, like this one, is usually all that's
needed, especially with your analysis of Riker's infamous statement
in "The Pegasus."

If a photorp was gigaton-class, sub-surface detonations outside the shield would EASILY destroy the facility through seismic shock. If their only goal was to destroy rather than capture, there would be no reason not to do this (unless, of course, their torps aren't that powerful).

Right. Sisko etc. didn't like the idea of "spilling a little Klingon blood
to get the job done," but there's no way in hell that ship could've
used torpedos outside the shield to create such effects. If Dukat had
that sort of ordinance onboard, he would've used it; lap-dog Damar
wouldn't have even had time to say "I recommend..." before the spread'd
been fired.