Trek Photon Torpedo Yields

[vivftp]

Ok ladies and gentlemen, I need some assistance. SOME people are questioning where we get medium megaton yields for photon torpedos from in Trek, and I need to provide some examples. I don't have the resources to pour through every episode/movie, so what do we have to use?

Preferrably, I need an episode, a description of the instance, and whatever means were used to calculate the yield.

I had to create this thread to ask because the thread where it's partially being discussed is far too large and complex, and I don't wish to subject any of you guys to it

[Major Diarrhia]

DITL, STvsSW, SD.net cover the major torpedo events. I think the calc from the Voyager episode "Rise" is the clearest, the tricky part is actualy getting the scale of the asteroid. Anyway, I think it's clearest because it's stated clearly that the torpedo used on it should have vaporised it and I think they state what its composition should have been. So you take the composition they originaly assumed it to have, find its size, and then use the SD.net asteroid calculator in vaporise mode and you can get the torpedo yield.

[wyldstallionryder]

Major, the problem is that they said they expected to vaporize it...but they *also* said they expected the fragments to be no bigger than a few centimeters. It is therefore unclear whether they actually meant "vaporize" or "pulverize".

[Major Diarrhia]

You go with the second one then since it's far more specific.

[Blair]

There was an Enterprise episode (The Expanse?) where Reed made some comment about photon torpedo power. Something about being able to put a kilometer-wide crater in an asteroid, but I don't remember much about it

[consequences]

Originally Posted by Blair

There was an Enterprise episode (The Expanse?) where Reed made some comment about photon torpedo power. Something about being able to put a kilometer-wide crater in an asteroid, but I don't remember much about it

Well, that narrows it down to 377.2 kilotons for an Ice asteroid, 1.4 megatons for hard granite, or 37.8 megatons for a nickel-iron specimen, presuming that the statement was factual, and not exaggerated in any way.

[vivftp]

Originally Posted by Blair

There was an Enterprise episode (The Expanse?) where Reed made some comment about photon torpedo power. Something about being able to put a kilometer-wide crater in an asteroid, but I don't remember much about it

He mentioned that the new photonic torpedos could either knock the comm array off a shuttpod (low end) or put a 3km crater into an asteroid. But unfortunately we don't know anything about the type of asteroid he might have been referring to. I guess the best we can do is get calcs for all the most common types of asteroids and see what occurs. But then again the size of said asteroid could also matter.

As for the whole Rise thing, heh, I've been going around and around with Light Soldier in the other thread trying to explain this bit to him. The asteroid was at least 100 meters wide from my scaling calcs (bare minimum). Here's the dialogue:

TUVOK: The asteroid is fragmenting, but most of the debris is still on a collision course with the planet.
JANEWAY: Target the fragments. Destroy them.
CHAKOTAY: That asteroid should have been vaporised. What happened?
KIM: Not sure. Sensors showed a simple nickel-iron composition. We shouldn't be seeing fragments more than a centimetre in diameter.
SKLAR: Ambassador, I'm afraid I was right. This isn't going to work. The same thing happened to us yesterday. We tried to vaporize two incoming asteroids but they fragmented and struck the surface.


So definately they were awknowledging the difference between fragmenting and vaporizing here - Chakotay meant actually vaporized. Considering they didn't expect to see any residual fragments over 1cm in diameter tells us that they expected over 99% of the asteroid to be completely vaporised - I mean, you can't reasonably think that they expected the asteroid to carve itself up into nice, tiny uniform chunks no more than 1cm in diameter.

They were using a single explosive device to vaporise a 100+ meter nickle/iron asteroid. It's natural to think that from such an occurance that a FEW tiny shards might be pushed away from the asteroid before they could be vaporised... it is an explosion occuring afterall. If this had been phasers, then I'd agree that it's odd that they'd expect fragments, but a photon torpedo? This makes perfect sense to me.

[consequences]

At three kilometer crater, it is likely that he was referring to a granite asteroid at most, again presuming no hyperbole, which is doubtful with the low-end example he gave.
10.2 megatons for Ice, 39.1 megatons for granite, and 1 gigaton for nickel iron at those figures.

For a thought, is it possible theat they don't normally use high-yield torpedos because it cuts to far into their antimatter reserve?

Vivftp, you'd have a better point on the fragmentation issue if it was an atmosphere, and something other than antimatter explosives. Anti-matter explosions are lightspeed, and the limited mass of the torpedo would be converted to energy before it could form any sort of shockwave. The mass of the facing surface of the asteroid will vaporise and push against the remaining mass, but this is part of the reason that the vaporisation figure is so much higher than the fragmentation figure in the first place

[vivftp]

Well the going theory that makes the most sense is that the M/AM warheads are loaded just before launch (which is why torpedo systems require their fare share of energy). We really don't know if the AM comes directly from the ships main storage pods or if there's a seperate storage for them - but I guess the most likely conclusion is that it comes straight from the main storage pods.

On the whole fragmentation/vaprosation bit, well one interpretation of the dialogue is that IF they did see any remaining fragments, they wouldn't have been any more than 1cm in diameter (since you can never be certain on everything). So they very well could have been expecting the entire thing to be vaporised, with the outside possibility of some miniscule fragments

[Major Diarrhia]

That makes sense since vaporisation is mentioned twice and complete vaporisation should be unrealistic considering that the energy isn't applied uniformaly, at the same time, on every molecule of the asteroid.