Naquadah Nukes & Railguns (Stargate related)

[l33telboi]

I was just watching SGA's "The Siege" again and two things hit me like a baseball bat to the head. The first thing conserns Naqudah nukes, the second conserns the railguns.

Alright, the newly arrived General, in Part 2, says that the Naq mines emitt almost 0 EM. Well, the EM is basically the bright light we see from a nuke, in the form of Gamma rays, right? So did the general just tell us not to be expecting bright light from the nukes? If so, it would explain e helluva lot of things.

Secondly, railguns. Up till now i've been under the impression that the muzzle velocity of the railguns used in The Seige was 1700m/s, or mach 5. But that's not the case. It's really the impact velocity at around 400km, which means the muzzle velocity is going to be friggin' huge. Any thoughts on how to calculate the air drag and extrapolate an approximate muzzle velocity from that?

[Mr. Oragahn]

1. Actually, I think it has more to do with the radioactive decay. Which is non existent with naqahdah. When you look at the mines in Siege, they're clearly not coated with stealth materials, and a nuclear mine emiting zero EM upon detonation would be pointless, not to say impossible. Otherwise, you'd get no X rays and gamma rays.

2. That's a think I noticed but I had no clue how to calc that.
However, we do see the size of the cannon, at a very close angle, and it seems we see a full clip of rounds rammed into a railgun, when the city is being prepared for the first attack.

Eventually, I can dig old physics books and get the necessary formulas, because we'll have to consider the slopeness of a round's tip. How pointy it is will matter, and I don't know how to apply basic friction calcs to a cone.
I'd have to assume a given air density, the value that's generally used as the default experience milieu.

But that's possibly more complicated than a method that would already use numbers traditionally attached to bullets, as how far they can go, how fast they loose velocity, and what is their initial velocity when exiting the gun.
I doubt you could quickly scale up the figures attributed to bullets by comparing its size to that of a railgun round, though. Or maybe you could, if we get something along the lines of a deceleration proportional to the surface area of the bullet's tip. We'd just have to assume that the railgun round is just the same bullet, but bigger.

Knowing the projectile's mass would also help a lot. Even knowing its size, we couldn't get a reliable mass.

A quote from the episode, though, if you have some information to start from.

"EVERETT: We brought along a few rail guns. They were originally slated for Prometheus to replace their current close-in armament for their next refit. They will deliver an impact velocity of mach-five at fifty miles; a standard magazine will hold ten thousand rounds."

Energies concerned, a 0.1 kg heavy round, fired at 1700 m/s, would provide a KE of roughly 144.5 KJ.

They fire between 4-8 rounds per salvo.

[l33telboi]

1. Actually, I think it has more to do with the radioactive decay. Which is non existent with naqahdah. When you look at the mines in Siege, they're clearly not coated with stealth materials, and a nuclear mine emiting zero EM upon detonation would be pointless, not to say impossible. Otherwise, you'd get no X rays and gamma rays.

We're more likely talking about a material surrounding the nuke that absorbs the radiation as it explodes, which would mean a higher kinetic energy. It would actually explain the visuals quite well. Though i wouldn't count a technobabblish effect out of the picture either.

And i can't really see any other reason as why to mention "almost 0 EM". We were talking about stationary mines, so it wouldn't make sense for them to think it emitting almost 0 EM while deployed would be significant. It should look like nothing more then piece of floating space-debris.

But in essence, the biggest piece of evidence for it is the fact that we have seen nukes go off while emitting "almost 0 EM".

2. That's a think I noticed but I had no clue how to calc that.
However, we do see the size of the cannon, at a very close angle, and it seems we see a full clip of rounds rammed into a railgun, when the city is being prepared for the first attack.

Eventually, I can dig old physics books and get the necessary formulas, because we'll have to consider the slopeness of a round's tip. How pointy it is will matter, and I don't know how to apply basic friction calcs to a cone.

I'm actually thinking it might be easier to just do a rough scaling and measurment based on the velocity of the projectiles in "The Siege", that should get us a close enough figure. Because air drag would be a bitch to calculate, especially given the many unknowns surrounding the rounds fired.

At a guess, i'd say the MV would be 10km/s plus. But that's just going by rough eyeballing.

In any case, these railguns are far more powerful then i initially thought.

But that's possibly more complicated than a method that would already use numbers traditionally attached to bullets, as how far they can go, how fast they loose velocity, and what is their initial velocity when exiting the gun.

I did some checking on wiki for just that. And found a few figures. Problem is that these things aren't really normal bullets. They have a much higher kinetic energy in comparison to momentum to normal firearms, so that could throw any comparison way off-chart.

Knowing the projectile's mass would also help a lot. Even knowing its size, we couldn't get a reliable mass.

Well, there was a guy lifting a clip of them and he didn't seem visibly strained by the effort. So we're probably not talking about more then 1kg per projectile. But that is rather odd, given their size. A projectile with a high mass and small size would be far batter then a large sized projectile with a low mass. And these things looked like something around 20mm. Hard to compare with real ammo though, seeing as these are solid rounds rather then cartridge+projectile.

[Mr. Oragahn]

Oh crap, I thought I had posted my message. lol :D

1. Actually, I think it has more to do with the radioactive decay. Which is non existent with naqahdah. When you look at the mines in Siege, they're clearly not coated with stealth materials, and a nuclear mine emiting zero EM upon detonation would be pointless, not to say impossible. Otherwise, you'd get no X rays and gamma rays.

We're more likely talking about a material surrounding the nuke that absorbs the radiation as it explodes, which would mean a higher kinetic energy. It would actually explain the visuals quite well. Though i wouldn't count a technobabblish effect out of the picture either.

And i can't really see any other reason as why to mention "almost 0 EM". We were talking about stationary mines, so it wouldn't make sense for them to think it emitting almost 0 EM while deployed would be significant. It should look like nothing more then piece of floating space-debris.

But in essence, the biggest piece of evidence for it is the fact that we have seen nukes go off while emitting "almost 0 EM".

My point is that the casing isn't made so it could reflect an active scanning, but more like it's every good at keeping what's inside from saying "Hey, I'm a big bomb ready to explode in your face".

The casing could never perfectly transfer all the energy to matter to get KE instead, and there would be a huge amount of radiations in the end.

There had to be anyway, otherwise a nuke that releases no EM waves when it explodes... huh no.

I think the whole point was that it was a silent bomb, quite what you expect from a space mine, to trap your enemy.

2. That's a think I noticed but I had no clue how to calc that.
However, we do see the size of the cannon, at a very close angle, and it seems we see a full clip of rounds rammed into a railgun, when the city is being prepared for the first attack.

Eventually, I can dig old physics books and get the necessary formulas, because we'll have to consider the slopeness of a round's tip. How pointy it is will matter, and I don't know how to apply basic friction calcs to a cone.

I'm actually thinking it might be easier to just do a rough scaling and measurment based on the velocity of the projectiles in "The Siege", that should get us a close enough figure. Because air drag would be a bitch to calculate, especially given the many unknowns surrounding the rounds fired.

At a guess, i'd say the MV would be 10km/s plus. But that's just going by rough eyeballing.

In any case, these railguns are far more powerful then i initially thought.

Shit, I have to retype all that as well. :)

I've been making plenty of caps. The magazines have a section that is transparent. We can see the rounds. They seem to be grouped by four, which is consistent with the bursts seen.
What I mean by bursts, is the lines. You could see the cannon fire seberal "lines", but in fact each line is composed of four glowy things.

So for example, if the railgun fires three lines, it has actually fire 12 rounds.
That's why I think each "pwee" sound is the energy pulse used to accelerate four rounds.

That said, the magazines are not full of rounds, and I can't see how they can cram 10,000 rounds in those boxes. A railgun can also use only one magazine at a time, so we have a problem here I thin.

As for the muzzle velocity, I've looked at large angle shots from the battle, and the rounds don't seem to cross a city radius that fast. I've been trying to find examples where I saw sure of the direction of the rounds, and when I got an example, it was about a railgun piece located in a tower not far from the central spine. The railgun was firing towards the central spire, and the rounds took around 10 frames to reach the central tower. So the muzzle velocity is pretty much what we get over 50 miles. This is not correct, and the only way to make that better is to get a bigger Atlantis.

Most measurements put the city between 3.2 km and 3.6 km wide. That's a radius of 1.6 km to 1.8 km.

Olny your latest 6 km wide city would fit, but I don't agree with it that much, considering how blurry the image, and how in the end, exact PJ measurements have not been made yet.

That's really why I never wanted to go into those visuals, because I knew there were chances that the VFX wouldn't exactly correspond to the expected speeds.

Besides, the railguns can also be moved around with vehicles, as their base shows the presence of two wheels which fold in (think GDF sentries in Quake Wars).

But that's possibly more complicated than a method that would already use numbers traditionally attached to bullets, as how far they can go, how fast they loose velocity, and what is their initial velocity when exiting the gun.

I did some checking on wiki for just that. And found a few figures. Problem is that these things aren't really normal bullets. They have a much higher kinetic energy in comparison to momentum to normal firearms, so that could throw any comparison way off-chart.

Well, we can still look what we can scavenge from these bits of info... ?

Knowing the projectile's mass would also help a lot. Even knowing its size, we couldn't get a reliable mass.

Well, there was a guy lifting a clip of them and he didn't seem visibly strained by the effort. So we're probably not talking about more then 1kg per projectile. But that is rather odd, given their size. A projectile with a high mass and small size would be far batter then a large sized projectile with a low mass. And these things looked like something around 20mm. Hard to compare with real ammo though, seeing as these are solid rounds rather then cartridge+projectile.

1 kg per projectile? :) Woah, that's over generous. Those clips are supposed to pack 10,000 rounds.
Considering how the magazines are lifted with ease, that would make the magazine not more than 20 kg top.

It would make each projectile like 2 grams heavy, top.

Weird. There's not much point having such a light projectile. It has a negligible inertia, and will suck against air drag.

We're really going to need to play with words here. Like 10,000 rounds corresponded to the total of magazines, even if that doesn't make much sense, considering that you can have as many magazines as you want.

Besides, the control screen clearly shows 10000 rounds counted, and we see it going down, even to 5000 rounds.

That's just like the pulserifle clip problem in ALIENS. They mention a number of rounds which can't be crammed inside the clips we see onscreen.

[l33telboi]

My point is that the casing isn't made so it could reflect an active scanning, but more like it's every good at keeping what's inside from saying "Hey, I'm a big bomb ready to explode in your face".

But this would have nothing to do with the EM, since the EM emitted from an inert object would be as big as from a piece of rock.

The casing could never perfectly transfer all the energy to matter to get KE instead, and there would be a huge amount of radiations in the end.

I never suggested a perfect transfer, "almost 0 EM" was said. And we do see small flashes from the nukes. It fits.

There had to be anyway, otherwise a nuke that releases no EM waves when it explodes... huh no.

It releases the EM, it's absorbed by the material around the bomb and turned to heat and kinetic energy. The nuke would have EM, it just wouldn't be visible to the occasional onlooker when it goes boom.

I think the whole point was that it was a silent bomb, quite what you expect from a space mine, to trap your enemy.

One would think it'd be very hard to not make one.

Shit, I have to retype all that as well. :)

I've been making plenty of caps. The magazines have a section that is transparent. We can see the rounds. They seem to be grouped by four, which is consistent with the bursts seen.
What I mean by bursts, is the lines. You could see the cannon fire seberal "lines", but in fact each line is composed of four glowy things.

So for example, if the railgun fires three lines, it has actually fire 12 rounds.
That's why I think each "pwee" sound is the energy pulse used to accelerate four rounds.

That said, the magazines are not full of rounds, and I can't see how they can cram 10,000 rounds in those boxes. A railgun can also use only one magazine at a time, so we have a problem here I thin.

Yes, 10,000 rounds seems way too much given the size of the bullets. Maybe he was mentioning this in refrence to what a BC mounted railgun could carry?

As for the muzzle velocity, I've looked at large angle shots from the battle, and the rounds don't seem to cross a city radius that fast. I've been trying to find examples where I saw sure of the direction of the rounds, and when I got an example, it was about a railgun piece located in a tower not far from the central spine. The railgun was firing towards the central spire, and the rounds took around 10 frames to reach the central tower. So the muzzle velocity is pretty much what we get over 50 miles. This is not correct, and the only way to make that better is to get a bigger Atlantis.

Most measurements put the city between 3.2 km and 3.6 km wide. That's a radius of 1.6 km to 1.8 km.

I have to admit that i was actually thinking of the size i got in the latest scalings when i made that statment, in any case, we're talking about something far higher then 1700m/s.

Olny your latest 6 km wide city would fit, but I don't agree with it that much, considering how blurry the image, and how in the end, exact PJ measurements have not been made yet.

I did new scalings with the HR HDTV version of the episode on SB. Though photobucket seems intent on converting pics to JPEG and nerfing the quality somewhat. In any case, you're not going to get much lower then 6km in whatever way you choose to scale.

Well, we can still look what we can scavenge from these bits of info... ?

IIRC the drop in m/s was more then 50 per every 100m. But like i said, i wouldn't be a fan of that metho.d

1 kg per projectile? :) Woah, that's over generous. Those clips are supposed to pack 10,000 rounds.

Yeah, but the one that was lifted doen't. Which is the problem.

It would make each projectile like 2 grams heavy, top.

...Which would mean it would be too light to be shot out of anything. :P

We're really going to need to play with words here. Like 10,000 rounds corresponded to the total of magazines, even if that doesn't make much sense, considering that you can have as many magazines as you want.

Besides, the control screen clearly shows 10000 rounds counted, and we see it going down, even to 5000 rounds.

Hmm, ok, maybe the magazines we saw lifted wasn't really the magazines, but something they just kept the ammo in before they loaded them into the gun?

It's stretching, but that's all i can come up with.

[Mr. Oragahn]

My point is that the casing isn't made so it could reflect an active scanning, but more like it's every good at keeping what's inside from saying "Hey, I'm a big bomb ready to explode in your face".

But this would have nothing to do with the EM, since the EM emitted from an inert object would be as big as from a piece of rock.

Well, sure, if it was rock. Now, we're speaking about electronics and still nuclear material (naqahdah amplifies the blast).

The casing could never perfectly transfer all the energy to matter to get KE instead, and there would be a huge amount of radiations in the end.

I never suggested a perfect transfer, "almost 0 EM" was said. And we do see small flashes from the nukes. It fits.

I don't really think so. Almost zero EM is like 0.021% EM. Having a gigaton nuke destroying a casing such as the one we see in the episode will let a huge amount of EM waves pass through.
It's a question, imho, of the casing's thickness. I don't see any matter to prevent 99.999% of the radiations from gong through.
Thickness and composition. There are just plenty of different radiations there, and some pass through matter with more ease.
Besides, I'm not sure you wouldn't achieve anything with vapourized casing. Propelling gas at high speeds is fun, but in terms of KE, that's going to suck.
The only thing good it could do is hope to deal damage with kinetics, but that's absurd, because it's simply way better to let all the radiations spread instead of trying to build an hazardous wall of plasma.
The radiations will travel at c, not the plasma. Plasma will cool down over distance, besides loosing intensity. Radiations will only loose intensity (in the sense that the inverse square law will make their concentration lower).

I'm sorry, but I see no interest, feasibility and advantage at having the bomb used as an impactor and heat system.

I think the whole point was that it was a silent bomb, quite what you expect from a space mine, to trap your enemy.

One would think it'd be very hard to not make one.

But that's thinking in terms of contemporary sensors though.
We're talking about a whole new level of sensors here. Wraith are able to beam people to the elementary particle scale. This makes their sensors extremely accurate.
Just as much as the Asgards'.

Yes, 10,000 rounds seems way too much given the size of the bullets. Maybe he was mentioning this in refrence to what a BC mounted railgun could carry?

Not much. The control screen of the gun shows the rounds numbered, starting from 10,000 and going down.

As for the muzzle velocity, I've looked at large angle shots from the battle, and the rounds don't seem to cross a city radius that fast. I've been trying to find examples where I saw sure of the direction of the rounds, and when I got an example, it was about a railgun piece located in a tower not far from the central spine. The railgun was firing towards the central spire, and the rounds took around 10 frames to reach the central tower. So the muzzle velocity is pretty much what we get over 50 miles. This is not correct, and the only way to make that better is to get a bigger Atlantis.

Most measurements put the city between 3.2 km and 3.6 km wide. That's a radius of 1.6 km to 1.8 km.

I have to admit that i was actually thinking of the size i got in the latest scalings when i made that statment, in any case, we're talking about something far higher then 1700m/s.

Not really if the city is only 3.2-3.6 km wide.
The distance crossed by the rounds appears even under one city radius / 12 frames (on a 24 frames medium).
So really, that's why I don't like that.

The battle looked neat, but the railguns always looked to slow for me. Especially back then, when the city wasn't even considered to be 3 km wide.
It's again a case where we got to stick with theory.
The initial velocity of rail rounds needs to be particularily high for them to keep a velocity of mach 5 at 50 miles.

Besides, the rounds are very pointy. I'll post a series of caps this WE.

Olny your latest 6 km wide city would fit, but I don't agree with it that much, considering how blurry the image, and how in the end, exact PJ measurements have not been made yet.

I did new scalings with the HR HDTV version of the episode on SB. Though photobucket seems intent on converting pics to JPEG and nerfing the quality somewhat. In any case, you're not going to get much lower then 6km in whatever way you choose to scale.

That's problematic. Though I dig the city being wider than a village, there has been more measurements ending in the +3 km ballpark.

Go figure. We also know that they sort of reset Atlantis with season 4, so who knows. Maybe they decided... to resize that city once more. That said, measuring the size of the damaged tower would also be a good indication of the city's size.

I remember most calcs put the central spire at something more than 600 m high.

Well, we can still look what we can scavenge from these bits of info... ?

IIRC the drop in m/s was more then 50 per every 100m. But like i said, i wouldn't be a fan of that metho.d

50 what? :)
50 m/s?

That would give a lower limit, considering that it comes from figures based on bullets with worse profiles than rail rounds... I suppose.
Do they give weight?

As for the magazine issue, well, let's see.

It's clear that the railguns are made to fire 10,000 rounds, in their lantian configuration.
But the magazines are too small, and still, they need to be clipped, one by one.
The other magazines are stacked next to the gun, somewhere on the base.

The only real problem here is the size of the magazine, really. If they had kept a big box plugged to the gun, there would have been no issue here.

Hmm, ok, maybe the magazines we saw lifted wasn't really the magazines, but something they just kept the ammo in before they loaded them into the gun?

It's stretching, but that's all i can come up with.

Yeah, you mean it. :)
No, it's really the magazine. It contains the rounds, and it's clipped next the cannon's base.

[l33telboi]

Well, sure, if it was rock. Now, we're speaking about electronics and still nuclear material (naqahdah amplifies the blast).

Nukes and electronics? I doubt they would put any electronics in them, and if they did, there would be no reason for the electricity to flow around before the nuke detonates.

As for Naquadah, what are you basing the fissionable material part on? IIRC it's always been somewhat of a mystery exactly how the material works.

I don't really think so. Almost zero EM is like 0.021% EM. Having a gigaton nuke destroying a casing such as the one we see in the episode will let a huge amount of EM waves pass through.

Almost 0 EM could mean anything. And there is actually a brief flash seen whey they go boom, so it fits. And he does say "almost 0 EM", not "an insiginificant percentage of EM", there is a difference.

It's a question, imho, of the casing's thickness. I don't see any matter to prevent 99.999% of the radiations from gong through.

Well, radiation resistant material in Stargate is quite easy to make. As example, think of the small Naquadah reactors that have an output far in excess of the largest modern nuclear reactors. Think of the F302s that are able to survive only a few solar diameters from a G-type star, yet the people inside not frying (heck, think of the window on the figher in relation to this.). Think of their ability to make directed explosives out of multi-megaton nukes.

They do have very radiation absorbant materials.

Thickness and composition. There are just plenty of different radiations there, and some pass through matter with more ease.

Only highly penetrative radiation i know if is Gamma radiation (or EM radiation in general), which is basically light at a wave-length higher then our eyes can perceive.

Besides, I'm not sure you wouldn't achieve anything with vapourized casing. Propelling gas at high speeds is fun, but in terms of KE, that's going to suck.

It doesn't need to be gas, we could very well be talking about nukes that are much like frag grenades. They would actually be able to create such with the tech they have. And such bombs would be more lethal then nukes relying on pure radiation to do its work, as kinetic enregy is far more dangerous to space ships then radiation, on a pure joule per joule basis.

In terms of pure energy though, it would have to be the same to appease CoE.

The radiations will travel at c, not the plasma. Plasma will cool down over distance, besides loosing intensity. Radiations will only loose intensity (in the sense that the inverse square law will make their concentration lower).

For plasma to lose intensity in space it would have to be there for a long long time. Remeber that heat doesn't get carried away from something due to the low density in space. Almost all the heat will be lost trough radiating, and that takes time. If there actually is time for the plasma to cool, then the nuke would've been detonated far, far away from the target.

As for the energy intensity from both weapons, it's exactly the same. CoE would dictate this.

But that's thinking in terms of contemporary sensors though.
We're talking about a whole new level of sensors here. Wraith are able to beam people to the elementary particle scale. This makes their sensors extremely accurate.
Just as much as the Asgards'.

Doesn't matter. A mine would have a minimal amount of EM coming from it when inert. So minimal that it would be indistingushable from rocks. In fact you'd be able to make it more indistiguishable then a normal rock with modern tech. So the almost 0 EM wouldn't make sense if this is what it's meant to describe.

Not really if the city is only 3.2-3.6 km wide. The distance crossed by the rounds appears even under one city radius / 12 frames (on a 24 frames medium).
So really, that's why I don't like that.

The rounds do travel more then half a city-width in a second, so it would be more then 1700m/s^2 even if we assume 3.2-3.6km wide radius.

The initial velocity of rail rounds needs to be particularily high for them to keep a velocity of mach 5 at 50 miles.

True enough.

Besides, the rounds are very pointy. I'll post a series of caps this WE.

All AP ammo tends to be very pointy, at these speeds it's going to be problematic though, since part of the slug will turn to plasma. This is why the rounds are actually glowing blue inside an atmosphere and yellow in space.

Unless they have a trinium tip with something heavier as a base, i suppose. It would make sense.

That's problematic. Though I dig the city being wider than a village, there has been more measurements ending in the +3 km ballpark.

Go figure. We also know that they sort of reset Atlantis with season 4, so who knows. Maybe they decided... to resize that city once more. That said, measuring the size of the damaged tower would also be a good indication of the city's size.

Aye, i suggested as much, but it would be really really hard. Far out of my league. In any case, i hardly see that measurment nerfing the 6km+ figure.

50 what? :)
50 m/s?

Aye.

That would give a lower limit, considering that it comes from figures based on bullets with worse profiles than rail rounds... I suppose.
Do they give weight?

Yes, i can link you to the page, hold on.

Ah, here we go.

[Mr. Oragahn]

Nukes and electronics? I doubt they would put any electronics in them, and if they did, there would be no reason for the electricity to flow around before the nuke detonates.

It has to, as the nukes worked on proximity fuses. This means sensors, and since they were in all likeliness passive, it also means good ones. Which means an activity.

As for Naquadah, what are you basing the fissionable material part on? IIRC it's always been somewhat of a mystery exactly how the material works.

I'm not saying it's fissionable, exactly, but that it surely enhances the explosion. It still requires, imho, a traditional nuclear warhead.

Almost 0 EM could mean anything. And there is actually a brief flash seen whey they go boom, so it fits. And he does say "almost 0 EM", not "an insiginificant percentage of EM", there is a difference.

Ho, that's hair splitting. Both indicate extremely low values. Almost zero is just a bit more specific.
As for the flashes, considering what we've seen on screen - huge double flashes - we would actually consider that they released a hell of EM radiations.

Well, radiation resistant material in Stargate is quite easy to make. As example, think of the small Naquadah reactors that have an output far in excess of the largest modern nuclear reactors.

Bottled reaction, possibly magnetic fields. It is irrelevant to a nuke.

Think of the F302s that are able to survive only a few solar diameters from a G-type star, yet the people inside not frying (heck, think of the window on the figher in relation to this.).

Was it that close?

Think of their ability to make directed explosives out of multi-megaton nukes.
They do have very radiation absorbant materials.

Yes, they seem to have good microsecond reflectors. Possibly some trinium-naqahdah alloy.

Sidenote: the sheer fact that there are forges which can melt naqahdah tells a lot about both Tau'ri and Goa'uld achievements in the domain or controlled high level reactions.

Back on topic.

This, however, doesn't change a thing. If the casing was flash vapourized and accelerated, the explosions would still blind us. Terribly.

I can't see how one can reasonably explain the space farts, safe saying that the nukes just fail undergoing the much planned reaction.

It's not easy to know when to detonate your nuke in advance, when you don't know if there's a shield and how far it extends from the ship.

Maybe the nukes should be equipped with sensitive proximity sensors or even antennas which would break first, when touching a shield, and thus send back a message to the nuke having it explode.

Only highly penetrative radiation i know if is Gamma radiation (or EM radiation in general), which is basically light at a wave-length higher then our eyes can perceive.

It's still an important quantity of gamma rays which can't be ignored.

It doesn't need to be gas, we could very well be talking about nukes that are much like frag grenades. They would actually be able to create such with the tech they have. And such bombs would be more lethal then nukes relying on pure radiation to do its work, as kinetic enregy is far more dangerous to space ships then radiation, on a pure joule per joule basis.

They'd need to be able to precisely shape the way the warhead cracks, and we'd have evidence of secondary debris impact against shields if that was so.
The explosions themselves don't look much shaped at all.
And again, they are nothing worth of even tons of energy released.

The radiations will travel at c, not the plasma. Plasma will cool down over distance, besides loosing intensity. Radiations will only loose intensity (in the sense that the inverse square law will make their concentration lower).

For plasma to lose intensity in space it would have to be there for a long long time. Remeber that heat doesn't get carried away from something due to the low density in space. Almost all the heat will be lost trough radiating, and that takes time. If there actually is time for the plasma to cool, then the nuke would've been detonated far, far away from the target.

The plasma will stretch over the distance. The distance between the most distant ionized particles, on each side of the expanding cloud, will greatly increase. Plasma is chaotic and gas expand very fast.

But that's thinking in terms of contemporary sensors though.
We're talking about a whole new level of sensors here. Wraith are able to beam people to the elementary particle scale. This makes their sensors extremely accurate.
Just as much as the Asgards'.

Doesn't matter. A mine would have a minimal amount of EM coming from it when inert. So minimal that it would be indistingushable from rocks.

Hardly. If sensors can decompose and reassemble people, they have to be so good that the mine could never be picked as mine.

In fact you'd be able to make it more indistiguishable then a normal rock with modern tech. So the almost 0 EM wouldn't make sense if this is what it's meant to describe.

I think it's pretty clear it's meant to be a mine that is like a rock. But it failed, as the Wraith thwarted this attempt.
Considering that the Wraith rarely seem to carry bags of asteroids with them, it seems fairly likely that they actually spotted those mines.

The rounds do travel more then half a city-width in a second, so it would be more then 1700m/s^2 even if we assume 3.2-3.6km wide radius.

That is not the impression I get from the video.
The screenshots I hope to post here will help to solve this issue.

All AP ammo tends to be very pointy, at these speeds it's going to be problematic though, since part of the slug will turn to plasma. This is why the rounds are actually glowing blue inside an atmosphere and yellow in space.

Unless they have a trinium tip with something heavier as a base, i suppose. It would make sense.

Trinium rounds would be expensive though.

Aye, i suggested as much, but it would be really really hard. Far out of my league. In any case, i hardly see that measurment nerfing the 6km+ figure.

We'll just have to wait to get another take I guess. :)

Yes, i can link you to the page, hold on.

Ah, here we go.

Cool, I'll check it out later on, to see what we can get from it.

[Mr. Oragahn]

Some article about new railguns, with speed and energy figures.

http://www.popularmechanics.com/technol ... 31461.html