SGA 4x01 & 4x02 Quantification thread *Spoilers*

[Mr. Oragahn]

Wow.

Sulu's got a cousin.

Who put a sort of F-Zero track on this video? Seriously, I couldn't help hearing the boost and engines SFX and other audio comments in my head.

Many of these asteroids, probably around 8 meters wide, were largely turned into dust.

Besides, it seems we get more evidence that the racks on a puddle jumper can materialize drones. We needed 4 seasons since Rising to get this confirmed once and for all.

Funnily, around 1:30, there's a salvo of four squids fired, and the last one goes wild and spins. That's bizarre, considering that we've never seen squids loosing control over their direction when blowing huge things up.
The squid in Adrift is not even hit by a rock.

The other extraits have revealed a couple of things. Rodney was trying to interface the ZPM with the PJ. I can't know if he succeeded.

[l33telboi]

So, McKay has finally learned how to fly a jumper.

Oddly enough, he didn't seem too thrilled about the prospect.

McKay: "Looks like the old videogame Asteroids."
Sheppard: "Whatever works for you."
McKay: "I was terrible at Asteroids, i think i actually scored zero once."

Many of these asteroids, probably around 8 meters wide, were largely turned into dust.

Most seem a bit larger, slightly larger and longer then puddlejumpers (which apparently are ~10m according to scalings on Gateworld), though it's harder to say since none of them are perfect spheres.

However, the big one McKay took out seemed a lot larger. Here's a pic, you can see it's close to the tower because of the reflection (though that might be better visible in the video), and because of the timing. Notice how big it is in relation to the windows.



Now here's a puddlejumper beside those windows.



The asteroid looks almost three times as wide as the jumper is long, that'd make it around 30m. And it's quite spherical as well.

Basically, we're talking about something this large, scattering it's mass in under a second. That means something like a 32 940 000kg (assuming granite) being accelerated to something like 30m/s. Using the KE formula, it gives us something around 1.5GJ of energy. Of course there's a ton of smaller details to note, like how the outer edge of the asteroid was being scattered a lot faster then the core, after something like 5 frames it had already moved the 30m.

So these drones are realistically something like double digit gigajoule weapons, though probably even more. Because the figures i gave above doesn't factor in heat, the energy needed to crack an asteroid, the energy needed to burrow inside the asteroid etc etc etc.

I'll probably end up doing something a lot more detailed later on.

Besides, it seems we get more evidence that the racks on a puddle jumper can materialize drones. We needed 4 seasons since Rising to get this confirmed once and for all.

Actually, this episode sorta speaks againt it. Sheppard says they have 'a full load of drones' and that they shouldn't have to worry about ammo.

Funnily, around 1:30, there's a salvo of four squids fired, and the last one goes wild and spins. That's bizarre, considering that we've never seen squids loosing control over their direction when blowing huge things up.

Actually, i missed it the first time, but it makes perfect sense given the dialouge:

[quote="SGA: "Adrift"]McKay: "They're coming in too fast, we're not going to get them all."
Sheppard: "Alright, double up, fire four a-piece."
McKay: "I can't control four drones at the same time!"
Sheppard: "Well then just consentrate."[/quote]

The scene you're refering too happens directly after this.

[Mr. Oragahn]

Many of these asteroids, probably around 8 meters wide, were largely turned into dust.

Most seem a bit larger, slightly larger and longer then puddlejumpers (which apparently are ~10m according to scalings on Gateworld), though it's harder to say since none of them are perfect spheres.

I actually looked at how wide they looked like when those which were left undestroyed were grazed by the PJs. A PJ can fit in a stargate, which is a 6.7 m wide ring.

It seems that the smallest asteroids were around 5-6 m wide.
Other asteroids are around 12 meters wide, with one asteroid exceeding 18 meters, but that one wasn't destroyed.

However, the big one McKay took out seemed a lot larger. Here's a pic, you can see it's close to the tower because of the reflection (though that might be better visible in the video), and because of the timing. Notice how big it is in relation to the windows.



Now here's a puddlejumper beside those windows.



The asteroid looks almost three times as wide as the jumper is long, that'd make it around 30m. And it's quite spherical as well.

Basically, we're talking about something this large, scattering it's mass in under a second. That means something like a 32 940 000kg (assuming granite) being accelerated to something like 30m/s. Using the KE formula, it gives us something around 1.5GJ of energy. Of course there's a ton of smaller details to note, like how the outer edge of the asteroid was being scattered a lot faster then the core, after something like 5 frames it had already moved the 30m.

So these drones are realistically something like double digit gigajoule weapons, though probably even more. Because the figures i gave above doesn't factor in heat, the energy needed to crack an asteroid, the energy needed to burrow inside the asteroid etc etc etc.

I'll probably end up doing something a lot more detailed later on.

I'd say that one was between 20 m and 30 m large.

One thing to note is that McKay flies through the cloud of debris. Thus, the debris must have been small. It's largely proved by the much less than 10 m wide fragments, with most of the asteroid turned into dust, with the core put to flames.

About details, there's an important detail that can be seen for every single asteroid: the squids burrow themselves into them, and detonate only frames later.

What happens is this: they hit the asteroid. I've only counted two cases where the impact left a flash of light. But sides that, it burrows inside the asteroid, leaving a cloud of dust. Much like in The Tower, and with the same effects. Considering the speed at which it dug inside the asteroid, the speed at which it entered, and the utter lack of glowing ejecta or bits flying, we have even more evidence of the NDF nature of the burrowing process. In only a few cases, a small flash occured, indicating a minimal energy bleeding, and yet, that was only what to notice, since they absolutely all ended as puffs of dust.

The final asteroid that was about to hit the tower was destroyed by two squids. The first frame showing a sign of destruction also shows the first sign of heated material, which appears where through where the two holes were previously made.



Doing some dirty scaling, and trying to scale a PJ according to the glow of the drones the last frame at impact (know that light largely reflects on the asteroid, so the glow is bigger than the drone), I get, for the longest dimension, 8 PJ heights. At 4.1 m the height, it gives more than 32 meters, and 19.5 m for the shortest dimension.

Looking at Wong's calculator, for a 20 m wide asteroid, we get a shattering energy of 8 tons of TNT, for igneuous rock. 950 megajoules per drone.
It takes 6 for the whole of the mass to expand in such a way that the densest right edge of the asteroid travels the asteroid's shortest dimension. At a fps of 23.976, that's 0.25 seconds (taking 6 frames) to cross 19.5 meters, and that's conservative, since many debris were already beyond that distance frames earlier.

Besides, it seems we get more evidence that the racks on a puddle jumper can materialize drones. We needed 4 seasons since Rising to get this confirmed once and for all.

Actually, this episode sorta speaks againt it. Sheppard says they have 'a full load of drones' and that they shouldn't have to worry about ammo.

Well, my initial idea was that they were stored that way. Not that they came in unlimited quantities either. It's like a stargate's stream. Though in theory, it could be made to replicate an object, by default it will only recompose what it decomposed.
The guys only recovered a limited amount of drones. First from The Tower, and then when the Asurans occupied Atlantis.

We see puddle jumpers with racks full, even after all of the fired at least two or three drones.
It's just that it was simply impossible to have a PJ fire that many drones in Rising, considering the little room there was to physically store drones, and the fact that Sheppard fired more than 3 from the same side.

Funnily, around 1:30, there's a salvo of four squids fired, and the last one goes wild and spins. That's bizarre, considering that we've never seen squids loosing control over their direction when blowing huge things up.

Actually, i missed it the first time, but it makes perfect sense given the dialouge:

[quote="SGA: "Adrift"]McKay: "They're coming in too fast, we're not going to get them all."
Sheppard: "Alright, double up, fire four a-piece."
McKay: "I can't control four drones at the same time!"
Sheppard: "Well then just consentrate."

The scene you're refering too happens directly after this.[/quote]

Well, considering that humans often count by packets of three, and that McKay had to manage plenty of things, three seems normal in the heat of the battle. It's in fact the first time I see someone firing more than three squids at the same time. Well, when Sheppard did that, he targeted only one ship at a time, safe one time when he attacked two ships at once, but when he fired three drones, he made them spiral as a group of three on a single target.
So basically we can see that a guy like McKay can mentally guide three targets at the same time, with the PJ's controls. It's worth to note that initially, the fourth drone was flying correctly.
Let's also note that it didn't deactivate from the moment McKay lost control. Possibly to let the pilot retake control of the device, I don't know.

[Mr. Oragahn]

A tried to do an estimation of my own on this.

Still using Wong's calculator:

A 10 meters wide asteroid has a mass of 1220 tons for a vlume of 524 m³.

That is 2,328.2442748091603053435114503817 kg/m³.

Rounded to 2,328.24 kg/m³.

Let's say that certain debris were 1 m wide.

An asteroid, assumed as a sphere, being 1 meter wide, has a volume of 1 m³.

The debris move at 19.5 meters over .25 seconds, or 78 m/s.

The kinetic energy is:

E = 1/2 x m x v²
E = .5 x 2,328.24 x 6084
E = 7,082,506.08 joules (for an asteroid of 2,328.24 kg)

So we get a ratio of:
E = 3,042 joules / kg

If applied to the whole asteroid's mass, and remembering that a noticable portion of the asteroid was beyond that range two frames earlier, I tried to get the total energy for an asteroid which was 24.75 meters wide:

Mass of a 24.75 m wide granite asteroid: 18,496,000 kg

Total E = 56,264,832,000 joules.

Squid's E = 28,132,416,000 J.

I don't know if it's quite a good way to obtain the energy...

[l33telboi]

Made a thread on SB.com where i used the above proposed methodology to get the energy involved in the blast.

Although the figures there agree with what we get from Wong's calculator, i still believe the total energy content would be higher if i could get a way to gauge the expanding core more accurately. And if i could find a way to calculate actually cracking the rock and not just scattering it.

I'll dig around to see if i can come up with something.

[l33telboi]

I just realized something. Remember the F-302s and their hyperdrives that didn't work? The problem was that they needed a lot more power then the Naquadah-generators could produce, right? They tried to get this extra juice with Naquadriah generators, but it turned out the hyperdive became too unstable to work.

So what now when we have a Jumper that's capable of going much faster then the supposed F-302 hyperdrive, yet being in the same size-class? Does it mean that a jumper has a powersource better then Naquadriah?

[Mr. Oragahn]

The trouble with naqahdria is that it was getting more and more unstable as you were trying to get energy from it.

It could be that the puddle jumper just benefits from a power source that is simply stable, not necessarily more, or even as powerful as a naqahdria core.

Besides, we never had the proof that puddle jumpers had reactors.
I suspected that they just had good capacitors, which were charged somehow, maybe when inside the city or an outpost, or a ship.

Considering how a DHD and stargate can exchange energy, we know that it's largely feasible.

[l33telboi]

Besides, we never had the proof that puddle jumpers had reactors. I suspected that they just had good capacitors, which were charged somehow, maybe when inside the city or an outpost, or a ship.

It doesn't really make a difference if it's a reactor or a battery of some sort. You just have to switch around the term refuel to recharge and it's basically the same thing. Yeah, i know there mechanically is a big difference. But this is stuff, we as people watching the show, don't really have to mind. And neither does it affect the performance of the Jumper in any real way.

And there have been tech powered by mini-crystals and by drawing power directly from sub-space, so what exactly powers these things in the end is unknown.

So, this stuff might not be exactly as powerful as a Naquadriah-generator, but it would have to be pretty darn close, since Naquadah doesn't cut it.

And like i said, there's the speed of these things to consider. 2000 lightyear jumps in short order? That's way better then even the first 303s IIRC. And power requirements go up with increased speed.

[Mr. Oragahn]

Besides, we never had the proof that puddle jumpers had reactors. I suspected that they just had good capacitors, which were charged somehow, maybe when inside the city or an outpost, or a ship.

It doesn't really make a difference if it's a reactor or a battery of some sort. You just have to switch around the term refuel to recharge and it's basically the same thing. Yeah, i know there mechanically is a big difference. But this is stuff, we as people watching the show, don't really have to mind. And neither does it affect the performance of the Jumper in any real way.

And there have been tech powered by mini-crystals and by drawing power directly from sub-space, so what exactly powers these things in the end is unknown.

So, this stuff might not be exactly as powerful as a Naquadriah-generator, but it would have to be pretty darn close, since Naquadah doesn't cut it.

And like i said, there's the speed of these things to consider. 2000 lightyear jumps in short order? That's way better then even the first 303s IIRC. And power requirements go up with increased speed.

But 303s still rely on naqahdah, and the hyperspace bubble they have to generate is well bigger than a PJ's one, and the mass of the 303 will be more affected by space oddities than the mass of a PJ.

That said, I think the PJ's power souce is between below naqahdria, but obviously above naqahdah, or on par with naqahdria.

[Mr. Oragahn]

One detail. The large asteroid about to impact Atlantis... once it gos blasted by two drones, we saw nothing noticable moving towards the tower.

It would mean the drones exploded on the other side of the asteroid. Considering that we were facing the asteroid, we couldn't see what would happen. To us, it would like the mass is expanding, nothing more. But if we had seen it from the profile, we'd have seen the asteroid exploding towards the puddle jumper.
The asteroid had to be destroyed in such a way that all the debris would be propelled away from the tower.

This may inrease the figure a little bit, considering that the asteroid ended being almost completely reduced to dust, safe a few small debris.

A drone's real power, and the way it outputs energy is most complex. There's no mere DET drilling or whatever.

We've seen drones explode on contact (e.g. The Defiant One, The Tower), entirely NDF matter away, or go through matter with minimal heat production (The Tower with McKay firing a drone through the roof, with proof of matter reorganisation, but utter lack of heat, Adrift by punching into asteroids without breaking them, and with no trace of heated rock), push objects (the Wraith Lord), break through ice, etc.
Most versatile.

That said, since this is a quantification thread, here are a few other notes.

If Lifeline, McKay says that the Asurans have dozens of ZPM. I don't know where he got that number from, and considering the conditions, he may have simply pulling up a number just to reaasure Sheppard that this wouldn't make much of a difference.

At the end of Lifeline, Atlantis' (very) long range sensors pick up a "massive fleet of ships" leaving Asura, and being headed for a Wraith planet.
What are these ships?
Are they like the cloaked one? Something else? Was the cloaked ship a new ship they built just after First Strike?
If that fleet was new, then it's quite impressive.

We'll also note the lack of any disturbance in the planet's atmosphere, something like mere hours, or maybe one day after Fisrt Strike - it didn't take long for the Asurans to retaliate from the moment they were attacked. They did that actually fast, considering that it looked like they barely finished debriefing the attack on Asura.
Considering that the satgate was going to drain the shield within less than a day, and that they departed before the ZPM would be dry, it happened within a tight timeframe.

[l33telboi]

It would mean the drones exploded on the other side of the asteroid. Considering that we were facing the asteroid, we couldn't see what would happen. To us, it would like the mass is expanding, nothing more. But if we had seen it from the profile, we'd have seen the asteroid exploding towards the puddle jumper.
The asteroid had to be destroyed in such a way that all the debris would be propelled away from the tower.

This may inrease the figure a little bit, considering that the asteroid ended being almost completely reduced to dust, safe a few small debris.

Indeed. I had thought of this earlier, but since there was no way to actually prove that this happened, no matter how logical it was to try to detonate the drones so that the expanding debris goes away from Atlantis, i didn't mention it.

However, i must say that the logically, it seems like a sound assumption.

As for the power. On Wong's destruction page, it's mentioned that rock blasting with surface mounted shaped-charges need to be roughly four times stronger then a centrally buried explosive.

[Mr. Oragahn]

Interesting, that bit with surface detonators.

Another thing that you might like. There are many asteroids, notably the first one we see getting blasted, which actually only leave debris.

I understood the first asteroid being destroyed. It takes the whole screen, and it was hard to know where the drones came from, especially on the crappy video.

But I've seen it with a higher quality, and that's what we can notice:

Though we don't know how many drones hit it, we know that each asteroid we saw being hit, was hit with one drone only.
The explosion quickly grows inside, and cracks the asteroid. But what it cracks is what matters here.
It does not blow huge chunks apart, like if you slammed it. No. There's that massive fireball that already cracks through the outer shell, while the inside is completely turned into hot matter. Debris are left, but they mainly come from the outer shell.
At worst, they're not more than 3 meters wide, but most of them barely come as 1 meter wide.

2 seconds after it exploded, after the fireball almost entirely faded out, we can clearly see through where the asteroid previously was, and only small and distant debris scattered left and right, forming an expanding sphere.
Going frame by frame, we can even see a small drone fly through where that asteroid was, which would help to gauge its size.

We know that if the asteroid was largely cracked, and dusted, we couldn't see that the fireball that easily. The debris wouldn't be so neatly silhouetted against the fireball.

Rememeber the video Mike posted in the "other" subforum, about the simulation of an asteroid destruction with a nuclear charge planted in its middle.
What it showed was that the core was completely vapourized, while the outer layer of the asteroid was cracked and debris propelled away at various speeds.

Well, that's precisely what we get here. Considering the thickness of the largest debris, which were ripped from the asteroid while they comprised its circumference, we see that anything under the surface has been vapourized.

How much? Well, based on your estimation of a PJ being 3 meters high, I gauged that a drone had a glow width of 0.2 meters.

This gave me, for the asteroid, by taking the latest frame as the drone of reference goes through the debris field, this gives me the following dimensions:





The part on the bottom of the picture is an extract from the frame with the drone reaching the bottom of the screen as it closes on the camera's position.

6.7 x 4.6 meters.

Many debris were eaten by the flames and destroyed. The debris were, at best, 1 m wide, for those which survived, but most of them were 0.5 m wide.
If you remove a "crust" of .5 meter on each side, and try to obtain an averaged diameter, you get 4.65 meters for a sphere of vapourized rock.

V = 4/3 x pi x r³
V = 421.16 m³

Density being roughly 2330 kg/m³, we get a total mass of 981,302.8 kg of rock.
Once again, using the figures from Wong's calculator (the specific heat for granite is 800 J/kg ... energy required to melt silicon (heat it from 150K to melting point and then add latent heat of fusion) is roughly 2.65 MJ/kg), we obtain the following base figures:

Minimum melting energy: 785 MJ
Minimum vapourization energy: 2,600,452.42 MJ

The asteroid measurements provided a conservative stance, as the asteroid was at a good distance of the camera, largely farther than when the drone which was reaching the edge of the picture. In the end, the asteroid could be one to two meters wider and longer.

Considering that it was one of the first asteroids to be destroyed, if not the first, and considering that we were seeing more drones coming in, the one, or those, which destroyed it, would have been part of the whole salvo's front wave.
Going back to the firing sequence, we see that half a dozen drones were fired, as far as the front wave is concerned, while more were fired in the following seconds.
To be conservative, we could say that it was hit by three drones max at the same time. We saw that it was hard for McKay, the first to open fire, to control more than three of them later on, when Sheppard ordered him to destroy more asteroids. McKay fired four of them, but he lost control of the fourth one.

So free to you to divide that energy figure by one, two or three drones.




We also see that though all debris are roughly of the same size, the level of destruction they're subject to varies slighly. Either this means we're looking at difference charge levels for the drones, or just various effects due to the composition of the asteroids.

When two PJs veer off, towards the end, one of them fires a drone into an ovoid larger asteroid, which, with perspective in play, would be two PJ wide for its lenght, and 1.5 PJ wide for its width, and it explodes in a big ball of flames. It expands within 18 frames to the double of its size. After a full second, many debris and jet dusts have already reached beyond one lenght of that asteroid.

With its pods out, a PJ is 6.5 meters wide.
That's an average diameter of 11.375 m.

EDIT: visuals aside, for the whole operation to be relevant, regarding the city's safety, each asteroid would have to be considerably destroyed, up to the point where a significant amount of its mass is pushed out of the city's path, and where another significant amount is simply rendered harmless, either by being turned into extremely small debris (centimeter wide) or vapourized.

On screen, many explosions were seeing propeling many debris in all directions, and thus providing even more kinetic energy to those which would be moving towards the city.

The reality is that now, all the front of the city which was facing the asteroid field must have been turned into swiss cheese, unless the asteroids were largely vapourized.
Which, for nearly all of them, is not exactly what happened.