Brian Young's Stargate Atlantis Analysis

[Lucky]

BabTech is going offline.

To bad it was the best Babylon 5 site I know of.

[Mike DiCenso]

Although agenda driven, which thus affected many of the conclusions, Young's site was very good for reference.
-Mike

[Tyralak]

Brian has given me permission to archive it at ASVS. It will be included in an archive section on the front page that we're working on.

[Mr. Oragahn]

Brian has given me permission to archive it at ASVS. It will be included in an archive section on the front page that we're working on.

That's good news actually.

[Mr. Oragahn]

It seems I have skimmed some of this points when rereading one of his former posts, and missed a couple of erroneous claims from the last page. This took me quite some time to write this, again.
It's been practically one week since I begun typing this. I wish we would spend more time thinking instead of making asinine claims that require ten times more text to debunk. :(
I'll have to check out if anything new came in afterward btw.

*The other technology that destroyed a solar system is not a ZPM. In terms of modern tools, a ZPM is comparable to an air tank, with a large, but finite energy potential. Like air pressure in a tank. The other is akin to a leaf blower, with virtually limitless energy to draw upon. Like limitless air in my yard. It did not work. The fact that it exploded and destroyed a star system has nothing WHATSOEVER to do with the usable power output of a standard ZPM. Yes, McKay said at 50% power, etc, etc. But the problem was the potential ENERGY of our ENTIRE UNIVERSE was too much to control, and a star system was destroyed. A ZPM has not only a smaller power output, but an exponentially lower energy potential. Possibly finite vs infinite. This example does not support your position.

It did work, as it was able to produce power. However, McKay pushed it farther than the last time it was used. Before hand, the cannon kept firing left and right, still managed to destroy a Wraith capital ship, but kept spitting energy all around. Oddly enough, the wave of destruction that ruined the city precisely stopped at the footprint of the Lantean building. Was there a shield? Unknown. Fact is, we never ever see how far the ruins extended. That thing probably fired its shots far away, but some of the blasts still were too close to the city it was built in.
Notice that the bolts, despite being slow, had no problem to graze the puddlejumper in orbit, so there's much likely a homing capacity involved there (a bit like the Tollan ion cannon), if we have to take visuals literally.

McKay pushed the reactor at 50%, and power built up too fast. We don't know how powerful the bolts were. The cannon started to fire automatically, but there's no proof that it was set to fire at its maximum potential. Actually, if it were, those PJ sized hull debris that were destroyed would have blown up nuclear style, because that's what would happen when firing at such debris with the equivalent of dozens of terawatts of firepower. They didn't.
So yes, the device worked as long as you needed power, but the exotic particles kept piling up, and that's the part that failed. Still, the point is that this power source would render ZPMs pointless, and at 100%, it was stated to have the output of 24 ZPMs.

Of course you'd ask how much 24 ZPMs are supposed to output?
Is the star system busting event a reliable way to gauge that? Well I initially thought yes, as it seemed straightforward enough, but time passed and it became quite possible that the planet or system busting events could be totally due to the exotic particles: a form of energy that clearly does exist, otherwise we wouldn't get those massive explosions, but which is near impossible to exploit; what is exploited is a minuscule amount of that energy.

Now, another question: When a ZPM explodes with such an overload of energy, what really destroys the planet to bits? Obviously if an overload occurs, it's that energy is added into a given system that has a finite limit of energy it can contain (the ZPM obviously has its own buffer of some sort). However, nothing tells us that this limit equals the total energy needed to destroy a planet. There could be a wide variety of reasons why a bursting ZPM loses its ability to contain the exotic particles to its own finite artificial subspace universe.
We also know that the overload threshold can be dialed up and down, since the overload of the Asuran city's ZPMs didn't provoke a powerful nova.

Interestingly, it's totally possible that the blast's energy is exponentially related to the fixed threshold. This would in a way mirror what took place in "Trinity", since the Lanteans maintained a low output which still killed them and resulted in a wide scale destruction of the local surface of the planet at least and anything in orbit (via the turret fire), but it didn't blow up: the exotic particles did not pile up beyond the point of no return.
Now this is just a theory and can easily be contradicted by the implication from the same episode that if enough energy could be bled off, the "raging fire" could have been tamed and the reaction killed.

However, anyone mad enough to weaponize this system and precisely wanting to drain the core of its exotic particles and energy would have a star system busting gun at hand's reach. A sort of super Death Star on steroids.
It's quite confirmed, in fact, by the episode "McKay and Mrs. Miller", wherein an inter-dimensional bridge is used to dump the exotic particles in another universe: the Tau'ri made core was producing tame amounts of power, yet the particles piling up on the other side literally threatened to destroy the alt-universe. Of course it was an estimate.
The core ran at 5% for more than 20 hours.
Later on, they needed to put the core back online. Something odd was going on:

ZELENKA
Shutting the experiment down only made things worse for us, not better. The matter bridge is still active, but we are not drawing any power, creating pressure like a dam. If we didn't turn it on again, it could have resulted in a catastrophic overload.

Same problem as with Trinity as far as the particles are concerned: they draw power from those particles or something related to them, but obviously the particles are still there and they are considerably dangerous. The bridge was still active, probably because it contained particles which couldn't be released just like that, and the Tau'ri had no way to dump them.

Worst, we see that as long as the particles exist, the problem grows in importance.
So there are several ways to look at the dam analogy:

1. As long as particles remain in a given volume, more keep coming. Therefore energy increases merely because there's more matter.
2. As long as particles remain in a given volume, the power output increases but the quantity of particles remains the same. This one is more curious, but since laws of physics are stated to be raped.
3. Both.

Most obviously, the vast amount of energy which is obtained is related to the exotic particles, and it's likely that they tear apart the universe they belong to, from which they extract phenomenal amounts of energy. Draining a given amount of energy calms them down, if we can say that.

Late EDIT: Actually, there's a much more simple explanation. The core created the bridge. The bridge itself was both a source/leak AND a channel. The core's function was to extract energy from said bridge, and eventually close the bridge when done.
So as long as the bridge would remain present, whatever "rift" through which the exotic particles came through would remain open as well and continue to spill such particles, since it seems the bridge and the rift are one and the same.
With this in mind, you can compare what I previously said (including stuff below) to my latest suggestion here, which clarifies the situation.
It even offers a suggestion as to how a ZPM works, that is a bit different from the variable capacitor theory.
In this new idea, the ZPM opens a local bridge as well, inside itself. The bridge will not contain the energy, but the exotic particles from the finite and contained subspace universe. The difference with the model I describe later in this post is that the overload threshold is not defined by an amount of energy you can store and leak into realspace, but by the quantity of exotic particles you can work from.
The "bridge" (the term isn't very accurate btw) is best imagined as a tank with a variable volume, generally set to high, which defines the quantity of particles you work with, and the ZPM has a way to tap that sac/tank/bridge to obtain energy, an extractor.
The existence of a buffer of some sort for the "produced" energy is still a likely concept, but in this model, and could obviously overload, but would have nothing to do with the overloads of exotic particles which would produce the big explosions.
That said, the capacitor itself would have an output rate which could be dialed up or down, but in all logic, whatever system that would extract energy from the exotic particles at a given moment, would be designed to work hand in hand with the buffer's settings and the required power from the user to flow into real space, otherwise the buffer would immediately begin to overload. That said, it's also obvious that the buffer would provide a certain margin of tolerance, just to be sure to cope with any surge of power coming from the extractor. Just in case.



More:

ROD
Look, this *is* just a temporary solution. The Zelenka in my space time estimates that there is at least a week and a half before the tear expands as far as the city ... *my* city.

JEANIE
What'll happen when it does?

ROD
Well, imagine what would happen if you just threw the laws of physics out the window.

JEANIE
Entropy, and chaos.

ROD
Mmm. Worst-case scenario, the entropy expands as far as the subspace layers underneath our space time.

McKAY
It could travel almost instantaneously. I mean, your entire universe could just ... (he clicks his finger) ... flash out of existence.

Rod knew that the particles on the other side kept piling up as well. Obviously when a rift is open, it keeps getting larger unless you move the particles away, like through the matter bridge, or literally collapse the containment, which is how the problem was solved.
Perhaps draining energy from the rift would have calmed the whole reaction, but there was just no way for the alt-guys to drain energy from the rift located in space: it wasn't taking place inside a core.

This could exactly be what happens inside a ZPM: if you don't drain the energy of the exotic particles and yet keep increasing their quantity, the thing explodes. Therefore, it all comes down to how many particles you're bringing closer to realspace, but still inside that ZPM. The more you bring, the more power, but the greater the destruction.
Now, since there's never been any warning about how to deposit depleted ZPMs, it's most likely that the contained exotic particles are totally harmless as long as they're inside that artificial sub-universe (perhaps the status of the containment is equivalent to a collapse).

The size of the singularity in the alt-verse, which initially started out in space above the planet, would be far bigger than what was seen to be initially contained in the Arcturus core.
"In space" would at least be understood as a low orbit, which is easily several hundred kilometers at least. A singularity with a radius of 200 km is obviously immense.
This singularity was actually growing even faster than alt-Zelenka estimated.

Apparently, only a singularity that big would begin to threaten the very fabric of the entire universe's spacetime.
It still is incredibly small, all things considered.


Another thing we need to cover before closing this topic, is the battery analogy: since the first year the ZPMs were introduced to the Gateverse, some fans wondered if the faster you drained a ZPM, the less total energy you'll be able to extract. In other words, it would not be necessarily linear at all.
But this totally flies in the face of the trick used by Janus to keep the shield up, and which is best explained by the existence of a produced waste of some sort that may pile up as well: rotating 3 ZPMs enabled the city's systems to last longer than by using 3 ZPMs at a third of their output each, but simultaneously.
Therefore, the total energy you can obtain from a ZPM running at max power is greater: the lower the power output, the lesser the efficiency.

*The energy released by a bomb. Ah yes. A ZPM must be greater, because it was built by the Ancients. Circular logic. Show me an instance where one of those was used against Atlantis' shield. Just one. Recall the missiles that took out targets on the Replicators' planet. No shields prevented it, and they have many ZPMs.

The missiles in question were six gatebusters and four decoys fired from a MIRV, the Horizon.
I initially thought the Asurans were smart, as they immediately replied with the satgate weapon, but everything looks like they had it lying somewhere in a warehouse: it was just too swift and smart from them.
The Asurans were hardly original in their thinking. They were good at what they knew to do, but never really diverged from those spirit and knowledge to exploit their tech competently. For the most part, they just were nanites acting like their parents.

Any other competent faction would have quickly used such mighty abilities to quickly turn their own planet into an impenetrable fortress that would have made even a wanked version of Warhammer 40,000's Terra a killing joke.
Anything from hyperspace mines, cloaked mines, space defense platforms, drone silos, yellow beams, red beams, blue pulse cannons, shields and a wide variety of nanite-ships.

So they're certainly not the example you want to pick up in order to gauge the proper application of good and basic principles of advanced space defense.
Only a few of them seemed to do some research, but clearly they didn't have the minds of war streategists crazy or desperate enough to put up a real solid defense after having seen their world hit multiple times by weapons capable of leveling continents and knowing what their enemies were capable of.

However, what you'd want to do is consider that the millions of them, once gathered into a giant blob and forced to generate insane amounts of power to resist both their own increased density that made them plow through the crust by sheer weight, and the pressure of the planet's core, still managed to blow up the planet once they finally gave up (like for the classical Replicators, the more there are, the greater the power per unit).
These bunches of nanites make the ZPM look stupidly weak by comparison.

All it means is that the Ori were unable to produce the power to dial another galaxy and keep it open indefinitely. It has nothing to do with the amount of power that can be transmitted through the gate. It simply means that the Ori cannot produce the power of a black hole by ordinary means.
Shockwaves are not transmitted through space. Period. Please give it up.

Yes, instead they *just* build giant space gates which even seven Ha'taks can't destroy after a prolongated bombardment, which still require many gatebusters to theoretically take down (see "Ark of Truth"), and of which the building segments can go through any shield and destroy any ship by sluggishly ramming them.

Does it need saying that the power required to open and maintain a gate open gets bigger the longer the distance btw?
For example, the whole human made McKay-Carter intergalactic bridge that consisted of several stargates (~34) was precisely assembled to allow a connection without a ZPM. There would be no gain if it weren't for power cuts.

The Ori also build shields which can crush planets. A shield which is good enough to tank a gatebuster detonation (multi-gigaton) and the firepower from several Ha'tak and Prometheus' missiles, and feed upon all that. Which would still be a pimprick in light of the energy required to bring the volume of a planet down to a schwrazchild radius the size of a marble. But I guess they cheated that and only needed some energy to kickstart that cheat. The energy just happened to be in the gigatons.
The Ori just have no problem to open a supergate. The problem was to throw enough energy through a standard stargate, which comes with a cap, otherwise the wormhole jumps, and this effect can be obtained on the receiving stargate as well.

So if that means the Ori still need black holes to get their free gigatons from some place, fine. I'm not gonna cry. Because it means anything below those gigatons per second, the Ori know how to get them. It's just making the terawatt power figure for the ZPM all the more asinine.
Besides, as I said, their ships can obviously tank a plasma stream more powerful than the 26 megaton focused blast which failed to make a wormhole jump (that's a point I already brought before, but it's always good to repeat it). The final energy was obtained from both an omnidirectional blast from the vaporization of a hiveship and its own kinetic energy.
See former posts for that.

Batman,

Good point. There is no specific evidence to support the presumption that a gate sucks the energy out of things passing through it.

Dammit. It's said in the episode: the gate takes power from the beam.
It doesn't mean anything would behave that way, it's possible that it's a function in the stargate that needs to be activated, but it doesn't matter.
It happens. Period.
He needs to read the script.

Yeah, I've been busy too, Chris. I'm kinda ready to move on to new topics anyway.
That page was never meant to be public, just to raise discussion. It did that.
I've learned a few tidbits about the technology I never would have without discussing it with fellow fans. And that is really what this is all about anyway.
For instance, I had forgotten all about the gate exploding and the CME.
And I didn't realize there was such a gap between the power output of a ZPM and its potential energy. But I guess it makes sense. The shields did hold back the ocean for 10,000 years!

And his calcs are... ?

I had never watched Stargate until this year, when my cousin forced it into my lap and made me watch it. And dang if I don't love it. In fact, after all is said and done, and I've had time to let it all settle in my mind, I think I like it more than B5. B5 has some great storytelling, but overall it is a bit over-dramatic for its own good. I think it might have been the best ever, had JMS been able to tell it like he intended. But with actors leaving the show, it suffered by having to recreate the arc on the fly. Also, the cancel-continue-cancel thing that sped up the arc in season 4 was a major blow.
Stargate had no planned story arc, but one developed anyway. And Michael Shanks leaving the show was a major blow. The characters are just so likable and the writing so intelligent, it is hard to beat.

I've always liked the movie, but after seeing the series, it was just a minor episode.
Everyone likes Ark of Truth, but my favorite is Continuum. And the one where they defeat the Replicators with the stargates. And the ones with Thor. And 200. And the one where Vala hijacks the Prometheus. And when they go back to the 60's. And, well, a lot of them. But I grabbed the clip from "The Sentinel" where they send missiles through the gate and "The Warrior" where Sam outshoots the Jaffa with the staff, and put them on my AppleTV, ipod, and iTunes so I can watch with a click.
Anyway, I've enjoyed the conversation, but I think it's winding down. I'm gonna move on and see if anyone reads my last Babtech page now.

I can't tell if it's just plain BS or if he has a very bad and selective memory, cause it's really hard to imagine how for someone who claims to have watched the whole of Stargate during this year, he still could miss so many obvious facts like the yields of nukes and so many crucial episodes which were quite spectacular and hard to forget. Yet he did that.

Well heck. Now I've got something else to add. Watched "Enemy at the Gate." Atlantis is finally powered by 3 ZPMs, and other than damage, should be fully operational.
They travel back to Earth just in time to intercept the Wraith hive ship. The doctor is operating the chair. During the battle, Atlantis begins to lose orbit, because the Wraith weapons are pushing it downward. The doctor complains that he doesn't have enough power to fire drones, maintain shields, and maintain orbit simultaneously. They decide to continue firing. The Atlantis team aboard the hive ship detonate a nuke, which destroys the hive ship. Atlantis crashes into the ocean.
Now, the doctor is not the best operator of the chair, but he made it clear the problem was power.

So, in "First Strike," a single ZPM can't put Atlantis into orbit alone. In "Enemy at the Gate," a full complement of 3 ZPMs can't keep Atlantis in orbit, maintain shields, and fire simultaneously.

As I've said before, compared to other SciFi technology, this isn't particularly impressive. Compared to modern technology, it is very highly advanced. But it wouldn't last long against ships from Star Wars, Star Trek, or the First Ones in B5. Even the aliens from Independence Day flew larger ships and could maintain antigravity, shields, and fire simultaneously.
The Wraith ship was a special one, but still only had one ZPM, and in the visuals, Atlantis was not gaining much momentum from the barrage.

Anyway, that should about do it. The Defense rests.

As I said before, many times, Stargate is choke full of large ships which have no problem to move around, keep shields up, land or take off from Earth-like planets.
Once again, the Wraith, with their incredibly inferior power sources (compared to ZPMs), have no problem to lift off their 11 km long hiveships.
But I'm not surprised by that new chapter of ridicule claims. It makes it hard to believe he has watched anything about Stargate.
His memory is terrible.

Echoing what Batman said. I just watched the relevant scenes again to be sure. There is no mention of the ZPMs being drained.
Sheppard made it clear that damage was the issue, and not the ZPMs, for getting back to the Pegasus galaxy.
So, again, a fully powered Atlantis with 3 ZPMs can't maintain orbit, fire drones, and maintain shields simultaneously.

Really, this guy never stops?

Let's just rewind this whole thing and see what happened.
Atlantis arrives in orbit of Earth with three ZPMs, necessary to power whatever experimental wormhole drive the Lanteans hadn't really finished. It would have probably been finished if they had nothing better to do than fight the Wraith and then leave the city: the gain wasn't particularly massive, strategically speaking. Sure, the trip would last seconds instead of days, or perhaps a couple weeks, but it would have been of no practical use during the war: if the Lanteans wanted to wage a war from another galaxy and spam the Wraith who were stuck in Pegasus, they could have done it. The reason why they didn't do what they logistically could do is just asking for speculation.
Clearly that wormhole drive was more like a pet project than something major.

So, we were talking about Atlantis arriving at Earth, right before the superhive is about to engage some targets on Earth. Atlantis fires drones while it tanks shots from the superhive.
In a relatively very quick amount of time, the shields are drained down to 70%.
Now this is new.
Shields were never drained at all before. The only time their efficiency diminished is when they had to cope, in an unusual way, with a multi-gigaton explosion that needed to be extinguished in less than a minute, and the problem wasn't the ZPM being drained, but the shield systems frying up. But there was no talk about shields failing by percents.

ZELENKA
I'll see if I can divert more power to the shield – see if we can block more of the radiation.

(He types and the shield whines as it strengthens around the destroyed Gate. John lowers his hand and walks closer to the balcony, looking down at the yellow ball of energy inside the field.)

SHEPPARD
OK, now what?

ZELENKA (wheeling himself back to his original console)
Well, the shield continues to diffuse the energy of the blast. Every second that it is contained within the shield, the explosion gets weaker.

SHEPPARD
How long does it take?

(An alarm beeps. Radek's eyes widen.)

ZELENKA
Oh no.

SHEPPARD (walking over to him)
What?

ZELENKA
The shield needs at least another minute to contain the full brunt of the blast, but we're frying out the emitters. I don't know how much longer I can hold this.

SHEPPARD
Shut down the city. Transfer all the power.

ZELENKA
Yes, I'm trying.

There's never a single mention of shield strength. Emitters are frying up because there wasn't enough energy being provided to the emitters to control and channel the energy of the explosion out to Lalaland. Power, once again, was the key.
The most amusing part of that is how this completely throws off Brian's calcs. Despite this stargate having naqahdah in it (just like the Milky Way ones), we're to believe that the explosion would just be as violent as 4 TW by two minutes tops.
480 TJ for our stargate explosion here.
It's also hilarious that a shield shrunk to an odd size, albeit small, couldn't handle the much more dangerous levels of energy from "Echoes" that the same shield, but powered by 3 ZPMs and stretched thin to cover a large portion of a planet, could.

In "Enemy at the Gate", the case is different in that it's the shield which was taking damage.
Obviously, the shield projectors were much more taxed than the ZPMs: this is what's new, because the limiting factor thus far had always been the power source.

So let's continue. We're at a time in the episode when the superhive fires at Atlantis: the city holds on but still gets slowly kicked down into the atmosphere.

ZELENKA
The force of enemy weapons fire has pushed us into a lower orbit! We're skimming the atmosphere!

BANKS
It's draining the shield, sir!

WOOLSEY
Doctor Beckett, can you adjust our course?

(In the Chair Room, Carson lifts his head and opens his eyes.)

BECKETT
I don't have enough power. I can keep firing or pull us up. Which is it gonna be?

And a couples seconds later...

BANKS
Shields are about to collapse. We can't take another hit.

Yes, the power grid configuration was quite odd here. So that's why I find it unwise from Brian to establish a limit on some key systems based on some setup which was totally new and cobbled up by the Tau'ri in the last minute, so to speak.
Again, since when shields get drained in Atlantis?
One way to rationalize that, perhaps, is if they ran on a stock of energy and little extra input in terms of sustainable power, most of it going into holding the city up and firing at the hiveship.
Of course that's also problematic, but I guess Young wouldn't be bothered to cope with this factor in any appropriate way, beginning with the "objective" one, eventually up to the "honest" grade.
See, if the shields are running on some fixed stock, then it leaves almost the entirety of three ZPMs to power the weapons and the stardrive, and that only to maintain orbit, not even to take off.
We already know that one ZPM is actually plenty enough to do so, contrary to his claim.
So it would only leave the weapons... and the wormhole drive (WHD).
First, the weapons.
Have we ever seen drones charged up to contain terajoules or petajoules of energy? Nope. Sure, they can make big explosions against hulls, but so did the drones fired by gateships. But perhaps he'd want to argue that gateships can produce more power than a ZPM?
Simply put, we would have like multi-gigajoule magitech weapons requiring the output of nearly three ZPMs (the stardrive would barely tax it considering that it only had to maintain orbit).
Which is stupid.

The other factor is the WHD. That thing, and only that thing required three ZPMs. It's stated in the episode.
Yes, that's three ZPMs, no less.
Three ZPMs to energize up an entire city and throw it through a stable and large wormhole, with neither a sending nor a receiving stargate, and that as fast as possible.
Why is it that Gateworld fans have objected to this plot issue and pointed out that the problem would be the WHD since the episode aired, but BY is incapable of doing so despite having quite a certain habit of "versus thinking"?
The most obvious suggestion would be that the power was largely routed towards the WHD and for some reason, most of it couldn't be freed up when Atlantis arrived and immediately attacked the hiveship.
We don't even know if its emergency use didn't damage a part of the city's power grid.
Sheppard says that the city took damage, so there's a door open there.

Sidenote: don't even ask how Atlantis found herself in the right spot... did they have the capacity to scan realspace while in the wormhole? Dumb luck is impossible considering the odds.

Meanwhile the heroes plant a nuke inside the superhive (yeah, that finale's plot just totally sucks ass) and the whole thing blows up, not too far from Atlantis btw.
Then we get to the second part of Atlantis' problems.

CARTER
Atlantis, this is Stargate Command. Well done!

(In Atlantis' Control Room, the city is shaking violently.)

WOOLSEY
Thanks for the kind words, Colonel, but I wouldn't pop the champagne just yet. We've lost orbit and Doctor Beckett is unable to compensate. We're going in.

CARTER
Do you have enough shield to survive re-entry?

(Richard looks across to Radek who looks at his screens, then turns and throws up his hands in a despairing "I have absolutely *no* idea" gesture.)

WOOLSEY
We're about to find out.

(The city plummets downwards, its shield burning. More consoles explode in the Control Room. Richard stares helplessly. At S.G.C., everyone waits anxiously.)

CARTER
Atlantis, this is Stargate Command, do you read?

(The city continues to fall. At S.G.C., Walter comes into the room.)

HARRIMAN
Colonel, we've been monitoring radio chatter. Several commercial vessels in the north Pacific have reported a giant fireball streaking across the sky.

Now remember "Lifeline"?
Yep, the city had taken a beating as well, gone through an asteroid field and got hits by small particles the PJs couldn't destroy, and sometimes even bigger rocks since we saw the aftermath of a tower's upper floors having literally been gutted.
Zelenka and co had to cannibalize crystals from other systems to repair the power conduits after the Asuran attack in "First Strike", but clearly the damage was not limited to the base of the main central spire.
In "Lifeline", a single ZPM proved enough to slow down and protect Atlantis from a fast (re)entry.
Of course it doesn't take a genius to know that this would require far more power than to merely lift a city through the airs at a slower pace, without the shields suffering.
And therefore, it's quite obvious it would take very little of a single ZPM to merely maintain orbit.

Plus notice that the problem in "Enemy at the Gates" was not to slow the city down, but if the shields were capable of coping with the heat. Remember that some minutes earlier, they were literally nearly depleted.
As we obviously guess, they actually managed to shield the city and land it safely.

As a final note, I guess he never bothered to look at the very beginning of "Rising" either.
This episode shows Atlantis departing from Earth million years ago. The Lanteans are in charge, and their city, Atlantis, is so well managed that at best with three ZPMs, they easily lift it up, and they can even allow themselves a super boost.
A boost that was so powerful that even many dozens of kilometers away from the outpost where the city was anchored, the camera is hit hard by a huge wall of snow kicked off as a result of the sudden exhaust.

That happens while the city is nowhere close to the ground, and with the potentially added bonus that the city was located down in a valley while the camera could have been located on one of those plateaus, meaning a portion of the blast would be stuck down inside the valley first.
That wall of snow moves so fast that a mere double click during play is enough for it to cover a full Atlantis width. A second double-click is about four times that. And the compressed shockwave is long gone beyond the sides of the screen before it ever hits the camera, giving you a nice idea of the great distance.
I am not sure what provoked that, but somehow, I doubt a mere kinetic push powered by three 4 TW sources of power could do that.

On a positive note, it reminds me of how awesome the first season was. A pity they just ruined the show after "Intruder". :(