Starfleet Jedi

Some people like to claim Gigatons, Terratons, Perratons,... as standard firepower for what ever Sci-Fi series(40K and Star Wars come to mind, but I'm sure there are others).

The problem is that these setting often only have theater shields that barely cover the targets to protect things like cities, military bases, ect. What good are shields that the attacker can just fire next to, and kill everything under the shield? What good are theater shields if the planet becomes an airless ball of rock?

Well, if planet is already lifeless ball of rock, with only small outpost on surface, then theater shield is usually enough, presuming that shield is large enough and that installation can withstand earthquakes. But if it is inhabited planet, theater shields do not make sense with anything more than kilotons (maybe low megatons, if you stretch it) in play.

Picard wrote:Well, if planet is already lifeless ball of rock, with only small outpost on surface, then theater shield is usually enough, presuming that shield is large enough and that installation can withstand earthquakes. But if it is inhabited planet, theater shields do not make sense with anything more than kilotons (maybe low megatons, if you stretch it) in play.

Every theater shield I know of stops at the surface of the ground. Just firing near the edge should end up with the blast going under the shield.

But it will only be a fraction of yield, and if edge of shield is far enough from base, it might not do any real damage at all. Plus, what prevents them from having 2 shield layers? (Never heard about it, thought).

In some cases theater shields make sense. For example, in TNG's "Gambit, Parts 1 & 2", the idea was to have shields that would provide some protection for archeological sites against pirates and thieves, not against full up capital ships and armadas. So shields prevent valuable artifacts or other materials from being stolenI, and given some protection against low-level weapons fire. I would imagine similar reasoning for Star Wars, as well as for other science fiction franchises. But for full blown military bases and core planetary systems, no it does not make any sense.
-Mike

The Hoth shield has a wide radius for the size of the base that it protected, iirc. 25 km from what I gathered on internet.

In Stargate, there aren't many instances at all.
There's the Ori shield, but this one is quite an extreme, powered by enemy fire and finally crushing a whole planet.
There's one Carter talked about when saying that if there had been one above the temple at Dakara, even their most powerful nuke would most likely fail to penetrate.

The other cases are related to the Lanteans:
1. Atlantis' shield which could be stretched to cover a large portion of a planet and save it from a mass extinction level event.
2. The planetary shield that tapped some super volcano and protected a Lantean base from Wraith bombardment.
3. A sort of "shield", which actually was the dome resulting from the stringent temporal tide ; there was a sanctuary built inside a valley surrounded by mountains, and you could enter only through a door. Trying to come into the valley from the air would get you literally pulverized because of the concentration of sudden time dilation on a very small area.

Picard wrote:But it will only be a fraction of yield, and if edge of shield is far enough from base, it might not do any real damage at all. Plus, what prevents them from having 2 shield layers? (Never heard about it, thought).

A faction of just a gigaton is still a lot of energy. The energy released during a magnitude 9 Earthquake is about a 2 exo-joule event or 480 megatons. In other words a magnitude 9 earthquake is like the release of less then half a gigaton.

Earthquake bombs and modern torpedos only explode near the target, and then use less compressible materials to transmit the energy.

A direct hit from a torpedo will cause a lot of damage to a ship, but a torpedo exploding under the ship can break the ship in half.

An Earthquake bomb destroys things by basically causing a localized earthquake. They bury themselves underground and then explode. They were created to deal with fortified bunkers that could easily shrug off direct attacks from above and the sides.
http://en.wikipedia.org/wiki/Earthquake_bomb

My point is that a setting that only uses theater shields can only have weapons of a certain magnitude as standard before the shielding becomes pointless.

Mr. Oragahn wrote: The Hoth shield has a wide radius for the size of the base that it protected, iirc. 25 km from what I gathered on internet.

Well if you can figure out the speed of an AT-AT at Hoth then you can get an idea of how large the radius of the shield was.

Given Eco base was falling apart from the AT-AT just walking towards it I highly doubt the shield could protect the base from 200 gigaton weapons that can be set to explode underground.

Mr. Oragahn wrote: There's the Ori shield, but this one is quite an extreme, powered by enemy fire and finally crushing a whole planet.

Was that really a shield? I don't recall anything like it before or after.

Mr. Oragahn wrote: There's one Carter talked about when saying that if there had been one above the temple at Dakara, even their most powerful nuke would most likely fail to penetrate.

Could you be more specific? How would it stop someone from from bringing down the temple with an Earthquake?

Mr. Oragahn wrote: 1. Atlantis' shield which could be stretched to cover a large portion of a planet and save it from a mass extinction level event.

But standard operating parameters had the shield barely covering the city. The reason Atlantis was safe was because the attackers wanted it in one peace.

Mr. Oragahn wrote: 2. The planetary shield that tapped some super volcano and protected a Lantean base from Wraith bombardment.

If the shield covers a planet it is not relevant to this topic. That would make it the only shield of it's kind in Star Gate would it not?

Mr. Oragahn wrote: 3. A sort of "shield", which actually was the dome resulting from the stringent temporal tide ; there was a sanctuary built inside a valley surrounded by mountains, and you could enter only through a door. Trying to come into the valley from the air would get you literally pulverized because of the concentration of sudden time dilation on a very small area.

That's not really a shield is it?

Lucky wrote:

Mr. Oragahn wrote: The Hoth shield has a wide radius for the size of the base that it protected, iirc. 25 km from what I gathered on internet.

Well if you can figure out the speed of an AT-AT at Hoth then you can get an idea of how large the radius of the shield was.

The AT-ATs, like 22 meters high, weren't even visible at first. So they were not close at all. Plus they're not very fast either. They're about 22 meters long, and they take a shit ton of time to cover their own length.

Given Eco base was falling apart from the AT-AT just walking towards it I highly doubt the shield could protect the base from 200 gigaton weapons that can be set to explode underground.

That seems to be a fair statement.

Mr. Oragahn wrote: There's the Ori shield, but this one is quite an extreme, powered by enemy fire and finally crushing a whole planet.

Was that really a shield? I don't recall anything like it before or after.

Oh yes it was. It started as a small theater shield around the stargate. Then it progressively grew by phases. Firing at it made it grow, and when it was already covering an area of a very large nation or a small continent, the gatebuster inflated it to absurd proportions. Firing at it with spaceships' weaponry finally closed the gap on the other side. From there, the shield "schwarzilded" the planet.

Mr. Oragahn wrote: There's one Carter talked about when saying that if there had been one above the temple at Dakara, even their most powerful nuke would most likely fail to penetrate.

Could you be more specific? How would it stop someone from from bringing down the temple with an Earthquake?

She says that IF a shield was put over the temple, nothing could pass.

Now that I've looked at the script a second time, it is not sure

Reckoning, Part II wrote: CARTER: How much time do we have before Baal's fleet reaches Dakara?

O'NEILL: Why?

CARTER: Baal didn't say exactly where the device was, did he?

O'NEILL: No. He said it was hidden.

CARTER: Well, chances are it's in the ruins, but we can't be sure. I mean, short of blowing up the entire planet, we can't be a hundred percent positive we've destroyed it -- and if it's protected by a shield, even our biggest naqahdah-enhanced nuke might not do it.

At that point, they had achieved yields of 1.2 GT.
Alteran structures have been known to be quite sturdy. Even a tincan like Destiny, more like a science pet project, survived for hundreds of thousands of years while being active and going through trouble (it was already damaged when the humans came on board).
We don't know the dimensions of that shield, so you may discount it as a theater shield, although imho it would make no sense to have a shape hugging shield around a temple, even if the Alteran structure encased inside was obviously much more advanced than the mere disguise the temple offered. In fact, it was called a temple by the Goa'uld because they had not spotted the device inside the rock formation, which was shielded from scans. It was very well cloaked.

Mr. Oragahn wrote: 1. Atlantis' shield which could be stretched to cover a large portion of a planet and save it from a mass extinction level event.

But standard operating parameters had the shield barely covering the city. The reason Atlantis was safe was because the attackers wanted it in one peace.

But it shows it can be stretched to obviously cover at the very least a whole continent, considering that the latest deadly burst took place some thousands of years ago and if the shield had not been wide enough, too much of the planet would have been damaged for it to recover in time.
The shield's default size, probably the one at which it is the most optimal, is about 3.5~4 km wide.
It can also be shrunk.

Mr. Oragahn wrote: 2. The planetary shield that tapped some super volcano and protected a Lantean base from Wraith bombardment.

If the shield covers a planet it is not relevant to this topic. That would make it the only shield of it's kind in Star Gate would it not?

It wasn't said that it covered the entire planet. It could have, just like it could have covered just a small area.

Mr. Oragahn wrote: 3. A sort of "shield", which actually was the dome resulting from the stringent temporal tide ; there was a sanctuary built inside a valley surrounded by mountains, and you could enter only through a door. Trying to come into the valley from the air would get you literally pulverized because of the concentration of sudden time dilation on a very small area.

That's not really a shield is it?

Technically, as long as you try to fly something solid through it, it will be destroyed. Beams or bursts of particles may likely not suffer at all.

Lucky wrote:

Picard wrote:But it will only be a fraction of yield, and if edge of shield is far enough from base, it might not do any real damage at all. Plus, what prevents them from having 2 shield layers? (Never heard about it, thought).

A faction of just a gigaton is still a lot of energy. The energy released during a magnitude 9 Earthquake is about a 2 exo-joule event or 480 megatons. In other words a magnitude 9 earthquake is like the release of less then half a gigaton.

Earthquake bombs and modern torpedos only explode near the target, and then use less compressible materials to transmit the energy.

A direct hit from a torpedo will cause a lot of damage to a ship, but a torpedo exploding under the ship can break the ship in half.

An Earthquake bomb destroys things by basically causing a localized earthquake. They bury themselves underground and then explode. They were created to deal with fortified bunkers that could easily shrug off direct attacks from above and the sides.
http://en.wikipedia.org/wiki/Earthquake_bomb

My point is that a setting that only uses theater shields can only have weapons of a certain magnitude as standard before the shielding becomes pointless.

True. But this is sci-fi, and in Star Trek, in particular, earthquake caused by multi-gigaton device probably wouldn't be much of an issue due to insane construction materials (tritanium is about 21.5 times harder than diamond), as well as inertial dampening and SIF.

EDIT: Maybe dampening and SIF might be applied to ground under and around building, therefore negating negative effects of earthquake in that particular area?

Mr. Oragahn wrote: The AT-ATs, like 22 meters high, weren't even visible at first. So they were not close at all. Plus they're not very fast either. They're about 22 meters long, and they take a shit ton of time to cover their own length.

http://www.youtube.com/watch?v=C6uQ1ROQm0k
7:09 is the first time we see the AT-AT, but we can't see where they land because of a strange fog, but it can't take long to deploy the AT-AT, and as you say AT-AT are extremely slow.

Wouldn't trying to figure out how long it took the rebels to deploy tell us how long it took the AT-AT to come into view? I mean in all honesty the entire battle of Hoth from AT-AT landing can't have been more then a few hours at most.

The AT-AT move at what, 5 kilometers an hour?

Mr. Oragahn wrote: That seems to be a fair statement.

People often forget about the secondary effects of weapons. It's rather surprising they don't pop up more often in VS debates.

Mr. Oragahn wrote: Oh yes it was. It started as a small theater shield around the stargate. Then it progressively grew by phases. Firing at it made it grow, and when it was already covering an area of a very large nation or a small continent, the gatebuster inflated it to absurd proportions. Firing at it with spaceships' weaponry finally closed the gap on the other side. From there, the shield "schwarzilded" the planet.

I meant I thought that was an example of psychic/Ascended powers

Mr. Oragahn wrote: She says that IF a shield was put over the temple, nothing could pass.

Now that I've looked at the script a second time, it is not sure

Reckoning, Part II wrote: CARTER: How much time do we have before Baal's fleet reaches Dakara?

O'NEILL: Why?

CARTER: Baal didn't say exactly where the device was, did he?

O'NEILL: No. He said it was hidden.

CARTER: Well, chances are it's in the ruins, but we can't be sure. I mean, short of blowing up the entire planet, we can't be a hundred percent positive we've destroyed it -- and if it's protected by a shield, even our biggest naqahdah-enhanced nuke might not do it.

At that point, they had achieved yields of 1.2 GT.
Alteran structures have been known to be quite sturdy. Even a tincan like Destiny, more like a science pet project, survived for hundreds of thousands of years while being active and going through trouble (it was already damaged when the humans came on board).
We don't know the dimensions of that shield, so you may discount it as a theater shield, although imho it would make no sense to have a shape hugging shield around a temple, even if the Alteran structure encased inside was obviously much more advanced than the mere disguise the temple offered. In fact, it was called a temple by the Goa'uld because they had not spotted the device inside the rock formation, which was shielded from scans. It was very well cloaked.

That sounds more like they can't be sure the target would be destroyed because they don't know where it is.

Mr. Oragahn wrote: But it shows it can be stretched to obviously cover at the very least a whole continent, considering that the latest deadly burst took place some thousands of years ago and if the shield had not been wide enough, too much of the planet would have been damaged for it to recover in time.
The shield's default size, probably the one at which it is the most optimal, is about 3.5~4 km wide.
It can also be shrunk.

One thing to keep in mind is Atlantis was not designed for combat, it's a glorified RV, and that kind means normal operating parameter are not going to be designed to defend against attack.

Didn't expanding the shield use a bleep load of more energy then would normally be consumed by the shield?

Do you know at what point an impact or explosion will start directly effecting things on the opposite side of a planet? It seems like I read something about volcanoes being formed that way or something, but I can't remember.

Mr. Oragahn wrote: 2. The planetary shield that tapped some super volcano and protected a Lantean base from Wraith bombardment.

Lucky wrote: If the shield covers a planet it is not relevant to this topic. That would make it the only shield of it's kind in Star Gate would it not?

Mr. Oragahn wrote: It wasn't said that it covered the entire planet. It could have, just like it could have covered just a small area.

How do we know that the shield could cover the entire planet?

If the shield wasn't covering the planet, what is stopping an attacker from triggering an eruption?

Mr. Oragahn wrote: 3. A sort of "shield", which actually was the dome resulting from the stringent temporal tide ; there was a sanctuary built inside a valley surrounded by mountains, and you could enter only through a door. Trying to come into the valley from the air would get you literally pulverized because of the concentration of sudden time dilation on a very small area.

Lucky wrote: That's not really a shield is it?

Mr. Oragahn wrote: Technically, as long as you try to fly something solid through it, it will be destroyed. Beams or bursts of particles may likely not suffer at all.

Why was that field created?

If it is so effective why is it used only once?

Picard wrote: True. But this is sci-fi, and in Star Trek, in particular, earthquake caused by multi-gigaton device probably wouldn't be much of an issue due to insane construction materials (tritanium is about 21.5 times harder than diamond), as well as inertial dampening and SIF.

EDIT: Maybe dampening and SIF might be applied to ground under and around building, therefore negating negative effects of earthquake in that particular area?

But this is often not done for what are likely very practical reasons like the super materials being rare, and mundane building materials being good enough. I don't believe you should assume the use of super-tech or super-materials unless there is actually a reason to think they are being used.

I doubt that any target worth attacking by ships - even if these ships are runabouts - would be built by bricks and/or concrete. Besides, based on size comparation, Runabout torpedoes are most likely in single-digit to double-digit megatons, which is about most one can expect larger theater shields to be useful against.

Lucky wrote:

Mr. Oragahn wrote: The AT-ATs, like 22 meters high, weren't even visible at first. So they were not close at all. Plus they're not very fast either. They're about 22 meters long, and they take a shit ton of time to cover their own length.

http://www.youtube.com/watch?v=C6uQ1ROQm0k
7:09 is the first time we see the AT-AT, but we can't see where they land because of a strange fog, but it can't take long to deploy the AT-AT, and as you say AT-AT are extremely slow.

Wouldn't trying to figure out how long it took the rebels to deploy tell us how long it took the AT-AT to come into view? I mean in all honesty the entire battle of Hoth from AT-AT landing can't have been more then a few hours at most.

The AT-AT move at what, 5 kilometers an hour?

The better thing to do would be to gauge distance based on known height and visual size. There are formulas for that but I don't know them. Still, for structures that are about 22 meters highs to appear like mere pimpricks and require super duper googles to get spotted, they had to be very far.
Then, wookieepedia's page claims a silly max speed, like 60 km/h. Yeah, whatever. That's over 16 m/s. Bollocks. Over 3/4s of the AT-AT's length. They'd need to be very agile to cover such a distance that fast, but they're not. Besides, this is ice and snow, so they'd rather have to be careful.
In the movie, they only moved at a few meters per second tops. At that speed, it would take a full minute to cover their own length.
Well, if you want to do some maths, now...

That sounds more like they can't be sure the target would be destroyed because they don't know where it is.

They work in the Tok'ra and the Jaffa. Dakara is well known to them, and the ruins is actually a fairly small area around the temple. There's no real need to aim when firing a 1.2 GT device at the ground.

Mr. Oragahn wrote: But it shows it can be stretched to obviously cover at the very least a whole continent, considering that the latest deadly burst took place some thousands of years ago and if the shield had not been wide enough, too much of the planet would have been damaged for it to recover in time.
The shield's default size, probably the one at which it is the most optimal, is about 3.5~4 km wide.
It can also be shrunk.

One thing to keep in mind is Atlantis was not designed for combat, it's a glorified RV, and that kind means normal operating parameter are not going to be designed to defend against attack.

The shield is extremely efficient and strong. The city was not designed as a starship, but they strapped a shield system on it that's simply the best out there.

Didn't expanding the shield use a bleep load of more energy then would normally be consumed by the shield?

Only if considerably stressed.

Mr. Oragahn wrote: 2. The planetary shield that tapped some super volcano and protected a Lantean base from Wraith bombardment.

If the shield covers a planet it is not relevant to this topic. That would make it the only shield of it's kind in Star Gate would it not?

Well since covering a whole planet would be an upper end, it's safer and more reasonnable to consider it a theater shield.
In theory, I think only Halla, once turned into a Replanet, would be capable of complete planetary shielding.

Mr. Oragahn wrote: It wasn't said that it covered the entire planet. It could have, just like it could have covered just a small area.

How do we know that the shield could cover the entire planet?

No.

If the shield wasn't covering the planet, what is stopping an attacker from triggering an eruption?

Obviously, if it were a theater shield, it would be built in order to prevent such problems. Most likely it will offer a very good area of protection so even a high seismic event, like a distant low gigaton explosion, wouldn't be hurting the base.

Mr. Oragahn wrote: 3. A sort of "shield", which actually was the dome resulting from the stringent temporal tide ; there was a sanctuary built inside a valley surrounded by mountains, and you could enter only through a door. Trying to come into the valley from the air would get you literally pulverized because of the concentration of sudden time dilation on a very small area.

That's not really a shield is it?

Depends on what you want in the form of a shield. It will pulverize any missile and solid projectile. I'm not sure how it would react to projectiles thrown at fractions of c, and there's no evidence that it would block particle beams.
It's not a complete shield, but if you look at modern defense systems, very few are polyvalent. The vast majority are only geared at stopping one kind of weapon.
Even some types of armour do well against kinetics, but are quite shitty against heat.

Mr. Oragahn wrote: Technically, as long as you try to fly something solid through it, it will be destroyed. Beams or bursts of particles may likely not suffer at all.

Why was that field created?

It's hinted at being an after effect of the time dilation field of this santuary, although we've seen other time dilated areas where there's no such effect at all.

If it is so effective why is it used only once?

It's not as good as those polyvalent generic SF shields the Lanteans use, that's why.
But what it means is that if they were to weaponize it, they could have time dilation fields be shaped to literally turn planets to bits.

One very valid use for theather shields would be to stop anything smaller than said capital ships and huge weapons from being a threat. If it would be akin to a Star Trek forcefield you could effectively stop infantry and most small craft without them being able to do anything about it.

A second point here, which is often forgotten about, is that the attackers may not actually want to blow up/irradiate/otherwise destroy the surrounding land. Most modern day attacks are not done with nukes either ;)

I know that the argument is that the situation is not comparable because in Sci-Fi stories there are usually multiple planets so losing part/all of one is no big deal, but I don't buy it. 99% of military actions do not have the goal of random destruction, but getting rid of opposition or getting access to resources. Bombing worlds into the stone age and further won't make the natives any friendlier (see Babylon 5 and the Narn for one example), nor will it get you anything worthwhile to own.

In short, in my opponion theather shields probably work because a sane military (esp. one that belongs to a civilized bunch) generally won't blow up a chunk of planet to get below them.