Getting WMDs out of the equation at TL8+ (Endwar etc.)

[Icelander]

Originally Posted by Molokh

What I'm trying to figure about this setup: if LASERs are so übercool, why aren't they used to deny other types of vehicles too?

Because a laser that can shoot down an ICBM may not be capable of shooting down other vehicles.

ICBMs are constructed with exactly the tolerances required for reentry and no more. They can be shot down with a well placed thrown rock (theoretically, at least, but you'd need to throw the rock well before they arrived).

[panton41]

Originally Posted by Icelander

Because a laser that can shoot down an ICBM may not be capable of shooting down other vehicles.

ICBMs are constructed with exactly the tolerances required for reentry and no more. They can be shot down with a well placed thrown rock (theoretically, at least, but you'd need to throw the rock well before they arrived).

Not to mention ballistic missiles fly nice, straight paths which means the laser (likely mounted in a 747) can hit it for the length of time it takes to destroy it, whereas most other vehicles can maneuver fast enough to not take enough damage to destroy it. It's part of why with anti-missile missiles it's both very easy and very hard to intercept them. It's easy because the target is unlikely to suddenly change course, but you're also trying to hit a bullet with a bullet.

[Tinman]

Although, from what I've heard the latest generation of anti-missle missles can do that consistantly. The navy is rplacing the point defence systems on their ships. It used to be the phalanx gatling guns, but now they are putting on anti-missle missle systems.

Check out video's of the THAAD missile tests. It's sweet.

[Tinman]

In answer to the OP's nuke question, I belive you can have an epic scale war with out nukes. Just because a country is loosing a war does not equal the total destruction of the country or even it's leadership.

Take WWI frx. The gemans lost the war but not to the point that they & their leaders would be 'no worse off' by launching nukes.

The book 'Red Storm Rising' by Clancy also gives a plausable backround for a massive war without an apocalypse ending.

[Johnny1A.2]

Originally Posted by ciaran_skye

Not to mention ballistic missiles fly nice, straight paths which means the laser (likely mounted in a 747) can hit it for the length of time it takes to destroy it, whereas most other vehicles can maneuver fast enough to not take enough damage to destroy it. It's part of why with anti-missile missiles it's both very easy and very hard to intercept them. It's easy because the target is unlikely to suddenly change course, but you're also trying to hit a bullet with a bullet.

Plus many long-range missiles operate high enough that the air is thin or absent, making laser attacks simpler.

Still, it's far from a trivial technical issue to take out ICBMs or their ilk with lasers.

[Icelander]

Originally Posted by Johnny1A.2

Still, it's far from a trivial technical issue to take out ICBMs or their ilk with lasers.

The point was how much easier it was to take out ICBMs with lasers than it was to use the lasers to shoot down other aircraft. No one said that actually shooting down ICBMs was easy, just that shooting down aircraft would be much harder.

[SuedodeuS]

Originally Posted by Tinman

In answer to the OP's nuke question, I belive you can have an epic scale war with out nukes. Just because a country is loosing a war does not equal the total destruction of the country or even it's leadership.

Take WWI frx. The gemans lost the war but not to the point that they & their leaders would be 'no worse off' by launching nukes.

The book 'Red Storm Rising' by Clancy also gives a plausable backround for a massive war without an apocalypse ending.

You need sane leaders to prevent a nuclear launch. A single crazy despot would be enough to basically wipe out the world's population, provided his country had sufficient nukes. I'm fairly confident that if, say, Hitler had access to the USSR's Cold War nuclear stockpile, he would have launched every last one of them.

Note also that the Germans were humiliated and economically ruined in the aftermath of WWI. This was a huge reason behind the Nazi party's rise to power, its expansionist doctrine, and thus WWII. Judging by the humilitation and malcontent following WWI, I suspect there may have been a member or two of the German leadership who may have felt the end of the world was preferable.

[David Johnston2]

Originally Posted by SuedodeuS

You need sane leaders to prevent a nuclear launch. A single crazy despot would be enough to basically wipe out the world's population, provided his country had sufficient nukes. I'm fairly confident that if, say, Hitler had access to the USSR's Cold War nuclear stockpile, he would have launched every last one of them.
.

He might give the order, but I don't know if it would be followed. His orders about Paris, for example, weren't. At the same time though, the mere existence of nuclear arsenals on both sides large enough to devastate most of an opponent's major population centers discourages a go-for-broke confrontation. Really effective ground to air or space based interception systems changes that calculus. It doesn't have to be perfect. It just has to be perceived as adequate.

[lwcamp]

Originally Posted by Molokh

What I'm trying to figure about this setup: if LASERs are so übercool, why aren't they used to deny other types of vehicles too?

Realistically, they probably are. A laser that can shoot down a ballistic missile can also shoot down thin skinned aircraft and, as has been shown in tests, artillery and mortar projectiles (in fact, you can shoot down aircraft, drones, mortar rounds and artillery rounds at several km with a significantly less powerful laser than is needed to take out an ICBM at its most vulnerable point at long range - its boost phase as it is lofting its payload out of the atmosphere). Effective lasers will change the way war is fought.

Luke

[lwcamp]

Originally Posted by Icelander

The point was how much easier it was to take out ICBMs with lasers than it was to use the lasers to shoot down other aircraft. No one said that actually shooting down ICBMs was easy, just that shooting down aircraft would be much harder.

The available evidence does not appear to support this. The ABL is in the megawatt class - exact figures are hard to come by but probably about 2 MW to 3 MW. This is what you need to shoot down a ballistic missile in its boost phase. Boeing has tested a laser 2 kW laser that can shoot down UAVs in flight (I'm a bit skeptical that Boeing isn't cherry picking the evidence and staging demos under ideal conditions - 2 kW seems a bit too low powered for operational ranges). 100 kW is expected to be a useful weapon against light skinned aircraft. Lasers on the order of 100 kW have been demonstrated to shoot down mortar projectiles, artillery projectiles, and tactical rockets.

Unfortunately, available videos of the M-THEL shooting down mortar rounds are shown in slow motion, so it is hard to tell how long this takes - less than 10 seconds, but how much less is not clear. By my estimate, a 100 kW beam directed into a 3 cm diameter spot would drill through aluminum at about 1 cm/s (effective at an anti-aircraft role), while a 10 cm spot would be down to about 60 microns per second (much less effective - a maneuvering target might well avoid significant damage if the laser has poor target tracking capabilities). With an approximately 30 cm diameter beam pointer primary, you could get 100 kW within a 3 cm spot at about 2.5 km from a 115 kW beam at 3.8 micron wavelength under ideal conditions - my estimates of the M-THEL's operating parameters. Actual weaponized lasers will probably be using 1 micron or shorter wavelengths, giving you about 4 times the range or more. All of this would seem to indicate that any multi-megawatt laser capable of shooting down boost-phase ICBMs would make short work of most aircraft at ranges of tens of km. Lasers powerful enough to destroy re-entry warheads at strategically relevant distances would have even greater tactical effects against aircraft.

In practice, the use of lasers within the troposphere (Earth's lowest layer of atmosphere, where all the weather is) will aperiodically be hampered by clouds or haze, although there will be times when they are at nearly full effectiveness and in some regions you will have good shooting nearly all the time while other regions may frequently have sufficiently poor visibility to make surface lasers only relevant at short ranges. Lasers will likely be regularly employed from aircraft in the stratosphere where the laser beam can travel unimpeded.

Luke