(Spoilers) Future technological developments.

kzt wrote:No, the damage a nuke does at more then a km or two is pretty minimal. It’s an inverse square function, so the energy delivered to a target 10s of km away during that very short X-ray event is just not that much.

And the people designing this are not dumb. It’s an obvious target.

Galactic Sapper wrote:Sorry, no. Even in canon we have examples of fairly large robust targets being damaged by nukes at significant range. Missile pods, for instance.

The individual bits don't have to be vaporized to be rendered nonfunctional, and sensors designed to be as sensitive as possible are even more vulnerable to energy spikes than usual equipment.

Theemile wrote: It seems contradictory - because in ship-ship combat, they are called "contact" nukes for a reason - you need to be practically in contact to do any damage. Yet, we hear that Pods are susceptible to proximity nuke explosions - I would assume they are not armored in any way, and it's the EMP or radiation that fry them.

Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

There is a lot of plot hidden inside things like Haven going "how about we set off a bunch of nukes in front of those RMN missiles and they all lose lock?" Funny how they set off 24,000 nukes per salvo at BOM and they didn't interfere with target acquisition.

It's also odd how nobody has exploited this weakness by simply expelling a gigaton nuke every 50 ms when missiles are within say 80,000 km. They should make it impossible for them to aim the xray lasers, right?

No, it's plot. Missiles mostly run on grav sensors, and they won't even notice a nuke.

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

Nukes in space don't generate an EMP at all - that is a phenomenon related to the release of fast charged particles interacting with the planetary magnetic field, which then induces currents in conductors.

A nuke in space has to depend on the radiation released and the high energy plasma that is the physical remains of the weapon.

Galactic Sapper wrote:

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

Nukes in space don't generate an EMP at all - that is a phenomenon related to the release of fast charged particles interacting with the planetary magnetic field, which then induces currents in conductors.

A nuke in space has to depend on the radiation released and the high energy plasma that is the physical remains of the weapon.

We keep pushing on the missiles. Far more likely there will be a greater concentration on anti-missile defenses. When ships can toss off tens of thousands of missiles (a fleet doing it), it is not that difficult to target a lot of ships.

Finding ways to defeat the missiles is far more important. The Manties are very good but as opposition forces start shooting more at them, finding ways to stop the missiles will probably be far more important.

tlb wrote:

kzt wrote:No, the damage a nuke does at more then a km or two is pretty minimal. It’s an inverse square function, so the energy delivered to a target 10s of km away during that very short X-ray event is just not that much.

And the people designing this are not dumb. It’s an obvious target.

Galactic Sapper wrote:Sorry, no. Even in canon we have examples of fairly large robust targets being damaged by nukes at significant range. Missile pods, for instance.

The individual bits don't have to be vaporized to be rendered nonfunctional, and sensors designed to be as sensitive as possible are even more vulnerable to energy spikes than usual equipment.

Theemile wrote: It seems contradictory - because in ship-ship combat, they are called "contact" nukes for a reason - you need to be practically in contact to do any damage. Yet, we hear that Pods are susceptible to proximity nuke explosions - I would assume they are not armored in any way, and it's the EMP or radiation that fry them.

Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energydensity can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

Realistic weapons effects.

Assume that a nuke would inflict damage by the X-rays and UV as well as kinetic energy of plasma vaporizing target material.

Most likely armor is Carbon because of thermal properties.

Heat of vaporization of Carbon is 715 Kilojoules per mole.

(Advertisement. Got Mole problems? Call Advogodro's Mole service at 602-1023)

Carbon has an atomic number of 12 meaning one mole ofCarbon masses 12 grams.

Heat of Vaporization of Carbon is then 60 kiloJoules per gram.

Assume that the skin of a ship or missile is 1 centimeter of Carbon. Density of Carbon is 2.5 grams per cc. Heat of vaporization 150 kiloJoule per square centimeter or 1.5eex9 Joule per square meter.

A One Gigaton nuke (massing several hundred tons) would yield 4.2eex18 Joules. Lethal range would be about 15 kilometers.

(KZT knows this but has been polite enough to not embarress everyone by showing the math. Weber can be granted literary license).

There is a potential impulse loading effect which might increase effective range by a factor of ten. Modern ballistic missiles which are little more than inflated, highly pressurized balloons that are very near yield stress can withstand may be Ten KiloJoules per square centimeter. Russia and China know this which is why they are developing hypersonic vehicles. Motivating an adversary to convert a very large ICBM like the SS-18 or Peacekeeper which costs $100 million each and nominally carries ten warheads into a booster for a single, hypersonic glide vehicle which costs may be $200 million to deliver only one warhead of comparable yield is a big win for strategic defense.

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

TFLYTSNBN wrote:Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energy density can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

Are you saying the equation I found on the web is wrong? Or are you repeating that the decrease is a function of R squared, but not simply the inverse of R squared (which is normally what is meant by an R squared law)?

tlb wrote:

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

TFLYTSNBN wrote:Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energy density can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

Are you saying the equation I found on the web is wrong? Or are you repeating that the decrease is a function of R squared, but not simply the inverse of R squared (which is normally what is meant by an R squared law)?

The diameter of the wavefront decreases lineraly with distance or "R".

The area of the wavefront is proportional to the diameter of the wavefront squared. (Remember the formulae for area of a circle?). No matter how precise your optics might be, while optics can bebeesigned to concentrate energy on a spot much smaller than the optics, the phenomenon of diffraction will inevitable result in the beam diverging at long distance. (The phenomenon of diffraction can result in some interesting side lobes outside of the notional spot diameter which enables some interesting electronic warfare techniques against radar)

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

TFLYTSNBN wrote:Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energy density can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

tlb wrote:Are you saying the equation I found on the web is wrong? Or are you repeating that the decrease is a function of R squared, but not simply the inverse of R squared (which is normally what is meant by an R squared law)?

TFLYTSNBN wrote:The diameter of the wavefront decreases lineraly with distance or "R".

The area of the wavefront is proportional to the diameter of the wavefront squared. (Remember the formulae for area of a circle?). No matter how precise your optics might be, while optics can bebeesigned to concentrate energy on a spot much smaller than the optics, the phenomenon of diffraction will inevitable result in the beam diverging at long distance. (The phenomenon of diffraction can result in some interesting side lobes outside of the notional spot diameter which enables some interesting electronic warfare techniques against radar)

That is not what the formula says, so you are saying it is wrong? Yes, I do remember the formula for the area of a circle and I agree that the density is related in that way to the beam width. And you are mistaken in saying that the laser beam width decreases with distance.

tlb wrote:

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

TFLYTSNBN wrote:Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energy density can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

tlb wrote:Are you saying the equation I found on the web is wrong? Or are you repeating that the decrease is a function of R squared, but not simply the inverse of R squared (which is normally what is meant by an R squared law)?

TFLYTSNBN wrote:The diameter of the wavefront decreases lineraly with distance or "R".

The area of the wavefront is proportional to the diameter of the wavefront squared. (Remember the formulae for area of a circle?). No matter how precise your optics might be, while optics can bebeesigned to concentrate energy on a spot much smaller than the optics, the phenomenon of diffraction will inevitable result in the beam diverging at long distance. (The phenomenon of diffraction can result in some interesting side lobes outside of the notional spot diameter which enables some interesting electronic warfare techniques against radar)

That is not what the formula says, so you are saying it is wrong? Yes, I do remember the formula for the area of a circle and I agree that the density is related in that way to the beam width. And you are mistaken in saying that the laser beam width decreases with distance.

The formula applies to radiation from a point source. A laser is not a point source. For a laser, the "point source" is a very long way behind the laser itself. Trying to apply the formula using the distance from the laser is going to give you a very wrong answer.