Random science questions

[mr friendly guy]

Ok on another board I am having a debate with comic book fans, one of whom is apparently mechanical engineer (he confused the nuclear forces with the electromagnetic force, and when I corrected him on it he said he was distracted because he was also playing WoW - take that as you will).

Any way in debating I realised they are a few things I don't know. My knowledge of physics is high school level (and bits and pieces of it is now "blurry") and I only pick a few things up from boards like this and any science books I read for interest.

So I thought I would ask the board to help. I am not asking you to do the calculations for me, merely point me out in the right direction and say where I made a mistake etc. Rather than put this in the fantasy board, I think the general science question are more appropriate to be asked here in SLAM and as a result I will avoid making references to the comic and concentrate on the meat of the science.

1. Survivability in the sun

Say for an example a human size object / superbeing was placed in the Sun (assuming it survives quite nicely and then leaves).

What factors do we need to consider when gauging "resilence"
Presumably a) the sun's gravity, b) temperature and c) energy from the sun

For the first part a simple google search or text book will give one information required on the sun's gravitational pull. First question is how would we use this fact to calculate resistance to stress.

For part b), temperature isn't that impressive. From the Juggernaut vs Sith Lords thread Darth Wong mentioned some industrial torches are twice the temperature of the surface of the sun.

Now for part c)

How would I be able to calculate upper and lower limits to the amount of energy its exposed to.

My line of thought for an absolute upper limit.

Given the sun produces 1.26 E 34 joules in one year. From there work out how much energy is produced a second. From there we could comfortably say half the energy would not hit said object (since the sun is radiating energy in all directions, so energy radiating to the other side would not hit said object). Now this is being very generous.

Is there any other way I can refine the calculation. Perhaps by using the size of the object.

2. "Yield" of a physical blow

Say for example a physical blow hits an object and the shockwaves generated alone destroyed nearby mountains. The shockwave supposedly spread throughout the entire planet, although I don't think this would make a difference in calculation since we are only using the mountains to derive yield.

My question is this blow would be the equivalent of a nuke of what yield. I have looked at Darth Wong's Nuclear yield calculator, but that just gives me the size of the fireball.

If I assume the mountain peaks are say 2-2.5 km tall (the average) and the mountain range has say 20 peaks would this help with the calculation.

3. Directed energy and yield

Ok, basically someone linked to a site saying that on average lightning bolts have 1 kilotons of energy. Contrast to say the more destructive MOAB which has yield of only 11 tons of TNT (ok the resource is wiki, so it might not be correct).

The argument is that if the energy is directed and controlled like in a lightning bolt, you can have high levels of energy but when it does damage, it causes little collateral damage. In other words you can't look at the collateral damage in this case to gauge yield.

Two questions
a) what other forms of directed energy will also have the property of having high energy but little collateral damage

b) using the example of lightning, how much damage would expect for a more powerful bolt. Say for example if we had a lighting bolt (somehow) of one MT instead of one KT, what would we expect the collateral damage to be.

Thanks to anyone who can help me out.

[Admiral Valdemar]

1. Survivability in the sun

Say for an example a human size object / superbeing was placed in the Sun (assuming it survives quite nicely and then leaves).

What factors do we need to consider when gauging "resilence"
Presumably a) the sun's gravity, b) temperature and c) energy from the sun

For the first part a simple google search or text book will give one information required on the sun's gravitational pull. First question is how would we use this fact to calculate resistance to stress.

For part b), temperature isn't that impressive. From the Juggernaut vs Sith Lords thread Darth Wong mentioned some industrial torches are twice the temperature of the surface of the sun.

I assume you mean the core, which is quite a bit hotter, but it's density is what gets you. You don't worry about gravity when you're in a null zone, given the centre has no gravity well to speak of. Pressure-wise, you're going to die very quickly and the fusion going on around you will consume what's left. Just because the equivalent mass of humans being formed into a sun sized ball has more thermal output, doesn't mean the heat there won't vape you.

Now for part c)

How would I be able to calculate upper and lower limits to the amount of energy its exposed to.

My line of thought for an absolute upper limit.

Given the sun produces 1.26 E 34 joules in one year. From there work out how much energy is produced a second. From there we could comfortably say half the energy would not hit said object (since the sun is radiating energy in all directions, so energy radiating to the other side would not hit said object). Now this is being very generous.

Is there any other way I can refine the calculation. Perhaps by using the size of the object.

If you can gauge the surface area exposed to the sun, then you can calculate, depending on where the object is within the celestial body, how much energy it is being exposed to.

2. "Yield" of a physical blow

Say for example a physical blow hits an object and the shockwaves generated alone destroyed nearby mountains. The shockwave supposedly spread throughout the entire planet, although I don't think this would make a difference in calculation since we are only using the mountains to derive yield.

My question is this blow would be the equivalent of a nuke of what yield. I have looked at Darth Wong's Nuclear yield calculator, but that just gives me the size of the fireball.

If I assume the mountain peaks are say 2-2.5 km tall (the average) and the mountain range has say 20 peaks would this help with the calculation.

To shake mountains apart like that would take gigatonnes to teratonnes. It depends on how far the mountains are from the impact and so on, since even an asteroid falling to Earth will make a fireball and a mushroom cloud.

3. Directed energy and yield

Ok, basically someone linked to a site saying that on average lightning bolts have 1 kilotons of energy. Contrast to say the more destructive MOAB which has yield of only 11 tons of TNT (ok the resource is wiki, so it might not be correct).

The argument is that if the energy is directed and controlled like in a lightning bolt, you can have high levels of energy but when it does damage, it causes little collateral damage. In other words you can't look at the collateral damage in this case to gauge yield.

Given most of the energy is never used up to cause thermal damage and is simply earthed, you won't see such destruction anyway. Lightning, for all its power, is not a good weapon since it inherently seeks the path of least resistance and so even a standard saloon car will direct bolts of immense energies around it via the metal chassis. You can usually get some pretty funky effects when not all the energy passes by safely, such as carbonised trees, soil fulgurites and people flying through the air minus some clothing and brain cells.

Two questions
a) what other forms of directed energy will also have the property of having high energy but little collateral damage

Any other type of particle beam. Lightning is just electrons for the most part, but this static charge is incredibly large. A directed energy weapon using a high-density beam of electrons, positrons, alpha particles etc. would focus a lot of its kinetic energy into the molecular make-up of a target, rather than simply ablate the surface like a visible light or any other modern laser. This would, however, end in the mass likely exploding anyway, but with a deeper wound than a laser would inflict. Yield is important here, since a MeV weapon won't cause as much damage to a brick house as a GeV rated beam weapon.

b) using the example of lightning, how much damage would expect for a more powerful bolt. Say for example if we had a lighting bolt (somehow) of one MT instead of one KT, what would we expect the collateral damage to be.

Thanks to anyone who can help me out.

If it converted energy efficiently to heat upon impact, you'd have a big boom. Unsurprisingly, it'd be a good chunk of a megatonne. That this doesn't happen is a good thing.

[Ariphaos]

Say for an example a human size object / superbeing was placed in the Sun (assuming it survives quite nicely and then leaves).

What factors do we need to consider when gauging "resilence"
Presumably a) the sun's gravity, b) temperature and c) energy from the sun

Not exactly. For a) the Sun has no 'solid' surface, so this only applies when you are stationary at some level. Most measure the Sun's gravity in g's at the outer edge of the photosphere, which is extremely rarified (about 1% of the particle density of Earth's atmosphere). This ends up getting written as pressure applied to your feet - ie, if you weight 100 kg on Earth, 981 Newtons is your 'weight' - the pressure applied to your feat, a bit less to your knees, and so on. Atmospheric pressure exerts more force on your body as a whole - about ten thousand newtons per square meter.

No numbers you're talking about regarding the Sun's gravity are going to compare favorably with the pressure you'll find at the Solar interior. You'll find a wide variety of estimates, but it's often on the order of a few 10^16 newtons per square meter.

b) is pointless. I could hit you with something at a trillion degrees and you might not even notice it. Temperature in this context is meaningless - what you're talking about is heat. The difference between the ~50,000 Kelvin of a harmless electric spark and falling into a vat of molten iron.

c) we might as well combine with be for heat energy. Temperature at the center of the Sun: ~15M K. Unfortunately it's been too long since DifEQ for me to run through Newton's cooling equation, and the radiative cooling equation is not appropriate for this sort of situation, given that much of the energy will be simply passing through the target.

2. "Yield" of a physical blow

Say for example a physical blow hits an object and the shockwaves generated alone destroyed nearby mountains. The shockwave supposedly spread throughout the entire planet, although I don't think this would make a difference in calculation since we are only using the mountains to derive yield.

Define destroyed. Leveled? Vaporized?

3. Directed energy and yield

Ok, basically someone linked to a site saying that on average lightning bolts have 1 kilotons of energy. Contrast to say the more destructive MOAB which has yield of only 11 tons of TNT (ok the resource is wiki, so it might not be correct).

The fallacy is in calling the lightning bolt more directed than a bomb. It isn't. The lightning bolt spreads its destructive force across a length of air a kilometer or more long.

Two questions
a) what other forms of directed energy will also have the property of having high energy but little collateral damage

IIRC, a major supernova (I think SN1987A but I'm not sure) is thought to have output 10^46 joules purely in neutrinos. Since they are, effectively, dark matter, we barely even noticed. The more impressive point is that it emitted so many that we -did- notice.

Naturally, at any respectable distance (not within the star itself), these neutrinos aren't doing any damage.

b) using the example of lightning, how much damage would expect for a more powerful bolt. Say for example if we had a lighting bolt (somehow) of one MT instead of one KT, what would we expect the collateral damage to be.

Thermal blast effects for a point source scale at a rate of y^.41, where y is in units of 2.5 kilotons and the result causes lethal burns at a given range in kilometers. When dealing with the lightning bolt, however, the length makes this inappropriate.

Similarly, blast effects scale with the third power - but again, the length of the bolt needs to be considered also.

[Dooey Jo]

First question is how would we use this fact to calculate resistance to stress.

Considering the Sun has no real surface for him to stand on, and his magical method of flying probably exerts a force spread evenly over his whole body (and not just his feet as a surface would), I guess the only way to use the gravity to measure that, would be to calculate the difference in gravity between his head and his feet. Mind you, that difference is going to be negligible.

[mr friendly guy]

If it converted energy efficiently to heat upon impact, you'd have a big boom. Unsurprisingly, it'd be a good chunk of a megatonne. That this doesn't happen is a good thing.

Ok, so if I have directed energy weapon say particle beams or lightning, which don't cause from observation massive collateral damage, is it possible for this weapon to be in the range of say MT but it just so happens to do most of the damage to the target and little collateral damage.

Or to put it another way, would I expect a) most of it to be converted to heat on impact or b) expect (using lightning as the example) it to travel along the path of least resistance and have the energy dispersed elsewhere or c) most of the energy goes into the target

Define destroyed. Leveled? Vaporized?

Leveled into rubble. Definitely not vapourised. Keep in mind this was from the shock wave alone. The original force was directed against another target, which I guess I can estimate as a few kilometres away.

The fallacy is in calling the lightning bolt more directed than a bomb. It isn't. The lightning bolt spreads its destructive force across a length of air a kilometer or more long.

Can you explain that in terms of destructive potential? Do you mean that by the time it hits an object, most of its energy has been used up.

Thermal blast effects for a point source scale at a rate of y^.41, where y is in units of 2.5 kilotons and the result causes lethal burns at a given range in kilometers. When dealing with the lightning bolt, however, the length makes this inappropriate.

Similarly, blast effects scale with the third power - but again, the length of the bolt needs to be considered also.

Just to see I have understood this correctly. Say a blast effect of 2.5 MT. Put that into the equation I have 1000^0.41 = 17 km (rounded). However a lightning bolt of say 2.5 MT would do even less damage?

[Sikon]

Say for an example a human size object / superbeing was placed in the Sun (assuming it survives quite nicely and then leaves).

As implied by Admiral Valdemar, there is pressure too, depending upon whether you are talking about the object being in the surface of the sun or closer to the core. At the core, the pressure is many billions of atmospheres, many orders of magnitude beyond what would crush an object made with any materials known.

Regarding temperature, such as exposure to the surface of the sun, the key is the amount of heat transfer and how long is the exposure. One method for briefly dealing with extreme temperatures is to use ablation, like the ablative material on heat shields of spacecraft reentering earth's atmosphere. The length of exposure determines how much material is burned off. The other main method used in rocket engines that can temporarily handle temperatures even as high as 4000 K or 7000 degrees Fahrenheit in the combustion chamber is regenerative cooling. Channels carrying fresh cold fuel like LH2 enroute to the chamber keep the metal walls of the combustion chamber from melting. 4000 K wouldn't be a strict limit. For that, the temperature of the environment in itself matters less than the heat transfer, with the ordinary goal being to prevent more than hundreds of degrees elevated temperature, particularly since metals lose strength even well below their melting point (1800 K for iron alone, different for different metals and alloys). But having a rocket engine with super hot reactants in the combustion chamber is much different from trying to make the entire outside surface of an object withstand even the solar surface that varies from under 4000 K in some sunspots to 5800 K elsewhere.

The extreme radiation and heat transfer deeper towards the solar core would be far worse. The rate of energy generation per unit volume per unit time in the sun's core is relatively limited, but the actual heat transfer would still be astronomical to an object in the core. As an analogy, if there is a mass of molten iron in a foundry, removed from the furnace, the iron is generating zero energy itself, just having thermal energy it absorbed earlier from the fire, but that certainly wouldn't prevent great heat transfer to an object immersed into the molten iron. The sun's core is far hotter, denser, and under extreme pressure.

Actually, I can't see a real-world manufactured object going into even the surface of the sun, let alone deeper towards the core. To make the exposure to the heat flux survivable, the exposure time would have to be really short, except a problem is that the extreme velocity involved in making an object skim by the surface of the sun that quickly would normally result in it being destroyed by heating and stresses from the extreme velocity of passage through the sun's corona.

The superbeing would have to be rather extreme anyway, as the escape velocity from the sun's gravity is 600 km/s, the energy equivalent of tens of thousands of times the mass involved in TNT explosive.

Given the sun produces 1.26 E 34 joules in one year. From there work out how much energy is produced a second. From there we could comfortably say half the energy would not hit said object (since the sun is radiating energy in all directions, so energy radiating to the other side would not hit said object). Now this is being very generous.

Is there any other way I can refine the calculation. Perhaps by using the size of the object.

For an object magically hovering above the sun's corona, above the sun's atmosphere, you might approximate radiative heat transfer by treating the nearby solar surface as a semi-infinite flat plane emitting 6E7 W/m^2 (solar output divided by surface area). For example, if the object is treated like a flat plane, an imaginary 1 square-meter hovering plate would receive on the order of 60 MJ each second, of which some may be reflected. However, for an object instead actually within the sun, bathed in convecting plasma, the situation would be worse and more complicated to estimate.

Ok, basically someone linked to a site saying that on average lightning bolts have 1 kilotons of energy. Contrast to say the more destructive MOAB which has yield of only 11 tons of TNT (ok the resource is wiki, so it might not be correct).

A website saying lightning bolts have 1 kiloton of energy is utterly wrong. A kiloton of energy is around 1/20th of the energy of the first atomic bombs. 1 kiloton = 4200 gigajoules. (See Nuclear Weapons FAQ). That a lightning bolt is orders of magnitude less is apparent from its reduced destruction. Actually, lightning bolts are in the low gigajoule range, like around one to three gigajoules.

The argument is that if the energy is directed and controlled like in a lightning bolt, you can have high levels of energy but when it does damage, it causes little collateral damage. In other words you can't look at the collateral damage in this case to gauge yield.

That argument isn't valid for any realistic situation with real-world substances. Consider a mass of dirt hit by any form of energy delivered in nearly an instant. Assume one isn't talking about energy that would simply pass through it without being significantly absorbed (i.e. neutrinos). The greater the energy absorbed, the greater the resulting temperature of the material. That is true whether the energy is delivered by photons, particles, or any other means. For example, if a few kilograms of material are hit by and absorb much of the total energy of a narrow beam pulse of kiloton energy, that corresponds to many billions to trillions of joules of energy absorbed per kilogram.

Any real-world material has limited specific heat. A few million joules is enough to make a kilogram of any substance from iron to rock reach a temperature of thousands of degrees, and billions to trillions of joules do far more. The material reaches millions of degrees and explodes outwards much like a nuclear blast of the appropriate yield. Thus you can look at collateral damage to gauge yield if a narrow energy pulse hits real-world material, like a beam hitting the ground.

If concentrated kiloton-level energy, even a particle beam would likewise heat the ground where it hit to astronomical temperature and cause an explosion much like a nuke. The reason one doesn't see that happen with ordinary particle beam pulses is because they are many orders of magnitude less powerful, not delivering enough energy to heat material to millions of degrees or even to cause much temperature rise at all.

a) what other forms of directed energy will also have the property of having high energy but little collateral damage.

As previously implied, the whole thought that kiloton-level energy can be absorbed by material without super-heating it and causing the equivalent of a nuclear explosion is wrong, unless either:

• The energy is delivered over a long period of time instead of a brief pulse:
  
  As an extreme example, deliver one kiloton or 4.2E12 J of energy to a 10cm by 10cm patch of dirt over a period of 67000 years, and 2 J would be delivered per second to a 0.01 m^2 area. That would correspond to about 200 W/m^2, not far from the average intensity of sunlight on the ground, so in that case a narrow beam could deliver a kiloton of energy to a small area of ground while only raising its temperature a relatively small number of degrees. One could give other examples, like delivering that energy over 1/1000th of the preceding time or 67 years to give 200,000 W/m^2 intensity, enough to make the material hot while still not making an explosion. But a near-instant pulse delivering the energy would be totally different.
• The energy is delivered to a large area instead of a small area:
  
  Have a sufficiently wide beam instead of a narrow beam, and the energy delivered per unit area can become arbitrarily low.
• The energy is not actually significantly absorbed:
  
  Normally any energy or radiation from photons to neutrons doesn't pass through more than at most meters of dirt before getting absorbed. But neutrinos would pass through with practically no absorption, though nothing would be accomplished.

b) using the example of lightning, how much damage would expect for a more powerful bolt. Say for example if we had a lighting bolt (somehow) of one MT instead of one KT, what would we expect the collateral damage to be.

Ok, so if I have directed energy weapon say particle beams or lightning, which don't cause from observation massive collateral damage, is it possible for this weapon to be in the range of say MT but it just so happens to do most of the damage to the target and little collateral damage.

No. The reason lightning doesn't cause a lot of collateral damage is because, for example, a 2 GJ lightning bolt is literally 2 million times less energy than 1 MT, which would be 4.2E15 J. Considering conservation of energy, think of where the energy is going, how a small mass can not absorb a pulse of astronomical energy without extreme temperature rise, like the temperature of a nuclear bomb right after detonation. When a substantial mass of gas or rather plasma is that astronomically hot, it expands rather violently in all directions.

The result would be much like that implied in the nuclear weapons destruction versus yield discussion here, except there ordinarily wouldn't be neutron radiation or fallout.

[SWPIGWANG]

As an analogy, if there is a mass of molten iron in a foundry, removed from the furnace, the iron is generating zero energy itself, just having thermal energy it absorbed earlier from the fire, but that certainly wouldn't prevent great heat transfer to an object immersed into the molten iron. The sun's core is far hotter, denser, and under extreme pressure.

I think when we are considering this problem, we can make the assumption: The superbeing is ejecting as much energy as it is reciving to maintain its temperature, which will always be the case unless it has absurd specific heat capacity or very short trip duration. In other words, to an "observer in the sun", the super being must look like it has the same temperature.

As to how much energy the being has to eject, one can set a lower limit to use the blackbody radiation formula at temperature of the surrounding environment, intergrate it over all spectrum and surface area of the being. I'm not sure if other forms have heat transfer have to be considered in this case.

Of course, this shows nothing about the amount of energy the superbeing actually absorbs. That said, most superbeings are not close to perfect reflectors so the effect still works.
------------

No numbers you're talking about regarding the Sun's gravity are going to compare favorably with the pressure you'll find at the Solar interior. You'll find a wide variety of estimates, but it's often on the order of a few 10^16 newtons per square meter.

I'm just thinking, maybe a superbeing wouldn't drop alway into the sun. At some level the being will simply float in the plasma. Just consider the extreme case of a neutron star, the density means no non-neutronium dense object is going to go beyond the surface.

Can someone provide a little pressure-to-density graph? It is not the traditional gas due to plasma properties. This will set an upper limit on the pressure the superbeing have to withstand for a given density. The difference may differ by orders of magnitude.

[SWPIGWANG]

2. "Yield" of a physical blow

Say for example a physical blow hits an object and the shockwaves generated alone destroyed nearby mountains. The shockwave supposedly spread throughout the entire planet, although I don't think this would make a difference in calculation since we are only using the mountains to derive yield.

My question is this blow would be the equivalent of a nuke of what yield. I have looked at Darth Wong's Nuclear yield calculator, but that just gives me the size of the fireball.

If I assume the mountain peaks are say 2-2.5 km tall (the average) and the mountain range has say 20 peaks would this help with the calculation.

Leveled into rubble. Definitely not vapourised. Keep in mind this was from the shock wave alone. The original force was directed against another target, which I guess I can estimate as a few kilometres away.

Sadly, there seems to be no easy way to really calculate this. The best way is to look into historical earthquake for a case that is similar to the one you want (distance and effect), and use the Richter scale of the earthquake to calcuate the energy output.

For reference:
http://en.wikipedia.org/wiki/Richter_magnitude_scale

The main problem is really, finding the correct richter scale. Things like mountain breaking is a very non-linear process where the detailed geology matters quite significantly on how much damage is done. A land slide can happen with heavy rain despite the lack of energy input.

And no shockwave actually "levels" mountains nor to they convert mountains into rubble as mountains are loose rubble to begin with. The real damage you simply will have to think hard about it.

[Kuroneko]

For the first question, the foremost concern would of course be pressure. It's almost impossible to answer in terms of conductive transfer, simply because the properties of the superbeing are not known. One can certainly get an upper bound by simply treating estimating how many collisions the superbeing will have with the particles inside the sun and assume that the collisions are completely inelastic. At a given temperature, the energy per particle is given through the Boltzmann constant; a kind of 'average' can be found by estimating the number of particles in the Sun and dividing into the total thermal energy of 3.1e41J.

As to how much energy the being has to eject, one can set a lower limit to use the blackbody radiation formula at temperature of the surrounding environment, intergrate it over all spectrum and surface area of the being. I'm not sure if other forms have heat transfer have to be considered in this case.

In terms of radiative transfer, the most relevant question is the bond albedo of this superbeing. The superbeing's immediate surrounds at some temperature T would have the same 'surface area' A as the being itself, so it absorbs σ(1-α)Τ^4 W, where α is the bond albedo and σ is the Stefan-Boltzmann constant. We can expect α<0.9 to be a very reasonable upper bound.

Can someone provide a little pressure-to-density graph? It is not the traditional gas due to plasma properties. This will set an upper limit on the pressure the superbeing have to withstand for a given density. The difference may differ by orders of magnitude.

The pressure-to-density relationship inside the Sun is almost exactly linear: ρ = 1.638e3 + 6.462e-12 P, where P is in pascals and ρ is in kg/m³. Data taken from a numerical simulation by Guenther and Demarque [1]. According to this model, the gravitational binding energy of the Sun is 6.31e41J, meaning the internal thermal energy is half this amount.


From top to bottom: pressure (Pa), temperature (K), density (kg/m³), in terms of radius fraction.

[mr friendly guy]

<snip>

Thanks for that info. I thought the part about lightning seemed dodgy. However I can predict what they are going to say next. Assume for a minute we fire a concentrated burst of energy, lets just say a particle weapon at 1MT at object A. Lets just say this object A has a ridiculous specific heat not matched by any real world object and can absorb this.

From my understand of science we would still expect an explosion because this beam would still have to transfer heat to the air that it passes through to hit object A, hence we would still expect a giant explosion.

[Ariphaos]

Leveled into rubble. Definitely not vapourised. Keep in mind this was from the shock wave alone. The original force was directed against another target, which I guess I can estimate as a few kilometres away.

The easiest thing to do, for the mountain, is to calculate the energy needed to lift and move it whatever average initial velocity it got rubbled into.

Can you explain that in terms of destructive potential? Do you mean that by the time it hits an object, most of its energy has been used up.

That's another way to put it. Also note Sikon's point that most bolts are going to be in the sub-tonne range. They will 'strike' when the total voltage difference becomes greater than the path of least resistance between two points.

A significant amount of the energy involved gets radiated as light and the thermal expansion of the air.

Just to see I have understood this correctly. Say a blast effect of 2.5 MT. Put that into the equation I have 1000^0.41 = 17 km (rounded). However a lightning bolt of say 2.5 MT would do even less damage?

I meant to say 3rd root for blast effects, not third power... oi...

Anyway, it depends on the profile of the bolt. When calculating thermal damage, it's based off of o*A*T^4, where o is the Stefan-Boltzmann constant (5.67*10^-8 W/(m^2*K^4)), A is area (in meters), and T is Kelvin, giving you a result in Watts. If the lightning bolt's 'face' is greater than that of the initial bomb, then T drops by a notable amount, greatly reducing the amount of distance lethal burns can be caused at.

[Sikon]

<snip>

Thanks for that info. I thought the part about lightning seemed dodgy. However I can predict what they are going to say next. Assume for a minute we fire a concentrated burst of energy, lets just say a particle weapon at 1MT at object A. Lets just say this object A has a ridiculous specific heat not matched by any real world object and can absorb this.

From my understand of science we would still expect an explosion because this beam would still have to transfer heat to the air that it passes through to hit object A, hence we would still expect a giant explosion.

Yes. A little like a lightning bolt that dissipates a significant fraction of its total energy going through the air (as Xeriar mentioned), particle beams tend to not go far through the atmosphere very well. As one illustration, a brief discussion of neutral particle beams is in an Air Force document here. The relevant pages are 25 to 27, which show up as pages 34 to 36 in a PDF reader. Admittedly, one might not be able to rule out the possibility of a multi-stage-pulse extremely narrow-beam weapon that might go through the atmosphere to the target with only a proportionally tiny fraction of total energy dissipated in the air. Still, when one is talking about megaton-level energies, it wouldn't take a large fraction being dissipated in the air (or scattered off the super-armor if applicable) to cause a lot of collateral damage, even if the weapons fire never hit anything other than the super-armor.

[Admiral Valdemar]

For military grade weapons, in atmosphere you'd need CPBs and they'd be better utilised with a short laser pulse clearing a path for them. In space you have to use your NPBs. Our LINAC technology is nowhere near good enough to make such weapons feasible today anyway.

[Sikon]

Admittedly, it would have been best if I had looked up an illustration with charged particle beams (CPBs) as well in my last post. While a multi-stage pulse with a laser first and then a particle beam is possible, the main point was that there is going to be a tendency for at least some beam energy dissipating in the atmosphere, rather significant when the energy involved is megaton-level. Indeed, there is a bit of an analogy with the electrical discharge of lightning, which is high velocity charged particles going through the atmosphere. An endoatmospheric charged particle beam experiment with a guide path made with a laser first like that described here even has some similarities to the concept of using UV lasers to create a plasma path for lightning diversion away from locations like airports or utilities.

[Sikon]

EDIT: I see that I mentioned using UV lasers above but then gave as a reference a link to an article about an experiment doing so with CO2 lasers, presumably not UV. That was careless, but actually multiple types of lasers have been used in different experiments.

[Admiral Valdemar]

Particle beams are inherently inefficient, but their purpose would be to utilise that more penetrating energy attack, if possible. Lasers, especially solid state ones that are translucent to the atmosphere in their wavelength, would be far better pound-for-pound. Thermal blooming and general beam dissipation is unavoidable, plus, if you do have a megatonne level beam, that waste heat is going to cook your projector.