Nuclear detonation in outer space

[Alan J.]

What would be the reprocussions of detonating a nuclear device in outer space? Would nothing happen except the explosion... would it create a black hole? Would it become a ball of energy self contained in its own atmosphere?

 

[mgb_phys]

Rather less effect than detonating it in the atmosphere.
A bright light, a bit of electromagnetic field, no bang and a small amount of radioactive metal drifting down to earth. Depending on how big and how close it might creae a few radioactive gas ataoms in the upper atmsophere.

 

[Astronuc]

A nuclear explosion would not create a black hole. The energy is insignificant.

The plasma would simple expand and dissipate into space. If close enough to earth, it could interact with the Earth's atmosphere are mgb_phys mentioned.

 

[JeffKoch]

What would be the reprocussions of detonating a nuclear device in outer space?

Lots of political fallout, I suspect.

 

[Alan J.]

In quantum mechanics. There are theories in which if 2 electrons were created at the same time and one was effected by a force then the other would respond instantly. The theory goes on to say that the electrons are still connected with a force not yet determined or perceived by man. Now if this was true and the big bang theory was correct. Then everything is connected. Would a nuclear device have any effect on these connections or is a nuclear explosion in space still too primal or elementary to effect such connections?

 

[mgb_phys]

In quantum mechanics. There are theories in which if 2 electrons were created at the same time and one was effected by a force then the other would respond instantly.

Not quite - the entanglement principle says that certain properties of the particles are uncertain until you measure them, if you measure the state of one particle you know the state of the other and so in some way you have set it's value even though they are separated.
This has nothing to do with forces.

Would a nuclear device have any effect on these connections or is a nuclear explosion in space still too primal or elementary to effect such connections?

A nuclear explosion is pretty pathetic on an astronomical scale.

 

[Alan J.]

Ah i see. Thanks for enlightening me on that.

 

[Astronuc]

A nuclear explosion is pretty pathetic on an astronomical scale.

Along those lines,

http://en.wikipedia.org/wiki/TNT_equivalent
1 MT ~ 4.184×10¹⁵ J

http://en.wikipedia.org/wiki/Sun
Solar output - 3.846×10²⁶ J/s

Supernova (from the Wiki TNT_equivalent article) - On a much grander scale, supernova explosions give off about 10⁴⁴ joules of energy, which is about ten octillion (10²⁸) megatons of TNT.

Humanity's activities are insignificant in the grand scheme of the universe. They are only significant as far as humankind is concerned.

 

[mheslep]

Yes certainly the total energy of a fission bomb is not that impressive. Indeed, one could load that much equivalent energy in TNT or LNG on a couple of large ships. Its the power of a nuclear weapon that is impressive. All of that 10^15 joules is put into play in under a microsecond, so in terms of power its right there with some celestial events & bodies, at least for a microsecond ;-)

 

[Astronuc]

But 10¹⁵ J in 10^-6 s is only 10²¹ W, still puny compare to things stellar.

On the other hand, one does not want to be in the neighborhood of a nuclear explosion.

Humans are low energy entities anyway.

Just think about how hot air is from a hair dryer at 1 to 1.5 kW.

And big electrical power plants are measured in GW.

 

[rewebster]

What would be the reprocussions of detonating a nuclear device in outer space? Would nothing happen except the explosion... would it create a black hole? Would it become a ball of energy self contained in its own atmosphere?

I think they (the USA) did it back in the 60's or early 70's

 

[mheslep]

But 10¹⁵ J in 10^-6 s is only 10²¹ W, still puny compare to things stellar.

Ok, take a thermonuke then. 10²⁴ W. And, guessing wildly, the nuclear portion of the detonation is complete in 100ns? ( ~ 2¹⁰⁰ fissions) Then 10²⁵ W. Fair to say that for a moment, a nuclear weapon radiates energy at the same rate of (small) star. No surprise really, given the lousy reaction rate of proton proton fusion. A cubic meter of stellar core wouldn't run my toaster oven.

 

[JeffKoch]

A cubic meter of stellar core wouldn't run my toaster oven.

Hmm, with a core temperature of 15,000,000K, Stefan-Boltzmann says your cubic meter of stellar core radiates around 1e22 watts, not including energy from particles. That's a lot of toaster ovens. Nuclear bombs produce similar sorts of temperatures and densities, but over MUCH smaller volumes. Laser experiments can do the same, but over smaller volumes still.

 

[mheslep]

Hmm, with a core temperature of 15,000,000K, Stefan-Boltzmann says your cubic meter of stellar core radiates around 1e22 watts, not including energy from particles. That's a lot of toaster ovens. Nuclear bombs produce similar sorts of temperatures and densities, but over MUCH smaller volumes. Laser experiments can do the same, but over smaller volumes still.

No, that's a misapplication of Stefan-Boltzmann. YOU produce more, much more heat energy than a M^3 of core. Think about it. How could 1M^3 put out 1e22 W if the entire Sun produces ~1e26 W? The actual power density is a measly 83 W/M^3 in the averaged over the core and 1/3 W/M^3 over the entire solar volume. Sorry, no toaster.

See 'Core' here:
http://en.wikipedia.org/wiki/Sun

About 3.4×10^38 protons (hydrogen nuclei) are converted into helium nuclei every second (out of ~8.9×10^56 total amount of free protons in the Sun), releasing energy at the matter–energy conversion rate of 4.26 million tonnes per second, 383 yottawatts (3.83×10^26 W) or 9.15×10^10 megatons of TNT per second. This actually corresponds to a surprisingly low rate of energy production in the Sun's core—about 0.3 µW/cm³ (microwatts per cubic cm), or about 6 µW/kg of matter. For comparison, a candela of light (roughly one candle) produces heat at the rate 1 W/cm³, and the human body at approximately the rate 1.2 W/kg—millions of times more heat production. The use of plasma with similar parameters for energy production on Earth would be completely impractical—even a modest 1 GW fusion power plant would require about 170 billion tonnes of plasma occupying almost one cubic mile. Thus, terrestrial fusion reactors utilize far higher plasma temperatures than those in Sun's interior.

 

[A/4]

I think they (the USA) did it back in the 60's or early 70's

Operation Argus:

http://en.wikipedia.org/wiki/Operation_Argus

 

[JeffKoch]

No, that's a misapplication of Stefan-Boltzmann.

Not at all. You have a cubic meter of 15,000,000K material (never mind how you got it, or how long it'll stay there), and you ask how much energy is radiated away assuming it's optically thick to that radiation. MKS power per unit area is then 5.67e-8 times (15,000,000)^4, and total power is 6 times this (6 square meters for the cube). Even if it's not perfectly optically thick, that's still a lot of toasters. I invite you to show me what's wrong with this calculation.

You can ask about power produced from fusion reactions in that cubic meter, and you'll get a different number.

 

[mheslep]

Not at all. You have a cubic meter of 15,000,000K material (never mind how you got it, or how long it'll stay there), and you ask how much energy is radiated away assuming it's optically thick to that radiation. MKS power per unit area is then 5.67e-8 times (15,000,000)^4, and total power is 6 times this (6 square meters for the cube). Even if it's not perfectly optically thick, that's still a lot of toasters. I invite you to show me what's wrong with this calculation.

The radiator calculation is fine; my point was its not indicative of the steady state exothermic fusion reaction, the power density of which is lousy for any practical earthly purpose. The 15,000,000K (1.4keV in core) is essentially the kinetic energy required to keep our M^3 reactor ignited. Allowing all that energy to radiate away would quench the reaction, akin to leaving the door open on a furnace, and its a one time deal. I want the toaster oven to run awhile. In the sun's core, radiation loss would also be proportional to Trad^4 but its mostly blocked or reflected by the mantle. Likewise our M^3 reactor has to have some kind confinement (magnetic or other) that serves a similar purpose. Note that ITER will have 5-10keV temperatures over several M^3 of plasma. Certainly you don't expect to measure its power output from T^4.

You can ask about power produced from fusion reactions in that cubic meter, and you'll get a different number.

Yes its ~80Watts/M^3 in the core, and will be for another 5-10^9 years, i.e. steady state.

 

[joema]

The typical energy distribution of a fission warhead is usually described as:

50% blast, 35% thermal radiation, 5% prompt radiation and 10% residual radiation

However this assumes an atmospheric detonation.

Does anyone know the energy distribution (by category) for the various main warhead types (fission, regular fusion, enhanced radiation) in the vacuum of space?