4 ms·
Very large nuclear bombs are inefficient because most of the energy goes into heating up air, so not relevant to the current thread.
by hollerith 2y ago
Very large nuclear bombs are inefficient because most of the energy goes into heating up air, so not relevant to the current thread.
- taneq 2y agoThey're only inefficient if you want them to do something other than heat up a lot of air by a very large amount very fast. :)
- hollerith 2y agoOK: they're inefficient at killing people and destroying buildings and other structures relative to bombs with yields like 500 kilotons.
- connicpu 2y agoPretty efficient in their mass to destruction ratio, it's only inefficient if you compare it to how much energy the fissile/fusible material could be worth in a nuclear reactor.
- hollerith 2y agoIt's also an inefficient use of ICBMs or whatever "system" is being used to "deliver" the bomb to the target (which BTW is more expensive than the bombs themselves).
- jajko 2y agoWell that heat does a lot of damage too, on top of other damaging radiation, blast wave, irradiating everything etc. which is proportional to bomb yield. Sure the biggest ones are comparatively ineffective, thats why the focus on manufacturing was on small/medium yield one, one can produce many more and saturate defenses more easily rather than one/few MOABs.
- kamaal 2y agoAgreed that I know very little about this subject. But heat itself can be imagined as a kind of field. For eg: A candle, the closer you move to the flame, every point closer to flame, the temperature is higher. The farther you move apart the temperature reduces. Same with the Sun. Take for eg- Sound. The closer you move to the source of it, the louder it sounds, the farther you move from it, the fainter it gets. Now you could call this a wave. Like the wavelength stretches with distance, also decreasing frequency and amplitude. Another way of looking at this a field. Imagine 3D space with points, like a lattice. Each point has a value, and the values get denser to the center, and move farther apart as move away from center. If Im not wrong a lot of physical phenomenon exhibit this behaviour. Including thing like light, sound, temperature, gravitation etc. While you can make a beam of light, I doubt you can make a beam of magnetic field(ray?) or gravity for that matter?
- vlovich123 2y agoHeat is only a field in radiation because it’s literally being carried by electromagnetic waves. Heat is also conduction and convection - in those cases it’s decidedly not a field.
- itishappy 2y agoThe heat and wave equations have an important difference: heat: ∂u/∂t = k ∂²u/∂x² wave: ∂²u/∂t² = c² ∂²u/∂x² Note the extra time derivative on the wave equation. The heat equation is dissipative, moving towards the average value, spreading energy out over time. The wave equation, on the other hand, allows for solutions that oscillate and maintain their shape while they travel. This means that waves such as electromagnetic (light) or gravitational can in theory be focused and beamed significant distances without much loss. A plane wave solution is lossless, but requires an infinite emitter. Finally, note that this does not apply to static fields, such as magnetic, electric, or gravitational fields, which if not oscillating will still spread out and dissipate over distance.
- barrenko 2y agoSo the second equation does not cover my induction cooktop?
- naasking 2y agoThere are many efficiency metrics. For instance, how much energy went into constructing and deploying the bomb vs. how much destruction it caused. I think large nuclear bombs would look quite ok on this metric.
- hollerith 2y agoPeople have known how to make very large bombs for a long time (e.g., in 1961, the USSR tested a bomb with a yield of 50–58 megatons) so it says something that for decades, no military has had any bombs larger than about 1.3 megatons.