Why when the atomic bomb explodes everything gets instantly dusty,

>>8158063
Heat.

>>8158063
>It almost looks like it reached there with lightspeed.
because it did
that's the heat wave and all the other radiation

that's what sets fire to stuff after a nuclear blast

the shockwave comes after

The flash from an atomic bomb delivers a lot of energy. So, shit gets lit on fire just from the amount of energy delivered by the wave of photons emitted from the reaction a rather impressive distance from the detonation.

>>8158063
notice how the camera goes white upon detonation? that's a lot of light, and much like how direct sunlight feels hotter than shade, the light of the nuclear blast heats up the material it is incident upon.
in this case the light delivers enough energy to cause spontaneous combustion, or maybe even ionization of surface materials.

>>8158063
>dusty
That's not dust. It's smoke and fire.
The intense light is igniting everything.

>>8158072
>>8158082
>>8158084
>>8158098

Are you telling me it's photons that are moving the dust before the shockwave?

>>8158105
basically yes

>>8158105

See >>8158103
And yes, the photons are moving it.

>>8158105
the surface of everything is instantly roasted
with rapid expansion due to the material getting heated, some parts of the material detach

File: 1462788975291.webm (939KB, 490x320px) Image search: [Google]

939KB, 490x320px

posting nukes because they're amazing

>>8158108
lol no they arent. radiation pressure is fucking miniscule, even under an atomic blast.

it takes years and a fucking literal interstellar trajectory before you can observe it on a space probe, you arent going to see several feet of movement in suspended particles in the space of seconds.

>>8158105
That's vapor and smoke not dust. It comes from instant incineration/vaporization.

>>8158115
Best one really,

https://www.youtube.com/watch?v=rtH0EDLcbwA

>>8158120
Then what is it, Mr. Smartass, if it isn't radiation/heat?

>>8158201
there's a difference between radiative pressure, and heat

File: glasgow.jpg (145KB, 640x480px) Image search: [Google]

145KB, 640x480px

>>8158063
Thermal radiation. Gives a whole new meaning to the term "Heat wave"
There is no time to seek shelter when a nuke hits, since you'll be burned to a crisp as soon as you see it.

>>8158204
You said it was radiative pressure. The person you replied to said it was radiation. Why did you even bring up radiative pressure?

>>8158214
So the first wave is literally an electromagnetic shock packed with heat ?

>>8158063
That's smoke not dust. The intense light from the blast heats things up and they burn or vaporize.
>>8158222
Nice trips, but no. It's just really, really bright light.

>>8158106
>>8158108
that's pretty fucking neato.

>>8158201
Dipshit.

Radiative heat is light, it travels at light fucking speed (or pretty fucking near to it in the thin atmosphere of earth). When the stuff all catches on fire at once, that also releases heat and everything starts expanding and moving around, thats what you see.

Light can also exert pressure, called radiation pressure, which is when the photons physically push on a surface. That is not what is happening here, at least in any measureable sense of the term.

>>8158242
it's wrong though

>>8158251
My point is that no one said or even implied that the light was physically pushing anything dumbass. The person you quoted even referred to another post stating it was smoke and heat, not dust

>>8158270
>My point is that no one said or even implied that the light was physically pushing anything

>>8158105
>Are you telling me it's photons that are moving the dust before the shockwave?
>>8158106
>basically yes
>>8158108
>And yes, the photons are moving it.

Not to take sides, but excitement from radiation heat transfer is a kind of momentum transfer.

>>8158280
no, it's energy transfer.
you're talking about radiation pressure.

>>8158282
you're wrong.

temperature is defined as average kinetic motion of atoms in a system, aka pressure

but this isn't the same radiative pressure being referred to in the thread.

>>8158287
kys, you're confusing so many concepts it hurts.

>>8158063
I think it's smoke, and vapor. The light/heat hits immediately, and vaporizes volitiles, which rise as smoke, then the shockwave pushes things around.

>>8158072
>>8158063
This anon, the energy released from detonation is in the form of radiation, heat being one of the more infamous type as most things a few miles from ground zero tend to vaporize and incinerate instantly. This in turn heats up surrounding molecules, which move very fast, and that disturbs the dirt. Then the shockwave happens, which creates a vacuum and draws everything back to the center.

File: Threads.png (2MB, 1848x472px) Image search: [Google]

2MB, 1848x472px

Can't have a thread about without threads
https://www.youtube.com/watch?v=MrHoMSRZOS4

https://vimeo.com/18781528

>>8158063
Its a wave in the ground, which has a higher speed of sound than air(its incompressible and travels faster in the ground)?

>>8158688
Very unlikely.
https://www.youtube.com/watch?v=RqyBzXYZPoM
The same effect can be seen here, and notice that the smoke/vapor is being blown by wind in a completely different direction than the blast causes when the shock wave hits.

Most of the radiation is thermal, not ionizing radiation. So this is probably just water that has condensed from the air onto surfaces being instantly vaporized. Alternatively, for something close enough to the blast site, it's possible that the heat has caused the wood products to combust.

>>8158063
That webmd gets me so hard bro

>>8158934
Jesus. Which test was that? How many megatons?

Convection currents picking up dust and flammable materials burning.

https://www.fourmilab.ch/etexts/www/effects/eonw_7.pdf

2 miles from ground zero, a 5 kiloton nukebomb will deliver about 40 joules per cm2. It takes 4.2 joules to raise the temperature of a gram of water by 1 degree so it doesn't sound like much, but the mass of the surface affected is considerably lower.

If you find yourself out in the open facing an imminent atomic blast, covering yourself with mud might help, a little.

>>8158229
light is technically em radiation

>>8158934
Jesus fucking christ, why do we have these things?

I just realized how odd the giant fireball is. What exactly is burning? The fissile material that didn't convert to energy upon detonation has been blown apart and is no longer critical at this stage. Is it 'just' the atmosphere on fire?

>>8159121
Castle Bravo, 15 MT

>>8158934
It's so beautiful.

>>8159167
>technically

>>8158772
Actually the ground tremor is faster than the shock wave in the air, and almost certainly helps to jolt some of the vaporizing dust up off the immediate surface of the ground.

File: mud_predator.jpg (29KB, 610x333px) Image search: [Google]

29KB, 610x333px

>>8159156
>covering yourself with mud might help, a little.

>>8159156
Interesting thing is, is that even things that do not usually catch fire are vaporized in the heat as a result.

>>8159354
Isn't everything being ionized by the energy of the heat wave ?

Against what seems the common ground here Im pretty sure that its not the heat wave that lifts duat of the ground, but much more likely the shockwave that travels through the ground instead of the air, where the speed of sound (aka the speed of shockwaves) is much faster that in the air.
So first is obviously the photons magnitudes faster than the other waves, but there is no reason for it to blow dust vertically up into the air.
Second is the "earthquake" which I find much more likely to cause a force in the direction the dust moves.
Last is the shock traveling through the air.

>>8159391
The shockwave has an effect, but you have to remember that it is primarily transverse as the bomb is not being detonated under the ground.

The vaporisation effect is going to be more pronounced. All that gas has to go somewhere, the rapid expansion is what gives the majority of the "lifting" appearance.

>>8158063
Shit tons of EM radiation. You'll see things getting similarly 'dusty' if you heat them up with a powerful laser. And remember a nuclear chain reaction is basically a micro sun.

>>8158072
>>8158082
To be more precise it's heat transfer by EM radiation from the nuclear reaction.

>>8158251
This.
Radiation pressure = macro level force due to EM radiation
In a nuclear blast a shirt on of EM radiation is released and it does push things but at a micro level (heat)

If you suddenly heat up just the surface of a material by a lot you'll see shit like Op pic

>>8159391

This is without a doubt wrong because it happens in an instant also sound speed travelling through gas vs. solid isn't that different as you see in the webm

>>8159391
Look at the telephone pole. Only the side facing the blast has anything coming off of it because that is the side that ignited.

>>8159172
>Is it 'just' the atmosphere on fire?
Basically, yeah. The bomb produces an x-ray hot plasma similar to what you'd find in a stellar core. This radiates x-rays at ludicrous speed, but all matter absorbs x-rays, so they are absorbed by the atmosphere. That energy being absorbed turns the air around the bomb (and up to a radius of a few miles depending on the yield) into a plasma that reradiates energy and continues to ionize the air around it until it reaches a low enough temperature that the radiant photons aren't energetic enough to continue ionizing the air. The immediate fireball may be hundreds of millions of degrees, but because of this effect, what is visibly seen is only a few tens of thousands of degrees. Gamma rays released from the nuclear reactions themselves are energetic enough to continue burning through the air for a ways longer than that, so ionizing radiation still hits for a good distance, though it's not the main danger from a nuke at any distance.

>>8158934
Am I the only one, who thinks, that we should detonate one more of these, and record it with modern high speed cameras?

>>8159685
I dont know if we really should, but yes I definitely want more like this


https://www.youtube.com/watch?v=KQp1ox-SdRI
>First Milliseconds of Nuclear Bomb Test Fireball


https://www.youtube.com/watch?v=dflLFFZcZ0w
>Grable, the Atomic Cannon test in 1953

>>8159685
We have computer simulations now, that's why we no longer test them live.

>>8158063
Heat and radiation travel at the speed of light. Shockwave travels at the speed of sound.

File: nukemap.png (675KB, 1325x623px) Image search: [Google]

675KB, 1325x623px

the "heat wave" usually goes way beyond the shockwave. It burns you before the the detonation blows you away or even reaches you at all.


Some of you might have fun dicking around with this:

http://nuclearsecrecy.com/nukemap/

I guess second wave is a recoil wave

>>8158934

I would pay to see this! I imagine a luxury
cruise to some deserted atoll, with this as the show at the end.

>>8159696
>Shockwave travels at the speed of sound.
Sort of. Shockwaves travel at the speed of sound IN THEIR OWN AIR. Since they compress and heat the air as they pass (which raises the speed of sound), they can travel significantly faster than sound travels through the normal atmosphere.

Tanning in the radiation here, lads. Keep it coming =)

>>8159709
>cropping out the estimated casualties

come on dude

File: ZarBombOnMecca.png (1MB, 1287x605px) Image search: [Google]

1MB, 1287x605px

>>8160063

File: GE.jpg (965KB, 1180x798px) Image search: [Google]

965KB, 1180x798px

>>8160063
You can just set it yourself

Mostly all the water instantly boiling off from all that sweet gamma rays.
People close to the blast in Hiroshima and Nagasaki literally vaporized from fucking too much light.

>>8160080
>>8160092
>>8159709
More IPs to add to the watch list.

>>8160092

that seems too low

>>8160092
Try Jerusalem with 6 gorillian megatons

File: stumped.png (52KB, 155x171px) Image search: [Google]

52KB, 155x171px

>>8159709
>Bottom left
>Doylestown, Perkasie (cut off), Quakertown (cut off)
>MFW I live right by Perkasie

I mean, fuck New York, but holy shit.

modern military nukes aren't as large as Tsar Bomba, are they?

>>8160452
Also guys don't look at the Fallout from a surface detonation.

>>8158105
the "dust" is moving because all organic matter -and some other less stable stuff- in it is combusting.

when you light a match, does the smoke just sit ther around the match head, or does it rise up or blow away in the wind?

>>8160504
>combusting simultaneously.
FTFY

File: Nuclear Comparison.jpg (96KB, 800x494px) Image search: [Google]

96KB, 800x494px

>>8160452
No.
And I even used the original design (100Mt).
They thought that this might be too much and made it about 50Mt for the real one

>>8158063

From combustible surfaces like the powercords and poles it's smoke as they vaporize. The ground is a mix of burning vegetation and combustibles and the ground shockwave.

Look at subterranean detonations like this: https://www.youtube.com/watch?v=Hy0cjVobjOs

The ground kick in an airburst is far less violent in magnitude but the shockwave transduction speed would be the same.

>>8158276
Not that guy, but he didn't say the photons are moving it directly.

File: Peacekeeper.jpg (761KB, 3000x2272px) Image search: [Google]

761KB, 3000x2272px

>>8160452
The soviets knew that their guidance systems sucked, so they concentrated on bigger bombs for a while. The preferred delivery method among advanced nuclear powers these days is an ICBM that delivers several warheads (each in the neighborhood of a megaton) over a wide area. It's much more efficient at wrecking up a place than a single large (much heavier) warhead. Had the Soviets decided to nuke the USA, NYC would have probably gotten worse than that, though Manhattan probably wouldn't be outright glassed, and with less collateral damage you'd be at less risk unless there's an actual target nearby. Cheyenne Mountain would have been blown clean away.

>>8160574
>They thought that this might be too much
A uranium tamper would have doubled the yield and greatly increased fallout. And probably destroyed the bomber that dropped it.

>>8158063

I can only conclude that the larger shock wave is subsonic, but with greater force.

>>8163689
>I'll just ignore the thread
>sound goes as fast as light
>sound waves travel at less than the speed of sound
you should just kys instead of spreading your shit everywhere.

>>8160574
That image is completely misleading. The eye is tricked into believing that the relative areas are the relative strengths of the bombs, when it's actually just the height. Tzar Bomba and Bravo are about 3-to-1 but it looks more like 8-to-1. Difference is even bigger for Little Boy.

>>8158063
One simple observation
Shockwave move faster through solids than gasses.
The bedrock and hard pack will have a faster speed of sound than the air thus allowing a Shockwave to reach from point a-b in the ground disturbing the topsoil and dust then later the Shockwave reaches it a second time through the surface air

>>8164434
that's not enough to explain what you see.
please refrain from posting if you don't know. The explanation has been given several times in the thread.

>>8164384
>unironically failing to realize the common usage of *speed of sound* is utilizing air, at sea level as the medium.
Wew lad... just wew

>>8164436

File: 1460941329509.png (128KB, 237x218px) Image search: [Google]

128KB, 237x218px

>>8164439

File: Screenshot_2016-06-26-02-32-22.png (2MB, 1080x1920px) Image search: [Google]

2MB, 1080x1920px

>>8160092
Fixing le EU problem this would

anus
is like burned paint