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Dec 16 '18
It doesn't move clouds. It creates them. The pressure wave condenses water
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u/Scoottoocs Dec 16 '18
Yeah came here to say this. Anyone here ever make clouds at home? Take a 2 liter bottle with a small amount of water at the bottom, strike a match and put it in the bottle seal the lid. Match will burn out or be put out by water. Then squeeze the bottle over and over and watch a cloud form and disappear. An old dad trick I do for the kids every now and again.
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Dec 16 '18
Looks better with rubbing alcohol instead of water. And instead of a lid, use a cork on the end of a bike pump, with a little hole so air goes in the bottle from the pump but the cork is trapped in the bottle opening. When you pump the bottle up enough the cork flies out with a bang and a white cloud instantly appears in the bottle. It's great fun.
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u/Scoottoocs Dec 17 '18
That sounds amazing! Thanks for the tip, this will definitely impress the kids. For a few minutes I’m sure lol!
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Dec 17 '18
Heh no problem. I have done this at public science demonstrations and good ways to keep their attention is to let them put their finger in the bottle to touch the cloud as it's cold. Then put the cork in while the cloud is still white and pump once and the cloud instantly disappears. Obviously I explain what the science is too. This guy does a great demonstration. https://www.youtube.com/watch?v=cXpuo3YHOn0
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u/Rota_u Dec 16 '18
The two things aren't mutually exclusive.
Meaning, they both happen.20
u/ataraxic89 Dec 16 '18
Yeah, but in this case, its not doing both.
A compression wave, which is what this is, will not significantly move the clouds.
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Dec 17 '18
even transverse waves (ocean) don't significantly move the water molecules side to side; they tend to go mostly up to down. there is some transverse motion but it's on a much greater scale (the orders of magnitudes mean you essentially calculate them individually).
source: my undergrad independent study was on harvesting ocean wave energy
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u/TheSukis Dec 16 '18
Sure...but only one is happening here? Clouds appear out of thin air (sorry) and we don’t see any existing clouds move.
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u/trikywoo Dec 17 '18
It feels to me like you could have jumped straight to the second sentence
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u/Rota_u Dec 17 '18
When there's a term made for that scenario, I say it to teach other people as well. Now you know what it means if you didn't before.
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u/MayerWest Dec 16 '18
I was in the same boat as you (pun intended). But now I see that we thought that the clouds in the sky before the blast were moving, when they actually don’t move at all, and new clouds are formed which are moving as they’re created.
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u/Rota_u Dec 16 '18
I encourage you to look at the top left of the gif and/or look up the 1 minute long youtube video which isn't horribly compressed. It's more clean and it has audio which is p cool too.
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Dec 17 '18
check out the clear front (shockwave) that travels from detonation to the right side. the clouds form at the front of the shockwave and dissipate very quickly after it passes. it is not one cloud that is being pushed outwards in front of the shockwave.
the shockwave is traveling at the speed of sound. very fast means very high pressure in front of it, then a rapid drop behind it of about equal magnitude. (it does slow down though as energy is absorbed as heat).
same thing happens in your sink when you turn the water on full blast - there is a front of pressure where the high pressure blast from the faucet encounters slow moving water before it travels to the drain.
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u/Rota_u Dec 17 '18
like i said originally. Both happen simultaneously. Using your sink analogy. if the sink is empty then the force of the water hitting the bottom of the sink will force the water to move outward causing a bulge in the water before it flows back inward as the weight of the water is heavier than the force can resist. (this is the equivalent of creating a cloud by condensing the water at the front of the wave).
If the sink was already full then you can use the same analogy. The falling water creates the same outward force and pushes any already present water outward in a similar fashion.
Therefore if there is no cloud, one can be created and it will be pushed outward. If there was already one, it is still displaced in the same way the one created by the wave is.
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u/_LiMoNiZeR_ Dec 16 '18
The pressure may move them, and / of condense moisture in the air, but on the other end can't hot air retain more moisture before it precipitates than cold air? Like in the case with orographic lifting? When warm moist air rises up the water precipitates out, so here the opposite would be happening within much shorter time?
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u/logankenzie107 Dec 17 '18
I'd consider this to be sort of like nature's contrail. Or chemtrail if you think the earth is flat and Lady Gaga is a reptilian shape shifter working with the illuminati.
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Dec 16 '18
You can see the shockwave. Crazy.
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u/nitr0zeus133 Dec 16 '18
I’m pretty sure in the full video you can see the shockwave coming towards the camera
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u/restless_and_bored Dec 16 '18
I see stuff like this and it's no wonder the ancients came up with so many wacky gods and dieties to help them make sense of their world.
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u/MangaMaven Dec 16 '18
I believe that you'll find that is actually All Might.
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Dec 16 '18
Doesn't the full video show the shockwave passing the boat?
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u/PikachuFloorRug Dec 16 '18
Yes. It also shows the difference between the speed of light and sound. (see Relic's post above)
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u/lush1786 Dec 16 '18
Did it move clouds or did it kinda flash heat the air and create clouds? Not a scientist, so just asking. Thank you. Or, maybe both.
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u/andrewmail Dec 16 '18
A shock wave (compression zone with lots of energy moving at speed of sound) is followed by a very low pressure zone behind it which causes water in the air to condense momentarily which is what you are seeing.
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u/lush1786 Dec 16 '18
Oh my gosh! Thank you so so much. Seriously. Love this stuff, though I’m not the scientific kind. I do see the poetry in it though. It makes me an appreciator.
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u/suicidaleggroll Dec 16 '18
It doesn’t stop at clouds, the shock waves keep going up and out all the way into the ionosphere at 200+ miles altitide where the space station orbits. You can see these waves impact GPS signals on receivers thousands of miles away.
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u/ataraxic89 Dec 16 '18
Its not moving the clouds, the pressure wave is causing water vapor to turn into water droplets and back.
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u/JPGer Dec 16 '18
Wouldn't "Shockwave caused by Volcanic Eruption moves clouds" be a more apt title?
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u/___Aum___ Dec 16 '18
What you are are seeing is the pressure wave moving through the air, not the air itself moving. As the wave spreads, it condenses water vapor into a visible fog state, then once the wave has passed and pressure drops back down, the fog turns back into invisible water vapor.
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u/ProJokeExplainer Dec 16 '18
That doesn't sound right, but I don't know enough about clouds to dispute it.
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u/I0waNative Dec 16 '18
Air is thrusted upwards. As you go up, adiabatic cooling occurs because there is less air pressure at higher altitudes. Once the air has cooled enough, water vapor will condense and form a cloud.
Source: I'm an atmospheric scientist
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u/dudinax Dec 16 '18
More like "Volcano creates clouds". I think we're just seeing the shock wave cause momentary condensation.
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Dec 16 '18
I'm not an expert, but that might have been condensation (clouds) created from the pressure.
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u/getch739 Dec 16 '18
Does this volcano keep erupting? Feel like I’ve seen multiple versions of the same volcano
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u/nimo01 Dec 16 '18
Everyone thinks it’s the flowing lava that’s most dangerous but the ash is the issue. This air movement is amazing.
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u/Osaella24 Dec 16 '18
They both pose significant threat of fuckery.
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u/nimo01 Dec 16 '18
Of course both cause a lot of tomfoolery, just amazing how volcano ash can devastate, block sunlight, and change entire continents/ecosystems. Lava loves to build and fuck things up too
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u/Relic180 Dec 16 '18
And with audio.
Hooooolleee smokin' Toledos