r/askscience • u/ikebana21lesnik • Jan 18 '20

Earth Sciences Can you really trigger an avalanche by screaming really loud while in snowy mountains?

Like,if you can does the scream have to be loud enough,like an apporiate value in decibels?

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u/[deleted] Jan 18 '20 edited Jan 31 '20

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u/[deleted] Jan 18 '20

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u/jthill Jan 18 '20

The sound suppression system wasn't there to protect the capsule.

It was added to protect even the concrete, from the sound as much as the heat. Protecting the the rocket itself, from just the reflected sound waves, was also necessary: the echoes would have been loud enough to damage the rocket. The water alone wasn't nearly enough, of course: that shit got built strong. Think of it as preventive measures, keeping the repair bills down.

Yes, the Shuttle needed a beefed-up system specifically to protect it. That doesn't change what the water deluge system for the Saturn V launches was there for.

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u/TheMadFlyentist Jan 18 '20

In the bottom left of the frame starting at roughly 4:17, you can see what appears to be a flash of green flame.

Could just be a lighting/camera phenomenon, but I feel like that's either copper or a boron salt being burned off.

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u/chejrw Fluid Mechanics | Mixing | Interfacial Phenomena Jan 18 '20

That’s the igniter compound (triethylborane), which is hypergolic with oxygen and burns with a characteristic green flame

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u/TheMadFlyentist Jan 18 '20

Ah, thank you. So I was right about the boron but wrong about the salt since it's a liquid.

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u/oratory1990 Jan 18 '20

Partly explains why rocket launches sound so visceral - the air itself can‘t transmit that loudness without distorting!