Name: 如何將聲音變成光。聲光效應 (How to Turn Sound Into Light: Sonoluminescence)
Uploaded: 2021-01-14T04:43:57.000Z
Duration: 2 min 7 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

The pistol and mantis shrimps are both crustaceans that snap their claws and perform magic. Well,

at least a sound and light show: the jet of water squeezed out from between their claws

情態副詞

travels at such speeds that it cavitates - the liquid water under negative pressure is literally

pulled apart into bubbles of water vapor. When the bubbles collapse in on themselves,

they give off a loud "snap," and amazingly, a small flash of light. The shrimp use the

sonic shock wave to stun or kill prey, but physicists are far more interested in the

flash of light, because we still don't exactly know why it happens.

Collapsing bubbles can also be created in a laboratory simply by using sound - since

sound, as we know, is basically just molecules repeatedly pushing against each other and

then pulling apart, if the sound waves are intense enough, the low pressure will again

be low enough to pull the liquid apart into vapor and cause cavitation bubbles. The bubbles

then collapse, and under certain circumstances, they produce light even brighter than the

shrimp. This phenomenon of turning sound into light is called "sonoluminescence."

We know that the light flashes are incredibly short - lasting only about 100 picoseconds

- and are surprisingly high energy, meaning the collapsing bubbles may be up to 10 times

We don't know for sure, though, how the inside of the bubble gets that hot, or what exactly

is giving off the light. The bubble collapses so quickly that the gases inside are heated

by compression, but the increased pressure might also cause water vapor in the bubble

to rapidly condense back to a liquid, releasing large amounts of latent heat.

And the flash itself might come from glowing red-hot Argon or Xenon gas in the air bubble,

OR from heat tearing water vapor apart into hydroxide and hydrogen ions which then recombine

and give off light, OR from the whole interior of the bubble getting hot enough to become

a glowing plasma - OR it might be a combination.

Either way, the cool thing about sonoluminescence is that it's still not fully understood despite

being fairly simple to create - I mean, you can buy a basic sonoluminescence kit off the

If you want to hear about more unexplained phenomena in science, a whole bunch of youtubers

like vsauce, veritasium, thebrainscoop, and so forth have made videos about "unanswered

science questions" which you can find listed in the "All Time 10s" video of the same name.