What causes lightning? The answer keeps getting more interesting
83 points
2 days ago
| 5 comments
| quantamagazine.org
| HN
nomilk
4 hours ago
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That 7 second video of a small rocket shot into a cloud to induce a lightning strike (about half way down the article) is incredible.

https://www.youtube.com/watch?v=5BJIiX9_c_M

Any ideas why the lightning strike appears mostly green (and momentarily purple and orange)?

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postalcoder
39 minutes ago
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Copper emits a green-blue light in the flame test https://www.youtube.com/watch?v=dwsexjcROH4
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deepandmeaning
4 hours ago
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I'm imagining it's something related to the copper wire.
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teh_infallible
3 hours ago
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I always wanted to replicate this with a helium balloon and a long, wet string coated with copper filings.
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batch12
1 hour ago
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You'd probably need a very large balloon to overcome the weight of the string
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CamelCaseCondo
1 hour ago
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Maybe just salt water and skip the filings?
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freehorse
2 hours ago
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Tl;dr lightings may be caused by electrons/positrons from outer space hitting a cloud and initiating an "avalanche" of electrons.
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pfdietz
1 hour ago
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Cosmic rays are mostly protons, not electrons or positrons. You're mixing up to separate theories in the article.
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nephihaha
26 minutes ago
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Much of the time they occur when two weather fronts of different temperatures collide with each other.
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metalman
3 hours ago
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just in case you missed it, all matter carrys a charge, and all space(and matter) has energy radiating through it, making the universe an energy gradient.

sometimes you can see it happening.

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fguerraz
2 hours ago
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So, nothing new?

The cosmic ray hypothesis has been dominant for a few years now.

This magazine…

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JadeNB
10 minutes ago
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> So, nothing new?

> The cosmic ray hypothesis has been dominant for a few years now.

> This magazine…

I think saying "This magazine…" as if the flaws of Quanta are well understood and agreed may need additional elaboration. If you mean that experts have known this—well, the role of Quanta is to disseminate and explain expert research to scientifically literate non-experts; it is not meant to be distributing the latest research itself.

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joshikarthikey
42 minutes ago
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Soooo you are telling me that we still haven't fully understood something as fundamental as lightning and it's still an active area of research...
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JadeNB
9 minutes ago
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Not to be flip, but, depending on what "fully" means, we haven't fully understood much of anything about the real world.
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nephihaha
27 minutes ago
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Never mind this kind of lightning, it gets really interesting when we start to look at ball lightning, which is very real but rarely sighted.
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Tomte
5 minutes ago
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As a child I saw an acted segment about ball lightning in childrens‘ TV, following a person around the house, and had nightmares for a long time afterwards. The thing is spooky as hell.
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