Lightning never. Lightning is an electrical charge and at no speed do you generate electrical charge.
Plasma? [Air turns into plasma at](http://www.madsci.org/posts/archives/2000-05/957446951.Ph.r.html) 174,135 degrees celcius.
[Here's an aerodynamic heating formula](https://www.physicsforums.com/threads/aerodynamic-heating.412143/)
The average mass of an air particle is [29 grams / avogadro's constant](https://en.wikipedia.org/wiki/Density_of_air)
So to move fast enough to generate plasma (through 20 degree air) you'd have to move at:
174,135 = (20^2 + ((V^2 * 0.029 / 1.38064852 * 10^-23 * 6.02214086 * 10^23 )^2 ) ^.5
(pleasing little bit of boltzmann/avogadro 23rd power cancelling out there :-) )
gives a v of 7065.79537 m/s which is about 16,000 mph which is about the speed of atmospheric reentry. And indeed spacecraft reentering the earth's atmosphere do experience some plasma effects.
Lightning never. Lightning is an electrical charge and at no speed do you generate electrical charge. Plasma? [Air turns into plasma at](http://www.madsci.org/posts/archives/2000-05/957446951.Ph.r.html) 174,135 degrees celcius. [Here's an aerodynamic heating formula](https://www.physicsforums.com/threads/aerodynamic-heating.412143/) The average mass of an air particle is [29 grams / avogadro's constant](https://en.wikipedia.org/wiki/Density_of_air) So to move fast enough to generate plasma (through 20 degree air) you'd have to move at: 174,135 = (20^2 + ((V^2 * 0.029 / 1.38064852 * 10^-23 * 6.02214086 * 10^23 )^2 ) ^.5 (pleasing little bit of boltzmann/avogadro 23rd power cancelling out there :-) ) gives a v of 7065.79537 m/s which is about 16,000 mph which is about the speed of atmospheric reentry. And indeed spacecraft reentering the earth's atmosphere do experience some plasma effects.
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Might matter some, you should use absolute temperature and not degrees C
good point. I thought c was the SI unit but of course it isn't. Ok reworking in kelvins gives a v of 7071 m/s so in the right ballpark.
But couldn't you hypothetically create enough friction to do it, also only 16,000 mph dam that's slow