Static electric shock appears blue, but why?

[iNow 5899]

It’s winter in the Midwest US. The air is extremely dry. This leads us to more easily build up static... picking up electrons. Our hair goes in funny directions. We shock each other when touching. It’s a fun part of winter.

We also get shocked when touching the light switch on the wall since it’s connected to the ground of the house. 

The shock becomes visible at night, which adds a layer to the experience. 

Touching the light switch, feeling the jolt as the electrons flow from the finger to the lower resistance copper wire of the toggle switch into the ground, I can see the little micro lightening bolt jumping away from me toward the house ground. 

But why does it look blue, and not orange or white or something else? Is it just the temperature... the wavelength of the current being transferred?

[Endy0816 454]

Comes from the Nitrogen mainly.

 

Quote

Deexcitation of nitrogen

The excited nitrogen deexcites primarily by emission of a photon, with emission lines in ultraviolet, visible, and infrared band:

N₂^* → N₂ + hν

The blue light observed is produced primarily by this process.^[1] The spectrum is dominated by lines of single-ionized nitrogen, with presence of neutral nitrogen lines.

https://en.m.wikipedia.org/wiki/Ionized-air_glow

 

You have an... interesting.. idea of 'fun' lol. Kills me visiting relatives up North during the winter.

[swansont 7466]

Scuffing your feet on the carpet while holding a fluorescent bulb is another way to pass the time leveraging static electricity (My childhood was pre-Star Wars, so we didn't know to pretend it was a light saber)

[iNow 5899]

Thanks, y'all. I'll need to grab a fluorescent tube and give that a try with the kids.