# Electrical sparks
**URL:** https://boards.straightdope.com/t/electrical-sparks/51205
**Category:** Factual Questions
**Created:** [January 22, 2001, 3:24am UTC](https://boards.straightdope.com/t/electrical-sparks/51205 "2001-01-22T03:24:22Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)
#### Post date: [January 22, 2001, 3:24am UTC](https://boards.straightdope.com/t/electrical-sparks/51205/1 "2001-01-22T03:24:22Z")
In a dark room when we see a spark due to static electricity, what is the nature of the spark that we’re seeing? Is it a path of ionized air? Oxygen? Would we see it if it were in a vacuum?
(BTW, as usual, this is another question that my daughter asked that I was (barely? not?) able to answer)
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### Author:  [@Ms2001](https://boards.straightdope.com/u/Ms2001)
#### Post date: [January 22, 2001, 6:53am UTC](https://boards.straightdope.com/t/electrical-sparks/51205/2 "2001-01-22T06:53:36Z")
Ionized air, according to my high school physics teacher.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [January 22, 2001, 2:04pm UTC](https://boards.straightdope.com/t/electrical-sparks/51205/3 "2001-01-22T14:04:58Z")
I think there would be a glow even in vacuum. Not from ionized air, but because the electrons get accelerated by the electrical field and hit the target at a high speed. There’d be lots of UV and X-ray emission as well, if the voltage is high enough. In fact, that’s how most X-ray generators work, including the one your dentist has.