Tesla coils
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/31383674@N00">JMacPherson</a> from Calgary, Canada
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/lipstickproject/44845089092/">Beakernight</a>