What is St. Elmo's fire?
6/15/2022 (Permalink)
Most people have heard of “St. Elmo’s fire” from one of two sources – they’ve seen the 1985 Rob Lowe vehicle, or they’ve seen the weather phenomenon.
We’re going to focus on the latter.
St. Elmo’s fire is usually spotted as a strangely persistent blue glow, usually during a storm.
The name is a bit misleading – it’s not fire at all. It’s actually closer to an electrical phenomenon.
Usually, it forms around a pointy object like a spire or a chimney. Pilots may also see it when they fly.
St. Elmo’s fire is actually a form of plasma, the fourth state of matter. As the electrical field around the pointy object intensifies, the air molecules surrounding it start to ionize and gain a positive or negative charge.
Storms cause differentials in voltage between the cloud layer and the ground, which is why people see St. Elmo’s fire during storms.
While it may sound a bit scary, St. Elmo’s fire itself is basically harmless – though we wouldn’t recommend standing outside during the storm that’s causing it.