A typical stroke of lightning stretches as long as eight miles, and forms when a negatively charged region in a storm cloud begins to send out a stepped leader. This leader is met by another leader rising from the earth, allowing the cloud to discharge to the ground, reducing the negative electrical charge. That's typically [...]

Lightning is not always confined to thunderclouds. For hundreds of years, people have observed lightning in the pillar of ash from an erupting volcano; these lightning displays are sometimes huge and much more fierce than the lightning from ordinary thunderstorms.
Scientists have long believed that these fearsome lightning displays are caused by friction between particles of [...]

When you were growing up, you probably heard all kinds of stories about lightning. In this post, we'll talk about some of the ideas you've probably heard. Some of the popular conceptions about lightning are true; others are not. We've talked about some of these beliefs in previous posts, so we'll link to other posts [...]

Let's start with an interesting fact: A typical cloud-to-ground lightning bolt is hot. Very hot. The air surrounding a lightning stroke is superheated plasma, which can be anywhere between 30,000 and 50,000 degrees Fahrenheit. By way of comparison, the outer layer of the sun is around 11,000 degrees Fahrenheit.
Worldwide, there are about six thousand lightning [...]

"One one-thousand, two one-thousand…" Counting the time between a flash of lightning has long been a popular way to figure out how far away a lightning flash is. Even today, some people still recommend this method to determine if you're safe from a direct strike, though this is something of a fallacy–thunder isn't audible very [...]

Lightning, when you get right down to it, is essentially nothing but static electricity on a grand scale. Rising water vapor condenses into droplets or tiny ice crystals, which acquire a static electric charge as they pass through the air. This mechanism is responsible for all the forms of lightning found in thunderstorms–cloud to cloud [...]

Normally, a lightning bolt (as we talked about before) hits the ground after a long, complex chain of events that concludes with a streamer from the ground reaching up and making contact with a descending ionization channel.
Throughout history, that's the way lightning has worked. People have not always understood the mechanism, of course; lightning's often [...]

Today we're not going to talk about lightning of the natural variety, and instead talk about lightning of the man-made variety. Specifically, we're going to talk about the Z-Machine, an enormous X-ray generator at Sandia National Laboratory.
How enormous? This enormous:

(You can click on the picture for a bigger version. Believe me, it's worth it.)
What you [...]

In our last post, we talked about the way lightning forms in stages, where a high electrical field will cause the formation of an ionization channel that grows in stages from a cloud toward the ground.
This same process occurs in solid materials under the influence of a large, powerful electrical field. Any time you have [...]

So, if you're over the age of six or so, you probably know that lightning tends to strike the highest point around. This is why staying under a tree during a thunderstorm is a bad idea; lightning will tend to prefer tall objects, and if you're under the tree when it gets hit, you're likely [...]