Quiet Lightning

Yesterday I was introduced to Midwestern weather. I didn’t really think it was going to be that impressive. Eh, tornadoes. So what.

Dude, I was wrong.

It’s really rather impressive, if not a tiny bit frightening. We were under a tornado watch for most of the day yesterday and while most of the weather wasn’t anything to be worried about, there were several sporadic times where it changed suddenly and dramatically. Downpours, hail storms, rapid temperature changes.

But the thing that impressed me the most was the lightning. I’ve never seen so much lightning in one storm in my entire life. Big, impressive, cloud to cloud arcs and clouds lit up from behind. Pretty. Powerful. Majestic.

But quiet. None of the lightning was followed by thunder. It was something I didn’t understand. And none of my Midwestern friends could tell me why. Thankfully, I have the internet at my disposal and an unquenchable curiosity for randomness. Therefore, should you also wonder why there was all of that lightning without thunder; I am here to share the information.

It seems when lightning strikes, the air around it becomes extremely hot - so hot that the heat causes the air around it to expand rapidly. When the air heats up and expands, it creates a compression wave that propagates through the surrounding air for the first 10 yards. This compression wave then manifests itself in the form of a sound wave that decreases with distance. Ta-dah! Thunder.

We’ve been taught that sound travels much slower than light, so we see the flash of lightning before we hear the thunder. In air, sound travels roughly 1 mile every 4.5 seconds. Light travels at a blazing 186,000 miles per second.

It is impossible to have lightning without thunder, contrary to what I witnessed last night. Many people refer to this as “heat lightning”, although no such thing actually exists. If lightning is observed without thunder, the storm is simply more than 15 miles away. There is thunder… you’re just too far away to hear it.

Even if it looks like the storm is right on top of you, apparently.

And thus, this ends the science lesson for today.

End Blog.