Speed of sound

You see the sky rocket explode, but the boom doesn’t come for seconds. The lightning flashes, but the thunder is moments behind. The reason, of course, is that sound moves much, much, much slower than light.

Light is so fast — 186,000 miles per second — that everything we can see on Earth, we see almost instantaneously. Sound, however, travels at just 1,125 feet per second (more or less, depending on temperature, altitude, humidity). The source of the sound doesn’t need to be very far away for us to sense the lag.

Rule of thumb, it takes just less than 5 seconds for sound to travel a mile. If lightning flashes, count the seconds until you hear the thunder to calculate how far away it struck.

A bolt of lightning can be over five miles in length, have temperatures of 50,000 degrees F., and contain 100 million volts.

In 2007, 45 people were struck and killed by lightning in the U.S.; hundreds of others were injured.  Of the victims who were killed by lightning:

• 98% were outside
• 89% were male
• 30% were males between the ages of 20-25
• 25% were standing under a tree
• 25% occurred on or near the water

The reported number of injuries is likely far lower than the actual total number because many people do not seek help or doctors do not record it as a lightning injury.  People struck by lightning suffer from a variety of long-term, debilitating symptoms, including memory loss, attention deficits, sleep disorders, numbness, dizziness, stiffness in joints, irritability, fatigue, weakness, muscle spasms, depression, and an inability to sit for long.

National Weather Service

That’s funny, I don’t remember being struck by lightning and I have all those symptoms. Oh wait, including memory loss.