I have an old friend, who loses his marbles at the approach of a thunder storm. As dark threatening clouds appear over the horizon, he drops everything he is engaged in and rushes out to his verandah, where he sits gazing rapturously as the distant lightning draws closer and closer, until the sky above his home transforms itself into a stage, where nature presents the greatest and most awesome light and sound demonstration that mankind can ever witness. Friends and acquaintances think that this long time buddy of mine is one of a kind, but they are wrong for there are many like him including - ‘yours truly’.

I am aware that my behavior is considered anomalous by friends and family, but deep down I know that those, who shut themselves up inside their homes and draw their curtains at the approach of a thunderstorm are actually missing one of the greatest ‘sont et lumiere’ shows on earth – a show that is magnificent by any standard and which comes ‘free of cost’. It staggers imagination with its variations and colors, for lightning comes in various forms. What we generally see in our part of the world is sheet and forked lightning varying from dazzling white to bolts of electric blue and even pink. There are technically equipped groups of people with specially adapted vehicles, who detect and then chase thunder storms (especially tornadoes). These individuals are called ‘storm chasers’ and their observations help in understanding storm behavior and subsequently save lives. Overtime, storm chasing becomes passionately addictive – a result perhaps of the frequent rushes of adrenaline released in their systems.

Electricity measuring millions of volts travels from cloud to cloud, but frequently forms a connection with the ground. The phenomenon is generally referred to as a ‘lightning strike’ and is fraught with dangerous consequences. It can cause fires, burns out electrical equipment, takes out transformers by travelling along power lines. Most chilling of all, it can kill by striking airborne vehicles such as aircraft or can directly hit objects on the ground including animals and humans. There are however some rules to follow during a thunderstorm, which may save a life. These ‘rules’ are imperative to follow for even people like me, who love to watch this awesome display of power and are based on a single most important scientific fact i.e. lightning is attracted to the nearest and best conductors in the vicinity.

Watching a thunderstorm must be done from a place with overhead cover like a closed verandah or if travelling, from the inside of a hard top vehicle with windows rolled up. In the event of being caught in the open, one should assume a position that is as low as possible with minimal ground contact. This can be done by crouching down like a ball with feet and knees together, head tucked into the chest and hands over both ears. Lightning causes electric currents along the top of the ground that can be deadly over 100 feet away. Crouching down is the best combination of being low and touching the ground as little as possible. Relative safety is also offered by staying close to tall structures or objects, which will attract bolts away from you.

The most interesting and almost unbelievable fact about a lightning strike is that while the bolt visible to the human eye appears to be travelling from the cloud to the ground, it is actually doing the opposite. Cloud-to-ground lightning comes from the sky down, but the part you see comes from the ground up. A typical cloud-to-ground flash lowers a path of negative electricity (that we cannot see) towards the ground in a series of spurts. Objects on the ground generally have a positive charge. Since opposites attract, an upward streamer is sent out from the object about to be struck. When these two paths meet, a return stroke zips back up to the sky. It is the return stroke that produces the visible flash. It all happens so fast - about one-millionth of a second – that the human eye doesn’t see the actual formation of the strike. As I write this piece, my study has suddenly gone dark and I can hear the roll of distant thunder. Perhaps it is time to wind up this week’s story and head for the verandah.

 

The writer is a historian.