Passion Made In Heaven

Lightning is Heaven kissing Her Majesty the Earth way too passionately, this is what occurred to me while reading about it in Wikipedia. The reality is of course much less romantic, but very interesting. A Disclaimer would be fine, though: If you know anything/everything about lightning or are a specialist on it, don’t read the post below, for it is just some simple stuff put together by a she-blogger, who was simply very curious about the phenomenon. For all she knows, it may be simply an omnium-gatherum of mistakes and bad reasoning and, which is even worse, stupid humour. Everyone else: let’s go!

Lightning, as we usually live to see it, is an atmospheric discharge of electricity occurring within cumulonimbus clouds, also known as thunderclouds, or between these thunderclouds and the ground. The energy/electricity involved is breathtaking: A bolt of lightning can travel at 45 km/sec, which is 160,000 km/h. It can reach temperatures approaching 28,000 °C. An average bolt of negative¹⁾ lightning can transfer enough energy to power a 100 watt light bulb for about two months. An average bolt of positive²⁾ lightning could power a 100-watt light bulb for 100 years.

So how does a bolt of negative¹⁾ lightning come to life? It stems from thunderclouds with strong static electrical charges: they are full of particles with positive and negative charges, which form a strong electric field. Usually, our cumulonimbus will have more positive particles in the upper parts of its imposing mass and the negative particles will prevail in its nether regions. While it moves over the Earth’s surface, the old lady herself reacts by inducing an equal but opposite charge (also known as falling in love) and the induced ground charge follows the movement of the cloud.

Next come channels or so-called stepped leaders: the cloud reaches to the ground by means of those almost invisible electrical fingers, step by step, and the Earth’s electric field grows stronger. It is highest on trees and tall buildings and if it is strong enough, the ground sends its own fingers, positive leaders, to meet the negative leaders from the cloud midway. When the two leaders intertwine and caress each other, the electric current greatly increases and when it is strong enough, an electrical discharge occurs – a bolt of lightning. During the strike, the air surrounding the electricity becomes a discharge channel, too, and as a reward, it gets superheated by it (up to 30,000 °C). The air expands rapidly upon that, almost like rapid breathing, thus it produces shock waves heard as thunder.

Positive²⁾ lightning occurs when the fingers come from the positively charged cloud tops and the Earth responds with a negatively charged streamer. The overall effect is a discharge of positive charges to the ground. Positive lightning is much more dangerous, much stronger and can occur across greater distances (bolt from the blue).

Time for some related Trivia, also from Wikipedia:

1. Extremely large volcanic eruptions ejecting stuff (gases and solid material) high into the sky can trigger lightning, a phenomenon observed and documented by Pliny The Elder during the AD79 eruption of Vesuvius, before he died in it.

2. Trees can kill you if you stand under them during a thunderstorm because they are basically tall, natural lightning conductors; for the same reason they are known to provide protection against lightning damages to the nearby buildings. A frequently struck tree is the Pine, whereas Oak will get out of it unscathed, mostly, due to differences in their root system and some other.

3. Different locations worldwide each have their own potential for getting struck. It depends on the soil, the clouds, and the humidity, among other things. In Slovenia, you will be exposed to 3 lightning bolts hitting a square kilometre of the average ground in a year.

How about lightning safety?

The bad news is, there are no safe locations if you are reluctant to go indoors or do not get the opportunity to when the thunderstorm comes. The only safe place outdoors would be your car, but don’t touch the ignition key, it is made of metal!

The good news is the chances you’ll get hit are not really big: nearly 2000 people per year in the world are injured by lightning strikes, and between 25 to 33% of those struck die.

One would have thought this means one person can have only one of these close encounters with electricity and then it is somebody else’s turn. Mistejka to mejka! Roy Sullivan has the record for being the human who has been struck by lightning the most times. Working as a park ranger, he was struck seven times over the course of his 35 year career.

The most dangerous way of getting struck is the so-called ground strike, during which the bolt lands in the ground near you and is then conducted through you, frying you as it goes along.

The only thing we can determine during a rain storm is the distance between our position and the flash of lightning: (don’t read on if you know how…) Count the seconds between the lightning flash and the thunder. Divide by three to get the kilometres, by 5 for miles (reason: flash and thunder occur at the same time, but light is faster, so we see the strike before we hear about it).

Last but nor least:

Don’t panic. Always have a towel with you.

UPDATE: Should you become a victim of a strike, contact other survivors.