The odds of being struck by lightning are less than one in a million, but those odds were greatly reduced this month when more than 4.2 million lightning strikes were recorded in every Australian state and territory over the weekend of November 12-13.
When you consider that each stroke of light travels at over 320,000 kilometers per hour, that’s a huge amount of electricity.
Have you ever wondered about lightning? For the past 50 years, scientists around the world have debated why lightning zigzags and how it relates to the thundercloud above.
There has been no definitive explanation yet, as a plasma physicist at the University of South Australia has published a landmark paper that resolves both mysteries.
Dr. John Locke, a former CSIRO scientist and assistant research professor at UniSA, says the physics of lightning has baffled the best scientific minds for decades.
“There are a few textbooks on lightning, but none explain how zigzags (called steps) form, why the electrically conductive column that connects the steps to the cloud remains dark, and how lightning can travel for kilometers,” Dr. Says.
the answer? Monostable oxygen molecules.
Lightning essentially occurs when electrons strike oxygen molecules with enough energy to form single, high-energy delta oxygen molecules. After colliding with the molecules, the electrons ‘dissociate’ form a highly conductive – initially luminous – step that redistributes electric fieldcausing successive steps.
The conduction column connecting the step to the cloud remains dark when the electrons are bound to the neutral oxygen moleculesfollowed by the instantaneous separation of electrons by single delta particles.
Why is this important?
“We need to understand how lightning starts so we can work out how to better protect valuable buildings, planes, skyscrapers, churches and people,” says Dr. Lockie.
While it is rare for humans to be struck by lightning, buildings are struck many times, especially tall, isolated buildings (the Empire State Building is struck about 25 times each year).
The solution to protect structures from Lightning It remained the same for hundreds of years.
The lightning rod was invented by Benjamin Franklin in 1752, which is a thick fencing wire attached to the tallest building and connected to the ground. It is designed to attract lightning and earth electric chargewhich saves the building from damage.
There are also hundreds of currently unprotected structures, including shelter sheds in gardens, often made of galvanized iron, and supported by wooden posts.
This may change with new Australian Protective Standards recommending the earthing of these surfaces. was dr. Locke is a member of the Australian Standards Committee which recommended this change.
“Improving lightning protection is very important now due to extreme weather events caused by climate change. Also, while the development of environmentally friendly composite materials in aircraft is improving fuel efficiencythese materials greatly increase the risk of lightning damage, so we need to consider additional protection measures.
says d. Locke: “The more we know about how lightning occurs, the better informed we are about the design of our built environment.”
The paper, “Towards a theory of intervening leaders in LightningIt was published in Physics Journal D: Applied Physics. It was authored by Dr John Locke and Dr Andrey Szeli of the University of South Australia’s Future Industries Institute.
John J Lowke et al, Towards the ‘tiered leaders’ theory of lightning strikes, Physics Journal D: Applied Physics (2022). DOI: 10.1088/1361-6463/aca103
University of South Australia
the quote: Physicists Strike Gold, Solve 50-Year Lightning Mystery (2022, November 24) Retrieved November 24, 2022 from https://phys.org/news/2022-11-physicists-gold-year-lightning-mystery.html
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