Physicist strikes gold, solving 50-year lightning mystery:
[...] Ever wondered about lightning? For the past 50 years, scientists around the world have debated why lightning zig-zags and how it is connected to the thunder cloud above.
There hasn't been a definitive explanation until now, with a University of South Australia plasma physicist publishing a landmark paper that solves both mysteries.
Dr John Lowke, former CSIRO scientist and now UniSA Adjunct Research Professor, says the physics of lightning has stumped the best scientific minds for decades.
"There are a few textbooks on lightning, but none have explained how the zig-zags (called steps) form, why the electrically conducting column connecting the steps with the cloud remains dark, and how lightning can travel over kilometres," Dr Lowke says.
The answer? Singlet-delta metastable oxygen molecules.
Basically, lightning happens when electrons hit oxygen molecules with enough energy to create high energy singlet delta oxygen molecules. After colliding with the molecules, the "detached" electrons form a highly conducting step – initially luminous – that redistributes the electric field, causing successive steps.
The conducting column connecting the step to the cloud remains dark when electrons attach to neutral oxygen molecules, followed by immediate detachment of the electrons by singlet delta molecules.
[...] "The more we know about how lightning occurs, the better informed we will be in designing our built environment," Dr Lowke says.
Journal Reference:
John J Lowke and Endre J Szili 2023 Toward a theory of 'stepped-leaders' in lightning J. Phys. D: Appl. Phys. 56 045201 DOI 10.1088/1361-6463/aca103
