Historical research guide · 0707 · 2021
Toward a theory of ball lightning occurring in houses and aircraft
John J. Lowke · Wilfried Heil · Eugene Tam · Anthony B. Murphy
In one minute
John Lowke and Anthony Murphy of CSIRO in Australia, with Wilfried Heil and Eugene Tam, take on the hardest version of the ball lightning problem: the balls that appear inside houses and aircraft cabins, where no lightning channel can reach. Their answer is a gas-discharge calculation. Track four populations at once — electrons, positive ions, negative ions and metastable singlet delta oxygen molecules, an excited form of oxygen that stores energy without radiating it — and a stable, self-standing ball of plasma appears once the metastable density is high enough. The metastables act as a fuel tank: they knock electrons back off negative ions as fast as the oxygen recaptures them, so the ball holds its own ionisation instead of decaying. Because it conducts well, the electric field inside is almost nothing, while the field at its rim is strong enough to make more metastables and prolong its life. The proposed supply is corona from any sharp metal point in a thunderstorm field.
Connection
Chapter 9 needs a physical account of self-organised luminous balls that survive without a wire, a fuel line or a container, and Lowke’s group supplies one built entirely from measured discharge chemistry. Chapter 1 gains a clean rung on the evidence ladder: a mechanism that makes a number — the required metastable density — which a laboratory can go and test.
From the source
Solving the gas-discharge equations for electrons, positive ions, negative ions and metastable singlet delta oxygen molecules together yields a stable ball-like plasma, provided the metastable molecules reach densities of the order of ten to the seventeenth per cubic centimetre. The resulting electron density is about ten to the eleventh per cubic centimetre.Abstract, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
The ball can exist independent of the electrodes — it is not an arc tethered to a contact, but a free-standing structure that carries its own energy store.Abstract, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
Its persistence rests on an internal equilibrium: metastable molecules detach electrons from negative ions at the same rate that electrons re-attach to oxygen atoms and reform those negative ions, so the ionisation is continuously replenished rather than decaying away.Abstract, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
Because the ball is highly conducting, the electric fields inside it are very low — which is why it can drift through a room without behaving like a discharge channel.Abstract, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
Significant electric fields do exist at the edge of the ball, where its potential has to match the ambient potential, and the authors calculate that these rim fields are strong enough to excite further metastable molecules and extend the ball’s lifetime.Abstract, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
The proposed source of the metastables is corona pulses from any high-voltage point inside a structure — a metal tip in a house or an aircraft fuselage — since large local fields appear at such tips in the ambient field of a thunderstorm. Whether corona in air can actually accumulate metastable densities of that order is the measurement this account waits on.Abstract, closing sentences, Journal of Atmospheric and Solar-Terrestrial Physics 213, 105532
The way in
https://doi.org/10.1016/j.jastp.2020.105532How to cite it
John J. Lowke, Wilfried Heil, Eugene Tam, Anthony B. Murphy (2021) Toward a theory of ball lightning occurring in houses and aircraft doi:10.1016/j.jastp.2020.105532