Science
Related: About this forumThunderstorms churn up a 'boiling pot' of gamma rays
https://www.sciencenews.org/article/thunderstorms-radiation-gamma-rays(See cool photo at link)
A view from a retrofitted spy plane soaring at 20 kilometers up revealed storms glowing and flickering in gamma rays, high-energy light invisible to the eye. Ten flights with the plane, NASAs ER-2 aircraft, captured the shimmer of gamma-ray outbursts over a variety of timescales and intensities, suggesting that the emissions are more complex and more common than previously thought. And the study unveiled a brand-new type of gamma-ray blast the researchers named a flickering gamma-ray flash.
Scientists knew of two main types of thunderstorm gamma-ray emissions. Short, intense blasts called terrestrial gamma-ray flashes are so luminous they can be seen from space, and last for mere fractions of a millisecond (SN: 1/10/23). Then there are longer, dimmer emissions called gamma-ray glows. Scientists spotted both on the flights.
Glows, the scientists found, were unexpectedly persistent and prevalent. They continued for hours, covered thousands of square kilometers, and were seen in nine of the planes 10 flights, physicist Nikolai Østgaard and colleagues report in the Oct. 3 Nature.
(More at link)
jaxexpat
(7,764 posts)It's not just coincidence anymore. Randomness may fuel the universe or at least create it.
Bernardo de La Paz
(50,872 posts)The "quantum foam" at the Planck lengths is essentially random, kind of randomly poking itself up into larger lengths where it has an effect on the observable universe.
We can in principle observe down near the Planck length but practically speaking we are nowhere near that so the foam is unobserved and only hypothesized. Planck lengths are exceedingly tiny.
jaxexpat
(7,764 posts)Never had mental acuity for the sort of math which takes over where spoken language fails. Vague images explicable in only meanest terms are about as good as it gets. All this stuff and nary an equation to be seen.
eppur_se_muova
(37,366 posts)Last edited Sun Oct 27, 2024, 09:53 AM - Edit history (2)
X-rays are produced by electrons being bumped into high-energy orbitals from the very lowest-energy orbitals in an atom. As the electrons drop back down into the core orbitals, they emit EM radiation at very short wavelengths. Gamma rays, in contrast, are formed by similar excitations of nucleons with the nucleus, and since the energies involved are typically much larger, can reach much shorter wavelengths. The least energetic known gamma radiation is actually in the far UV, though.
The wavelengths involved in the two types of radiation overlap extensively, so there is, TBOMK, no way to distinguish between gamma and X-rays within the range of overlap, unless possibly there is some difference in polarization, which is (again TBOMK) not easy to measure.
The point being: gamma rays from lightning need not imply nuclear process are taking place; it could be, instead, that X-rays are being emitted by highly excited multiply charged ions, which will have larger energies as the charge increases. It's hard to know what atoms with high atomic numbers (which give shorter-wavelength X-rays) would be present at high altitudes, though it's plausible that very common ions like Ca, Fe, Zn might be present in miniscule quantities. It wouldn't necessarily take much.
The article mentions that gamma rays are due to collisions of high-energy electrons with air molecules, which I suppose could imply (it's not clear) that the electrical energy is being converted directly radiation on impact (Brehmsstrallung, or "braking radiation" ), just as in an X-ray tube, without necessarily any intermediate excited states involved. X-ray tubes typically operate at a few kilovolts; higher voltage in an electrical storm could generate much shorter wavelengths.