Phosphine is a molecule made of one phosphorus and three hydrogen atoms. On planets like Jupiter and Saturn, pressure and temperature are so high that phosphine can form by coincidental chemical reactions, and indeed phosphine has been observed in the atmosphere of these two planets. On planets like Venus, however, the pressure isn’t remotely large enough to produce phosphine this way.
And the only other known processes to create phosphine are biological. On Earth, for example, which in size and distance to the Sun isn’t all that different to Venus, the only natural production processes for phosphine are certain types of microbes. Lest you think this means that phosphine is somehow “good for life”, I should add that the microbes in question live without oxygen. Indeed, phosphine is toxic for forms of life that use oxygen, which is most of life on earth. In fact, phosphine is used in the agricultural industry to kill rodents and insects.Sabine Hossenfelder, “Whatever happened to Life on Venus?” at BackRe(Action) (March 20, 2021)
Anyway, the researchers were convinced they had found phosphine, therefore maybe life or past life. So what happened?
Well, briefly, there were inconsistencies between the measurements from two telescopes and they had not processed the data correctly. Still, with corrections, there was a tiny bit of phosphine, “something between 1 and 4 parts per billion.” But then,
It was not only that finding phosphine was surprising, not finding sulphur dioxide was not normal either; it had been detected many times in the atmosphere of Venus in amounts about 10 times higher than what the phosphine-discovery study claimed it was.
Already in October last year, a paper came out that argued there’s no signal at all in the data, and that said the original study used an overly complicated twelve parameter fit that fooled them into seeing something where there was nothing. This criticism has since been published in a peer reviewed journal. And by the end of January another team put out two papers in which they pointed out several other problems with the original analysis.Sabine Hossenfelder, “Whatever happened to Life on Venus?” at BackRe(Action) (March 20, 2021)
Hossenfelder ends by reminding us, re phosphine on Venus, that “ absence of evidence is not evidence of absence.” True, but that’s just a corollary of the fact that one can’t prove a negative. No, we can’t but that doesn’t prevent us from drawing reasonable conclusions. The proverb has been used to cover far too many situations where a more realistic conclusion would be “There is no particular reason to believe this.”
See also: Sabine Hossenfelder Reassures Us That Schrodinger’s Cat Is Still Not Dead. Hossenfelder: It’s no secret that I myself am signed up to superdeterminism, which means that the measurement outcome is partly determined by the measurement settings. In this case, the cat may start out in a superposition, but by the time you measure it, it has reached the state which you actually observe. So, there is no sudden collapse in superdeterminism, it’s a smooth, deterministic, and local process.
Remember “ET!” space junk ‘Oumuamua? A conventional explanation is now offered: Nitrogen ice from Pluto. It’s curious how folklore can prevail for ages in science as long as it has a naturalistic origin. Maybe Top People shouldn’t count on everyone just forgetting that now.