This leaves (2), which is a bear because it states a negative. The claim that the phosphine on Venus is biological in origin requires no feasible route to the substance given the known chemistry of the planet's atmosphere.
Given that Venus' atmosphere is a complex mixture held at very high temperature and pressure, the "sign" seems pretty weak here.
>Given that Venus' atmosphere is a complex mixture held at very high temperature and pressure, the "sign" seems pretty weak here.
The phosphine signal is coming from a portion of Venus' atmosphere that has pressure and temperatures similar to that of the the Earth's surface, according the the Earth and Sky article.
Not really. Phosphine is broken down by UV light so having it be concentrated higher in the atmosphere, where it's exposed to more UV light, would be difficult to explain via transport from a lower altitude source.
This is a possibility but we’ll have to see what the paper makes of this, if anything. It may depend on knowing more about the motion of the atmosphere. It was also an unexpectedly large amount of phosphine apparently, more than would normally be stable at that altitude (so it’s definitely being renewed).
But again, this is just a string of tweets—hard to say anything without the paper!
I think it's debatable, at best, whether Occam's razor would favor "an unknown process" over a known biological process. Especially when some research apparently has already been done, without success, to discover alternate processes.
(And, by the way, the unknown process could also be biological!)
You're implying we don't have any information at all. We do.
Even if you argue is it's limited, to our knowledge bio processes outside of earth has been zero. Whereas, non-bio chemical processes is greater than zero. So now people want to bet on that it's bio??
Milky Way contains on the order of half a trillion star systems. Would having, say, a million planets carrying some form of life in our galaxy alone qualify as “rare”?
To be fair, I wouldn't consider that rare. When we talk about life, we usually think in terms of are we alone. If there are a million planets with life, life isn't rare, regardless of what percentage of planets have life.
You don't know if an unknown route to phosphine generation would be simpler and more likely, you would just find such an announcement more mundane, which you mistake for it being more plausible.
Invoking Occam's razor to compare two unknowns makes about 0 sense.
1. phosphine is found on earth in low-oxygen environments that harbor life (e.g., swamps)
2. abiological routes to phosphine, although known, require unusual reagents and/or elevated temperatures
This 2019 article gives some background:
https://news.mit.edu/2019/phosphine-aliens-stink-1218
Here's some evidence of phosphine production in a swamp:
https://www.sciencedirect.com/science/article/abs/pii/014663...
This leaves (2), which is a bear because it states a negative. The claim that the phosphine on Venus is biological in origin requires no feasible route to the substance given the known chemistry of the planet's atmosphere.
Given that Venus' atmosphere is a complex mixture held at very high temperature and pressure, the "sign" seems pretty weak here.