22 October 2020 at 1:22 pm #583270Robert Ian HendersonParticipant
It had to be bad science or spiders in the waveguide.22 October 2020 at 2:30 pm #583271
It seems the alma data has been withdrawn temporarily while they review the initial calibration. It is not known if this will impact the results.
Regards Andrew22 October 2020 at 10:23 pm #583272Dr Paul LeylandParticipant
Although the original data has been withdrawn from its original repository it is still available if you know where to look. If there is any interest I will try to dig it out and let you know where to find it.28 October 2020 at 5:36 pm #58330528 October 2020 at 9:13 pm #583313
Looks like life is slipping away. I wonder if the same will happen to water on the bright side of the moon?
Regards Andrew31 October 2020 at 2:16 pm #583327Dr Richard John McKimParticipant
I have to write, as a chemist, that amounts of phosphine in the atmosphere of Venus, however small, must be regarded as dubious. In the presence of tiny amounts of oxygen, the gas is spontaneously flammable, forming phosphorus pentoxide as a white smoke, and water vapour. We know that photolysis of oxygen-containing compounds by short-wave UV radiation can produce oxygen radicals in the atmosphere of Venus, so there is certainly going to be a short lifetime for any phosphine. By the way, I often demonstrated its flammability to my A level classes, though I don’t recommend it as a home experiment. You take a tiny piece of white phosphorus, which of course can no longer be bought, and cover it with a few cc of very concentrated NaOH solution, and heat gently it in the fume cupboard. Attach a delivery tube and after a few moments the apparatus will emit beautiful white smoke rings from the end, as each bubble of phosphine combines with the air. No need to add that caustic soda is dangerous, and white phosphorus even more so!31 October 2020 at 4:57 pm #583328
I have a fondness for Phosphorus chemistry. Reactions of phosphorus studied during A Level chemistry resulted in the necessary attendance of the local fire brigade in the chemistry lab. Great fun!17 November 2020 at 9:15 am #583379
The team responds to criticism of their announcement of phosphine discovery here. They say the ALMA data support PH3, but at lower concs than previously claimed. Standing by their conclusion, they call for further data.17 November 2020 at 10:12 am #583380
I have just been reading the new paper and they are relying on the centriod of the spectral line to distinguish PH3 from SO2 in the 0.3 k/s range. While I feel sure they will have corrected for the Earths velocity as that would be standard for stellar work, I can’t find any reference to correction for the motion of Venus. Does anyone know if this was done.
Also the high wind speed on Venus could shift the line if it did not average out in the measurement.
Regards Andrew26 January 2021 at 10:28 am #583747
Further doubt cast on the ALMA detection of phosphine in Venus’s atmosphere: “Complications in the ALMA Detection of Phosphine at Venus”
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