> Here are the 10 most upvoted stories of all time on Hacker News:
Whisky: Wine Supercharged with the Power of Apple's Game Porting Toolkit - Score: 185
First Is the Worst: Nintendo's Color TV Game 6 and 15 - Score: 39
VectorDB: Vector Database Built by Kagi Search - Score: 198
Periodic Table of Tools - Score: 94
Apertus – Open-Source Camera - Score: 45
Write Guix package definitions in a breeze: Introducing Guix Packager - Score: 102
Grimoire: Open-Source bookmark manager with extra features - Score: 174
Updated a Complex Function Plotter that lets you sketch curves and see its image - Score: 8
They're Made Out of Meat (1991) - Score: 144
City of Boulder Open Data - Score: 45
Is there anything else you would like to know?
That spectrum is so noisy. How can they infer the blue fit from the (noisy) white points? The data look almost consistent with flat (no detection). And even if there is a detection, it looks like many other models could potentially fit the data...
> How can they infer the blue fit from the (noisy) white points?
By having a detailed model, and modern probabilistic techniques:
The planet’s terminator is modelled as a plane-parallel atmosphere in hydrostatic equilibrium, with uniform chemical composition. The chemical abundances and pressure-temperature (P-T) profile are free parameters in the model. The retrieval framework follows a free chemistry approach, whereby the individual mixing ratio of each chemical species is a free parameter....
Our canonical model comprises of 22 free parameters overall: 11 corresponding to the individual mixing ra- tios of the above chemical species, 6 for the P-T profile, 4 for the clouds/hazes and 1 for the reference pressure Pref , defined as the pressure at a fixed planetary radius of 2.61 R⊕. The Bayesian inference and parameter estimation is conducted using the MultiNest nested sam-
pling algorithm (Feroz et al. 2009) implemented through PyMultiNest.
In the paper they analyze 3 models, "no offset", "offset" and "offsetx2". It's strange that they get better fit for CO2 and CH3 en the "offsetx2" model, but in that model the DMS disappears. So there it at least one model.
Also, they analyze common molecules like CO2, CH4, H2O, NH3 and biologically interesting molecules like CH3-S-CH3 (DMS), HCN, CH3-Cl. From the discussion in the paper it looks like the CH3- part is important, so I'd like to see a brute force search with everything that is in https://en.wikipedia.org/wiki/Atmosphere_of_Titan and has a methyl group, like CH3-CCH, CH3-CN. My Chemistry and Astronomy is no so good, so I'd like to add CH3-OH, CH3-NH2, CH3-SH, CH3-CHO and a few more from https://en.wikipedia.org/wiki/List_of_interstellar_and_circu... I removed the ones that are big or has too many oxygen (like CH3-COOH).
[Sorry for the sources, but I'm not an expert is spectroscopy.]
My guess is that they assumed something like
a% * CH4 + b% * CO2 + c% * H2O + others
and get the best fit for a%, b%, c%, ... using the white points. Later, using these numbers they draw the blue line.
The peak for DMS is not clear for my untrained eye, so I can't guess what they did there. (Perhaps it's just the best fit.) It would be nice to see the a graph of the blue line they guessed with DMS and a superimposed red line with and atmosphere with an alternative atmosphere where the DMS is replaced with something uninteresting (N2? H2O? More CH4? I have no idea what is uninteresting here.)
> Here are the 10 most upvoted stories of all time on Hacker News:
Whisky: Wine Supercharged with the Power of Apple's Game Porting Toolkit - Score: 185 First Is the Worst: Nintendo's Color TV Game 6 and 15 - Score: 39 VectorDB: Vector Database Built by Kagi Search - Score: 198 Periodic Table of Tools - Score: 94 Apertus – Open-Source Camera - Score: 45 Write Guix package definitions in a breeze: Introducing Guix Packager - Score: 102 Grimoire: Open-Source bookmark manager with extra features - Score: 174 Updated a Complex Function Plotter that lets you sketch curves and see its image - Score: 8 They're Made Out of Meat (1991) - Score: 144 City of Boulder Open Data - Score: 45 Is there anything else you would like to know?