3 ms·
"In our view, the ring-like image found by the EHTC is not the intrinsic structure of Sgr A* but arises from the sparse u-v coverage of the EHT array in 2017; t
by aaroninsf 2y ago
"In our view, the ring-like image found by the EHTC is not the intrinsic structure of Sgr A* but arises from the sparse u-v coverage of the EHT array in 2017; that is, from the corresponding [...] structure in the PSF."
I.e. authors assert the image processing path inserted rather than revealed the famous correlation with Interstellar black hole imagery.
- somat 2y agoI hesitate to comment on something I know so little about, but that has never stopped me before. The EHTC approach would appear impossible to calibrate correctly, My understanding(the thousand foot view really) is they calibrated a generative model on what they expect to see based on their expected inputs, fed in the actual inputs and got what they trained their model on. great success, good work everyone. I guess my unease with this approach is it feels there are too many assumptions baked in.
- rcxdude 2y agoIt's not so biased as that: the process makes some assumptions (mainly, that the image structure is relatively simple) but it is agnostic to whether it's looking at a black hole or some other image (it's not like an image generation AI where they fed it in a bunch of existing images of what they thought black holes might look like). The techniques they used are used in other areas of astronomy. The criticism in this paper seems to be focused on how one of those assumptions could lead to the ring structure, not because they biased it with presupposed images, but due to the mathematics of how the techniques attempt to determine the image from the raw data. It makes some sense to me that this could happen, but I'm not really equipped to evaluate who seems to have the better points.