Transient 'objects' after nuclear tests are quite possibly high energy radiation from the tests themselves. Remember these are on film, and the film is likely removed from its protective housing for some time before, during, and after imaging. (And in many cases protective housing wouldn't help anyway.)

I get the sense that this topic is popular because "aliens y'all". It's much more likely to be radiation. It's possible that atomic tests kick luminous particles into the upper atmosphere. But it's not aliens.

When I was a research physicist I spent a lot of time looking at the effects of ionizing radiation in pictures, although mostly in the context of digital images. The mechanisms are a bit different for photo emulsions, but to me the reason I'd discount radiation is because they're specifically filtering for features that exhibit the expected point spread function (which is a geometric property of the telescope's optical assembly itself). I guess you could test by exposing emulsion plates to ionizing radiation and seeing how often you get PSF-like images by chance. Also, their search is for +/- 1 day of nuclear testing, which seems weird. Certainly radiation from fallout wouldn't make sense on the day before testing. It would have been useful to see +1 day and -1 day separately. Or 0-2 days. The way it's chosen makes me suspect they couldn't find a signal in those windows, and therefore it's probably just statistical noise that they've massaged out of the data.

But to me the biggest flag is that these images are from 50 minute exposures. The objects don't appear as streaks, so they are either very, very short flashes (much shorter than 50 min), or they are very far away. The authors interpret this to mean the objects should be in geosynchronous orbit, which doesn't make sense; objects in geosync would still appear to move relative to the star background over the course of 50 min. Yet this is the entire basis for their "shadow deficit" window calculation. You could constrain the duration vs distance by looking at the effect it would have on smearing the PSF, which would be interesting.

Overall it seems pretty unscientific. If you go looking through enough statistically noisy data for signals in enough places, you'll eventually find it.

"Not aliens" seems obvious but shouldn't be a basis for dismissing this either. I feel like sometimes we are so determined to dismiss aliens that we accept any plausible alternative too quickly, when there might be something else more interesting that is neither obvious nor aliens.

They're there before the tests though, and potentially more frequent around nuclear testing calendar days. The argument has never been "these only showed up after a nuclear test."

no, i think it's worse than that, and it's right in the study: "the nuclear correlation is just a function of which days Palomar was observing on... even that is not statistically significant. It's just noise." - https://www.metabunk.org/threads/transients-in-the-palomar-o...

another POV is the paper is sloppy in the parts that matter

Machine Learning goes both ways. A chatbot is not predisposed to ruin aliens enthusiast's days. It just does what it is told to do, like repro a paper, and it can tell you the problems in some limited, but globally important, objective way, and it did, and the paper has problems, and they're basic.