[_alternator_]

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.

[cshimmin]

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.

[_alternator_]

Yes, 50-minute exposures would certainly rule out geosynchronous; I've used image stacking to look at geo and you get visible movement relative to the star background after even a few seconds. Fifty minutes would be almost 15 degrees of movement relative to the background! This isn't even accounting for the fact that you would need to be looking in a narrow region above above the equator to get something geosynchronous to begin with.

There are other possiblities that are likely: Upper atmosphere tests resulting in transient luminous phenomena. This would be more likey in certain conditions where the sun could reflect off of specular matter (e.g., bits of metal). You would see this most likely within 1-2 hours of sunset or 1-2 hours of sunrise (source: I've used optical equipment to spot satellites professionally).

I'd note that thier pipeline for removing "plate defects" is not based on the PSF but on some vaguely defined "expert review" training. This can, and should, be a quantifiable step.

[dd8601fn]

> 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.

Couldn’t be aberrations in equipment, like lenses? Or film development?

[ted_dunning]

As stated in the abstract, the anomalies occur more within a window around a nuclear event.

[_alternator_]

This precise point has been challenged, FWIW. See https://arxiv.org/pdf/2601.21946.

[urig]

+/- 1 day of nuclear testing because these are old records so dates and times reported might be inaccurate.

[godelski]

  > Overall it seems pretty unscientific.

I'd agree with all your points and add some things to help people better "sniff-test" these kinds of papers.

  1) The paper is suggesting aliens... your suspicion hats should always go on
    - Carl Sagan said: "Extraordinary claims require extraordinary evidence". Is the evidence extra-ordinary?
  2) The authors aren't experts
    - Stephen Bruehl: A doctor of Anesthesiology
    - Brian Doherty: "Independent Researcher"[0]
    - Alina Streblyanska: Actually maybe a astrophysics researcher?[1]
    - Beatriz Villarroel: The top Google hit for her is for a UFO wikipedia[2]
  3) Authors don't share affiliations
    - Corresponding author has no domain expertize and no clear affiliation to others.
  4) Authors have hints of metric hacking
    - Villarroel has 8 citations in a paper with only 18[3]
  5) The GitHub repo is dead: https://github.com/dca-doherty/VASCO-ML

None of these things are enough to conclude that the paper is wrong, but they are red flags and don't require actually understanding any of the details of the paper.

If you do understand statistics there's clearly more red flags. The +/- windowing being a pretty big one, since there are much better tools for this (errors don't need to be symmetric! Nor do they need to be uniform!). There's also a pretty big assumption made that cshimmin didn't mention: the paper assumes all nuclear tests are in the public record. But I also assume if you have a strong statistics background then there's a high probability you didn't upvote the post.

[0] The man has effectively no online presence. Google searching his email yields effectively nothing except people posting about this paper in UFO groups (https://www.google.com/search?q=%22briandohertyresearch%40gm...). His linked GitHub also makes him anonymous (https://github.com/dca-doherty/) and his website linked is just about finding day care in Texas. He has one more paper on ArXiv, but it is from a few weeks prior

[1] Found their Linkedin (https://www.linkedin.com/in/alina-streblyanska-95b2375b/). Their most recent paper is also on UAPs, along with Villarroel. But also, they work for "Society of UAP Studies", which should be a big red flag. Also, they were working as a Post-doc for 12 years, which is a bit insane

[2] https://www.wikidisc.org/wiki/Beatriz_Villarroel and here's here Google Scholar https://scholar.google.com/citations?user=_Jc8gm0AAAAJ

[3] I looked at some other papers of hers and they show a similar pattern. This explains her citation count (which is rather low) and h-index (it's better to just click on the references and you'll see it's predominantly her referencing herself):

  - 2602.15171: 9 citations total, 8 are hers
  - "A cost-effective search for extraterrestrial probes in the Solar system" has many more, but still 6 to herself (and 3 to Loeb)
  - Transients in the Palomar Observatory Sky Survey (Yes, this is in "Nature"): 20 citations, 5 hers
  - Aligned, Multiple-transient Events in the First Palomar Sky Survey: 11/36
  - On the Image Profiles of Transients in the Palomar Sky Survey: 5/5
  - A Civilian Astronomer's Guide to UAP Research: 7/98 (actually not a red flag, but the title sure is...)
  - and so on

[cshimmin]

Not gonna lie, the first thing I noticed was that the first author was in an anesthesiology department. Your guidelines for sniff-testing are not unreasonable, and can definitely be helpful to people who are unfamiliar with the research area. But I quite intentionally did not appeal to any of those. As a (somewhat) subject matter expert, it's important to _ignore_ things like ad hominem judgement, and instead address the paper on its self-contained merits. And more importantly, to share my assessment of those with the lay public.

[godelski]

I'm glad you did it that way. I hope, my comment works well as an addendum to your type of comment. I don't think would have worked well on its own, nor prior to yours. Especially since nothing I said is an absolute rule that allows one to reject a work. But this paper sure does smell suspicious. I think it's good to have the stronger reasons to be suspicious and then understand some softer flags to navigate in unfamiliar territory.

[causal]

"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.

[WalterBright]

Aliens are not plausible.

[kristerj]

I think you just did the thing, but with his comment

[causal]

Agreed, and I don't think you understood my comment.

[WalterBright]

Perhaps you didn't write what you meant. I read it as we shouldn't think it is obvious that they aren't aliens.

[causal]

> there might be something else more interesting that is neither obvious nor aliens.

[kristerj]

I tend to think there is a really good chance all the "its aliens" phenomena are natural phenomena that we are hundreds of years away from even having the tools to study. Probably like early humans trying to guess what the sun is made of.

[shepardrtc]

Why not?

[WalterBright]

Nobody has ever found the slightest smidgen of evidence of aliens, nor any plausible theory of what aliens would be like. It's about as likely as someone inventing a car that runs on water.

[shepardrtc]

Plenty of evidence has been found. For one, the US government has leaked/released a video showing instant acceleration of a flying object. Nothing on earth can do that.

[WalterBright]

You're heaping one implausibility (aliens) in with another implausibility (violating the laws of physics) making the combined plausibility indistinguishable from zero.

It's not necessary for me to debunk your theory. It is incumbent upon you to prove it valid.

[LocalH]

While it's always good to elevate evidence-based knowledge above "woo" or "belief", it's not healthy to close your mind off completely against anything that isn't currently proven. We might know that we don't know a lot of things, but the most interesting thought experiments happen in the area that concerns the things we don't know that we don't know.

[krapp]

One can go to /r/UFOs and see plenty of "interesting thought experiments" happening in that area, and while that might be entertaining, it isn't compelling.

I think closing one's mind off 99.999% to "it's aliens" is perfectly healthy and justified. When you remove the folklore, memes, psyops and apply Occaam's Razor to the "evidence" and sort out mistaken natural phenomena, misinterpreted data, classified but terrestrial technology and outright hoaxes, you aren't left with much of anything, and certainly nothing definite. There is no reason to assume the phenomenon mentioned in the linked paper demonstrates the presence of alien spacecraft but the UFO community is going to run with it anyway.

Call me when David Grusch comes through with that "catastrophic disclosure" we were promised or when Lue Elizondo can tell the difference between a starship and a chandelier. This is just Bob Lazar and Majestic-12 all over again.

[WalterBright]

When an engineer tells me he built a car that runs on water, he'd better bring some pretty amazing evidence. And no, I'm not going to waste time reading his paper looking for the inevitable flaw, either.

I've heard "evidence" of aliens my entire life. Guess how many panned out. Zero. But that never seems to discourage anyone from believing that an artifact on a photo must have the most implausible explanation ever - aliens!

Where do you draw the line? Time travel? Teleportation? Astrology? Fortune tellers? Razor blade sharpening? Reincarnation?

[BobbyJo]

... wouldn't this be a slight smidgen of evidence?

[WalterBright]

Nope

[WalterBright]

Sorry to bring the bad news.

[doctorpangloss]

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.

[recursivecaveat]

Chatbots are certainly not objective. There are countless articles are this that and the other bias with them. The whole sycophancy blowup or their basic inability to choose a fair random number without assistance should clearly demonstrate that they have many implicit biases. The distribution of answers chatbots give to questions is being constantly and deliberately tweaked by their developers.

[ordinarily]

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."

[_alternator_]

Two things here: radiation exposure could explain this, since there's a period after exposure and before developing where you can get radiation exposure.

Second, and perhaps more importantly, is that there's a detailed criticism of this line of research available, including evidence against the argument that these are more likely ±1 day of nuclear tests. See https://arxiv.org/pdf/2601.21946, and also https://arxiv.org/pdf/2402.00497 for a study of plate defect issues.

I think the current paper continuing this line of research should be read cautiously. I don't love discounting ideas out of hand, as these folks clearly have put effort into the analysis. But the rebuttals read as at least as high quality analysis, and "it's aliens" requires a lot of evidence for me to take it seriously.