Rui

Worth naming why the genre is so durable, because that explains why debunking one never kills it.

These items are cheap to repeat and expensive to check. Writing one costs nothing; verifying one means reading a legal code. That asymmetry means the claims propagate faster than corrections, regardless of truth.

They also flatter the reader — the pleasure is in feeling that officialdom is absurd — and content that flatters travels further than content that complicates. Which is why the same items reappear every year with a new headline, long after each has been individually checked and dismissed.

On your instinct about the lighting: trust it enough to investigate, and not enough to conclude.

Human intuition about composites is genuinely quite good on the things we evolved to notice — shadows pointing in inconsistent directions, edges that are too clean, scale relationships that do not work, reflections that do not match. Those are worth flagging.

It is also unreliable in the other direction. Real photographs frequently look wrong because of unusual lens compression, overcast light with soft shadows, heavy processing, or simply an unfamiliar scene. "This looks fake" has a high false positive rate.

So use the instinct as a trigger for step 1, never as the verdict.

There is a triage, it is quite reliable, and the key insight is that you do not have to find the error to know one exists.

The signals that get a manuscript set aside quickly:

• It is too short and too elementary. Famous problems have been attacked for a century by people with every available tool. A short argument using only undergraduate techniques would have been found. Not impossible, but the prior is extremely low.
• It does not engage with why previous approaches failed. Serious work on a hard problem knows the graveyard: which strategies were tried, what obstruction killed each. A manuscript that shows no awareness of that is usually walking into a known wall.
• It proves too much. If the same argument, applied slightly differently, would also prove something already known to be false, the argument is wrong and you do not need to locate the step.
• The claim outruns the machinery. A technique with known limits is being used past them without explaining why the limit does not apply.

That third one is the workhorse. It converts "find the mistake in eighty pages" into "exhibit one counterexample", which takes an afternoon.

Worth separating what people are actually buying, because for some buyers the product is fine.

If you know you are purchasing a nicely presented certificate as a joke gift, and possibly a small contribution to land conservation depending on the seller, that is a legitimate thing to want. Novelty gifts are allowed to be novelties.

The problem is the buyers who believe they have acquired a title and then use it — on documents, on bookings, on identification. That leads to embarrassment at best and to real difficulty where the document matters. Airlines and banks are not amused by a title from a certificate.

So the practical advice is: fine as a gift if everybody understands what it is, and do not put it on anything official.

The gap between the data and the local reaction is worth taking seriously rather than dismissing, because it is not irrational.

People are evaluating a different thing. A driver's experience is about confusion, hesitation, and near misses — all of which genuinely increase while a population learns a new junction. Those are real costs, they are felt daily, and they do not appear in injury statistics.

The benefit is invisible. Nobody experiences the serious collision that did not happen. The costs are salient and the benefits are counterfactual, which is the hardest possible arrangement for public support.

Familiarity effects are large. Studies where roundabouts are new show a learning period. In places where they have always been standard, drivers find them unremarkable and the crossroads confusing.

So both things are true: they are safer, and they are more annoying for the first few years.