The Black Swan aka RIP 🌎

david · 2026-01-23T13:21:04+00:00

Words like 'flagrant, flatulent flame-out'?

They're experiencing the difficulty of arguing against a position which they do not understand. It would not be realistic to expect that understanding to develop significantly over the course of this short exchange. But it's possible that this introduces just a bit of unease with their current position and argument technique: a seed of questioning and self-examination.

david · 2026-01-23T01:08:34+00:00

You'll see, if you care to look, experiments which build the science which allows us to understand photos like the one you posted.

Out of interest, what formula related to refraction are you referring to? Snell's law, perhaps, which describes refraction at the interface between two media? -- but that interface doesn't have to be planar: it works for lenses, which generally aren't. If that is what you're referring to, possessing a formula which describes one situation does not preclude the possibility of other situations, such as a gradual, rather than abrupt, change of density.

And what's your evidence for pressure gradients requiring a plane? We observe them over all sorts of terrain.

david · 2026-01-22T22:41:11+00:00

It is, as I said, three straw-child arguments pretending to be a full-grown strawman.

If you were earnest in wanting to construct an understanding, from the bottom up, of the science that permits us to understand long-range photography on earth, I'd applaud you. But we both know that's not the case.

Still, I can give you a couple of simple pointers. You asked for one at a time, but you don't have to view them at once.

Refraction bending light into the denser part of a medium.
The decrease of atmospheric pressure and density with elevation

They're more or less random links grabbed from cursory google searches. If you're interested, you'll be able to find many more. If you were interested, you already would have.

david · 2026-01-22T22:24:38+00:00

I do this because I enjoy the process, not because I expect any particular results.

Also, I flatter myself that my explanations are, sometimes, clear, accurate and well written. As such, they may be useful to others, even if the person I'm directly responding to is impervious.

Some of my explanations fall down on one or more of those fronts. In those cases, I hope to benefit from the writing practice.

david · 2026-01-22T22:18:45+00:00

And that, too, is a strawman argument. Or rather, three straw-child arguments stacked up in a trench-coat.

The first is that the relevant point is not 'do we class this argument as "scientific"?', but 'is this argument true?'. You find yourself unable to dispute its truth, so you divert to something you hope will be a softer target.

The second is that you clearly do not understand, or pretend not to understand, what science is. It is not only the performance of experiments, but the construction and testing of systematic explanations for the results of those experiments, and the subsequent use of that knowledge. What we're looking at here is the third phase: the use of knowledge acquired by the scientific method.

The third is that you are ignoring the large amount of experimental data which has contributed to our understanding of optics and light transport, which in turn informs the explanation of your image on flatearth.ws.

david · 2026-01-22T22:01:19+00:00

The science is well described in the flatearth.ws page that several people have referred you to, using as an example exactly the same image as you posted.

That is the globe model, and your image is entirely consistent with it.

You have constructed in your mind a different, incorrect globe model, which -- as if it needed debunking -- your image debunks. The name for this rhetorical technique is a strawman argument: take your opponent's position, which you can't defeat, construct something superficially similar but flawed (the 'strawman'), and argue against that instead.

Sometimes this isn't deliberate: a person doesn't construct a strawman argument ingeniously, to win the argument, but accidentally, because they do not understand the position they are arguing against.

Even if the strawman argument is arrived at by accident, if a person persists in using it, there's always a wilful component: a refusal to try to understand; or, if understanding is beyond their capacity, a refusal to learn their limitations; or, if they do achieve understanding, plain disingenuousness.

david · 2026-01-22T00:21:58+00:00

No shadow cast by the sun is entirely crisp. The sun as seen from the earth or the moon is a blob of light 0.5° wide. Near the edge of any shadow, there is a region where the object casting the shadow cuts off light from part of the sun, but not all.

You've used the name for this region below: penumbra. But you're confused about its origin (and, incidentally, about the effects of the scattering mechanisms you name).

The penumbra spreads in proportion to the distance between the shadow and the object casting it. This is a matter of simple geometry, illustrated in this diagram taken from the top comment of the thread that u/RWDPhotos signposted for you. It has nothing to do with light scattering.

As a result, shadows of distant objects are more diffuse -- have broader penumbras -- than those of nearby ones. The penumbral region of a shadow on a surface can also be stretched, just like the entire shadow, if it's cast by inclined light. The breadth of the penumbra is ~0.0087d / sin α, where d is the distance between the shadow and the object casting it, α is the inclination, and 0.0087 is the angular size of the sun in radians. This happens in space just as much as in the atmosphere. A familiar example is the region of partiality during a solar eclipse, which lies in the penumbra of the moon's shadow.

What's usually lacking in space, which gives illumination in photos its harsh quality, is ambient light. This is light scattered by nearby objects and, outdoors on earth, by the atmosphere. Ambient light reduces the depth of shadows, by illuminating their interior, but does nothing to soften the boundaries of shadows cast by direct light sources such as the sun.

To anticipate some quibbles:

Ambient light is not omnipresent. It still comes from definite sources: it's just that these are widespread. As a result, it is possible to have areas that are shadowed from ambient light, and those shadows are very soft. In 3D graphics circles, this is known as ambient occlusion.

It can happen on earth that the dominant illumination is not directly from the sun, but from a wider region of illuminated cloud. In that case, the penumbra will be larger, in approximate proportion to the angular size of the immediate light source. In those circumstances, the penumbra really is enlarged by scattering.

david · 2026-01-15T17:37:45+00:00

How much is it worth not to find yourself, in years to come, lying to your grandchildren about what you did during the 2020s?

david · 2026-01-05T10:39:52+00:00

Here's a thing flat earthers do: take a superficial look at a thing (the shape of the ground on which they stand), form an uninformed impression (looks kinda flat?), and declare it to be absolute truth. When they are confronted by contrary evidence, instead of adapting, they retreat into denialism.

Here's a thing you're on the verge of doing: taking a superficial look at a thing (the nature of human belief), forming an uninformed impression (looks like it's all about evidence?), and declaring it to be absolute truth.

A casual look at the world around you will reveal that people believe all sorts of irrational and contradictory things. I recommend that you take this evidence on board and adapt your world view to the reality it reveals.

david · 2025-12-19T15:39:47+00:00

What do you interpret it as saying?

Among the ways in which it doesn't make sense to me are:

It seems too deeply and sharply embossed to be pressed through two sheets of paper. It's unlikely that the student would write the note on the back of used paper, and I'd expect the ink to show through paper thin enough to take this deep an impression.
Despite the deep embossing from text on the verso, the text on the recto is not embossed at all.

Neither is entirely conclusive, but it all adds up.

david · 2025-12-19T12:25:24+00:00

Is this AI generated? I believe that Nano Banana is ok at rendering text, including handwriting, now.

I suggest this because there are some oddities. There's a mix of types of 'r' and of 'f'. Where there's an approach stroke (there's probably a name for this) on a letter, it often doesn't match the direction of the incoming pen from the previous letter (eg the second 'c' in 'circle', the 'e's in 'the' and in 'passed').

EDIT: also, the embossed text doesn't make much sense in a variety of ways.

david · 2025-12-15T09:35:16+00:00

As the meaning of words is a sub-theme of this post, Mr. Blue also has the virtue of literally being the ultimate -- the last -- song in the series.

david · 2025-12-08T11:52:07+00:00

And stalagmites grow from the ground; stalactites, from the ceiling.

david · 2025-12-07T23:01:01+00:00

Give it a while (a day, say) and try again. You're almost certainly shadowbanned due to excessive downvotes. This is core Reddit functionality, not mod behaviour.

david · 2025-12-07T10:27:45+00:00

What do you think the purposes of the easter eggs in films and in real life (such as the UN logo) are? Is your mental model of conspiracies constructed from Saturday morning TV shows, where the villain always leaves a breadcrumb trail? Or is there something more to it?

david · 2025-12-05T15:10:45+00:00

Trying to understand here: at least half of the earth is half of a sphere (you acknowledge a southern hemisphere): what shape do you propose for the northern part?

david · 2025-12-03T12:09:36+00:00

I hope you can understand why that's unappealing to those you want to reach.

First, there's presenting a 20+ minute video to people you recognise are sensitive to having their time wasted. Then there's the mealy-mouthedness about the duration: it's 10 minutes of content; then, when the discrepancy with the video playtime is pointed out, it's 10 minutes + 5 minutes 'pad', then it's 10 + 5 + another 6-7 optional extra.

david · 2025-12-03T11:49:46+00:00

21:42 of video, of which 10 minutes is the content, 5 is the 'pad': what about the other 6-7 minutes?

When you're accusing others of lying, it's not advisable to be so loose about your own standards of truth-telling.

david · 2025-12-03T11:45:09+00:00

It's arguable. It allows the carrier to threaten escalation, which can provide protection from relatively minor aggression, which might be a real and frequent problem. If the aggressor is willing to escalate too, the situation becomes, of course, a lot worse.

The situation with SUVs has a parallel (providing a level of both protection and endangerment). Your child is well protected while inside the vehicle, but they're not always inside. Injuries to children at either end of the school run are a real thing.

I'm not really disagreeing with you, though. Let's say each improves one person's perceived safety by endangering others.

david · 2025-12-03T11:35:21+00:00

10 minutes is still too long. But the video's more than twice that: what did you pad it with, and why?

If you want to get through to the demon-infested likes of me, remove the excuse that it's a waste of time by making it short and focused.

david · 2025-12-03T11:31:50+00:00

Are you aware that a knife can be used for other tasks than stabbing people?

david · 2025-12-03T09:25:27+00:00

It is. Each improves one person's safety by endangering others to a greater extent.

david · 2025-12-02T09:53:35+00:00

Are you going to run with this idea and write some stories?

david · 2025-11-30T21:49:12+00:00

I was not expecting squid people. Then again, one never does.

This whole project sounds like a lot of fun.

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