For example, Humphrey Bogart as Indiana Jones in Raiders Of The Lost Ark. Or say Gregory Peck in Saving Private Ryan. Or how about James Dean as Luke Skywalker!

In the color lines of a spectrograph and what seems to be an area with a certain color, zooming in shows that this color is delicately split in half by a black vertical hairline, on one side it's the emission of photons of color by a hydrogen atom with a spin up electron, on the other it seems to be the same color but it's a spin down electron.

Whenever I hear that gap mentioned, 1/137 is invoked, but I'm not sure precisely what that means, and I'm visualizing that the color of the spectral emission can be divided or deconstructed into a total of 137 vertical lines, and the one in the middle is black.

Maybe it represents 1/137 of a photon's wavelength at a certain color?

For example, places like HistoryPorn have some bizarre pictures of weird inventions or WWII experimental weapons.

How come I'm only just now coming across them? Why didn't we see them five or ten years ago, even in specialized forums and subreddits?

Places like ArtPorn or TraditionalArt are a trickier proposition. Here my lack of knowledge is vast, but I've really loved the history of painting for over two decades now, and have recently kept coming across a lot of 18th-to-20th century paintings and painters I've never heard of before; some of these are excellent, I should have known about them... I think. But like I say, there's more that I don't know than what I do.
If they are real and not recent AI creations, where are the original and who is digitizing and/or publishing so many of them all of a sudden in the past year?