It's the color scheme. I think in matplotlib it's called "hot". I do a lot of 2D kernel density plots that by having a black zero level and dozens of contour levels produce a smooth look with aesthetics similarities to this. I used to use that scheme because "heatmaps" but stopped because of the pulsing illusion.

I'm not sure if this image is real color or just lightness value and they used a color scheme for drama.

Grrr, why aren't scientists all using perceptually uniforms color schemes! This would still look awesome in `plasma`. Is there any where I can get the data and do it myself?

One of my favorite talks ever is on this subject: https://www.youtube.com/watch?v=xAoljeRJ3lU

'Inferno' would be nice for this, also perceptually uniform, and has the benefit that space is still black.

Can you run it through the colormap in reverse to (approximately) recover the data?

Based on my analysis the published image is too processed to be able to invert the colormap to get to the brightness temperature data. I had better luck with Paper IV Fig. 15. See: https://physics.stackexchange.com/questions/472641/what-woul...

Technically yes -- colormaps are 1-dimensional non-self intersecting curves in RGBA space. You just grab them by the... I mean just straighten them.

I don't know if an explicit formula for the colormap is given, but you can always do "xs = np.linspace(0,1,100); ys = { cm.hot(x):x for x in xs}" and recover an approximate inverse. Then apply this function to each pixel of the image.

You can easily remap it between different colour maps if you assume that is is a standard hot map.

It's the latter. This is an image in radio-frequency brightness of the object, so not visible frequencies of light. But yeah, it also looks like the 'hot' colormap to me.

I think my eye is trying to bring it into focus. It is like when the camera on your phone can't quite figure out what it is looking it and keeps adjusting.

I suspect this is because it's extremely blurry, if you watch it on a large screen it might trick your eye into trying to refocus, obviously without success.

Interesting that so many people see this but for me it's absolutely static.

If you are focused and calm, or have bad sight, you won't see it naturally. To force it, move your focus from 1cm to the left, then right, again and again, quickly.

Yes, reminds me of the Eye of Sauron.

Funnily, it reminds me of Soundgarden's album, Superunknown, which had the famous song 'Black Hole Sun.'

https://www.amazon.com/Superunknown-Soundgarden/dp/B00IXLQJ8...

The supreme astronomical example of the Eye of Sauron is this Hubble shot of the star Fomalhaut and its debris disk: https://en.wikipedia.org/wiki/Fomalhaut#/media/File:Fomalhau...

Yes, fascinating! If you shift the focus of your eyes from the outside to the inside of the hole, it seems to "pulsate"

looks like the image data was cleaned up with bicubic interpolation, or something of the like.

https://en.wikipedia.org/wiki/Bicubic_interpolation

I don't even have to move my eyes, I stare at it and it's constantly moving away from me. I had to check that it's not actually a movie. Strangest thing.

Yes, and I also see a spot in the shape of it after looking away, though that may just mean my monitor is too bright

Some time ago I've seen a picture over the Internet where the description said the more you see it "moving" the more likely you're stressed.

As for the black hole, looking it at full screen I see it pulsating a little.

Yes if you dance your focus around the image, it appears to pulsate. Probably your pupils constricting and dilating due to the high contrast in the image.

It does look like it pulsates to me! That's an interesting illusion :)

Stare at it till there are two, then have fun snapping them in and out.

Relieved it isn't just me

I get it if I move a bit when on an angle, I assume it's just my crappy monitor's viewing angles causing it.

moving the picture on my screen caused some eye bug

You mean to tell me this is not a gif?!

I literally did double-check the file extension