10 ms·

Does that image have a weird pulsing optical illusion for anyone else?

by hrdwdmrbl 8y ago

luizfzs 8y ago
Relieved it isn't just me
- geoah 8y ago
  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.
chki 8y ago
Yes, fascinating! If you shift the focus of your eyes from the outside to the inside of the hole, it seems to "pulsate"
pcmaffey 8y ago
Yes, reminds me of the Eye of Sauron.
- deleted 8y ago
  [deleted]
- manaskarekar 8y ago
  Funnily, it reminds me of Soundgarden's album, Superunknown, which had the famous song 'Black Hole Sun.' https://www.amazon.com/Superunknown-Soundgarden/dp/B00IXLQJ8U https://www.amazon.com/Superunknown-Soundgarden/dp/B00IXLQJ8...
- EForEndeavour 8y ago
  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:Fomalhaut_B_entire-Hubble_Telescope.jpg https://en.wikipedia.org/wiki/Fomalhaut#/media/File:Fomalhau...
thanatropism 8y ago
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.
- 317070 8y ago
  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.
- Mizza 8y ago
  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 https://www.youtube.com/watch?v=xAoljeRJ3lU
  - kardos 8y ago
    Can you run it through the colormap in reverse to (approximately) recover the data?
    - yehar 8y ago
      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-would-the-event-horizon-telescope-m87-black-hole-image-look-like-if-we-saw https://physics.stackexchange.com/questions/472641/what-woul...
    - thanatropism 8y ago
      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.
tacone 8y ago
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.
Tor3 8y ago
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.
Insanity 8y ago
It does look like it pulsates to me! That's an interesting illusion :)
mrhappyunhappy 8y ago
You mean to tell me this is not a gif?!
- hrdwdmrbl 8y ago
  I literally did double-check the file extension
dreamcompiler 8y ago
Interesting that so many people see this but for me it's absolutely static.
- sametmax 8y ago
  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.
simias 8y ago
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.
bparsons 8y ago
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.
banehoodie 8y ago
looks like the image data was cleaned up with bicubic interpolation, or something of the like. https://en.wikipedia.org/wiki/Bicubic_interpolation https://en.wikipedia.org/wiki/Bicubic_interpolation
neom 8y ago
Stare at it till there are two, then have fun snapping them in and out.
agumonkey 8y ago
moving the picture on my screen caused some eye bug
kyllo 8y ago
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
anonytrary 8y ago
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.

Does that image have a weird pulsing optical illusion for anyone else?

luizfzs 8y ago

Relieved it isn't just me

geoah 8y ago
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.

chki 8y ago

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

pcmaffey 8y ago

Yes, reminds me of the Eye of Sauron.

deleted 8y ago
[deleted]
manaskarekar 8y ago
Funnily, it reminds me of Soundgarden's album, Superunknown, which had the famous song 'Black Hole Sun.' https://www.amazon.com/Superunknown-Soundgarden/dp/B00IXLQJ8U https://www.amazon.com/Superunknown-Soundgarden/dp/B00IXLQJ8...
EForEndeavour 8y ago
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:Fomalhaut_B_entire-Hubble_Telescope.jpg https://en.wikipedia.org/wiki/Fomalhaut#/media/File:Fomalhau...

thanatropism 8y ago

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.

317070 8y ago
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.
Mizza 8y ago
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 https://www.youtube.com/watch?v=xAoljeRJ3lU
- kardos 8y ago
  Can you run it through the colormap in reverse to (approximately) recover the data?
  - yehar 8y ago
    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-would-the-event-horizon-telescope-m87-black-hole-image-look-like-if-we-saw https://physics.stackexchange.com/questions/472641/what-woul...
  - thanatropism 8y ago
    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.

tacone 8y ago

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.

Tor3 8y ago

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.

Insanity 8y ago

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

mrhappyunhappy 8y ago

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

hrdwdmrbl 8y ago
I literally did double-check the file extension

dreamcompiler 8y ago

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

sametmax 8y ago
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.

simias 8y ago

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.

bparsons 8y ago

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.

banehoodie 8y ago

looks like the image data was cleaned up with bicubic interpolation, or something of the like. https://en.wikipedia.org/wiki/Bicubic_interpolation https://en.wikipedia.org/wiki/Bicubic_interpolation

neom 8y ago

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

agumonkey 8y ago

moving the picture on my screen caused some eye bug

kyllo 8y ago

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

anonytrary 8y ago

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.