[math-fun] NeilB's latest eye pickle
Some animations I demoed in 1986 illustrated that you can't tell if an enlarging hyperbola is scaling anisotropically. One of them was actually stretching horizontally and shrinking vertically at a lesser rate, which only became clear as the background faded up some crazy chewing gum wallpaper. Thus an apparently fixed hyperbola might be stretching one way and shrinking the other at complementary rates. This is shown by Neil's vastly subtler chewing gum: gosper.org/hyperbolicV2.gif . Staring at this for a few periods and then suddenly freezing it produces a strong and amusing variation on the moving bar illusion. The problem: how to freeze an mgif without moving your eyes? https://addons.mozilla.org/en-US/firefox/addon/toggle-animated-gifs/ enables Firefox to alternately play and pause mgifs with the keystroke Control-m. --Bill Gosper
* Bill Gosper <billgosper@gmail.com> [May 14. 2015 08:26]:
[....]
chewing gum: gosper.org/hyperbolicV2.gif .
Whoa! Instead of freezing the gif, do the following. Stare at the (moving) image for 30 secs or so, keep your eyes fixed at center. Then look on some text (e.g., this email). Enjoy the text going warpy! I am impressed!
Staring at this for a few periods and then suddenly freezing it produces a strong and amusing variation on the moving bar illusion. The problem: how to freeze an mgif without moving your eyes? https://addons.mozilla.org/en-US/firefox/addon/toggle-animated-gifs/ enables Firefox to alternately play and pause mgifs with the keystroke Control-m.
Doesn't work here, pressing escape used to stop animations, now shift-escape does that. For restarting the animation it seems I have to reload the image.
--Bill Gosper _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
A quick search for "moving bar illusion" failed to find anything obviously relevant to RWG's impressively effective post. So I'll point out that it demonstrates very neatly the way our perceptive mechanisms filter out constant background frequencies, allowing through only changes in the signal spectrum --- visual, auditory, tactile, olfactory(?!). In this case, the subsequent apparent stretching of the text is patently opposite to that induced by the video, as our internal DPU continues to cancel out the assumed previous motion. I am reminded of an incident late one night when standing beside the Victorian clock in the hall of my home: completely unable to hear its normal loud tick, I inspected the pendulum to check whether it had stopped. As I watched in some bafflement, the tick gradually became perceptible, accompanied by the realisation that it had actually been present throughout. Fred Lunnon On 5/14/15, Joerg Arndt <arndt@jjj.de> wrote:
* Bill Gosper <billgosper@gmail.com> [May 14. 2015 08:26]:
[....]
chewing gum: gosper.org/hyperbolicV2.gif .
Whoa!
Instead of freezing the gif, do the following. Stare at the (moving) image for 30 secs or so, keep your eyes fixed at center. Then look on some text (e.g., this email). Enjoy the text going warpy!
I am impressed!
Staring at this for a few periods and then suddenly freezing it produces a strong and amusing variation on the moving bar illusion. The problem: how to freeze an mgif without moving your eyes? https://addons.mozilla.org/en-US/firefox/addon/toggle-animated-gifs/ enables Firefox to alternately play and pause mgifs with the keystroke Control-m.
Doesn't work here, pressing escape used to stop animations, now shift-escape does that. For restarting the animation it seems I have to reload the image.
--Bill Gosper _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (3)
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Bill Gosper -
Fred Lunnon -
Joerg Arndt