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My new glasses and the nature of reality - Arvind Narayanan's journal [entries|archive|friends|userinfo]

My new glasses and the nature of reality [Dec. 22nd, 2005|10:09 pm]
Arvind Narayanan

So my optician says I have a little bit of a cylindrical vision or something, and that my new glasses will compensate for it. Even though it's probably just a question of getting used to it, everything looks weird through these lenses and it's almost creepy. My depth perception is subtly off balance, and something else is wrong that I just can't put my finger on.

All this started me wondering about which image is reality and which one is my skewed perception, and I realized there is no way for me to answer the question. Worse, an objective answer probably doesn't exist. What I see with and without my glasses are both projections of a 3D world onto a 2D retina, and neither is "superior" to the other, neither is the "correct" version. It's one thing to be aware of the subjective nature of reality in a vague and abstract philosophical sense, and quite another to see it through your glasses.

Incidentally, the reason that the new projection screws up my depth perception is that depth is not directly seen by the eye; instead it is inferred by the brain based on other data in the image. My algorithms are currently tuned to the old projection, and they don't work correctly for the new one. Apparently it takes about a day to adjust.

All humans by default model themselves as perfectly perceiving their environment and acting perfectly rationally upon that input. (That's AI-speak, but I believe the meaning is pretty clear.) Descartes assumed the contrary of the first part of that premise, hence his statement "cogito, ergo sum". For most lesser mortals, however, it is quite jarring to be made aware of the limitations of human evolution in such an abrupt fashion. Which is incidentally why optical illusions are so catchy. Color, another staple of optical illusions, is another thing that is extremely crudely approximated by the brain, the actual physical property (the spectral distribution of the light source) being infinite-dimensional.

Anyways, if there is one thing this journal entry shows, it's that I'm way too much of a daydreamer; if I were a halfway normal person what I would probably be thinking now is that I should have seen a real optometrist instead of an optician.

[User Picture]From: jeweleddragon
2005-12-22 11:03 am (UTC)


I really like your journal. Is it okay if I add you?
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[User Picture]From: arvindn
2005-12-22 11:12 am (UTC)

Re: ^_^

You are totally welcome.
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[User Picture]From: sunson
2005-12-22 09:02 pm (UTC)
I totally dig consciousness, perception, etc.,.

Have you heard/read the Reith Lectures 2003? I wanna buy Phantoms in the Brain too.
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[User Picture]From: sunson
2005-12-22 09:10 pm (UTC)
Added you to one of my lj friends-groups. You might want to check this out.
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[User Picture]From: arvindn
2005-12-22 09:58 pm (UTC)
Yeah, the Reith lectures were awesome. I had real fun one time when Ramachandran came to the IITM 2004 convocation. I astonished those sitting next to me during his lecture by predicting his next words now and then :)

I've bought a few books about the brain, but I haven't found much time to read them so far. There's a whole bunch of excellent material available online though. This is one of the best books I've read about the brain, even though its written from the point of view of trying to create true AI.
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[User Picture]From: sunson
2005-12-22 11:08 pm (UTC)
oh, and I thought you might like this.
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[User Picture]From: arvindn
2005-12-22 11:34 pm (UTC)
I love this part:

"Somebody recently proposed in a discussion that it would be really cool to hack the genome and compromise it so as to insert code that would copy itself to other genomes, using the host-body as its vehicle. 'Just like the nimda worm!'

He shortly thereafter realised that this is exactly what biological viruses have been doing for millions of years"

The guy must have felt like a gigantic ass :)
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[User Picture]From: sunson
2005-12-23 12:48 am (UTC)
Haha. yes. I liked it too.

I think that entire write-up is easy to "relate to" :)
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