7 ms·
Eigengrau
- agf 13y agoI've experienced this any number of times, mostly when backpacking in the Adirondacks in overcast conditions. I've woken up in the middle of the night with no feeling of vision at all -- no sense of light or dark. It can be extremely disconcerting and similar to the feeling of drowning, for anyone who's also experienced that. The article also suggests the phenomenon is temperature related, which I'd confirm. The times I've approached true panic for feeling "blind" have been between -20 and 30 degrees Fahrenheit, while I've always seen more of a mid to dark brown at warmer temperatures, from 50F up.
- salmonellaeater 13y agoI'm pretty sure the temperature of the rhodopsin in your eye was above 30 degrees Fahrenheit :) A toad's eye temperature can vary because it's cold-blooded. If humans' experience of eigengrau varies with outside temperature, well that's interesting and deserves study.
- agf 13y agoSure. I assume I'd be truly blind if the fluid in my eye eve went below zero C. I'm talking about the perception only.
- coldarchon 13y agoThe feeling of drowning probably comes from a sort of "residual charge" of sleep paralysis after you woke up. In sleep paralysis only your stem brain has control over your body, any signal your mind sends to your body is blocked. Furthermore your mind doesn't get any signal from your body, you don't get a feedback the breath of air you wanted to take has been done, while you are breathing. This is how the nightmare about drowning comes into existence.
- tagabek 13y agoNeat find! I really dislike the feeling that 'seeing' this causes. I can only describe it as helpless and vulnerable, while I search for light.
- jlgreco 13y agoI use to do some spelunking and on many occasions lost light while underground (usually failed batteries, one time my light took a bad hit. Thankfully I always had backups). I wouldn't really describe the color as "gray" though, there is too much randomly colored static for that. More of a very dark soupy brown. Sort of like construction paper perhaps.
- agf 13y agoDefinitely mirrors my experience.
- xyzzy123 13y agoFor full sensory deprivation this becomes especially trippy when you can only hear the white noise of rushing water and you're numb from cold.
- josht 13y agoOr you can find yourself an isolation tank.
- wahnfrieden 13y agoAre there tanks engineered for those with tinnitus? Sensory deprivation + tinnitus only means screamingly loud ringing for me - nightmarish.
- maaku 13y agoThis is a total aside, but I've always wondered: is the ringing a repeating waveform? If you could discover its structure through trial and error (e.g, cycling through pure tones and looking for beat frequencies), could you create an anti-ringing real waveform that nullifies the tinnitus? In other words make a hearing aide + your ear physiology act like a noise cancelling headphone, at least as far as your auditory nerves are concerned.
- ElongatedTowel 13y agoI wonder how that is connected to phenomena like visual snow. Many people including me see similar effects not only in dark environments but troughout the day. Some resembling swarms of color, some seeing snow or something that resembles television static. For me there is no evenly colored surface anymore because a very faint swarm of colors washes over them. It affects my vision rather negatively and the darkness magnifies the effect immensely making it hard for me to be aware of the countours of objects. There are forums on the net were people experiment with various drugs with bizarre effects, spontaneous healing or no improvement at all were others see immediate effects. My doctor send me to the optometrist, his assistant wondered why he didn't send me to a neurologist, the optometrist dismissed it because there wasn't anything wrong with my eyes.
- spullara 13y agoIANAD but that sounds serious to me. Visual field distortions are often brain issues. I would go to a neurologist to be sure. Could be a tumor applying pressure to your optic nerve or something.
- ElongatedTowel 13y agoI've became aware of it about 15 years ago, so it would probably have already killed me if it was anything like that.
- shardling 13y agoNo, not necessarily. I've met someone who had a benign brain tumor -- it caused them to have mood swings, but was not in any danger of spreading. In their case the doctors didn't remove it because the operation would have been more dangerous than the tumor itself, and the symptoms were not too severe. But it's obviously better to be aware of such things.
- pavel_lishin 13y agoMy wife had a growth removed from her brain a few years ago. Apparently it had quietly sat around since she was a child, not doing anything, until it decided to get its shit together and try to kill her. ElongatedTowel ought to go to the doctor and deal with a few weeks of feeling like an embarrassed jerk by demanding that they scan his/her brain.
- shardling 13y agoI found wikipedia's section on "The mathematics of color perception" very, err, illuminating. It made me realize just how complicated the topic is... http://en.wikipedia.org/wiki/Color_perception#Mathematics_of_color_perception http://en.wikipedia.org/wiki/Color_perception#Mathematics_of...
- fnordfnordfnord 13y agohttp://www.feynmanlectures.info/docroot/I_35.html http://www.feynmanlectures.info/docroot/I_35.html There is a video of Feynman presenting this lecture somewhere, sorry I couldn't find it.
- shardling 13y agoThanks -- I'd previously read a passage where Feynman talks about the idea of "negative" colors, but I somehow had missed that there was a whole chapter in the Lectures about vision!
- alok-g 13y agoA question also comes on why humans have three color channels. Or more generally, why is the number of cones relatively small (some species have more than three). While I cannot find the reference, some researchers recorded full visible-range spectrum for a very large number of naturally occurring objects. Then they performed principle components analysis of these spectra and found that for naturally occurring reflection spectra, nearly all signal energy is recovered with a small number of independent components like three or four. In other words, the spectra of naturally occurring materials does not vary as widely as it could to exercise the full Hilbert space available. A downside of having a larger number of cones is of course that the percentage area available to each cone will be less, so a higher density of cells would be needed to maintain the resolution and color perception under dark will suffer more. The nature then has chosen a near optimal number of cone types for vision. One issue I had discovered with the above study was that it was possibly cyclic. The database of spectra they used did not had too many samples of (different) objects with the same apparent colors since the latter was collected primarily to count the number of human-distinguishable colors occurring naturally in nature. If the number of primary colors visible to humans were significantly larger, I can on the very least say that TVs and printers would have been significantly different than what they are, if at all they would have been practical. The above however does not answer the question of the electromagnetic radiation frequency span sensed by the eyes. In other words, why is the visible range not wider than what it is. Again, some animals do have a wider range. Had the visible range been wider, it may have required a larger number of primary colors to cover the expanded Hilbert space. What a physicist once told me is that the range of frequencies that are visible to humans and animals correlates very well to the frequency range under which water is transparent. See [1]. This according to him offers a solid indication that life originated in water. A few more interesting thoughts: 1. Figure out what determines the shape of the locus of the spectrum (monochromatic) colors on the color chart [2]. It is an interesting exercise to derive this locus from the measurements of the spectral responses of the three cone types. Note that the outer boundary of the color chart has a straight line bottom with purple to magenta in the middle. While the non-straight boundaries span monochromatic colors, the colors on the straight edge at the bottom cannot be monochromatic. Figure out why. 2. A question comes if the spectral responses of the cones could have been such that the above locus would have concavities. I am not sure of the answer, though am sure colors outside of the locus but within its convex hull would still have been visible. [1] http://en.wikipedia.org/wiki/File:Absorption_spectrum_of_liquid_water.png http://en.wikipedia.org/wiki/File:Absorption_spectrum_of_liq... [2] http://en.wikipedia.org/wiki/File:Cie_Chart_with_sRGB_gamut_by_spigget.png http://en.wikipedia.org/wiki/File:Cie_Chart_with_sRGB_gamut_...
- endgame 13y agoLet's post random wikipedia articles without commentary, turning HN into /r/todayilearned.
- pcl 13y agoSo generally, I'd agree with you. But the thing is, this is so much more interesting than another 30 articles and links to tweets about Edward Snowden's current location that I'm perfectly happy to upvote it. At least I've learned something from the article, and something about how my body works, no less. And then something more from the HN discussion, in which jlgreco and agf posted interesting anecdotal about the topic.
- d0m 13y agoGo ahead, post all random wikipedia articles you want. The cool thing is how only the most interesting ones will be upvoted. Now that I think of it, that could be a neat small script to hack.. post random wiki articles on HN, let HN-ers upvote the good ones, and only read the best ranked ones.
- endgame 13y agoVoting works well with small-to-medium communities of readers invested in the quality of discussion, but breaks down in large groups. Look at some of the larger subreddits - people in the comments complain about the quality of frontpage articles because the voting group becomes much larger than the commenting/discussion group. I wonder what's going to be the next big innovation in filtering the firehose?
- eru 13y agoThere are more interesting algebraic operations you can do on the voting vector than just adding it up..
- lifeformed 13y agoHow did they decide on the RGB values? Or did someone just make that up?
- anigbrowl 13y agoYes.
- jkuria 13y agoWhy is this #1 on the front page? And how is it useful? I think a common pitfall for techies is amassing lots of useless knowledge (a habit I have weaned myself off over the last few years).
- datadata 13y agoHow did you wean this habit, and has it made things better for you?
- krapp 13y agoDo you know how useless I find knowledge about Rails? Utility is relative, and sometimes things are just interesting. I don't know why it's #1 though. Maybe pg's skewing the numbers against all the NSA content? Maybe people are just upvoting anything that's not NSA/Snowden/etc?
- pcl 13y agoI kinda feel like useless knowledge is an oxymoron. If knowledge about our world is a pitfall, then I'm happy to seek out new traps.
- wahnfrieden 13y agoGerman adds mystique.
- deleted 13y ago[deleted]
- illtakesix 13y agoAnother interesting color is Cosmic Latte: http://en.wikipedia.org/wiki/Cosmic_latte http://en.wikipedia.org/wiki/Cosmic_latte
- tuneafish 13y agothis isn't particularly surprising. every photo-sensor known to man has "dark" noise and it is indeed temperature dependent. noise goes up for a fixed temperature for sensors that are sensitive to longer wavelengths, so the fact that people report a more brownish color makes more sense than perfectly grey to me. the sensors in your eyes that are sensitive to deep red will be noisier than ones sensitive to blue.
- beemoe 13y ago1) Close eyes. 2) Point flashlight at eyes. I observe that the intensity of the "Eigengrau" depends on how tightly I close my eyes. With the flashlight, the image is clearly more red than gray. This could explain some reports of "brown", to the extent that brown is a dark red.
- dave809 13y agowhen it says that the half-life of the rhodopsin molecule is about 420 years, does that mean that if we would live that long, half of our rhodopsin will be gone? how would that affect our eyesight?
- eru 13y agoYour rhodopsin get replenished.
- jpatokal 13y agoI'd be quite keen to hear how they determined that #16161D is the color of Eigengrau. Stick somebody in a pitch black room, show him various shades of grey on an illuminated display, stop when indistinguishable? But alas, the [citation needed] suggests it was simply pulled out of someone's Eigengrau-colored orifice...
- coldarchon 13y agoActually it is pretty easy to do the math. The molecules in our eyes to perceive light decay at a measurable rate and the remains create a signal. Then you take #000000 and add the value of this rate.
- huhtenberg 13y ago@coldarchon - you are hell-banned.
- dbbolton 13y agoHow could you tell?
- ColinWright 13y agoTurn on "showdead" in your profile.
- schoper 13y agoDidn't Goethe describe this in his Theory of Color? Amazing physical/physiological study of sight.
- program 13y agoI find the Eigengrau to be a very relaxing color and I use it as the background of my desktop. It always puzzled me that it's not a pure grey but it has a little blue. I thought he had more sense that there was a little red because of the minimal amount of light that passes through the capillaries of the eyelids. I suffer from epilepsy and often I see scintillating scotoma, visual snow and other strange light phenomena. Given this I came to the conclusion that my brain associate this color to a quiet mental state.
- deleted 13y ago[deleted]