i like to think i have a decent understanding of light and optics. photons travel at c, varying frequency and intensity. retnia: cones and rods. red green and blue combine. and i know why black holes cannot be seen, and what visually happens when a large source of gravity passes in front of an object, and why this happens.
anyway, i noticed an odd anomaly with my eyes today. you can try to recreate this yourself: first you need an image with small meticulous details. printed text seems to work perfectly. have the text well lit and about 20 centimeters from your eyes. close one eye. now, pass something like your finger across your scope of vision, your finger being about 10 centimeters from your eyes. it is critical that you keep focusing ON THE text without moving your eyes, and that you move your finger VERY SLOWLY. i have noticed that, just as the edges of my finger are about to pass over the text, it begins to distort the text, kind of absorbing it. (this is what made me think of large gravity passing in front of another object). well i know my finger is not exhibiting such tremendous gravity, so what is going on? - i hope other people can see what i am talking about.

It's an optical illusion. I'm not exactly sure of the explanation but I think it deals with the compensation your brain makes between a focused and unfocused object. Since the brain interpolates your eye input, I'm assuming it's mixing the border of your finger with the focused text close to it and that zone tends to stand out a bit more. Can anyone give a better explanation or actually knows the answer?

Are you sure it's an illusion? It doesn't have anything to do with diffraction of light around the edge of the finger, does it?

For example, hold your thumb and forefinger together in front of a bright light source. View them with one eye. Then, separate them very slowly. When they are very close together (practically, but not quite touching), you will see dark bands between thumb and finger. I think this is a diffraction effect, too, but I could be wrong.

Does anybody have more information?

blackholesun - interpolation never occured to me. time and time again we find out that you can never trust your senses/brain.

James R - i believe what you are describing is the same effect i had. i think you might be close to a solution there. but maybe not quite. diffraction refers to a frequency-sensitive skewing, resulting in colors of the spectrum. i think the right word here is refraction, the much simpler bending of light. for example a pencil in a glass of water.

Originally posted by James R
Are you sure it's an illusion? It doesn't have anything to do with diffraction of light around the edge of the finger, does it?

For example, hold your thumb and forefinger together in front of a bright light source. View them with one eye. Then, separate them very slowly. When they are very close together (practically, but not quite touching), you will see dark bands between thumb and finger. I think this is a diffraction effect, too, but I could be wrong.

Does anybody have more information?

As I said, I wasn't sure. My logical conclusion was that it was a trick of the brain between focused and unfocused borders. But it could very well be diffraction.

I came to the conclusion that it is the light being physically bent. if you look at a door frame, and place your finger (parrellel to the door frame) not too far from your eye, then move your finger slowly closer and closer towardss the frame, jeust before they physically hit, they look like they "glorp" together. sort of extend out to meet each other. (if the conditions are right, however, the door frame will seem to move out of the way, bend away from your finger. I don't know what causes the different effects)

I think it is because your body gives off heat, similar to how mirrages work - you're body's heat 'aura' is causing the light to refract just enough to be noticeable.


this effect is noticable, however, with other objects which do not give off heat, though it is not as strong.

Originally posted by river-wind
I came to the conclusion that it is the light being physically bent. if you look at a door frame, and place your finger (parrellel to the door frame) not too far from your eye, then move your finger slowly closer and closer towardss the frame, jeust before they physically hit, they look like they "glorp" together. sort of extend out to meet each other. (if the conditions are right, however, the door frame will seem to move out of the way, bend away from your finger. I don't know what causes the different effects)

I think it is because your body gives off heat, similar to how mirrages work - you're body's heat 'aura' is causing the light to refract just enough to be noticeable.


this effect is noticable, however, with other objects which do not give off heat, though it is not as strong.

Do you have a video camera? Tape the effect and see if it shows up on tape. I still say it's probably an optical illusion. I think the brain is trying to interpret too fine of detail and compensates by "glorpping" (hehe nice word) them together. It's a boundary problem for the brain!

I have a video camera, I'll test it, and post the results...

Well, I did the thing with the camera. I did it with both my finger, and with a sharpie marker to see if it was the heat from my finger. Well, it didn't do it at all on the camera, but yet, ,when I did it with the marker (without the camera), it still did it. So, it's not the heat, and it must be something with us because it doesn't work on the camera. I pretty much only have two guesses.
1.Maybe it has something with the back of the eyeball being curved. Part of the eyeball can see just behind the edge of the marker/finger, but the other side can only see the edge of the marker, causing the affect that the light is being curved.

2.Maybe it's simply an illusion from our brain. The brain is used to seeing things in 3d, or focused with 2 eyes, and it might not know how far the finger/marker is, and tries to put it all together. So it might just be your brain trying to figure out what it's looking at.

Hope this helps

-strategicman

i like the "glorp" word. yes, the text glorped toward my finger edge. i have never encountered the reverse though, where it seems to repel.

another thing just crossed my mind. i was doing this while wearing contact lenses. possibly significant? i am so blind that it is impossible for me to test it without contacts/glasses.


originally posted by strategicman
Well, I did the thing with the camera. I did it with both my finger, and with a sharpie marker to see if it was the heat from my finger. Well, it didn't do it at all on the camera, but yet, ,when I did it with the marker (without the camera), it still did it. So, it's not the heat, and it must be something with us because it doesn't work on the camera


i would think that it is pretty difficult to test this with a video camera, unless all of your conditions are extremely controlled. if it is true that the camera does not yield the anomaly, and that only our visceral eyes percieve this, then the light is evidently NOT being physically bent, thus it is illusion. well this feels like back to square one. strategicman, if you can, please specify just how sure you are about youre camera results, possibly post a video.

if anyone has done this without corrective lenses because they have 20/20 vision, please let me know.

Well, I'm pretty sure I kept it under very controlled conditions. The camera was resting on the table, and the paper didn't move as I did the experiment. I can't post a vid cus the camera isn't digital, but I also thought about something. I kinda need glasses, but it's just stuff that's like 20 ft away that's all blury, so I don't know if it would affect it very much.

Originally posted by chris dlugosz
i like the "glorp" word. yes, the text glorped toward my finger edge. i have never encountered the reverse though, where it seems to repel.

another thing just crossed my mind. i was doing this while wearing contact lenses. possibly significant? i am so blind that it is impossible for me to test it without contacts/glasses.



I have 20/20 vision. No glasses or contacts. I got the same results. Again I still think it's a optical trick.

A plain old square edge can diffract light. So, in fact it is quite probable that your finger could diffract the light coming from the tex a bit, leading to distortion.

Pretty much shadows cats by an edge such as a finger arent perfect edges because of this diffraction, and the is some light i the area that should be dark...

I think it's an optical illusion, with maybe a bit of interpolation thrown in.

You can get the same sort of effect by squinting tightly, and looking through your eyelashes. I'm not really too sure what exactly is going on, but I believe it has something to do with the same principles that are behind pin-hole cameras.

The effect is documented, though. A google search for "squint 'optical illusion'" might bring something up. I'm really not that interested in this, so that's for someone else to query. :)

despite your apparent lack of interest, rapid transit, i appreciate your comment. thanks everyone for speculating.

Its definitely not to do with the gravity produced by your finger!!!!
LOL