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Human Eye Protein Senses Earth's Magnetism
chrb pointed out a story at BBC News about the discovery of a light-sensitive protein in the human eye that acts like a "compass" in a magnetic field. The molecule at the center of the study is called cryptochrome and is found in every animal on Earth. If removed from the eyes of flies, the flies lost the ability to respond to a magnetic field. From the article: "Despite much controversy, no conclusive evidence exists that humans can sense the Earth's magnetic field, and the find may revive interest in the idea. Although humans, like migratory birds, are known to have cryptochrome in their eyes, the idea of human magnetoreception has remained largely unexplored since pioneering experiments by Robin Baker of the University of Manchester in the 1980s."
Damn it. I read "cryptochrome" and now I have the song Kodachrome running through my head...
It must have been something you assimilated. . . .
There is a lot of research suggesting that women as a whole are less adept at that sort of thing. It also makes sense as to why many men prefer directions with set distances and instructions to turn on specific streets going north, south, etc. Women on the other hand tend to understand directions when they are relative, i.e "Take a left at the dunkin donuts, drive about a mile till you get to the T intersection..."
It turns out that breasts contain high concentrations of magnetic material.
Always amazed that so few people haven't been taught that you can see polarisation. It's so clear that it's visible in the large white space on this submission screen. AFAIK, we don't credit this further sense with any value. No surprise that little credence is given to any subtle magnetic influence.
It has a faint tinge of purple, like when you put a magnet up to an old CRT and screw up the ion gun.
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Up until a few years ago, I could be put in just about any given room in any given city, and if I took a minute, closed my eyes, I could point almost due North without any aid. I never knew how it worked, but I was pretty accurate. When I closed my eyes, I imagined I was standing on the south end of a major road in a city I was very familiar with. With my eyes closed, I'd picture looking up the street (North) as I slowly turned around. As I turned, the image just seemed to feel right, and I knew I was looking more or less North. I'd guess I was never out more than about 10 degrees.
I've since lost that ability. I was on Ritalin for a while in my early 30s, and I don't know if it was the Ritalin, or aging, but the ability went away. Even after I went off the drug, the ability never really returned. At the point I was losing the ability, I didn't realize it, and nearly got my wife and I lost in a city I'd only driven in a few times. I was sure I was headed North, and after years of trusting this instinct, even over other people with a map, I couldn't understand how we weren't getting where I was trying to go. She was insisting we were going the wrong way, and I wouldn't believe her. After I finally realized we weren't getting to our destination, I finally pulled over, looked at the map, and saw she was right. Spent a lot of time apologizing to her for that one.
While it sounds like the evidence is quite strong that we have a known-magnetic-sensitive protein in our eyes, it seems likely that (if we use it at all) we do so in only a very subtle way.
.3-.6 Gauss, depending on where you happen to be.
The earth's magnetic field, the one that would be mostly likely to be relevant across evolutionary time, is a puny
By comparison, an MRI will put a magnetic field of ~1-6 Tesla, depending on the system, across the subject being imaged. Even a boring HDD magnet(at it's surface, a magnet of such size will have its field strength drop to nearly nothing at even modest distances) can be good for more than a Tesla. Humans are exposed to such fields with reasonable frequency and don't seem to notice anything unusual. If our 'magnetic sense' were something clearly perceived, simply holding a rare-earth magnet against your closed eye should be a weird, disorienting experience. It doesn't seem to be.
I vote for aging. I also used to have a good sense of direction, particularly with maintaining a consistent travel direction despite roads angling and turning, or being underwater (handy as a teenaged lifeguard). I simply assumed that ability, same as being able to imagine a 3D object from engineering plans and projections. Over time, it has become much less reliable.
I don't believe in magic, but I do believe that humans have lots of little abilities that we haven't measured yet because we haven't found the things to measure and haven't invented the units to measure with.
What uses do you think humans have for a protein like this? How does it present?
Some thoughts I had just sitting here:
1) Supplements instinct to seek higher ground (mountains are traditionally heavy metals, which will even distort gravity slightly).
2) Couldbe responsible for migranes in people that are exposed to high electrical fields. 3) Could possibly cause unexplained dizziness from time to time. 4) Could be responsible for the moving light fragments (phosphene) I see when my eyes are closed.
Why isn't it more noticeable? Perhaps in animals that demonstrate magnetic knowledge, the eyeball mass to body mass difference is significant compared to humans, so we can't readily discern what our eyes are telling us in this regard.
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Humans DO do photosynthesis.
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"...and when I went on vacation to a pacific island I was utterly lost and couldn't find north and felt oddly disoriented until I had an idea of where I was on the island by looking at maps."
Apparently residents of Joplin, MO, are having problems navigating after part of the town was level by tornados. They removed all of the landmarks people used to find their way around, leaving nothing but rubble and flat fields.
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Psst.. Your moron is showing.
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