Human Eye Protein Senses Earth's Magnetism 103
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."
Re:Sense of direction (Score:5, Interesting)
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.
Bad logic (Score:1, Interesting)
There's some bad logic going on here:
* Flies need that protein for magnetic sensing.
* Humans have the protein.
* Therefore humans can do magnetic sensing.
Obviously humans also do photosynthesis:
* Plants need water for photosynthesis.
* Humans need water.
* Therefore humans do photosynthesis.
Possible uses that Humans have for this protein? (Score:3, Interesting)
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.