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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."
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Human Eye Protein Senses Earth's Magnetism

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  • Some people, my wife for instance, can never seem to get the idea of cardinal directions. Perhaps the content or ability to perceive this just varies greatly among us.
    • 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..."

      • That seems to have a ring of truth about it, though I've never been crazy about the idea of labeling roads "North/South" or "EastWest", etc.. because few roads actually maintain any consistent kind of vector, or, they often run diagonally. When it's 6pm, and the setting sun is right in your eyes and in front of you as you're driving down a road that claims to run North/South, it's a little disconcerting..
      • by Nos. ( 179609 ) <andrew&thekerrs,ca> on Wednesday June 22, 2011 @04:00PM (#36533878) Homepage

        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.

        • I'm exceptionally good at picking North/South myself and have been able to do this since I was a kid, when I first noticed that other people often are unable to do this, and never been able to explain it. Later in life I'd guessed it was just good spatial awareness.

          I think it's rather easy to train yourself to have a sense of direction based on the sun and a sense of time of day, and this can become quite a subconscious thing. However I find I can still orient myself on heavily overcast days and without
          • by shmlco ( 594907 )

            "...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.

        • 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 fou
        • by vlm ( 69642 )

          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.

          You missed a truly golden scientific opportunity to try before and after taping a magnet to your baseball cap.

          From my fooling around with magnetic compasses for orienteering, obviously in the pre-GPS pre-geocache era, I don't think whatever you were doing was magnetic. I suppose it depends on the vehicle, but even something as small as an ATV made orienteering pretty much impossible, aside from the obvious (head 1.0 miles at 23 degrees and the only path is a ridgeline trail with impassible 30 foot cliffs o

        • by Nick Ives ( 317 )

          I can do this, although for me I think it's more to do with having an idea of the orientation of the building as I enter and remembering the changes as I've moved around internally.

          • Likewise. And occasionally I'll catch myself stopping to think about it, like in a huge, non-grid box store (I'm thinking of a particular menards).

            We had a discussion about this at work, my boss and I almost always know which way is which, but the women in the office had no idea if they weren't on a major road.

            I wrote it off as being and old eagle scout. You spend a little time with a compass and map, finding your way around without obvious landmarks.
            • by Nick Ives ( 317 )

              Definitely, I think it's more down to practice than to innate gender differences as I know plenty of guys with a terrible sense of direction. I remember I always used to run off in shops, get myself "lost" and find my way back. My mum used to get stressed at me but after a while, she figured out I'd always find my way back and I promised to just never leave whatever shop we were in.

              • Ah yes, back the in the day. Now everyone is sure their kid is going to be snatched up, anywhere they go.
        • by Fzz ( 153115 )
          I can also do this, though I'm better outdoors than in. I can pretty much always get north to within 45 degrees. I can also pretty much look at a map once, memorize the key features, and then mentally navigate on that map, mentally keeping the map orientated to north even if I'm travelling in some other direction. Few people I've talked to seem to do this.

          I'm not convinced any of this is magnetic though. I've travelled a fair bit, and I've noticed several failure modes in my navigation ability:

          • In countr
        • eyeball goo changes somewhat over the years, Vitreous Humor it's called, and perhaps that change is what caused your direction finding to fade
      • by Anonymous Coward

        I learned about this in some college course. The theory is, women were mostly gatherers. They gathered things from plant sources that were usually in the same place. Best way to find those things is via landmarks.

        Men hunted. They hunted things that ran and roamed around. Best way to keep track of where you are is vector navigation.

      • "Girls," said Edmund. "They never can carry a map in their heads."
        "That's because our heads have something inside them," said Lucy.

    • by jcoy42 ( 412359 )

      Maybe at some point she had her nose broken, since that's where the compass is for humans. [].

      The book The Compass In Your Nose: And Other Astonishing Facts About Humans [] is a fun read for all.

    • by Anonymous Coward

      Apparently some road builders have problems too. In Buck County, Pa, Route 202 south and Route 611 north share the same bits of concrete for a few miles. (As an interesting aside, 202 north and 611 south do too...).

      I believe that they both are running east/west at that point.

    • by rdebath ( 884132 )

      All this is actually rather simple; for people there are two main methods of navigating, call them the cartesian and graph.

      The mechanics is easy, you have a rather effective giro-compass in your inner ear most of the time it works very well, but it's not attached to any particular absolute directions. To provide the base for this you have what could be described as "local knowledge" -- at some point/times you know which way is north because there's a sign that says 'to the north' or the sun is in the sou

  • by fahrbot-bot ( 874524 ) on Wednesday June 22, 2011 @03:45PM (#36533624)
    Damn it. I read "cryptochrome" and now I have the song Kodachrome [] running through my head...
    • by Anonymous Coward

      And thanks to you, so does everybody else who's read this far in the thread.

      Well played, sir.

    • by jbengt ( 874751 )
      "Kodachrome" was a big hit the summer I worked in a GAF film processing plant. We had radios playing while we worked, and, of course, the GAF employees turned up the volume every time "Kodachrome" came on the radio (which seemed like it was at least once an hour). So I've had that song seriously stuck in my head before, and it's hard to get rid of, damn* you.

      *It's actually a harmless little song, I just got sick of it through overexposure.
  • by demonbug ( 309515 ) on Wednesday June 22, 2011 @03:48PM (#36533686) Journal

    It turns out that breasts contain high concentrations of magnetic material.

  • by fremsley471 ( 792813 ) on Wednesday June 22, 2011 @03:51PM (#36533740)

    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.

    • by SQLGuru ( 980662 )

      Polarization is really easy to see on the Internet.....all you have to do is say: Which is better, vi or emacs? You'll get a very polarized field almost instantly.

    • I, personally, am unable to perceive the Haidinger's Brush effect, which may be related to my poor night vision (in low light situations, I perceive an effect similar to the white noise static seen on televisions). In normal lighting, I have no apparent adverse conditions.

    • by astar ( 203020 )

      I have run across this a few times. Here is something cute: the last time was some recent larouche organization research articles on multiple related phenomena. I guess you could search for "extended sensorium" there. If you are enough of a cartesian, you will have a lot of fun playing there.

      Did you know that all the way back to Ben Franklin people have puzzled over audio sensations around Aurora. But we can at this point pretty much guarantee there are no air waves involved. But we can guarantee tha

    • by adolf ( 21054 )

      Always amazed that so few people haven't been taught that you can see polarisation.

      I'm amazed, too. I never knew my eyes could do that until a few minutes ago.

      And now that I do know that they can do this, and have been toying with it for a few minutes, I will henceforth be distracted by it forever.

      Thanks, or something.

      (Haidinger's brush [] at Wikipedia, for the lazy.)

  • by Rude Turnip ( 49495 ) <[valuation] [at] []> on Wednesday June 22, 2011 @03:58PM (#36533856)

    It has a faint tinge of purple, like when you put a magnet up to an old CRT and screw up the ion gun.

  • by fuzzyfuzzyfungus ( 1223518 ) on Wednesday June 22, 2011 @04:07PM (#36533976) Journal
    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.

    The earth's magnetic field, the one that would be mostly likely to be relevant across evolutionary time, is a puny .3-.6 Gauss, depending on where you happen to be.

    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.
    • Re:Hmm... (Score:4, Funny)

      by slinches ( 1540051 ) on Wednesday June 22, 2011 @04:19PM (#36534160)

      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.

      That's because you can't sense a single magnet, the poles are too close together. You have to use two of those hard drive magnets, one on each side of the eye to notice it.

      (Warning: Don't put strong magnets around remaining eye)

    • Great! Now I can't get this damn magnet off my eye. BASTARD!!!

    • by vlm ( 69642 )

      Don't forget flicker. We're immersed in pretty strong alternating 60 hz fields... almost everywhere. If the 60 hz magnetic fields interacted with eyes, then we should be able to see absolutely crazy interference patterns when looking at 60 hz TV screens.

  • 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.

    • See, that's what I used to say, when I was accused of being a couch potato. I was actually being quite productive at a cellular level.

    • That's not beautiful logic either. A better comparison:

      -Plants have chlorophyll, which they use for photosynthesis.
      -Humans do not have chlorophyll.
      -Therefore humans cannot perform photosynthesis.
    • Your logic is impeccable. Cryptochrome is also found in plants, so human magnetic sensors imply photosynthesis ability.

      Everything checks out.
    • by Uhyve ( 2143088 )
      You've got to remember the step where they removed the Cryptochrome from its eyes, and the fly lost its ability to sense electromagnetic fields. So, we actually know that Cryptochrome has something to do with that ability, even if it doesn't actually prove anything about humans. It's just not a very apt analogy.
      • Yeah, and without water, plants cannot do photosynthesis. Indeed, the whole point of photosynthesis is to produce sugar from water and carbon dioxide.

  • I think men have more of these midichlorians then women do and that's why men can tell direction better than women :)

    Ask a dude which way is North and most can tell you without much thought. Ask a woman the same question and they have to ask thier friends first.

    that's what I'd like to think anyway

  • I'd be really interested in seeing the structure of these proteins and what possible biochemical reactions could be taking place in the eye that could affect our brain/perception. Perhaps it's a vestigial protein that we no longer actually use or maybe the relative amounts that we make aren't large enough to actually use the ability as smaller creatures do.

  • by Jstlook ( 1193309 ) on Wednesday June 22, 2011 @04:28PM (#36534298)
    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.
  • That's why heading south always feels like going downhill. I thought I was just a descendant of Treebeard. Ba room.
    • by bware ( 148533 )

      That's why heading south always feels like going downhill.

      Well, for miles and miles around here, downhill is south.

  • Birds have been proven to be able to see magnetic fields by default, is this the same thing as birds?

  • use their eyes to look at a map, and see if they can sense what way is north now?

  • In studying linguistics, one of the examples we were given was that Australian languages don't generally have "left" or "right" but describe everything in cardinal directions. If I recall correctly, there were experiments done that found that Australian Aborigines could tell cardinal directions even inside a windowless room in an entire other hemisphere (i.e. Northern hemisphere) from their home. I don't recall if this particular ability was considered miraculous or simply neat, and of course we were intere

    • by TBBle ( 72184 ) [] has a reference to the linguistics details of what I was recalling poorly, with details more accurate than mine. And of course, Wikipedia has something about this too: []

      Nothing about the indoors stuff though.

      • Very intriguing. This still does not prove they can use magnetic field, though. Quite the opposite: if the culture/habit requires an aboriginal to constantly keep track of direction, he can simply keep track of all turns he made when entering the said windowless room. Normally, I always know my orientation inside a building relative to the streets outside. Of course, the rectangular shape of structures makes this skill pretty mundane. On the other hand, if any humans could sense magnetic field, aboriginals
  • There must a common ancestor between us and birds that developed the first magnetism sensitive protein. Hope someone does the study to pin point which gene was responsible and when it occurred.
  • I and a few of my friends who have spent a large portion of our lives backpacking and doing other out-doorsie things can tell where north is sans compass just by feel. This is not looking at moss or the sun or the stars -- it is really sensing north. In a closed room we can do it with very high success rates. I can recall a story from ./ some time ago that had a fella who wore a belt with a vibrating magnet that always "pointed" north, and after wearing the belt for some time, he claimed that he could natur

"The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts." -- Bertrand Russell