Geopuzzle # 17

It’s been some time since I posted a Friday geopuzzle, but I’m hoping to resurrect it as a semi-regular feature again this year. This one might be a little bit random: can you tell me what’s going on in this video?

If you need a clue, it does have a vague link to the last post; and if it’s too easy, you can apply yourself to the questions of how and why.

Categories: geopuzzling

Comments (6)

  1. Mel says:

    Well, it looks like a magnetic field is alternating direction and possibly magnitude based on the speed at which the “dots” are moving. This looks like it might be an image from a transmitting light microscope, although the image is oddly grey. Are those the bacteria (that use magnets to navigate) moving around in a magnetic field? Just my stab in the dark.

  2. Mel says:

    Or the magnetic “organelles” within a cell moving around. That barrier just seems kind of thin for a cell wall. But it could be…

  3. Andrew says:

    Some mean scientist, probably someone who used to pull the wings off of flies, is forcing those cute little magnetotactic bacteria back and forth and getting them all confused!

  4. MikeG says:

    Wonderful stuff. It’s magnetotactic bacteria. I’ve isolated them from the muck near me just for fun. In the northern hemisphere, 99% or so of them swim towards the magnetic north, opposite in the south. Since the magnetic field lines tend to point down as well as north or south, it’s thought that the adaptation helps the bacteria return to the bottom of their environments when the sediment is churned up.
    You will notice that there are a few that go the opposite way if you watch carefully. This is the persistent recessive allele that allows them to deal with the periodic pole reversals that our host spoke of 2 posts ago, or if a population is swept into the southern hemisphere.
    Really cool stuff. In fact, you can isolate them yourself with a batch of artificial seawater, a bar magnet and some marine muck.
    Here is the Wiki article.
    I’ll add another “cool stuff” just for fun.

  5. Greg Laden says:

    An amoeba having an orgasm?

  6. Peter says:

    I’ve been looking for this video (or one like it, attributed to Joe Kirschvink?) for a long time. Props to you for posting it!