A Few Powers of Ten

By Sean Carroll | August 22, 2012 9:10 am

Via the endlessly enjoyable It’s Okay to Be Smart, here’s a gif image that zooms in by about three orders of magnitude. (Not sure of the original source.) We start by looking at an amphipod, a tiny shrimplike critter about a millimeter across. For some reason (vanity?) it’s decorated by an even tinier diatom, a bit of algae that is common in phytoplankton. From there we zoom in on a yet-tinier bacterium, just chilling out near the middle of the diatom.

Human beings have about ten times as many bacterial cells inside them as “human” cells. The bacteria are the passengers, we’re just the bus.

  • http://www.astro.multivax.de:8000/helbig/helbig.html Phillip Helbig

    Most of the mass of living things on the Earth is bacteria.

  • Marshall Eubanks

    Is there a way to get the gif to stop, in order to look at individual frames? (Short of importing it and transcoding it.)

    Doing that, that bacteria (if that’s what it is) is about 700 x 300 nanometers, and thus contains roughly 200 billion atoms. It fascinates me that such a relatively small number of atoms can make something that lives and reproduces.

  • John is a very big number.

  • Andrew Munn
  • Trevor

    The bacteria aren’t just passengers on the bus; they help pick the route!

  • http://ahcuah.wordpress.com/ Ahcuah

    To stop the gif, hit the escape key .

  • Sili

    Isn’t there a poem about gnats with yet smaller gnats on them?

  • Z

    Sean, this visualization is also pretty good although it’s a cartoon rather than a SEM image: http://htwins.net/scale2/

    (warning, requires flash)

  • Mark Schnitzius

    This bit of doggerel seems appropriate:

    “So nat’ralists observe, a flea
    Hath smaller fleas that on him prey,
    And these have smaller fleas that bite ’em,
    And so proceed ad infinitum.”

    (Jonathan Swift)

  • Doron

    Bacteria in and on the human body are not only here for the fun of it, and we are not only the bus. Bacteria are. fundamentally important to our existence, and ,to a great extent, even control our evolution! (not mentioning behaviour). The most amazing relation to me is that of the composition of human breast milk. About 20% of the sugars in breast milk, are non digestible by any human (or infants). It is of the use of specific species of bacteria of the genus Bifidobacterium. You may ask yourself why did the human breast milk evolve to give nutrients to a bacteria? the answer here is fairly easy- the infant is born without any gut flora, and a suppressed immune system. Thus, feeding this bacteria, is of great importance- it colonizes the gut, protecting the infant of any infections! There is also strong evidence the bacteria are important to mammals (and humans of course) through the whole digestion process. If you look enough you may find more and more examples if microbes affecting humans…..
    So no, we are not the bus, they are not here for fun, some of them are here to help us (as we help them), other are here to harm us, few of them are freeloaders.

  • ampire

    Not entirely sure about the source either but it might be from James Tyrwhitt-Drake at the University of Victoria’s Advanced Microscopy Facility (http://www.stehm.uvic.ca/). Some more images: http://bit.ly/PNAoSn

  • Marshall Eubanks

    Escape does’t work on Mac OS X Safari. Transcoding (Quicktime 7) works like a charm.

  • https://plus.google.com/u/0/102948797489911917810/posts William Summer

    On Mac OS X, click and save as… It opens in Preview as a frame by frame sequence. (will need to view as actual size to avoid distortion.)


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Cosmic Variance

Random samplings from a universe of ideas.

About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] cosmicvariance.com .


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