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The Weight of an e-Book

Posted by samzenpus on from the because-he-can dept.

whoever57 writes "According to Prof Kubiatowicz from Berkeley, each time an additional book is downloaded to an e-reader, the mass of the e-reader increases. The effect doesn't really make the devices more difficult to carry: the professor calculates that 4GB of books would increase its weight by a billionth of a billionth of a gram— about the mass of a single virus or DNA molecule."

6 of 243 comments (clear)

  1. So it turns out.... by TheInternetGuy · · Score: 4, Funny

    So it turns out, pirating is stealing after all?

    --
    If my comment didn't sound as good in your head as it did in mine, then I guess we all know who's to blame
  2. this is the most retarded thing i've ever read by mug+funky · · Score: 4, Informative

    in other news, ipods get heavier as you fill them.

    maybe "the singularity" will happen when the internet gets so heavy the Earth collapses into a black hole?

  3. Real units? by GreennMann · · Score: 5, Insightful

    "billionth of a billionth of a gram" That is painful to read. How about scientific notation? 1*10^-18 grams Or the use of a prefix? 1 atto gram

    1. Re:Real units? by whoever57 · · Score: 4, Insightful

      Blame samzenpus. My submission said 1e-18.

      --
      The real "Libtards" are the Libertarians!
  4. Science? by No,+I+am+Spratacus! · · Score: 4, Insightful

    This belongs in the Idle section, at best, but probably not at all on /.

  5. If you read the source article at NYT... by xded · · Score: 5, Informative
    ... (which the editors should've linked to), it states:

    “Although the total number of electrons in the memory does not change as the stored data changes,” Dr. Kubiatowicz said, the trapped ones have a higher energy than the untrapped ones. A conservative estimate of the difference would be 10^(-15) joules per bit.

    As the equation E=mc^2 makes clear, this energy is equivalent to mass and will have weight. Assuming that all these bits in an empty four-gigabyte Kindle are in a lower energy state and that half have a higher energy in a full Kindle, this translates to an energy difference of 1.7 times 10^(-5) joules, Dr. Kubiatowicz calculated. Plugging this into Einstein’s equation yields his rough estimate of 10^(-18) grams.

    Of course Kubiatowicz also says that:

    [10^(-18) grams] is only about one hundred-millionth as much as the estimated fluctuation from charging and discharging the device’s battery.

    Which is a far better comparison than the one obtained from The Guardian where Graeme Ackland of Edinburgh University stated:

    "If Prof Kubiatowicz is really struggling with the extra weight, he is welcome to come to Edinburgh where it's cooler, and the lack of thermal energy in his Kindle will more than compensate."

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