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  • Re: Semi OT Grace Hopper lecture

    From Terje Mathisen@21:1/5 to Lawrence D'Oliveiro on Sat Nov 9 22:39:46 2024
    Lawrence D'Oliveiro wrote:
    On Fri, 8 Nov 2024 11:15:50 +0100, Terje Mathisen wrote:

    The standard paper size available in all printers and copiers is of
    course A4, and that A4 sheet is exactly(*) one nanosecond tall (29.97
    cm) as well as one nanosecond when travelling inside an optical fiber
    wide!

    Hey, I never noticed that. Proof, if any were needed, that international standard paper sizes and units of measurement were given to us by the
    gods ...

    By the way, that must mean the refractive index of optical fibre is close
    to 1.4. Is that plastic? Because glass would be closer to 1.5, wouldn’t
    it?

    You had to notice that one, didn't you?
    :-)

    Yeah, optical fibers, at least for long-distance communication, is very
    pure quarts with a refractory index typically in the 1.46-1.47 range,
    which for illustrative purposes is close enough to 1.4142, right?


    Terje (*) Within your ability to measure with a ruler, or a paper
    supplier to cut.

    Yes, the size of a sheet of paper can vary quite appreciably (by as much
    as a few percent), depending on the humidity particularly.

    Regards,
    Terje

    --
    - <Terje.Mathisen at tmsw.no>
    "almost all programming can be viewed as an exercise in caching"

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Stephen Fuld@21:1/5 to All on Thu Nov 7 13:21:59 2024
    NSA has recently released the video of a 1982 talk by Grace Hopper.

    If you don't know who she is, read up on her at e.g.

    https://en.wikipedia.org/wiki/Grace_Hopper

    before watching the video.

    If you know of her but have never heard her speak, you are in for a
    treat. She was an outstanding speaker.

    If you have heard her speak, watch it for some amazing memories.

    https://www.c-span.org/video/?538935-1/captain-grace-hopper-future-computers-1982

    It runs about 1.5 hours, but it seems like less.



    --
    - Stephen Fuld
    (e-mail address disguised to prevent spam)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Terje Mathisen@21:1/5 to Stephen Fuld on Fri Nov 8 11:15:50 2024
    Stephen Fuld wrote:
    NSA has recently released the video of a 1982 talk by Grace Hopper.

    If you don't know who she is, read up on her at e.g.

    https://en.wikipedia.org/wiki/Grace_Hopper

    before watching the video.

    If you know of her but have never heard her speak, you are in for a
    treat.  She was an outstanding speaker.

    If you have heard her speak, watch it for some amazing memories.

    https://www.c-span.org/video/?538935-1/captain-grace-hopper-future-computers-1982


    It runs about 1.5 hours, but it seems like less.

    It seemed like a lot less this morning!

    I have of course listened to/watched her before, but she certainly
    deserves re-watching.

    I was directly inspired by her nanoseconds as a way to show how long
    they were, without having to carry any with me: Here in Europe we do of
    course use A format paper, with A0 being exactly one square meter, with
    a height/length ratio of sqrt(2).

    You get smaller sizes (A1, A2, A3 etc) by cutting in half across the
    longer axis.

    The standard paper size available in all printers and copiers is of
    course A4, and that A4 sheet is exactly(*) one nanosecond tall (29.97
    cm) as well as one nanosecond when travelling inside an optical fiber wide!

    Terje
    (*) Within your ability to measure with a ruler, or a paper supplier to cut.

    --
    - <Terje.Mathisen at tmsw.no>
    "almost all programming can be viewed as an exercise in caching"

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Lawrence D'Oliveiro@21:1/5 to Terje Mathisen on Fri Nov 8 21:25:49 2024
    On Fri, 8 Nov 2024 11:15:50 +0100, Terje Mathisen wrote:

    The standard paper size available in all printers and copiers is of
    course A4, and that A4 sheet is exactly(*) one nanosecond tall (29.97
    cm) as well as one nanosecond when travelling inside an optical fiber
    wide!

    Hey, I never noticed that. Proof, if any were needed, that international standard paper sizes and units of measurement were given to us by the
    gods ...

    By the way, that must mean the refractive index of optical fibre is close
    to 1.4. Is that plastic? Because glass would be closer to 1.5, wouldn’t
    it?

    Terje (*) Within your ability to measure with a ruler, or a paper
    supplier to cut.

    Yes, the size of a sheet of paper can vary quite appreciably (by as much
    as a few percent), depending on the humidity particularly.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From MitchAlsup1@21:1/5 to Lawrence D'Oliveiro on Fri Nov 8 21:37:24 2024
    On Fri, 8 Nov 2024 21:25:49 +0000, Lawrence D'Oliveiro wrote:

    On Fri, 8 Nov 2024 11:15:50 +0100, Terje Mathisen wrote:

    The standard paper size available in all printers and copiers is of
    course A4, and that A4 sheet is exactly(*) one nanosecond tall (29.97
    cm) as well as one nanosecond when travelling inside an optical fiber
    wide!

    Hey, I never noticed that. Proof, if any were needed, that international standard paper sizes and units of measurement were given to us by the
    gods ...

    By the way, that must mean the refractive index of optical fibre is
    close
    to 1.4. Is that plastic? Because glass would be closer to 1.5, wouldn’t
    it?

    You can make glass (amorphous si-dioxide) in refractive indexes from
    about 1.1 through about 1.85; there is a special kind of glass with
    RI = 2.0 used to make the reflective paint on street signs. {{A round
    ball with RI = 2.0, reflects incident light back where it came from.}}

    Terje (*) Within your ability to measure with a ruler, or a paper
    supplier to cut.

    Yes, the size of a sheet of paper can vary quite appreciably (by as much
    as a few percent), depending on the humidity particularly.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)