1. Joined
    06 Mar '12
    Moves
    642
    08 Jan '21 08:152 edits
    As this video explains;
    The discovered two states of liquid water are temperature dependent.

    As you heat up the water;
    At around 40C its refractive index starts to change.
    Then, if it is completely pure water, its electric conductivity starts to change at around 55C.
    Then at around 57C its surface tension starts to change.
    Then at around 64C its thermal conductivity starts to change.

    All this suggests the water gradually changes from one state to another between about 40C and roughly 70C.

    This video doesn't give any explanation of what is going on at the molecular level during this transition, which I find disappointing, but the reason why it doesn't could be, for all I know, simply because nobody yet knows.

    YouTube
  2. Standard memberyo its me
    watch the acid...
    dosen't get you!!
    Joined
    14 Jan '07
    Moves
    59857
    08 Jan '21 08:36
    @humy
    Interesting thankyou.
    He says the report is in the notes- maybe there's more information in there.
    I wonder if a change in molecules has anything to do with why yeast is best with water at 38°
  3. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    53033
    08 Jan '21 15:45
    @humy
    Some of the machines I worked on, like ion implanters which have ultra high voltage power supplies, some of them a half million volts, and the preferred coolant is DI water. We have to use plastic fittings because metal gets torn apart by the polar nature of water.
    DI water has very low electrical conductivity so can be used to cross high voltage barriers and still be used as a coolant.

    But the water can get up to 70 degrees C so did it say anything about the change in conductivity? That could impact the ability of DI water to cross high voltage barriers if the conductivity went down.
    Pure DI water comes in at about 18 megohms/square cm.
    If it went down to say 2 or 3 megs a quarter million volt power supply could maybe start arcing through the cooling lines.
  4. Joined
    06 Mar '12
    Moves
    642
    08 Jan '21 16:22
    @sonhouse said
    @humy
    o did it say anything about the change in conductivity?
    Unfortunately no and it didn't give any details about the amounts of changes observed nor did it show any graphs.
    I also tried and failed to find the original study this OP video was based on, hoping the report of the original study would shed some sort of light on EXACTLY what was observed, and instead found only some vague short references to the original study which didn't tell me much!
  5. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
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    53033
    08 Jan '21 18:40
    @humy
    Well fortunately our DI cooling water seldom gets to 70 C. Usually runs 30 or so.

    I never saw DI water being responsible for arcing in our 200,000 volt PS system.
  6. In your face
    Joined
    21 Aug '04
    Moves
    55993
    13 Jan '21 22:33
    @humy said
    As this video explains;
    The discovered two states of liquid water are temperature dependent.

    As you heat up the water;
    At around 40C its refractive index starts to change.
    Then, if it is completely pure water, its electric conductivity starts to change at around 55C.
    Then at around 57C its surface tension starts to change.
    Then at around 64C its thermal conductivity star ...[text shortened]... be, for all I know, simply because nobody yet knows.

    https://www.youtube.com/watch?v=YsQXN-Kh2-w
    Could it be that below a certain temperature, water molecules tend to line up in chains due to their polar nature. Above that temperature then the chains become dissociated due to the increased energy of the molecules? This might explain the changes in the properties that you mention.
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