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Insights What Happens When You Flip the Light Switch? - Comments

  1. Aug 26, 2015 #1

    anorlunda

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  2. jcsd
  3. Aug 26, 2015 #2
    why is almost every paragraph finsihed with "this is physics"

    what else is it? black magic?
     
  4. Aug 26, 2015 #3

    anorlunda

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    I was trying to point out the difference between physícs, engineered features, and economics, because they are commingled.
     
  5. Aug 26, 2015 #4

    dlgoff

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  6. Aug 26, 2015 #5
    Very interesting! I learned a lot!
     
  7. Aug 26, 2015 #6

    anorlunda

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    Thanks for your kind words. I just read that paper on frequency response with interest.

    When I started in this business, just after the Northeast Blackout of 1965, every single generator used a 5% regulation (i.e. 20% change in power for 1% change in frequency); there were no exceptions that we knew of. The reason was that if everybody used the same gain, then all generators shared all load changes in proportion to their rated capacity. That is pretty close to optimum. There were rumors that some bad actors use wedges to force open the turbine valves the last couple of percent which would make them not respond to frequency, but it was never proved.

    Later in the 2000s, I was shocked to learn that very many plants no longer had frequency governing active full time. But I was told by many people that it's not a problem. FERC and NERC have standards about frequency and time and tie-line excursions and those standards were being met, so I had to concede that no harm was readily apparent. The paper you linked challenges that.

    I was also shocked to learn here on PF, that operators in New Zealand tuned they hydro governers for less than 5% (more than 20% per %). The argument is that hydro plants are uniquely able to respond rapidly to incremental changes. That too was news to me.

    I did not mention in the article that on a huge interconnection with billions of "light switches" around, that almost all random switch-on events are canceled by switch-off events. Thus frequency regulation by speed governors is most important on the smallest grids. I once vacationed on a small island and heard the refrigerator motor noticably speed-up and slow-down all day and night.

    Readers can make their own frequency measurement device, plug it into a wall socket, and keep an eye themselves on what is happening. Your socket is just as good as any other place on the grid to make that measurement.
     
  8. Aug 26, 2015 #7
    Thomas Edison didn't invent the light bulb. http://www.livescience.com/43424-who-invented-the-light-bulb.html
     
  9. Aug 26, 2015 #8

    anorlunda

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    I should have said first practical light bulb. I think he deserves the credit. According to https://www.amazon.com/Edison-Life-...pebp=1440616044725&perid=0PK3C47RNMHN37B61H6R, Alexander Graham Bell's phone was terrible, and not usable for long distance. Bell hired Edison and he designed the first practical phone for Bell under contract. Edison got cheated out of fame and credit for that work, I think he deserves payback on the light bulb thing.
     
    Last edited by a moderator: May 7, 2017
  10. Aug 26, 2015 #9

    berkeman

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    Small typo in the first paragraph...
     
  11. Aug 26, 2015 #10

    sophiecentaur

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    But the winners get to write the history.
    None of these things are ever down to just one person. Don't lose too much sleep over the injustice of it all. Edison made a seriously important contribution to what we switch on every day.
    P.S. Or is your family chasing some royalties on an ancient patent?
     
  12. Aug 26, 2015 #11

    dlgoff

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    Or they could find one of these old resonant reed type frequency meters like this one I found for my collection. But that's a different subject. :approve:

    frequencymeter.jpg
     
  13. Aug 26, 2015 #12

    anorlunda

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    WOW! A vibrating reed meter with both 50 and 60 Hz sets of reeds. That has got to be hightly unsual and rare. I would say that you have a valuable item there. Congratulations.
     
  14. Aug 26, 2015 #13

    sophiecentaur

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    I saw this meter on a visit to Pool (UK). It was from the local power station that was closed yonks ago. Not as exotic but it was an exciting find
    meter.jpg
     
  15. Aug 26, 2015 #14

    dlgoff

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    Excites me too. :oldlove:
     
  16. Aug 26, 2015 #15
    Do you think that not lying and then avoiding correcting a lie is any less immoral. o0)
     
  17. Aug 26, 2015 #16

    sophiecentaur

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    You seem to be a little bit emotionally involved with this issue (from the wording of your post). PF tries to be a bit more dispassionate.
    When someone reports on a historical event they may well write differently to someone else yet neither of them is necessarily "lying'". In any complex sequence of events (Science is a great example) there is often no truth involved. It's just interpretation. Do you have any hard evidence to support your introduction of the term "lying" in this context? Bearing in mind that this discussion is not PF style at all.
     
  18. Aug 26, 2015 #17
    @sophiecentaur,

    Let's discuss that PF-style, and the history of science. (Is there a flashy song akin to Gungam style for us to play?) o0)

    I posted the link to inform your readers to correct an assertion that Edison created the light-bulb, a well known myth. It would like being on a bulletin board dedicated to cars and saying that Henry Ford invented to the automobile, a rather indefensible act, or in a more obscure example, saying that RCA invented the television (though they may have beat the snot out of Philo Farnsworth to win the economic benefits). I guess a question I would pose to you, a thinker of the first-order, is why you would accept such an inaccurate assertion just because "winners get to write history"? It seems a little contradictory on your part to insist on a high-caliber of discussion and then defend well known inaccuracies, especially in a domain where reputation is important such as science. Now, while you seem to attribute to my motivations and use of figurative language aspirations which aren't present, let me rephrase my original post in a slightly less ambiguous manner:

    "For you, dear reader, man, woman, or child of intellect, dissever yourself not from the fact *wags fingers about* that Thomas Alva edison was not the first human being to have a glass ampule full of an inert gas and a filament to be used to create light in a modular and wonderfully complex innovation of technology to provide light to human-kind. And, lo, though the author has done a wonderful job of filling in some of the details of power distribution from a technical standpoint and considering physical ramifications, I bid you be more discriminating on what you accept as historical fact, for we live in a world where people in the first-world, the same consumers of these ripples through time-space understood by said physical and technological laws use said lighting to perpetuate pseudoscience and revisionist history and deny all manner of things mainstream physics such as the impact that burning fossil fuels and altering the global climate. And that there, dear reader, is a most remarked curiosity of note, that perhaps the most important thing that happens when you flip a light switch is that fifty years hence, the world is forced to deal with the rising sea levels and other manner of effects you might not think of."

    Of course, a quick posting to a link showing the OP's inaccuracy seemed just easier.

    So, no, dear moderator of discerning taste, no disrespect was meant, and I lose no sleep over ignorance of history. :wink: And, yes, history, is complicated, and often to the victor go the spoils. But there's confusion. Thomas Edison simply didn't invent the lightbulb. If you want the highest quality in posts, shouldn't it start with fact checking when building a narrative, especially when it has to do with the history of physics on a bulletin board aptly named PF? (And I accused no one of telling a lie.)

    I know this forum isn't truly a public sphere so many not have the same moral imperatives, and as moderator, you are charged with keeping order, but I would think anyone who has a love of science would prefer the more accurate to misleading perpetuation of a known myth.
     
  19. Aug 26, 2015 #18

    sophiecentaur

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    That was quite a tirade - out of nowhere.
    I think it may be more accurate (and relevant) to say, of Edison, that his laboratory team came up with the idea of using Tungsten for the filaments of bulbs. This was, I believe, after an extended programme of tests, using pretty well every substance know to man. It was, as he said (???) a matter of 99% Perspiration and 1% Inspiration. You may shed some light and tell me that is also a fiction.
     
  20. Aug 26, 2015 #19

    berkeman

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    I'd prefer that if you want to continue that discussion, you take it to a private conversation. Or if you prefer, I can break it off as a separate thread. We need to keep this thread on-topic about the Insights article. Thanks.
     
  21. Aug 26, 2015 #20

    sophiecentaur

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    No. It's no more than a hill of beans, as someone once said.
    The tungsten bit was fascinating though.
     
  22. Sep 10, 2015 #21
    Consider what happens during the flip of the switch. Let a galvanic cell be the power source.

    A galvanic reaction exports a single electron w/ chemical reaction energy (not a small energy change), after determination of circuit integrity.

    The anode and the cathode reactants must SIMULTANEOUSLY detect the integrity (no open circuit) of a (macroscopic) inductor, versus simply detecting that an adjacent molecule that is a conductor.

    The anode / cathode reactants must also detect the integrity of a path through the electrolyte between the anode and the cathode (sometimes including through a salt bridge), versus detection of w/ a nearby single electrolyte molecule.

    Applying chemical reaction energy to a single conductive molecule would result in high current through high resistance E = 1/2 LI^2. Limitation of thermal loss requires distribution of magnetic energy among the molecules in the current path within a macroscopic inductor, instead of a packet of magnetic energy passing from one molecule to the next.

    Electrical current would correspond to the number of times per second that this electron passes through any location (cross-section) within the circuit.

    eV = 1/2 LI^2

    The galvanic reaction will reclaim its electron, before the electron could make a second pass.
     
  23. Sep 10, 2015 #22

    sophiecentaur

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    Why do you use the word "simultaneously"? Just as with any arrangement of charges, the status takes time to establish itself. Not battery suddenly appears out of empty space but it will be assembled and charges will migrate to establish an equilibrium. The same point was discussed recently about the depletion layer in a solid state diode, which also does not suddenly appear.
    Once a circuit is connected across the galvanic cell, there will be another redistribution of charges. In this case, however, the charges will continue to flow until the chemicals, providing the potential energy, are exhausted.
    The fastest that any EM phenomenon can be established involves c. There is no need for Instantaneity to be involved.
     
  24. Sep 10, 2015 #23

    OmCheeto

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    0.01 through 10 seconds gave me a flashback to when they put young Om in charge of everything the day the external grid went down that was supplying power to his nuclear submarine, while the reactor was shut down, and the diesel was down for maintenance.
    Thanks for the memories!
    Lots of flashing lights and sirens.

    top.secret.nuclear.submarine.stuff.jpg

    ps. The reactor did not melt down. Pats self on back. :smile:
    pps. I would expand more on the story, but then I'd have to kill everyone.
    ppps. If you look closely at the image, there is a chrome bar running the width of the middle panel, about waist height. I've just realized that It is the equivalent of the handles they put in the passenger sections of automobiles. :oldsurprised: Never thought about that before.

    [edit]Ha! The profanity filter even works on links. I did not know that. Off to the TIL thread. :smile:
     
  25. Sep 10, 2015 #24

    analogdesign

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    What museum is that photo from? I'd very much like to go there.
     
  26. Sep 10, 2015 #25

    sophiecentaur

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    OmCheeto was clearly deeply immersed in his job.
     
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