[HN Gopher] Ohm Overlooked
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Ohm Overlooked
Author : pera
Score : 45 points
Date : 2022-04-09 13:05 UTC (9 hours ago)
(HTM) web link (spark.iop.org)
(TXT) w3m dump (spark.iop.org)
| samatman wrote:
| This is a case where reading the Wikipedia entry will round out
| one's impressions left from the article.
| https://en.wikipedia.org/wiki/Georg_Ohm
|
| After publishing his monograph on the galvanic circuit, he did
| resign from his position at Bamburg: after which he took up
| positions at Nuremberg and finally Munich, as a professor of
| experimental physics.
|
| Also, it's easy to criticize the critics with hindsight, but take
| a look at his acoustic law
| https://en.wikipedia.org/wiki/Ohm%27s_acoustic_law which is at
| best an approximation.
|
| It's easy to confidently think to ourselves, of course we would
| have accepted Ohm's law! But would we have rejected Ohm's
| acoustic law as well? What oracle gives us this amazing power?
| marcosdumay wrote:
| > What oracle gives us this amazing power?
|
| Hum... Ideally, you could replicate his experiment and verify
| his findings. That doesn't mean his theory is correct,
| obviously, but you don't go destroying the career of scientists
| with valid empiric knowledge just because you disagree with
| their pick of one of the many theoretical explanations that fit
| it.
|
| Or, well, people do that, even today, but they shouldn't.
| zeckalpha wrote:
| > In addition to his electrical law, Ohm proposed an acoustic law
| which proposes that musical notes may be decomposed into a number
| of pure tones.
|
| Sounds like FFTs! Anyone have a link for more about this?
| _0ffh wrote:
| Ohm proposed it and Helmholtz elaborated it in a book he
| published about "sound sensations", which I suppose would be
| called "psychoacoustics" in modern parlance.
|
| I found it online [1] and let Google translate it [2].
|
| [1] https://psychologie.lw.uni-
| leipzig.de/wundt/opera/helmhltz/t...
|
| [2] https://psychologie-lw-uni--leipzig-
| de.translate.goog/wundt/...
| dreamcompiler wrote:
| More precisely the power spectral density, which is always
| real.
|
| The human ear seems only sensitive to phase when locating
| sounds binaurally:
|
| https://physics.stackexchange.com/questions/277493/can-human...
| dmitriid_y wrote:
| > One of the reasons Ohm's work was not more readily accepted was
| because he used contemporary electrical terms that had ambiguous
| meanings. For example, he did not clearly distinguish between
| force and electrical potential, and confusingly drew on ideas
| from Fourier's theory of heat - he refers to the 'diffusion' of
| electricity.
|
| It's depressing that gatekeeping is such a pervasive human
| tendency. I wish I could project myself back into the minds of
| these critics and giggle incessantly about how good ol' `V=IR`
| has been such a foundation to my world that Ohm's name is utterly
| inescapable...while these reviewers' dust has all but been lost
| to the wind.
| sacrosancty wrote:
| I still have trouble working out the difference between
| electromotive force and potential difference. Teachers do a
| poor job of that one. I imagine it was even more of a blurry
| muddle to everyone back then.
|
| But if you don't define your variables, an equation becomes a
| bit useless. Was it really that Ohm didn't use the "gate-kept"
| language or that he didn't actually know what he was talking
| about?
| robocat wrote:
| https://www.electronics-
| notes.com/articles/basic_concepts/vo...
|
| EMF is a DC voltage present even in an open circuit, when no
| current is drawn. EMF comes from a cell/battery or DC
| generator. EMF is the cause; potential difference is the
| effect.
| willnonya wrote:
| I know 'gate-keeping' is the Boogeyman de jour but when
| attempting to communicate scientific ideas to a scientific
| audience it helps to have the proper vocabulary.
|
| It is much the same as your teachers not being able to bridge
| the gap between concepts you understand and those needed to
| understand EMF and PD.
| dmitriid_y wrote:
| With the benefit of history, we know Ohm was more right than
| wrong. So -- even if these critics where hitting on a very
| real inconsistency of Ohm's research in their pursuit of the
| virtue of peer review -- they fell victim to the arrogance of
| their ivory tower.
|
| The pitch-perfect critique would've had to be "You've got
| some great work, but this bit here is hard to follow or
| outright inconsistent". Instead, they shouted him out of the
| profession because of the surety of their convictions.
| hattmall wrote:
| This is still a huge problem today because at a certain
| level most people's benefit proposition switches from the
| pursuit of discovery to maintenance of the status quo.
| sp332 wrote:
| Or that other people didn't know what he was talking about.
| projektfu wrote:
| The potential difference can be measured between any two
| points in a circuit, but EMF is the source of electrical
| energy such as a battery or generator that produces the
| potential difference that can be considered to "drive" the
| circuit.
|
| As I understand it, an EMF has to come from nonelectrical
| energy, such as chemical, thermal, mechanical, or
| electromagnetic energy. So if you are drawing your circuit
| with a battery, you could call that EMF but if you are
| drawing it with a generic voltage source, you would not call
| that EMF per se.
| GuB-42 wrote:
| From my understanding, the problem with Ohm's law is that at
| the time, they had trouble characterizing internal resistance.
| You probably noticed that in the article, it is X=a/(b+x), not
| the familiar V=IR, because they didn't realize yet that
| internal resistance from the battery was the same as resistance
| from a length of copper wire. Remember that Kirchhoff's circuit
| laws came after Ohm and his law became universally recognized.
|
| Everything seems so obvious now, but now, we have accurate
| multimeters, low internal resistance power supplies and color-
| coded resistors. They didn't have anything like that in the
| early 1800s.
|
| Gatekeeping is a thing of course, and it certainly didn't help
| in Ohm's case, but it is easy to forget the context in which
| discoveries are made. It is a bit like heliocentrism, obvious
| now, but when the idea was first introduced, it was actually
| worse than the theories of that time, based on epicycles, it
| wasn't just obscurantism.
| _0ffh wrote:
| Um, "Reduzirten Lange" isn't quite right. It was "Reduzirte
| Lange" (the modern spelling would be "Reduzierte Lange").
|
| That translates to "reduced length" and was defined by Ohm as the
| length of a wire divided by it's cross section and specific
| conductivity.
| baus wrote:
| I fiddle around with tube amps and Ohms law is about the only
| math I use in that hobby. It is kind of beautiful in its
| simplicity
| pmarreck wrote:
| _...a web of naked fancies, which can never find the semblance of
| support from even the most superficial observation of facts:
| (and) he who looks on the world with the eye of reverence must
| turn aside from this... as the result of an incurable delusion,
| whose sole effort is to detract from the dignity of nature._
|
| is anything more "unfortunately human" than this statement, right
| here? Both in its creative wording and in its cocksure unwavering
| wrongness
| tonyedgecombe wrote:
| It would have been the top comment on HN if HN had existed at
| the time.
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