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#1
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Richard Clark wrote:
On Wed, 05 Sep 2007 00:04:23 -0000, Jim Kelley wrote: Richard Clark wrote: The description you offer requires a porous plate which is absent in every radiometer that has come down the pike On the other hand, the absence of porous plates in operating radiometers tends to cast some doubt on your claim that the plates must be porous. Not "my claim," my report. So be it. The absence of porous plates in operating radiometers tends to cast doubt on your report that the plates must be porous. The claim they must be porous arrives through the math necessary to balance the kinetic forces. But a balance of forces would result in the absence of an observable effect. An imbalance in forces is required in order to produce movement. Now, if we simply move to another radiometer (Nichols, Tear, Hull, and Webb already recited) without that partial vacuum, the vanes still move, and expressely by Radiation Pressure. By a different mechanism and in the opposite direction, yes. In essence, these instruments indicate, not measure. A description which applies beautifully to power meters as well, don't you agree? ;-) The coy context of the thread was measuring the mass of a Photon. Absolutely no SI Units have been named or any quantitative values offered (the rather standard omission from claims made here). However, feel free to introduce your own side thread's goal or even offer a guess (your own quatitative value for the mass). I'd like to offer m = E/c^2 as a guess. 73, ac6xg |
#2
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On Wed, 05 Sep 2007 17:02:38 -0700, Jim Kelley
wrote: Not "my claim," my report. So be it. The absence of porous plates in operating radiometers tends to cast doubt on your report that the plates must be porous. Hi Jim, You should distinguish between reporting, claims, and what you see. The point about being porous is to substantiate the expectation of explaining the full energy budget (and specifically for the Crookes radiometer). I don't know how many times I have to emphasize this, but NO METHOD achieves that balance. The claim they must be porous arrives through the math necessary to balance the kinetic forces. But a balance of forces would result in the absence of an observable effect. An imbalance in forces is required in order to produce movement. The balance is in the energy applied and the energy expended. You put an HP into a car, and it will accelerate 550 foot-pounds/sec. You put x photons into ANY radiometer, and the change in inertia WILL NOT balance. [This is why I expressed my question in Newtonian terms for the benefit of the twins who are so devoted to the master (that they are wholly lost in a simple 2 variable computation). The difference between that computation and performance is extreme. What is more compelling, is that it is quite a departure from what Quantum Mechanics would predict. NO METHOD achieves that balance.] Now, if we simply move to another radiometer (Nichols, Tear, Hull, and Webb already recited) without that partial vacuum, the vanes still move, and expressely by Radiation Pressure. By a different mechanism and in the opposite direction, yes. In essence, these instruments indicate, not measure. A description which applies beautifully to power meters as well, don't you agree? ;-) No. Power meters to even uncommonly high accuracy still conform to Newtonian mechanics. The coy context of the thread was measuring the mass of a Photon. Absolutely no SI Units have been named or any quantitative values offered (the rather standard omission from claims made here). However, feel free to introduce your own side thread's goal or even offer a guess (your own quatitative value for the mass). I'd like to offer m = E/c^2 as a guess. The photo-electron appears to even depart from that. More to follow. 73's Richard Clark, KB7QHC |
#3
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Richard Clark wrote:
In essence, these instruments indicate, not measure. A description which applies beautifully to power meters as well, don't you agree? ;-) No. Power meters to even uncommonly high accuracy still conform to Newtonian mechanics. So it is because of Newtonian mechanics that an RF power meter is actually measuring power rather than indicating power. What is the value gained by this strain on credulity? The coy context of the thread was measuring the mass of a Photon. Absolutely no SI Units have been named or any quantitative values offered (the rather standard omission from claims made here). However, feel free to introduce your own side thread's goal or even offer a guess (your own quatitative value for the mass). I'd like to offer m = E/c^2 as a guess. The photo-electron appears to even depart from that. I've often wondered how one might go about recognizing a photo-electron out of a group of other, less prominent electrons? :-) 73, ac6xg |
#4
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On Thu, 06 Sep 2007 09:54:43 -0700, Jim Kelley
wrote: So it is because of Newtonian mechanics that an RF power meter is actually measuring power rather than indicating power. What is the value gained by this strain on credulity? Hi Jim, Sounds like you should talk to your Chaplain about these issues. I've often wondered how one might go about recognizing a photo-electron out of a group of other, less prominent electrons? :-) It is like complaining the Nobel winners are indistinguishable from the crowd in the ceremonial hall. Prominent is key, certainly. How many electrons can you motivate to leap over the barrier of the work function of a metal? In Physics, a simple population count would reveal the prominence. Tubes usually have to boil them off incandescent filaments, or rip them out of their matrix with 10's of kilovolts of nearby potential. Hi All, Let's examine those last two motivators. Photons hardly raise the temperature of a metal vane to, what, 1000 degrees? And as for kilovolts of excitation, how much potential is there in a photon? Well, too often this group starves for information in response when I toss these questions out - too technical for this forum of light nappers I suppose. Too often, these threads turn into strings of slaps at the snooze button (and "ether" has been the biggest snooze of them all - self-fulfilling if one were to enlarge on the term's rhetorical baggage). Place a vane coated with sodium into an evacuated quartz tube. Illuminate the sodium coated plate such that it absorbs one microwatt per square meter. This is sufficient power to evoke the photo-electric response (hopefully this is not too arcane a term). The bulk of absorption will occur within a layer depth of 10 atoms. Sodium, one atom thick, measures out to 10^19 atoms per square meter, so we are absorbing the power throughout 10^20 atoms. Hence each atom is illuminated with 10^-26 Watts OR 10^-7 eV/sec. (eV: electron Volt, perhaps another prominence hard to embrace.) The conundrum (sorry for hard words - but even those who use English as a second language manage to cope) here is that to build a potential to at least 1eV (and usually 3 to 5 times that for many metals) would take nearly a year for a single electron to leap the Work Function barrier. In reality, it occurs in less than a nanosecond. It would be interesting to see Arthur's Newtonian math achieving a 10,000,000,000,000,000:1 leap of faith. False idolatry in place of work is like putting a lottery ticket into the collection plate. Strip away my stylistic excess and the facts fill maybe three sentences. Still, I am four sentences ahead of the rest. ;-) 73's Richard Clark, KB7QHC |
#5
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![]() Richard Clark wrote: Still, I am four sentences ahead of the rest. ;-) We now learn of the value in strained credulity. :-) jk |
#6
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On Sep 5, 5:02 pm, Jim Kelley wrote:
.... I'd like to offer m = E/c^2 as a guess. 73, ac6xg A link is worth a thousand words (perhaps 10k-100k of Richard's...): http://www.newton.dep.anl.gov/askasc...0/phy00332.htm (in particular the first paragraph of the second response). |
#7
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On Thu, 06 Sep 2007 12:47:46 -0700, K7ITM wrote:
On Sep 5, 5:02 pm, Jim Kelley wrote: ... I'd like to offer m = E/c^2 as a guess. 73, ac6xg A link is worth a thousand words (perhaps 10k-100k of Richard's...): http://www.newton.dep.anl.gov/askasc...0/phy00332.htm (in particular the first paragraph of the second response). Hi Tom, Your link is over valued (there is no second response), but it maintains the standard of excellence here in the tradition of 10k-100k more words than quantifiables - and someone else doing the work. Care to walk us through your proffered math? Well, I doubt it. Others may be interested in the curious form of argument offered to a 15 year old however. "For a particle with no mass, the relation reduces to E=pc." The long and short of it is that there is no discussion of mass for a photon (it is simply defined not to exist) and instead there is a shuffle of math that youngster must imagine this bozo is pulling the wool over his eyes through substituting p for Planck's constant h, and c for Planck's energy formula variable v. This wool pulling is another favorite past time here too. Of course, there may be other meanings behind "E=pc." but in the model of thorough work, the description of terms is sadly poor. The typical legacy of offering links. It has all the appeal of a Physicist's joke: "How many milliseconds does it take to do a 5 minute car wash?" 73's Richard Clark, KB7QHC |
#8
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On Sep 6, 2:53 pm, Richard Clark wrote:
....(there is no second response)... Pity you have so much trouble reading... |
#9
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Richard Clark wrote:
On Thu, 06 Sep 2007 12:47:46 -0700, K7ITM wrote: On Sep 5, 5:02 pm, Jim Kelley wrote: ... I'd like to offer m = E/c^2 as a guess. 73, ac6xg "E=pc." Yes, and p=mv, so when v=c as is true for photons, and we substitute mc for p in the equation above and then solve for m (the mass of a photon was the original question), we're back at the equation offered previously. But we usually relate more directly to the frequency (or wavelength) of the photon rather than its energy or momentum, so in such a case E=h*nu would provide a more direct route to its mass equivalent. ac6xg |
#10
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On Thu, 06 Sep 2007 16:07:09 -0700, Jim Kelley
wrote: Richard Clark wrote: On Thu, 06 Sep 2007 12:47:46 -0700, K7ITM wrote: On Sep 5, 5:02 pm, Jim Kelley wrote: ... I'd like to offer m = E/c^2 as a guess. 73, ac6xg "E=pc." Yes, and p=mv, Hi Jim, Tom opines about my reading, but it is about the writing from the good doctor that we find (in regard to your snippet above): "we find that the momentum relation p=mv is only an approximation. It is only correct when speed (v) is much smaller than the speed of light (c). which distinctly contradicts your tie-in: so when v=c as is true for photons, and we substitute mc for p in the equation above and then solve for m (the mass of a photon was the original question), we're back at the equation offered previously. The circularity of Dr. Ken Mellendorf's foggy writing might suggest it, if it weren't otherwise nipped in the bud by the bald statement. "For a particle with no mass, the relation reduces to E=pc. This works for a photon." Hence the proximity of this to p=mv is textual, not factual. What is the term p? Could it be (p)hoton? I've speculated about Planck's constant (which you comment upon, below), but I find it very sloppy writing for Dr. Mellendorf to wander into his own naming conventions. Migrating through E = mc˛ something all can agree is a fair basis to begin with, we then have expressly for a (p)hoton: E = pc Substituting for the previous E pc = mc˛ divide both sides by c p = mc which to me is new territory. What is mass times the speed of light for a particle that has no mass? Perhaps Tom's special reading skills can rescue this p term from the oblivion of E = 0 for a (p)hoton. But we usually relate more directly to the frequency (or wavelength) of the photon rather than its energy or momentum, so in such a case E=h*nu would provide a more direct route to its mass equivalent. Yes, and it seems your daughter trumped me on Planck once before. ;-) It is exceedingly obvious that the link offered amounts to considerable wool gathering. Or maybe its the late hour.... 73's Richard Clark, KB7QHC |
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