Primitive Radiometer Studies
in [Physics]
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From: Tim Golden BandTech.com on 19 May 2010 13:36 On May 16, 3:19 pm, Thomas Heger <ttt_...(a)web.de> wrote: > waldofj schrieb: > > I tried something similar, I put mine in the freezer. It never rotated > > backwards but when I took it out of the freezer (under low light > > conditions) it started running (normal direction) and continued to run > > until it warmed up. Still not sure what to make of that. > > I've read somewhere, that the vanes would rotate in opposite direction, > if the whole device is submerged in ice-water. But that may or may not > be the case. > As mentioned before, I have no possibility to do experiments and own no > light-mill. Hence I can only reproduce what I've read. Whether or not > these statements are correct, I can't tell, but it is certainly possible > to do some experiments in case someone has the required resources. > Maybe you do some 'research'. E.g. I would like to know, if the device > works in a horizontal configuration (with the axis horizontal). > I think, it would not rotate very well. > > Greetings > TH Here is a quote from Nichols published work: "At the close of the pressure and energy measurements when the reflecting power of the silver faces of the vanes was compared with that of the glass silver faces the reflection from the silver faces was found very much higher than that for the glass faces backed by silver. This result was the more surprising because the absorption of the unsilvered vanes was found by measurement to be negligibly small. This unexpected difference in reflecting power of the two faces of the mirrors prevented the elimination of the gas action by the method described from being as complete as had been hoped for. But by choosing a gas pressure where the gas action after long exposure is small the whole gas effect during the time of a ballistic exposure may be so reduced as to be of little consequence in any case." - http://books.google.com/books?id=8n8OAAAAIAAJ&pg=RA5-PA327&dq=torsion+balance+radiation E.F. Nichols and G.F. Hull, The Pressure due to Radiation, The Astrophysical Journal,Vol.17 No.5, p.315-351 (1903) There is a standard claim that the Nichols radiometer is operating on different principles than the Crookes radiometer, but this passage exposes that gas effects were never eliminated, and furthermore, if the Nichols radiometer truely operated in vacuum, then why shouldn't the Crookes? This question seems to go unanswered, and is to me a sore point. The stranger reversal in deflection from .05 mm Hg to .02 mm Hg seems to go observed yet unanswered within the analysis. Nichol's seems to have pushed for a specific result, and having gotten it, is happy not to look back. Is this science? The link is worth the read but above I've quoted a passage that my skepticism picks upon. Periods are missing, and this text is coming straight from Google's 'cut feature of their image reader; pretty damn slick and righteuous that we've got access to this information. If all journals would do this... I guess they will in time; that is, those that do not wish to exclude amateurs from access. To amplify the contradiction of the quote I pick out two portions: "the mirrors prevented the elimination of the gas action by the method described from being as complete as had been hoped for" "the whole gas effect during the time of a ballistic exposure may be so reduced as to be of little consequence in any case" There is no data demonstrating these nulls, and the sharp inversion from the 0.02 to 0.05 suggests some sort of nonlinearity at that null, which will prevent stable experimentation. Anyway, selection of that null should actually yield no results. The dynamics exposed by the experiment go ignored in the analysis. I do not feel strongly enough to declare a farce here, but I am leaning in that direction. - Tim
From: Tim Golden BandTech.com on 19 May 2010 14:55 And finally I've found some support from a third party: http://www.neumann-alpha.org/lightpressure.pdf So far little of the information that I've read has bothered to enter any theory of the radiation pressure, but here we see an investigation. - Tim
From: spudnik on 19 May 2010 22:11 can one tell a priori that a black surface will absorb more infrared, since it is invisible in the first place? I wish folks like Y'know and y'Know would at least *try* to write their syllogistical theories in terms of, "There Are No Photons?" just this afternoon, a lecturer showed a slide with a graph of "phonons from 0 to over 1 teracycles;" is that the sound of light? http://www.xs4all.nl/~johanw/PhysFAQ/General/LightMill/light-mill.html
From: Sue... on 19 May 2010 22:17 On May 19, 10:11 pm, spudnik <Space...(a)hotmail.com> wrote: > can one tell a priori that a black surface will absorb more > infrared, since it is invisible in the first place? > > I wish folks like Y'know and y'Know would at least *try* > to write their syllogistical theories in terms of, > "There Are No Photons?" ==== > > just this afternoon, a lecturer showed a slide > with a graph of "phonons from 0 to over 1 teracycles;" > is that the sound of light? Indeed! I see what you are saying. Sue... > http://www.xs4all.nl/~johanw/PhysFAQ/General/LightMill/light-mill.html
From: spudnik on 19 May 2010 22:29
on the wayside, please, attempt to "save the dysappearance" of Newton's God-am corpuscular "theory," by not using them in equations with "momentum (equals mass times directed velocity)." thank *you* and nice a have day. thusNso: actually, receding glaciers are probably better for rafting, compared to advancing ones, iff there's more water. thusNso: can one tell a priori that a black surface will absorb more infrared, since it is invisible in the first place, invoking, perhaps, blackbody curves (and, there are "line spectra" for both absorption & emmission) ?? I wish folks like Y'know and y'Know would at least *try* to write their syllogistical theories in terms of, "There Are No Photons?" just this afternoon, a lecturer showed a slide with a graph of "phonons from 0 to over 1 teracycles;" is that the sound of light? http://www.xs4all.nl/~johanw/PhysFAQ/General/LightMill/light-mill.html thusNso: I like all three of those; note that there is a raw infinity of trigona, two of whose edges are perpendicular to the other edge, as far as spherical trig goes, and I really like those "half lunes." --y'know dot the surfer's value of pi dot com period semicolon & I mean it! http://\\:btty |