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Richard Clark wrote:
On Thu, 30 Jun 2005 12:14:36 -0500, Cecil Moore wrote: More of the same personal stuff. How about some technical content for a change? http://www.qsl.net/w5dxp/weblaser.GIF (which I am sure you will soon hustle off in embarrassment) For an angle of incidence of 30° The angle of incidence is always 90 degrees. It is drawn that way because it cannot be drawn in one dimension. This is typical of physics textbook drawings. An angle of incidence of 30 degrees is irrelevant to this particular example. How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts Steady-state after re-reflection is 0.01010101 watts How much power is transmitted through all interfaces? One watt net to the "load". The steady-state forward power in the thin film is 1.010101 watts of which 0.010101 is a steady-state internal reflection from surface B. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#2
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On Thu, 30 Jun 2005 13:43:13 -0500, Cecil Moore
wrote: An angle of incidence of 30 degrees is irrelevant to this particular example. Changing the question to suit the answer, Hmm? As if it mattered! How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts depending upon the polarization r¬ = 1.583% and r|| = 0.5485% Splitting the difference (1.066%) 0.0107W or 0.9893W @ 24° available at the next interface How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts depending upon the polarization r¬ = 1.3381% and r|| = 0.7099% Splitting the difference (1.024%) 0.0101W or 0.9792W @ 19° available at the next interface How much power is transmitted through all interfaces? One watt net to the "load". Already provided as 0.9792W ********************************** Since you couldn't answer the original question, let's explore how accurate your answer to your own question was: How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts depending upon the polarization r¬ = 0.9999% and r|| = 0.9999% Splitting the difference (0.9999%) 0.0100W or 0.9900W @ 0° available at the next interface How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts depending upon the polarization r¬ = 0.9998% and r|| = 0.9998% Splitting the difference (0.9998%) 0.0099W or 0.9801W @ 0° available at the next interface How much power is transmitted through all interfaces? One watt net to the "load". Already provided as 0.9801W But, hey, what's 2% error in a conservation of energy equation? You can prove anything (especially your absolute proofs) if you simply discard precision. Pons and Fleishman proved cold fusion by throwing away fewer digits than you. Well, for 1W of light and presuming cancellation (you cannot achieve full cancellation); this leaves 100µW of light reflected from a non-reflecting layer - which is quite bright. So, energy is conserved, and there is no such thing as complete cancellation. By the way, the math is available from: Hecht, Eugene, Optics, 2nd Ed, Addison Wesley, 1987 or perhaps you should invest in: Hecht, Eugene, Optics, Schaum's Outline Series, McGraw-Hill ,1975 |
#3
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Richard Clark wrote:
But, hey, what's 2% error in a conservation of energy equation? The error is yours. During steady-state, the forward power in the thin film is 1.0101 watts. 1% of that is 0.0101 watts. 1.0101 - 0.0101 = one watt delivered to the "load". 100% accuracy is guaranteed because it is a mental conceptual exercise. To summarize: Forward power in air is one watt. Reflected power in air is zero watts. Forward power in the thin-film is 1.010101010101010101 watts. Reflected power in the thin-film is 0.10101010101010101 watts. Power delivered through Surface B is exactly one watt, exactly the output of the laser. Exactly the difference between the steady-state forward and reflected power in the thin-film. Well, for 1W of light and presuming cancellation (you cannot achieve full cancellation) That's the great thing about a mental conceptual example. Full cancellation is guaranteed. So, energy is conserved, and there is no such thing as complete cancellation. True for real world stuff. False for mental conceptual examples like the one being discussed. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#4
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Cecil Moore wrote:
Forward power in the thin-film is 1.010101010101010101 watts. Reflected power in the thin-film is 0.10101010101010101 watts. Darn, missed a zero. Should be 0.010101010101010101 watts. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#5
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On Thu, 30 Jun 2005 15:52:23 -0500, Cecil Moore
wrote: Darn, missed a zero. Should be 0.010101010101010101 watts. How could it possible matter? |
#6
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On Thu, 30 Jun 2005 15:47:19 -0500, Cecil Moore
wrote: So, energy is conserved, and there is no such thing as complete cancellation. True for real world stuff. False for mental conceptual examples like the one being discussed. Hi Tor, So, do you see by this example what I describe as the devil's in the details? Absolute proof of complete cancellation using referenced math, which is then abstracted to another field to prove imponderables (mental conceptual examples). And what purpose is served through this prostitution of citations? That thin films completely cancel reflections? - they do not. That optical interfaces exhibit complete transmission? - they do not. What makes the proofs of these unproven phenomenon necessary such as to dismiss the correct answers? Dare we follow the thread of a suspect theory to arrive at other, equally flawed steps along the way? 73's Richard Clark, KB7QHC |
#7
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Richard Clark wrote:
And what purpose is served through this prostitution of citations? Well Richard, since you are being so picky, I am going to have to insist that you prove that you exist. :-) -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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