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#351
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Noise level between two ant types
gravity wrote:
"Cecil Moore" wrote in message y.net... Gene Fuller wrote: How do you know there is no corona discharge? Because under passive fairweather conditions, corona requires 13 magnitudes more current than is available in nature. Please see my other posting. And just a comment on your seeming innocent question above. You seem to be asking me to prove that there is no corona discharge when proving a negative is impossible. The onus of proof is upon the one(s) who assert(s) the positive position. W8JI asserted that there is a corona discharge and you agreed with him. Therefore, the onus of proof is upon you. Please prove that corona can exist on a receiving antenna under passive fairweather conditions. People are free to assert negatives at any time without any proof. For instance, if I assert that you cannot dunk a basketball, my assertion will remain true until you prove that you can dunk a basketball. you can restate most negatives as positives. an example of this is a logical statement, in which case the contrapositive is always true. if P, then Q. if not Q, then not P. Afraid you have this wrong, gravity. Consider: P=today is my birthday Q=I will receive a present If (today is my birthday) then (I will receive a present). If (I will receive a present) then MAYBE today is my birthday and MAYBE it is not. 73, Chuck another example is Demorgan's theorem in set theory and electronics. if you say that general relativity is wrong, the burden is on you to prove otherwise. if the corona discharge theory is held by 90% of physicists and engineers, then anyone with a charged particle theory (a minority viewpoint) must do experimental verification or formulate a theoretical model. in this case, i think that both Cecil and others should cite peer reviewed articles. Gravity ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-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 =---- |
#352
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Noise level between two ant types
chuck wrote:
If (I will receive a present) then MAYBE today is my birthday and MAYBE it is not. Expanding: "If I receive a present today, then today is my birthday." Assuming no present is received today, that statement is true by definition. :-) -- 73, Cecil http://www.qsl.net/w5dxp |
#353
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Noise level between two ant types
Cecil Moore wrote:
chuck wrote: If (I will receive a present) then MAYBE today is my birthday and MAYBE it is not. Expanding: "If I receive a present today, then today is my birthday." Assuming no present is received today, that statement is true by definition. :-) Sorry, Cecil. I'm not following you on that. Whether the statement P implies Q is true has nothing to do with whether P is true. My point was that P implies Q does NOT mean if ~Q then not ~P. 73, Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-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 =---- |
#354
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Noise level between two ant types
chuck wrote:
My point was that P implies Q does NOT mean if ~Q then not ~P. Well, I screwed up again. Of course it does. Mixed up converse and contrapositive and sorry for the diversion. 73, Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-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 =---- |
#355
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Noise level between two ant types
chuck wrote:
Cecil Moore wrote: "If I receive a present today, then today is my birthday." Assuming no present is received today, that statement is true by definition. :-) Sorry, Cecil. I'm not following you on that. Neither do a lot of other people. Here's the truth table for an: (If A then B) = C logical statement A B C True True True True False False False True True False False True If the if-portion of an if/then statement is false, then the entire statement is true, by definition. For instance, this is a logically true statement. If I were ever to play in the NBA, then I would be a superstar. Since the A portion can never be true, the entire statement is true, by definition. In your earlier example, *both of these statements are true* if you didn't receive a present. Only if you actually received a present can one be true and the other false. 1. If I receive a present, it's my birthday. 2. If I receive a present, it's not my birthday. -- 73, Cecil http://www.qsl.net/w5dxp |
#356
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Noise level between two ant types
"chuck" wrote in message ... you can restate most negatives as positives. an example of this is a logical statement, in which case the contrapositive is always true. if P, then Q. if not Q, then not P. Afraid you have this wrong, gravity. Consider: P=today is my birthday Q=I will receive a present If (today is my birthday) then (I will receive a present). If (I will receive a present) then MAYBE today is my birthday and MAYBE it is not. that's not the contrapositive. that's the converse, i think. Gravity |
#357
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Noise level between two ant types
contraposition in logic.
http://en.wikipedia.org/wiki/Contrapositive affirmation of the consequent. http://www.fallacyfiles.org/afthecon.html Gravity |
#358
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Noise level between two ant types
Cecil Moore wrote:
Gene Fuller wrote: OK, energy exists, and it is even conserved. Do you feel better now? That's a good first step. Now where does the energy come from that supports corona under fairweather conditions? If the antenna is a vertical, ungrounded, uncharged wire, it is a conductor in an electric field (the fairweather field). The free charges in the antenna will move so as to cancel the fairweather field inside the antenna wire. At the top of the antenna, there will be a concentration of negative charge. If a single strand of wire sticks out, that concentration could be sufficient to ionize the air and cause corona. If the corona starting voltage is typically 30 kV/cm radius, then a tiny wire could ionize the air at only 300volts or so for a 0.01 cm radius. http://home.earthlink.net/~jimlux/hv/corona.htm Corona Based on that, it would seem the fairweather field can support corona formation by itself. If a charged particle now strikes the uncharged antenna, free charges will redistribute themselves to maintain no net electric field inside the conductor. The antenna's charge will increase until it exceeds some breakdown threshold. This process seems functionally similar to that due to the existence of the fairweather field, although either could exist independently. The question then seems to be whether the redistribution of charges that occurs when charged particles strike the antenna causes a current in the antenna which is detected by the receiver as noise. I believe this is the question Cecil has been posing. It occurs to me that the current due to charge redistribution could be rather significant if numerous particles are striking the antenna in a short time interval. Even a corona discharge will cause a redistribution of free charges that may show up as a detectable current at the receiver. This would be a different effect from the noise generating property of the corona itself. Any thoughts? Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-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 =---- |
#359
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Noise level between two ant types
chuck wrote:
If the corona starting voltage is typically 30 kV/cm radius, then a tiny wire could ionize the air at only 300volts or so for a 0.01 cm radius. http://home.earthlink.net/~jimlux/hv/corona.htm Corona As an update, I see that Llewellyn (not W7EL) in 1975 established experimentally that for a point radius of 0.01 cm, a corona will be formed with fields of only 100 V/m. These results differ a bit from what would be predicted by Paschen's curve. 73, Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-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 =---- |
#360
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Noise level between two ant types
chuck wrote:
Based on that, it would seem the fairweather field can support corona formation by itself. Even though the fairweather current is 13 magnitudes below the corona current? It occurs to me that the current due to charge redistribution could be rather significant if numerous particles are striking the antenna in a short time interval. Maybe aggravated by one element of the dipole being grounded and the other floating? -- 73, Cecil http://www.qsl.net/w5dxp |
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