How to get envelope from AM signal without phase shift
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From: glen herrmannsfeldt on 29 Mar 2010 19:02 WWalker <william.walker(a)n_o_s_p_a_m.imtek.de> wrote: > The first pulse is not the signal fed to the dipole. The first pulse is > just used to create a narrow banded pulse, which is then sent through the > dipole to be detected. Forget about the first pulse, the question is if I > send a narrow banded pulse through the dipole how long will it take to > arrive across a region of space in the nearfield of the dipole. If the > answer is less than the speed of light to cross the same region of space, > then the pulse has propagated faster than light. > "So if press a button with the same signal characteristics as the LPF > pulse, and if I use the threshold detector set jsut above the noise level > to detect the pulse and explode a bomb, the bomb will explode earlier than > if the pulse propagated at the speed of light. The pressing of the button > (Action) results in the exploding of a bomb (Reaction) faster than light > speed. This is clear cause and effect (information) which propagtes faster > than light." OK, back to Eric's comments. Note that the narrow band signal necessarily has a slow rise time. (If not, it wouldn't be narrow.) The begninning of the rising edge can't come before you push the button, and the peak will come sometime later. If you measure from button push to bomb explode, then you will find an appropriately long delay. If you measure from pulse peak to bomb explode, then it might be shorter than you believe it could be. Look at: A. Schweinsberg et al, 2006 Europhys. Lett 73, 218 -- glen
From: Rune Allnor on 29 Mar 2010 19:16 On 29 Mar, 23:25, "WWalker" <william.walker(a)n_o_s_p_a_m.imtek.de> wrote: > Rune, > > Now you are being rediculus! The dipole solution has been derived hundreds > of times in hundreds of ways over the last 100 years. As I said, you are totally incompetent. The number of times a solution has been derived is irrelevant. Whether it is correct or not, makes all the difference in the world. Th eexpressions you use are wrong in the near field. Answer me this: If the solution relies on the trivial exponential functions - why do you spend time and space on discussing Bessel functions? You don't know, because you haven't contemplated what happens. You are merely a mysticist who thinks that reciting the prescribed formulas is enough. Rune
From: Eric Jacobsen on 29 Mar 2010 19:36 On 3/29/2010 3:15 PM, WWalker wrote: > Eric, > > The first pulse is not the signal fed to the dipole. The first pulse is > just used to create a narrow banded pulse, which is then sent through the > dipole to be detected. Forget about the first pulse, the question is if I > send a narrow banded pulse through the dipole how long will it take to > arrive across a region of space in the nearfield of the dipole. If the > answer is less than the speed of light to cross the same region of space, > then the pulse has propagated faster than light. > > "So if press a button with the same signal characteristics as the LPF > pulse, and if I use the threshold detector set jsut above the noise level > to detect the pulse and explode a bomb, the bomb will explode earlier than > if the pulse propagated at the speed of light. The pressing of the button > (Action) results in the exploding of a bomb (Reaction) faster than light > speed. This is clear cause and effect (information) which propagtes faster > than light." > > > William Okay, if you can't follow that argument (although it's still correct, the narrow-band pulse peak isn't the information, or it's rise time would be non-causal), then, as Glen pointed out, use your button push. If the button push is represented with an ideal impulse or a step function, the rise time is the same (i.e., infinite). The narrow-band, filtered representation of either an impulse or a step signal will have delay, and the rise time will be proportional to the delay. The narrower the filter, the longer the delay. The bandlimitation allows the possibility of prediction due to the redundancy in the signal. Again, the same argument as before applies. The delay through the bandlimiting filter (of the step response of the button push) is X, a filter with negative group delay or other similar predictive capability has a delay of X-delta WHICH IS STILL A POSITIVE NUMBER. Measuring from the button push (or the incidence of an impulse, IT DOES NOT MATTER), there will not be any acceleration of propagation beyond c, just a reduction in filter delay in the predictive case. You can go back a couple of days and many posts and see people suggesting to you to measure either from signal onset or signal interruption, but you seem unwilling to do this. I suspect you know what the result will be and just refuse to let go of your theory. These are relatively simple arguments, especially to somebody who insists on a competence level high enough to claim such an unlikely explanation as exceeding c. -- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
From: Jerry Avins on 29 Mar 2010 20:17 WWalker wrote: > Eric, > > The first pulse is not the signal fed to the dipole. The first pulse is > just used to create a narrow banded pulse, which is then sent through the > dipole to be detected. Forget about the first pulse, the question is if I > send a narrow banded pulse through the dipole how long will it take to > arrive across a region of space in the nearfield of the dipole. If the > answer is less than the speed of light to cross the same region of space, > then the pulse has propagated faster than light. > > "So if press a button with the same signal characteristics as the LPF > pulse, and if I use the threshold detector set jsut above the noise level > to detect the pulse and explode a bomb, the bomb will explode earlier than > if the pulse propagated at the speed of light. The pressing of the button > (Action) results in the exploding of a bomb (Reaction) faster than light > speed. This is clear cause and effect (information) which propagtes faster > than light." Over what distance? Jerry -- Discovery consists of seeing what everybody has seen, and thinking what nobody has thought. .. Albert Szent-Gyorgi �����������������������������������������������������������������������
From: robert bristow-johnson on 30 Mar 2010 01:06
On Mar 29, 5:36 pm, "WWalker" <william.walker(a)n_o_s_p_a_m.imtek.de> wrote: > r b-j, > > But, the research presented in this thread indicates that the EM signal > speed in vaccuum is faster than light in the nearfield and only reduces to > the speed of light in the farfield. If this is true, then in your opinion, > how would this affect physics? As you said, a lot of physics is based on > the speed of light being constant, but what if it is not? speed of light, relative to what? the variation of a dimensionful quantity IN AND OF ITSELF is meaningless. the speed of light is always one Planck length per Planck time. now if the number of Planck lengths in the Bohr radius changes, that's a dimensionless quantity and a change thereof means something and we would know the difference. the relative size of platinum and iridium atoms to the Bohr radius is a dimensionless quantity and if that changed, it would mean something. the number of platinum and iridium atoms between two scratch marks on the prototype meter in Sevres is a dimensionless number and if that changed appreciably, we would know it (and that meter stick would not be a particularly good meter stick). so the number of Planck lengths in a meter (assuming we revert the definition to what it was in 1959) is a dimensionless quantity and its variation is meaningful. there's a similar song and dance regarding the Planck time and the second. if the number of meters (these would be ca. 1959 meters) traveled by light in the time elapsed by one second has appears to change from 299792458, then it's because one of those *dimensionless* quantities has changed. the number of current meters (post 1983) in one second of light cannot change, simply from how the meter is defined. another reference to look at is Michael Duff: http://arxiv.org/abs/hep-th/0208093 maybe also take a look at the Wikipedia articles about the subject: http://en.wikipedia.org/wiki/Faster-than-light http://en.wikipedia.org/wiki/Variable_speed_of_light http://en.wikipedia.org/wiki/Scharnhorst_effect this is a fundamental physical concept. it is not superceded by anything you're writing at the Los Alamos arXiv site (i think Duff would argue that the acceptance threshold for arXiv is low, compared to longstanding reputable journals, but with the Bogdanov Affair, anything is possible). don't believe me? then take it up on a physics newsgroup. those guys at s.p.r will set you straight (ask for John Baez or Steve Carlip). r b-j |