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![]() wrote in message oups.com... What do you mean? What errors you discovered? Well the one that is relevant to this thread is that you thought integrating a black-body source (starlight, although that isn't really a blackbody) over a range of redshift could give another blackbody curve as the result. It is obvious that adding multiple curves with similar fractional width but offset from each other will produce a sum that has greater width. Your own graph showed that (is it still on the web?) yet you still claim the integral can match the FIRAS data. http://www.astro.ucla.edu/~wright/Stolmar_Errors.html Note in particular: "When y_max is not infinitesimal, one gets a Rayleigh-Jeans low frequency tail rising to a peak corresponding approximately to a graybody with temperature exp(-y_max)T* ..." As I understand what you said of the program you wrote to work out this curve, y_max is just the limit you applied to stop the program running too long and in reality the universe is infinite and homogenous. y_max is therefore infinite and the f^-1 section should continue down to zero frequency. George |
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Joseph Lazio wrote in message
... "g" == greywolf42 writes: g Joseph Lazio wrote in message g ... g Not one CMBR device -- to my knowledge -- has ever attempted an g isolation test. That is, a test to determine whether the signal g was actually produced "within" the antenna -- or whether it had an g external source. For example, I know for a fact that Penzias and g Wilson did not do this test. They *did* cut out the antenna g connection. Right, so in the case of the P&W horn antenna, that means that the signal must be generated "upstream" of the input of the antenna backend. g The antenna is a single unit. The "backend" is electronics. I'm not sure of the point you are trying to make. I'm using standard RF terminology. On a non-standard RF problem. In any event, I'm trying to figure out if one would expect a signal in such a case. Given the shape of the P&W horn, would one expect a signal at the backend. g The signal would have no dependence on shape ... unless the source g is external to the antenna. Effectively it is. Only the surface of the antenna can radiate. The question is *whether* the source is external to the antenna. To the extent that I understand your suggestion (and I am not an RF engineer), it seems to me that the antenna would not radiate into the backend but out its front. g The antenna itself (as a unit) is not radiating the EM fields. So if the antenna is not radiating in the RF, what's the point of putting it in an isolation chamber? To see if the antenna is actually receiving an external signal. ------- Oh, and by the way, my apologies for significantly delayed response on a few other threads. I've had too much going on to spend much time on the groups, of late. And have been distracted by replies to the "Shadows" thread. So, I've only had time to respond to some of the 'quick' posts that show up. -- greywolf42 ubi dubium ibi libertas {remove planet for return e-mail} |
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"g" == greywolf42 writes:
g Joseph Lazio wrote in message g ... g Not one CMBR device -- to my knowledge -- has ever attempted an g isolation test. That is, a test to determine whether the signal g was actually produced "within" the antenna -- or whether it had an g external source. [...] [i] n the case of the P&W horn antenna, that means that the signal must be generated "upstream" of the input of the antenna backend. g The antenna is a single unit. The "backend" is electronics. I'm not sure of the point you are trying to make. I'm using standard RF terminology. g On a non-standard RF problem. I'm still not sure of the point you are trying to make. In any event, I'm trying to figure out if one would expect a signal in such a case. Given the shape of the P&W horn, would one expect a signal at the backend. g The signal would have no dependence on shape ... unless the source g is external to the antenna. Effectively it is. Only the surface of the antenna can radiate. g The question is *whether* the source is external to the antenna. As far as I can understand what you are trying to say, there are two possibilities, either the signal is generated external to the antenna or it is generated by the antenna. (This begs the question of why the backend electronics cannot generate the signal, but you've seen fit to ignore that issue.) (I suppose it also begs the question of why the strength of the signal differs depending upon pointing direction, but you also ignore that one by declaring the data suspect.) If the signal is generated by the antenna, the signal must come from the surface of the antenna, because the skin depth of metal to radio radiation is extremely small. Thus, the shape of the antenna and the (poorly described) emission mechanism become important in determining how much signal goes into the backend. -- Lt. Lazio, HTML police | e-mail: No means no, stop rape. | http://patriot.net/%7Ejlazio/ sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html |
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On 24 Jan 2005 21:03:10 -0500, Joseph Lazio wrote:
[i] "g" == greywolf42 writes: g Joseph Lazio wrote in message g ... g Not one CMBR device -- to my knowledge -- has ever attempted an g isolation test. That is, a test to determine whether the signal g was actually produced "within" the antenna -- or whether it had an g external source. [...] n the case of the P&W horn antenna, that means that the signal must be generated "upstream" of the input of the antenna backend. g The antenna is a single unit. The "backend" is electronics. I'm not sure of the point you are trying to make. I'm using standard RF terminology. g On a non-standard RF problem. I'm still not sure of the point you are trying to make. In any event, I'm trying to figure out if one would expect a signal in such a case. Given the shape of the P&W horn, would one expect a signal at the backend. g The signal would have no dependence on shape ... unless the source g is external to the antenna. Effectively it is. Only the surface of the antenna can radiate. g The question is *whether* the source is external to the antenna. As far as I can understand what you are trying to say, there are two possibilities, either the signal is generated external to the antenna or it is generated by the antenna. How about both? Look, here's the deal. There is a theory that says charge is simply a manifestation of a harmonic quantum fluctuation in the ZPE. It has the form, ------ 1 / / £ q = --- / h / -- 2pi \/ \/ 3µ Where in SI £ is permitivitty, µ permeability, and h Planck's constant. This same theory yields the physical dimensions of charge as mass per sec (like the classic mass attached to a spring). Thus the charge to mass ratio for a quantum particle will yield its base harmonic or signature frequency [¿]. i.e., q ¿ = - m For the lowly electron this is ~175.7 GHz. Now go look up the thermal black body temperature that radiates at this value. You'll find it to be ~2.8° K. (This begs the question of why the backend electronics cannot generate the signal, ... It can, but without a means of resonating. but you've seen fit to ignore that issue.) I don't think he ignore the issue, but thinks it moot. (I suppose it also begs the question of why the strength of the signal differs depending upon pointing direction, Ah, in the fifth decimal place? Sure, there electyrons all over the place (and if you want to count the virtual pairs, a great sea) so yes, if the source of the hum is from quantum fluctations then the majority that would be seen in the antenna would be radiated by its surfaces resonating in the cavity. That is the question. It NOT a simple answer however since one would have to reduce the background to well below 2.8° to look. but you also ignore that one by declaring the data suspect.) If the signal is generated by the antenna, the signal must come from the surface of the antenna, because the skin depth of metal to radio radiation is extremely small. Thus, the shape of the antenna and the (poorly described) emission mechanism become important in determining how much signal goes into the backend. Yes, but that IS the question. But to my knowledge no-one has set out to look at the issue. Paul Stowe |
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Joseph Lazio wrote in message
... "g" == greywolf42 writes: g Joseph Lazio wrote in message g ... g Not one CMBR device -- to my knowledge -- has ever attempted an g isolation test. That is, a test to determine whether the signal g was actually produced "within" the antenna -- or whether it had an g external source. [...] And still no one has done this relatively simple test. Or rather, no paper reporting the results has been published. [i] n the case of the P&W horn antenna, that means that the signal must be generated "upstream" of the input of the antenna backend. g The antenna is a single unit. The "backend" is electronics. I'm not sure of the point you are trying to make. I'm using standard RF terminology. g On a non-standard RF problem. I'm still not sure of the point you are trying to make. I believe you are the one trying to make a point, here -- about the meaning of the term "backend". And how it may relate to an internally versus externally generated signal. In any event, I'm trying to figure out if one would expect a signal in such a case. Given the shape of the P&W horn, would one expect a signal at the backend. g The signal would have no dependence on shape ... unless the source g is external to the antenna. Effectively it is. Only the surface of the antenna can radiate. g The question is *whether* the source is external to the antenna. As far as I can understand what you are trying to say, there are two possibilities, either the signal is generated external to the antenna or it is generated by the antenna. *Within* the electrons that make up the antenna. (This begs the question of why the backend electronics cannot generate the signal, but you've seen fit to ignore that issue.) LOL! I haven't ingored the issue at all. Any backend electronic signal is removed during calibration. That's one of the tests the P&W *did* do. All one has to do for this is disconnect the antenna from the system. If you see a signal, it is declared *noise*, and subtracted from the final values when the antenna is connected. (I suppose it also begs the question of why the strength of the signal differs depending upon pointing direction, It doesn't. Except for a slight overall dipole. As the electrons shape changes in response to motion through the aether. but you also ignore that one by declaring the data suspect.) Nope. I never claimed the *data* was suspect. The data is fine. I only declare the "analysis" using computer "enhancement" below the physical resolution of the device is invalid. If the signal is generated by the antenna, the signal must come from the surface of the antenna, because the skin depth of metal to radio radiation is extremely small. That is true from an external source. But not from an internal source. Thus, the shape of the antenna and the (poorly described) emission mechanism become important in determining how much signal goes into the backend. A false statement. You are again assuming your conclusion. -- greywolf42 ubi dubium ibi libertas {remove planet for return e-mail} |
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George Dishman wrote in message
... "greywolf42" wrote in message ... Joseph Lazio wrote in message ... "g" == greywolf42 writes: g Joseph Lazio wrote in message g ... [Regarding Reber's assertion that the CMB arises within radio telescopes.] g One doesn't have to have a theory for the mechanism, in order to g experimentally identify the difference between an internal signal g and an external signal. I just read the Penzias & Wilson (1965) paper and an associated Penzias & Wilson (1965) paper. From that, my understanding is that they did distinguish between an internal signal and an external signal. Specifically, they were able to show that, whatever the signal is, it must be entering through the antenna. g A completely false assertion. Because your claim is based on the g following distortion: It is not generated within the electronics at the backend of the antenna. g ROTFLMAO! No one claimed that it was generated in the electronics g that are attached to the antenna! ... Actually you did, though indirectly. What a pathetic lie. You said at one time that this radiation was produced by _all_ matter, and that is consistent with what you say again below. Another pathetic lie. It is produced by electrons. There is more to 'all matter' than simply electrons. g The point is that it is g generated by the electrons contained *IN* the antenna. In the second photograph you can see someone *IN* the antenna. http://www.bell-labs.com/user/apenzi...awfordhill.gif LOL! Pathetic. The person is not 'in' the material of the antenna. Since you draw no distinction between this and the spaceborne measurements, "This" is simply trash. I have previously assumed you meant the electrons in the metal of which the antenna is made. That is what I have repeatedly stated. Your current silly strawman is wasted. Incidentally, going back to your comments about putting the system in a screened room, these give an idea of the size of the antenna: http://www.pbs.org/wgbh/aso/databank...es/dp65co.html http://store.aip.org//OA_MEDIA/esva/penzias_arno_c3.jpg Dismantling that and taking it to a test house would be entirely impractical even if such a facility existed at the time. The fact that one might consider it "difficult" is irrelevant to the issue. How difficult do you think it is to build a light structure of metal, sufficient to block microwaves? My statement may be false, but I made it in good faith based on my reading of their papers. Your "faith" interfered with your eyes or your mentation. Why not try science, instead of Faith? Moreover, your response doesn't address my objections. Why are the electrons within the antenna itself special? They aren't special. Why don't the electrons in the backend generate emission by the same mechanism? They probably do. But they don't give rise to a signal in the mechanism. That's the function of an antenna. That's not true. The purpose of the antenna is twofold, firstly to match the impedance of free space to that of the feed cables or waveguide That's not a *purpose*. This is how to obtain the second. and secondly to gather incoming radiation from a larger aperture. The incoming radiation is converted to a measurable signal on at the terminating impedance of the down- feed which would be something like the base-emitter resistance of the front-end transistors depending on the technology used. The point is that the electrons in the cable or waveguide would produce signal just as much as those in the material forming the antenna No, they would not produce a "signal", unless that signal had something to read it. or even more since they are coupled directly to the receiver. And any such signal is calibrated out of the device -- when they pull the plug on the antenna. Look again at the image of the inside of the horn and consider how much of the omni-directional radiation from an electron in the metal would leave through the aperture. http://www.bell-labs.com/user/apenzi...awfordhill.gif Did you have a point to make? How would we know? Remember the design is to focus on a small part of the sky so radiation that wasn't within a small angle of the reflected ray at the same point will be rejected. But the design is valid only for the theory under which it is performed. And in this case, it is simply wrong. -- greywolf42 ubi dubium ibi libertas {remove planet for return e-mail} |
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Greg Hennessy wrote in message
... In article , greywolf42 wrote: As far as I can tell, your only objection is that you claim that COBE's result is below what you believe to be below its physical resolution. That is *an* objection that I have for claims made based on "results" that are below the physical resolution of COBE and FIRAS instruments. Since the instrument that took the data I referred to was the DMR, nto the FIRAS, why do you think using hte FIRAS sensitivity (not resolution) is valid? When are you going to learn to read, Greg? 1) I wasn't replying to you, but to Joseph's question. 2) I wasn't referring to DMR. I simply listed two cases where results below the physical resolution of the device were claimed. Of course, this might have been easier for you to understand, if you had left in the context, and the proper attributions. Bye again. it is well known that one can make specific kinds of measurements below the resolution limit of an instrument, Joseph, *why* do you keep repeating this silly statement? Many people make such claims, but it is not valid science or statistics. You can easily show me wrong, by directing me to a statistics treatise on how to perform measurements below the resolution of the instrument used. This is the problem with the incorrect terminology used by greywolf. The issue is the sensitivity of the radiometer, not the resolution. The resolution of the DMR is 7 degrees. The sensitivity is dependant on the exposure time. And the one year and longer measurements of the DMR have sensitivity limits in the microKelvin. I'm not discussing the experimental variations (sigma, or sensitivity). So, I am not using incorrect terminology. I am discussing the physical resolution of the multichannel intensity detectors, used to measure the radiation curve. -- greywolf42 ubi dubium ibi libertas {remove planet for return e-mail} |
#238
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![]() "greywolf42" wrote in message ... George Dishman wrote in message ... snip You said at one time that this radiation was produced by _all_ matter, and that is consistent with what you say again below. Another pathetic lie. It is produced by electrons. There is more to 'all matter' than simply electrons. But, unless we are discussing plasma or neutronium, one generally assumes all matter contains electrons, and since I later said: snip I have previously assumed you meant the electrons in the metal of which the antenna is made. and you agree: That is what I have repeatedly stated. you should have realised that I was not suggesting anything other than your own views. You seem determined to make any sort of conversation as unpleasant as possible. Incidentally, going back to your comments about putting the system in a screened room, these give an idea of the size of the antenna: http://www.pbs.org/wgbh/aso/databank...es/dp65co.html http://store.aip.org//OA_MEDIA/esva/penzias_arno_c3.jpg Dismantling that and taking it to a test house would be entirely impractical even if such a facility existed at the time. The fact that one might consider it "difficult" is irrelevant to the issue. How difficult do you think it is to build a light structure of metal, sufficient to block microwaves? P&W could have stretched "chicken wire" mesh over the aperture of the horn and perhaps, if nobody had suggested the CMBR, they might have got round to doing that. Putting it in a proper screened room would have been prohibitive. The one I use is thick steel panels bolted together every few inches with copper gasketing on all joints and a concrete base to prevent gaps due to stress. It's only about 12 feet square, 8 feet high and for in-house (pre-test) use only as it doesn't meet test-house standards, but moving it from one building to another a few years ago cost over 200k. You should also remember P&W weren't running a funded experiment to find the CMBR, they were trying to get rid of an annoying source of interference in another project. The situation for COBE and WMAP is quite different as these were funded and had to be tested. I don't have time to go through these myself but if you haven't already read them, they might be useful. I've given a lot of references but they all relate to calibration and testing so may help resolve some of the discussions in the group about that aspect: http://adsabs.harvard.edu/cgi-bin/bi...pJ...420..457F http://www.journals.uchicago.edu/ApJ...652/38652.html http://adsabs.harvard.edu/cgi-bin/np...53K&db_key=AST http://adsabs.harvard.edu/cgi-bin/np...8M&db_key=INST http://adsabs.harvard.edu/cgi-bin/np...0S&db_key=INST http://adsabs.harvard.edu/cgi-bin/bi...pJ...391..466B All are from http://lambda.gsfc.nasa.gov/product/...bliography.cfm My statement may be false, but I made it in good faith based on my reading of their papers. Your "faith" interfered with your eyes or your mentation. Why not try science, instead of Faith? Moreover, your response doesn't address my objections. Why are the electrons within the antenna itself special? They aren't special. Why don't the electrons in the backend generate emission by the same mechanism? They probably do. But they don't give rise to a signal in the mechanism. That's the function of an antenna. That's not true. The purpose of the antenna is twofold, firstly to match the impedance of free space to that of the feed cables or waveguide That's not a *purpose*. This is how to obtain the second. and secondly to gather incoming radiation from a larger aperture. The shape of the antenna should reflect all the incident signal into the feed, but if the impedance isn't matched a fraction of that power will be reflected back into space. There's no point having a large dish or horn unless all the power it collects reaches the receiver. The incoming radiation is converted to a measurable signal on at the terminating impedance of the down- feed which would be something like the base-emitter resistance of the front-end transistors depending on the technology used. The point is that the electrons in the cable or waveguide would produce signal just as much as those in the material forming the antenna No, they would not produce a "signal", unless that signal had something to read it. What do you mean? The thing that "reads" the signal is the first amplifier stage and specifically the input impedance of the receiver. It cannot differentiate between an external (cosmic) signal coming down the cable and something generated in the antenna or even in the feeder itself, the first stage amplifies the sum of them all. or even more since they are coupled directly to the receiver. And any such signal is calibrated out of the device -- when they pull the plug on the antenna. In which case there would have been nothing detected when the cable and antenna were reconnected. Look again at the image of the inside of the horn and consider how much of the omni-directional radiation from an electron in the metal would leave through the aperture. http://www.bell-labs.com/user/apenzi...awfordhill.gif Did you have a point to make? ... Two points. Imagine the insulation within the downfeed cable is transparent. What you see looking into the end is a metal central conductor and metal braid. Looking from the feed point of the antenna, depending on the geometry, you may see all metal or you may see some air through the aperture. At most, the solid angle covered by metal is the same as the cable or perhaps it would be less. The second point gets into an area where i'm not sure of your view, it hasn't been covered that I've seen. Imagine for a moment they covered the aperture with the same metal sheet that covers the rest of the inside of the horn. You now have the feed looking into a cavity in which radiation from the electrons is emitted from the metal surface. Now conventionally that radiation would bounces around in the cavity with some small absorption because the antenna works only because it is a good reflector of the incoming signal. However, you might suggest that, since the electrons emit this radiation, they also absorb it. That would appear as a significant loss against the calculated gain so I don't think that would be your view but correct me if I'm wrong. Assuming the radiation is just bouncing around, opening the aperture would allow it to be radiated into free space so depress the levels inside the horn compared to a closed cavity. The question then is where do you get your intensity levels. It seems to me you at least have to find the solid angle covered by the emitting material and multiply by the electron brightness and then show that matches the black body intensity. ... How would we know? You would need to get the plans of the horn I guess but showing your ideas can produce the observed intensity is your task, not mine. Remember the design is to focus on a small part of the sky so radiation that wasn't within a small angle of the reflected ray at the same point will be rejected. But the design is valid only for the theory under which it is performed. And in this case, it is simply wrong. So are you saying the metal in the antenna doesn't reflect the incoming signal into the feed? I suspect I am not understanding your point here, which bit of antenna design theory are you saying is wrong? George |
#239
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![]() "Paul Stowe" wrote in message ... On 24 Jan 2005 21:03:10 -0500, Joseph Lazio wrote: snip As far as I can understand what you are trying to say, there are two possibilities, either the signal is generated external to the antenna or it is generated by the antenna. How about both? Look, here's the deal. There is a theory that says charge is simply a manifestation of a harmonic quantum fluctuation in the ZPE. It has the form, ------ 1 / / £ q = --- / h / -- 2pi \/ \/ 3µ Where in SI £ is permitivitty, µ permeability, and h Planck's constant. This same theory yields the physical dimensions of charge as mass per sec (like the classic mass attached to a spring). Thus the charge to mass ratio for a quantum particle will yield its base harmonic or signature frequency [¿]. i.e., q ¿ = - m For the lowly electron this is ~175.7 GHz. Now go look up the thermal black body temperature that radiates at this value. You'll find it to be ~2.8° K. This goes back to an earlier question. A black body at 2.8K does not radiate a characteristic line, the signal is broadband so how does the proposed electron source produce a broadband signal and can you show that the mechanism would mimic the spectrum of a black body? (This begs the question of why the backend electronics cannot generate the signal, ... It can, but without a means of resonating. But resonating would _narrow_ the band while a black body is _broad_ band. but you've seen fit to ignore that issue.) I don't think he ignore the issue, but thinks it moot. (I suppose it also begs the question of why the strength of the signal differs depending upon pointing direction, Ah, in the fifth decimal place? Sure, there electyrons all over the place (and if you want to count the virtual pairs, a great sea) so yes, if the source of the hum is from quantum fluctations then the majority that would be seen in the antenna would be radiated by its surfaces resonating in the cavity. But the antennas are not cavities, they are open horns. .. That is the question. It NOT a simple answer however since one would have to reduce the background to well below 2.8° to look. but you also ignore that one by declaring the data suspect.) If the signal is generated by the antenna, the signal must come from the surface of the antenna, because the skin depth of metal to radio radiation is extremely small. Thus, the shape of the antenna and the (poorly described) emission mechanism become important in determining how much signal goes into the backend. Yes, but that IS the question. But to my knowledge no-one has set out to look at the issue. The dipole is also problematic. Notwithstanding the obvious flaw in his suggestion of Lorentz contraction as the mechanism, the angle between the direction of propagation from the electron to the feed point and the direction of flow of the aether past the electron also varies with the location of the electron in the antenna. You effectively have to integrate over the radiating surface and hence a variety of curves are again mixed when finding the total feed illumination. George |
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[George Dishman has already brought up a number of important issues,
I'll just clarify one point.] "PS" == Paul Stowe writes: PS On 24 Jan 2005 21:03:10 -0500, Joseph Lazio PS wrote: (I suppose it also begs the question of why the strength of the signal differs depending upon pointing direction, PS Ah, in the fifth decimal place? I was referring to the Sunyaev-Zel'dovich effect. Why does the signal change depending upon whether or not the telescope is pointed at a distant cluster of galaxies? -- Lt. Lazio, HTML police | e-mail: No means no, stop rape. | http://patriot.net/%7Ejlazio/ sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html |
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