Path: santra!tut!draken!kth!mcvax!uunet!munnari!otc!metro!basser!usage!ccadfa!anucsd!csc3!csc!gxm100 From: KQUWEDA%DHVRRZN1.bitnet@munnari.oz Newsgroups: alt.fusion,sci.physics Subject: Ballinger's testimony 1st of 2 messages Message-ID: <26@csc.anu.oz> Date: 3 May 89 08:12:00 GMT Organization: Carnegie-Mellon University, CS/RI Lines: 685 Xref: santra alt.fusion:1135 sci.physics:6774 To: GUSTAV CC: Subj: FUSION To: GUSTAV%MSO.ANU.oz%australia%csnet-relay.csnet@csnet-relay Comment: CROSSNET mail via SMTP@INTERBIT Originally-From: vac@sam.cs.cmu.edu (Vincent Cate) Originally-From: Steve Strassmann Date: Wed, 3 May 89 04:12 EDT Originally-From: Steve Strassmann Subject: Ballinger's testimony 1st of 2 messages To: vac@cs.cmu.edu Hi there! I've downloaded so many fusion papers off of your repository, I figured I owed you one in return. I asked Ronald Ballinger for a copy of his testimony before congress on April 26, and his secretary gave me a Mac disk with the document as a Microsoft Word file. I'm sending it to you in two forms, one as plain ascii, the other as a binhex'd MSWord document. If you need any help translating this into any other format, just let me know. ------------------------------------------------------------------------------ Comments on "Cold Fusion" Testimony presented to Committee on Science, Space, and Technology U.S. House of Representatives Washington, D. C. by Professor Ronald G. Ballinger Department of Nuclear Engineering Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, Massachusetts April 26, 1989 Mr. Chairman, Members of the Committee: I am Ronald Ballinger, a faculty member of the Departments of Nuclear Engineering and Materials Science and Engineering at the Massachusetts Institute of Technology. I am very grateful for your invitation to convey my views related to the recent reports of the achievement of "cold fusion". I am a member of an interdisciplinary team at MIT that is involved in an attempt to reproduce the reported "Cold Fusion" results of Professors Pons and Fleischmann of the University of Utah. The teams' principals include Dr. Ronald R. Parker, Director of MIT's Plasma Fusion Center; Professor Mark S. Wrighton, Head of the Chemistry Department; and myself. (A complete list of team members and areas of expertise is included). The team is composed of experts in the fields of physical metallurgy, electrochemistry, plasma physics, instrumentation, and radiation detection. The team has been involved in attempts to reproduce the results, reported by Professors Pons and Fleischmann since shortly after their results were released to the press and for publication in the Journal of Electroanalytical Chemistry. As I am sure that you and the members of this committee are aware, any breakthrough in the area of energy production that has the potential to supply current and future energy needs in a non polluting manner must be given serious attention. Quite apart from its impact on basic science, the results recently reported by Professors Pons and Fleischmann, should they prove to be correct, represent such a breakthrough. The basic nature of their results have been described and discussed by earlier testimony before this committee. Basically, the team at the University of Utah has reported the fusion of deuterium atoms in a palladium matrix at room temperature. As evidence that "cold fusion" has taken place the production of excess heat and neutron radiation has been reported. The reported magnitude of both of these is such that their presence could be verified by other investigators. Much more modest results have been reported by a team of investigators at Brigham Young University. We feel that it is important to distinguish between the BYU results, which are of scientific interest but of limited or no practical significance and those of the University of Utah which, should they prove correct have major implications for future energy production. Since the reports of these results, a number of teams worldwide have been attempting to reproduce these results. To my knowledge, with the possible exception of the Stanford results and results from Europe and the USSR of which I have no personal knowledge, no team has been successful. As far as the results of attempts by the team at MIT are concerned, we have been thus far unable to scientifically verify any of these results. This is in spite of the fact that we are employing calorimetry and radiation detection methods of even greater sophistication and sensitivity than those of the University of Utah. Having said this I can assure you that these negative results have not been the results of a lack of effort. The MIT team has been, as I am sure is the case with other teams, laboring around the clock. However, we and the other teams have been handicapped by a lack of enough scientific detail to guarantee that we are actually duplicating these experiments. In the scientific community the soundness of experimental or theoretical research results is evaluated through peer review and duplication. For results such as those reported, whose potential impact on the scientific community and the world are so great, this review process is absolutely essential. Unfortunately, for reasons that are not clear to me, this has not happened in this case - at least so far. The level of detail concerning the experimental procedures, conditions and results necessary for verification of the Pons and Fleischmann results have not been forthcoming. At the same time, almost daily articles in the press, often in conflict with the facts, have raised the public expectations, possibly for naught, that our energy problem has been "solved". We have heard the phrase "too cheap to meter" applied to other forms of electric energy production before. And so the scientific community has been left to attempt to reproduce and verify a potentially major scientific breakthrough while getting its experimental details from the Wall Street Journal and other news publications. Experiments conducted in haste and based on insufficient detail coupled with premature release of results have often resulted in retractions and embarrassment on the part of the scientific community - caught in the heat of the moment. I guess we are all human. The result of this unsatisfactory situation has been that a healthy skepticism and, in some cases, distrust of the reported results has developed. We at MIT share this skepticism. At the risk of becoming too technical in my comments, I feel that I must be a bit more specific with regard to the source of this skepticism. As I mentioned earlier the major results, reported by the University of Utah group are that there has been a generation of excess heat and the measurement of neutron radiation. By excess heat I mean that there has been a measurement of more energy produced than has been supplied to the system. From our standpoint, the key point of verification is the detection of neutron radiation. From an engineering point of view, however, the importance of excess heat production is critical. On these two critical points we have found that the results reported in the few available published documents from the University of Utah are inconclusive or unclear. For example, with respect to the detection of neutrons, critical products of the fusion reaction, the reported results are confusing. They either do not agree with or are not presented completely enough to show that they are consistent with what one would expect from the emission of neutrons from the deuterium fusion reaction. Specifically, the g-ray spectrum shown in the Fleischmann/Pons paper and attributed to neutron emission does not exhibit a shape and intensity that demonstrates the increase reported in the number of detected neutrons above normal background. Further, the reported rate of neutron emission and level of tritium production are consistent with natural background. The results have nevertheless been reported as "significant". Those inconsistencies can only be resolved by a full disclosure of the details of the experimental measurements for examination by the scientific community. Until such time as this occurs we feel that the data is insufficient to demonstrate the presence of neutrons. As far as the issue of excess energy is concerned we are also faced with a confusing situation. While the presence of excess energy is documented in the Journal of Analytical Electrochemistry paper, the method by which this excess energy was determined is not clear. With metals, such as palladium, which act as hydrogen storage media and at the same time as catalysts for many chemical reactions, both situations which can result in discontinuous chemical energy releases, it is critical that a total energy balance over time be done. To us it is not clear that this has been the case. Until this issue is clarified we are unable to make a judgement concerning the excess energy issue. In conclusion I feel that it is safe to say that the scientific community is (1) excited about the possibility of a significant advance in the area of fusion energy research, (2) but is, at the same time, skeptical of results that have not been verified to this point and (3) is very frustrated at the methods by which the discovery has been handled both in the scientific and non-scientific community. Thank you. -- -------------------- Date: 5 May 89 00:04:31 GMT From: hollombe@ttidca.TTI.COM (The Polymath) Subject: Re: real magic ?? Article-I.D.: <4369@ttidca.TTI.COM> In-Reply-To: Article(s) <26@prayf.UUCP> In article <26@prayf.UUCP> david@prayf.UUCP (David Brusowankin) writes: } To my knowledge, no one has yet explained the apparent }superluminal velocities necessary for probability function collapse. } }(Do the following gedanken experiment -- Take a photon emitter, a }half-silvered mirror, and two detectors. Orient the mirror at a 45 }degree angle to emitter, and place the two detectors so that one is }directly in line with the direction of the photon emission and the }other is at right angles to it - both detectors being, say a light }minute away from the mirror. The 2 detectors would therefore be }approximately 1.414 light minutes away from each other. The setup }looks like this: } } } (mirror at 45 degree angle) } ________ / } | Emitter| .... /............detector #1 } -------- / . } . } . } . } . } . } detector #2 } } Now, according to QM, for each photon emitted you get two }probability waves, one for each detector (actually read 'observer'). }When one encounters a detector, the entire wave collapses there and }you see a photon. The problem is that information has to arrive at the }other detector at what would seem to be superliminal velocities in }order for the second detector not to see a photon. }End of experiment). I'm no QM guru, but it would seem to me that Occam's Razor says to drop all the "probability wave" rubbish. If the emitter sends out one photon it either hits the silvering in the mirror, and is deflected, or it doesn't. One observer sees it, the other doesn't. Why complicate a simple explanation for the observed phenomenon? Especially one that doesn't violate relativity and/or speed of light limitations. The only chance involved is in whether the photon is deflected or not. Once past the mirror, its path is certain (assuming hard vacuum and all the usual caveats). If there is any "probability wave collapse", it should happen at the mirror's surface. Sorry if this is a really stupid misunderstanding on my part. I'm aware that common sense doesn't always apply to quantum effects. Still ... BTW, in the above experiment both probability waves arrive at their respective observers simultaneously (I know. Bad word.) What decides which collapses? The whole thing sounds pretty shakey to me. -- The Polymath (aka: Jerry Hollombe, hollombe@ttidca.tti.com) Illegitimati Nil Citicorp(+)TTI Carborundum 3100 Ocean Park Blvd. (213) 452-9191, x2483 Santa Monica, CA 90405 {csun|philabs|psivax}!ttidca!hollombe -------------------------------- Date: 5 May 89 16:49:41 GMT From: tbrakitz@phoenix.Princeton.EDU (Byron Rakitzis) Subject: Re: real magic ?? Article-I.D.: <8158@phoenix.Princeton.EDU> In-Reply-To: Article(s) <26@prayf.UUCP> <4369@ttidca.TTI.COM> John Wheeler proposed an interesting variation to this experiment: 1/2 path 1 1/2 Source----------mirror-----------------detector---mirror----photographic plate \ / \ / \ / \ path 2 / mirror_______________mirror Ok, check this out: the "detector" is a plate of some sort which traps photons. This detector can be put either in the path of the photons, or it can be left out. Now assume you slow the rate of photons so that only one at a time is transmitted. We have: No detector present: this is the usual story; you get an interference pattern on the photographic plate. Detector present: there is NO pattern on the plate, because the detector detects a photon going down EITHER one OR the other path; a positive result shows the photon went down path 1, a negative result shows the photon went down path 2. This "spoils" the interference pattern. Now something really weird is going on here! This is called Wheeler's "delayed choice" experiment (verified experimentally?) because I can choose to slip in the detector AFTER the photon has been "split" by the first mirror. That way, it seems that I can make the photon travel down both paths (remember, that's the only way to get an interference pattern) or I can suddenly limit the photon's position to being on one of the paths, by slipping my detector in. This is a demonstration of the weirdness of quantum mechanics. Weird, weird, weird. -- "I've found it much easier on my ulcer to stop trying to clean out the Augean stables of the net." Chuq Von Rospach Byron Rakitzis. (tbrakitz@phoenix.princeton.edu ---- tbrakitz@pucc.bitnet) -------------------------------- Subject: APS Cold Fusion Session notes Date: 2 May 89 21:43:17 GMT Organization: Carnegie-Mellon University, CS/RI Jon Webb already stated the bottom line of our trip to the APS meeting. Here are a few more details: The first sign that things may not look too great was the absence of long lines at the registration counter. We planned to be there very early in order to secure a good seat. It turns out that the session was very well organized in a large auditorium and they had a closed circuit TV setup to an other room (just in case, but wasn't needed). P&F were invited but did have time to attend. The 18 of the 40 papers (Vince will scan the abstracts) were presented on Monday from 7:30pm to 0:28am: *1*: Jones (BYU) presented his result in a low-key, professional manner. [I really liked him for staying through the entire session, heroically taking the heat] He started with an unequivocal 'NO' (in writing) to possibility of significant heat generation via cold fusion. He proceeded to present his neutron data and a copy of his lab-book from May 22, 1986 describing the electrolytic cell. Some questions were quite hostile, and several experts in the neutron detection business (one from CERN) were clearly unimpressed. *2*: Rafelski (BUY) presents the theoretical part to the BUY experiments. An other 'NO' to the heat question on theoretical grounds. This theory stresses the dynamics of D in the metal crystal to enhance fusion and makes several favorable assumptions for DD-fusion to explain the BUY results. *3*: Koonin (UCSB) start by tearing Rafelski's theory apart (sort of an introductory act). Once accelerated to full speed, he destroys P&F's gamma-spectrogram (their evidence for neutrons). To wit: the graph underwent strange shape and data-point changes between different versions of the same paper, lacks anything but the 'neutron' peak and peaks at the wrong place. It perfectly matches the peak from a 214Bi-decay which is part of the Radon decay chain. Radon is frequently present in concrete buildings and the Rn level of typical basements are more than sufficient to account for the data. (Many other made the same point later). He is the first to call P&F incompetent. *4*: Lewis (Caltech) delivers the decisive kill with a very good presentation of a long list of data. Lewis is chemist ant the list of collaborators list many physics, chemist, electro-Chemists and material scientists. plenty of data from various Pd rods (cast, annealed, etc). In particular, he collaborated with Texas A&M and got one of their 'working' rods. He shreds P&F's evidence one by one: - no radiation. - no tritium (show how easy it is to fool yourself: an fresh electrolyte shows high T-levels if chemical reactions are not properly neutralized) - too much He (uses the same mass-spectrometer as F&P, implies sloppy operation because the unit has a higher resolution than claimed by UU) and shows how much He is present in typical labs. The UU He measures too much He to be produced by fusion. - Deals in depth with calorimetry and how not to do it in electrolytes (needs stirring and a careful balance of the produced gases). He reconstructs P&F's data (down to cell geometry) and shows how to get there if you are careless. - Shows gross thermodynamics error in F&P efficiency calculation. - much more... This talks was rapid machine-gun fire of facts, an in-depth analysis of F&P and leaves little room for hope. All arguments seen on usenet to date were addressed very convincingly. After much applause, 1/2 of the audience left. The remaining talks were merely reduced to a dozen nails for the coffin. *5*: Whaley (UCB) had to fight the noise of the leaving audience. She gave an theoretical talk on how boson (such as D) may be helped by the Pd lattice to get closer. Some questioner was not impressed by her math and the results did seem directly applicable to the cold fusion problem. She did not comment on fusion rates. *6*: Brooks (OSU) presented F&P replication attempts. Again (as in most cases, a long list of chemist and physicist worked on this). no heat, no n, no gamma, no He. "future work - *IF* warranted - ..." *7*: Rocester team: same as *6*, but less impressive set up. *8*: more of the same: over 300 runs, various Pd shapes, treatments (annealed, preloaded, cold-worked, ...), negative results. *9*: Stanford/SRI team: in-depth analysis on calorimetry. Destroys the Stanford 'confirmation' in passing. Computer model of F&P cell with respect to heat transfer characteristics. Almost replicates the F&P data (the volume-effect of Pd) analytically. Then throws in residual D/Pd reactions (known to occur slowly in volume) and the last points for thick rods fall in line. Very convincing and in line with Lewis. *10*: Bailey (Toronto) looks for gammas from D+D->He, doesn't find any and has fun with F&P's gamma-spectrum. Old news by now. *11*: I has to take a break, so I only got the gloom conclusion. *12*: Berkely team reports negative results with better equipment. *13*: withdrew. *14*: This is the GDR work that was reported on the net earlier. No heat. ONE experiment produced some neutrons (these numbers were posted). All the other didn't work. *15*: Florida team reports theoretical limits on fusion rates in metals. Notes that P-D should work better here (that was echoed in several other presentations). Rates a bit to low to explain the BYU results. F&P is out of the question. *16*: U.Washington team: like *15*, but more pessimistic. *17*: no show *18*: Cantrell (Miami U) showed lots of slides of funny looking ZrPd electrodes. He run his set-up several time and got different results: 100% heat, no heat and wrong temp. coefficient, 50% heat. He indicates that the heat is due to a reaction with the glass that he placed between the electrodes. The electrodes show a contamination of Cu,Si,Zn,Fe,... It look like a rather uncontrolled environment. "We used a ZrPd electrode with unknown history because that's what we had on hand". *19*: Florida State U. team looks for X-rays of exited Pd atoms that should be present if fusion occurs (even for D+D->4He+lattice). None seen. *20*: Gai (Yale team): long list of negative results (as mentioned on the net). Is trying cast electrodes now. The abstracts to talks 21-40 on Tue. promise more of the same. The organizers seemed to anticipate that: they scheduled the session in a smaller room. I think that there is no need for sci.physic.fusion any more. -- -- Andreas Nowatzyk (DC5ZV) Carnegie-Mellon University agn@unh.cs.cmu.edu Computer Science Department (412) 268-3617 -- -------------------- Originally-From: brooks@Portia.Stanford.EDU (Michael Brooks) Newsgroups: alt.fusion Subject: Re: Yet another summary of the APS cold fusion session Date: 5 May 89 06:43:00 GMT Organization: Stanford University Organization: Stanford University Distribution: Organization: Stanford University Keywords: cold fusion, APS, session, Jones, Pons, neutrons First off, my Thanks to both of you and your cohorts in providing some badly needed data to our discussion on the net. In one of my most recent postings (article 5142, Message ID-113@sierra.stanford.EDU) I discussed my interest in Mass spectroscopy and some salient details, while in a later post I pleaded for some of Walling and Simons data. Could either of you provide such data, here or in another fashion, since apparently the numbers and description of controls are available (that is, judging by the info you have posted)? I assure you that many of us would be very grateful! From what I have read it seems that the investigators may have omitted an elementary control, that of analyzing ambient He levels, for the open air ambient of the cell. The quantity of 4He in atmosphere is known and background levels should have been checked as a routine step in calibrating the system with a known 4He test source (two very basic steps, obviously you don`t want atmospheric He leaking into you experimental source of gas). I am disturbed by a possible lack of controls from two scientists who have experience in this technique---and I find this difficult to accept. In addition, quantitative comparison between background levels and levels observed during experiment are of considerable interest to me, as they will tell the story (especially levels vs time). Was the amount claimed significant relative to background, and how did this change with time? And what of the "excess 4He", that level which is inconsistent with the heat evolved? In terms of numbers, what was that level---forgetting about calorimetric aspects for now? I would prefer to deal with something I could understand, rather than slog through calorimetric contortions. I`m working on obtaining some data on the Italian results and will try to get this available ASAP. Is the Lewis neutron detector limit of "100 neutrons/hr" an upper or lower bound? The preliminary data I have (hearsay actually so far) has the Italians counting at max. 200cnts/hour, or averaging ~70/hr for something like 10 or 15 hrs. If Bill Johnson at LANL is reading this, could you please comment on whether these numbers are reasonable. I should point out that the alleged background cnts/hr = 2-3 (neutrons/hr). I am trusting a poor memory on this, so these numbers may be wrong. I would like to encourage others to get data and put it out here so the rest of us can have a look at it. And once again my thanks to all who have already tried to do this. Mike Brooks/Stanford Electronics Labs (solid state)/SU MIT astronomer Walter Lewin: "Abscence of evidence should never be mistaken for evidence of abscence." -------------------- Originally-From: vac@sam.cs.cmu.edu (Vincent Cate) Newsgroups: alt.fusion,sci.physics Subject: 3 APS Abstracts in ascii Date: 5 May 89 21:06:47 GMT Organization: Carnegie-Mellon University, CS/RI ********************************************************************** aps.4 ********************************************************************** Calorimetry, Neutron Flux, Gamma Flux, and Tritium Yield from Electrochemically Charged Palladium in D2O. Nathan Lewis, charles Barnes, and Steve Koonin California Institute of Technology Pasadena, CA 91125 We report the results of our work on cold fusion using palladium. We have used extremely sensitive neutron, gamma ray, and photon counters, and can place strict upper limits on the flux of expected nuclear products emitted from charged Pd cathodes. Liquid scintillation counting has been used to measure tritium production, which was found at background levels for extended periods of time. However, a subtle chemical interference that generates chemiluminescence has been shown to yield tritium signals and lead to overestimates of the fusion yield based on tritium production. We have also performed accurate, calibrated calorimetry, and have identified several serious errors that can make the measurements appear to show excess power production. When these common errors are eliminated, a correct energy balance is obtained. We will also discuss the calorimetric experiments performed by the Utah researchers, will explain their calculations to the physics community, and will clearly state the assumptions and corrections implicit in the Utah calculations. ********************************************************************* aps.9 ********************************************************************* Abstract submitted for the Baltimore meeting of the American Physical Society. May 1-4, 1989 Special session on Cold Fusion Analysis of "Excess Power in Cold Fusion". W. E. MEYERHOF, Stanford University,* D. L. HUESTIS and D. C. LORENTS, SRI International. The apparent excess energy release of 4 MH in heavy-water electrolysis with Pd electrodes (1) is impossible to explain with known chemical or physical processes. Solution of the heat equation for cylindrical calorimeters with the geometries of Ref. 1 or 2 show that in steady-state calorimetry temperature gradients exist even with weak stirring. Hence, fictitious excess power can be found, depending on the placement of the thermometer. This is particularly severe in Pd+D electrochemical reactions because the dissipative part of the 0.8 to 2 V overvoltage releases heat at the surface of the Pd electrode. The observed differences between ordinary and heavy water can also be explained because for Pd+H the overvoltage is much smaller than for Pd+D. 1. M. Fleischmann and S. Pons, J. Electroanaly. Chem. 261, 301 (1989). 2. A. Belzner, U. Bischler, C. Crouch-Baker, T. Gur, G. Lucier, M. Schreiber, R. A. Huggins, to be published. Supported in part by NSF grant PHY 86-14650 W. E. Meyerhof Department of Physics Stanford University California 94305 ******************************************************************** aps.10 ******************************************************************** Abstract Submitted for the Special Cold Nuclear Fusion Session of the 1989 May Meeting of the American Physical Society. May 1, 1989 Gammas from Cold Fusion. D. Bailey*, University of Toronto ** The absence of both neutrons and gamma rays can be used to constrain possible cold fusion processes in deuterium-metal systems. In particular, milliwatt cold fusion processes in palladium producing fast protons, tritium, 3He or 4He nuclei would also usually produce easily observable numbers of Coulomb excitation palladium gamma rays. Typical expected yields are ~10**4 - 10**6 gammas per joule of fusion energy in lines at 0.374, 0.434, 0.512 and 0.556 MeV. Reported (1) 2.2 MeV np capture gamma rays are consistent with the ubiquitous radon daughter 214Bi 2.204 MeV background line. * BITNET address: DBAILEY@UTORPHYS ** Supported in part by NSERC (Canada). (1) M. Fleischmann, S. Pons, and H. Hawkins, J. Electroanal. Chem. 261 (1989) 301, and errata. -- -------------------- Originally-From: tjr@cbnewsc.ATT.COM (thomas.j.roberts) Newsgroups: alt.fusion,sci.physics Subject: Re: real magic ?? Date: 4 May 89 18:00:50 GMT Organization: AT&T Bell Laboratories From article <26@prayf.UUCP>, by david@prayf.UUCP (David Brusowankin): > > To my knowledge, no one has yet explained the apparent > superluminal velocities necessary for probability function collapse. > > (Do the following gedanken experiment -- Take a photon emitter, a > half-silvered mirror, and two detectors. Orient the mirror at a 45 > degree angle to emitter, and place the two detectors so that one is > directly in line with the direction of the photon emission and the > other is at right angles to it - both detectors being, say a light > minute away from the mirror. The 2 detectors would therefore be > approximately 1.414 light minutes away from each other. The setup > looks like this: > > > (mirror at 45 degree angle) > ________ / > | Emitter| .... /............detector #1 > -------- / . > . > . > . > . > . > detector #2 [I assume that the angle of the mirror is really meant to be \] > Now, according to QM, for each photon emitted you get two > probability waves, one for each detector (actually read 'observer'). > When one encounters a detector, the entire wave collapses there and > you see a photon. The problem is that information has to arrive at the > other detector at what would seem to be superliminal velocities in > order for the second detector not to see a photon. > End of experiment). This is a (somewhat simplistic) re-statement of the famous "EPR Paradox" (Einstein, Podolsky, Rosen) which has been important in the development of Quantum Mechanics. There are two major flaws in the argument above. The first is that to analyze a system in Quantum Mechanics, you ascribe a SINGLE wave-function to the ENTIRE SYSTEM. In general, this wave-function CANNOT be separated into wave-functions describing the (supposedly independent) parts. In this case, you DO NOT "get two probability waves, one for each detector", but rather you get a single probability distribution describing the actions of the emitter and the observations of both detectors. [Physicists often do separate wavefunctions into putatively independent ("separable") components. This is only valid to an approximation (often extremely accurate); Physicists would rather not do this, but the complexity of physical systems often requires such separation in order to make any analysis possible.] [It is often difficult to determine exactly what is contained in the ENTIRE SYSTEM (e.g. need we include the mirror in the description of the above system?).] The "Paradox" disappears when you realize that, unlike macroscopic particles, YOU DON'T KNOW WHEN A PHOTON HAS BEEN EMITTED. You only have a probability per time for the rate of photon emission. There is no necessity for "information" to be "propagated" between the two detectors; each one sees a rate of photon detection, and their sum equals the rate of photon generation (ignoring experimental difficulties). [You cannot "fix" this by attempting to detect photons near the emitter to determine their time of emission; detecting photons destroys them, and while you could use a detector that re-emits them very quickly, you cannot then fix their direction well enough to ensure that such re-emitted photons enter the apparatus (another Phyrric Victory for Heisenburg's Principle).] There are no shortcuts in physics. You have to carefully describe and justify every step in an analysis, as in a mathematical proof. Physicists do a lot of "hand waving", but it is just that, hand waving. Many APROACHES to interesting problems have first been discovered by waving hands; no interesting problem has ever been solved that way - you HAVE to do the mathematics in order to understand modern physics (which is often counter-intuitive). Tom Roberts att!ihnet!tjr --------------------