weemba@garnet.berkeley.edu (Obnoxious Math Grad Student) (03/20/88)
In-reply-to: pax@uiucdcsp.cs.uiuc.edu >> I don't understand. What possible connection could high Tc >> superconductivity have with cosmology? ... This is too funny! There IS a connection--a rather direct one!--between superconductivity and cosmology: both use the same methods to model phase transitions. Indeed, the first symmetry breaking mechanisms proposed for gauge theory were lifted straight from well-known formulas for changing energy density in superconductor theory as one crosses Tc. Following the analogy, gauge bosons acquire mass via the Meissner effect: just as super- conductors repel magnetic fields, so too does the Higgs field act to limit the range of the vector bosons. And--so says modern cosmology--the universe was born via just such a phase transition: the temperature dropped below Tc, symmetry was broken, a new lower energy minimum was reached, and all of matter and energy was created in compensation of that lowering of the en- ergy minimum. At the moment, the formula in superconductor theory can be derived for low Tc from the solid-state physics of Cooper pairing. In contrast, this cannot yet be done for either high Tc or the Higgs field. I'll speculate further on this state of affairs below. >I will explain. The point I am making is that the widely published >and popularized discussions of what happened during the first instants >of the universe (if you can believe that there ever was such a thing) >are not science in the sense generating hypotheses that can be tested >by experiment The microwave background and the primordial helium density are both sub- ject to experimental test. Both are difficult measurements, and individu- ally can be accounted for in many ways. Accounting for both at once is the tricky part. But cosmologists are not resting on their laurels, but always eager to test whatever new predictions they can make. For example, cosmological arguments predict that there are at most 4 lepton families. This will be put to test at SLAC, as soon as they get their W/Z factory going. More interesting to me is a paper I came across a year or two ago whose contents were, roughly, that with a two order of magnitude increase in clocking accuracy and the discovery of a few more millisecond pulsars, that it would be possible to detect the effects of the calculated background gravitational radiation predicted by most inflation cum supergravity theor- ies. This refers, of course, to events during the first 10^-43 seconds of the Universe. > but are very much science in the sense of religion. >And my argument to support both assertions is that discussions >about this primordial instant can only be so much nonsense. You can argue such, but the scientists who eventually followup on the paper I mentioned above are probably not the morons you would have us believe they are. I wish them all the luck in the world. [Anybody else out there think Taylor and Bacher deserve Nobel prizes?] > Why? >because we don't even know about the world around us (witness >high Tc superconductivity--there is even talk now of a fifth force!!!!!) >So how on earth :-) can someone pontificate about a time billions >of years distant, at densities of matter never otherwise attained, >and when the whole fabric of the universe was small enough to dance on the >head of an extra-universal pin. How??? Quite simply, the laws of physics were presumably much simpler under those circumstances! One force and one kind of particle. If the world back then was as complicated as the world is today, then yes, it would all be a silly project. As it is, this very simplicity allows for predictions. >Any physicist who seriously proposes that the laws >of physics as observed from earth are just as valid then and there >as they are here should be shot. Only if he thinks his act of assertion makes it true. Any physicist who makes such a proposal and follows it up with predictions about what astron- omers will see is only doing his job. > Such discussion is, as science, absurd, >but as religion, right at home. You seem to be describing the parts of your argument that I'm replying to, mostly--(I agree that there's a lot of bad eggs out there): various asser- tions about "science" that reflect on your beliefs about science, and not its actual practice. Your earlier characterization of OMNI as being a truer reflection of science than SciAm is only begging the question. I consider OMNI just another porn rag. (What a coincidence! Guess who publishes OMNI?) Which reminds me, a very recent Weekly World News had the amazing scientific result that old Stone Age man looked like Elvis Presley, with an artist's conception of the full reconstruction. Why should I believe the editors of WWN's assertions that *this* is science? >fmm@princeton also explained how the supercollider can not benifit >from the recent discoveries in high Tc superconductivity, >and while I am skeptical I must admit he may be right. So what if you are skeptical? Go read PHYSICS TODAY where the issue has been beaten to death for the past year in the letters column. If you know better, they'd love to hear from you. >Nevertheles he was silent on the issue >of why we have to do this research now Then I'll make some suggestions. (1) De Rujula, Weinstein, and others have proposed to use Tev-Pev neutrinos for doing whole earth tomography. One Earth diameter of rock and iron should be just the right distance. Earthquake prediction and the like would surely benefit. This requires SSC-level energies. Their actual proposals get further out: for maximum tomography benefit, they want to try floating the SSC out at sea! I posted a short description with references about a year ago. (2) I posted a summary last year of the economic high-tech spin-offs that CERN has been directly responsible for by always being on the cutting edge of engineering/computing/electronics techniques. Not a justifica- tion in itself, but it doesn't hurt to know that it isn't money down the tubes. (3) Perhaps high-energy physics will be able to repay its debt to supercon- ductor theory by showing how to re-interpret an explanation for the Higgs field (derived after extensive experiments on the SSC paved the way, us- ing limits imposed by cosmology to help) as a model for a really clever super high Tc superconductor. Perhaps not. (4) Questions in inflationary cosmology--uh oh, there's that subject matter again--have suggested the question of whether our vacuum is stable or only metastable. This seems to be dependent on the top quark's mass, with stability if the top mass is < 100 Gev. Currently it looks like its mass is > 50 Gev; this comes from an analysis of higher than ex- pected beauty mixing. If it turns out the universe is only metastable, I'm sure the sooner we figure out what to do about it, the better off we will all be. These are none of the reasons I favor SSC, by the way. I favor it because I'd like to see some real interesting physics. > and can't wait >til a time when we can better afford it. We *can* afford to do it now. Just stop spending 10x its cost on SDI and poof, we've got an SSC and lots more. Whether we should do so is another question: one of politics, not science. As to whether to postpone it or not: if it's postponed, the technical skill needed to make SSC will probably evaporate. NASA has had this problem. >Personally, if we are talking about big projects, I would rather >see an effort to decode the human genetic code, and after that >other species too or maybe even first. There are many things that >I would put at a higher priority: superconductivity, >peace in the middle east, truth, justice, better networks, parallel >computing, .... >Maybe planetary missions, Hey, this all sounds good to me! And throw in the efforts to first map the human genome and launch the AXAF (Advanced X-ray Astronomical Facility) while you're at it. And an observatory on the moon. And maybe a Lyndon LaRouche first colony on Pluto project. ucbvax!garnet!weemba Matthew P Wiener/Brahms Gang/Berkeley CA 94720 "We should consider it as one of the most astonishing errors of the present age that so many people listen to the words of pseudoprophets who, in place of the dogmas of religion offer scientific dogmas with medieval impatience but without historical justification." --Baron Lorand von Eotvos