Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cfa!willner From: willner@cfa.harvard.EDU (Steve Willner) Newsgroups: sci.physics,sci.philosophy.tech,sci.research,sci.misc,misc.misc Subject: Re: Einstein's relativity and daily life Message-ID: <694@cfa.cfa.harvard.EDU> Date: Thu, 1-Oct-87 11:54:25 EDT Article-I.D.: cfa.694 Posted: Thu Oct 1 11:54:25 1987 Date-Received: Mon, 5-Oct-87 03:49:46 EDT References: <391@nikhefh.UUCP> Organization: Harvard-Smithsonian Ctr. for Astrophysics Lines: 54 Keywords: science for the people Summary: nuclear magnetic resonance Xref: mnetor sci.physics:2346 sci.philosophy.tech:502 sci.research:236 sci.misc:519 misc.misc:1915 In article <391@nikhefh.UUCP>, jona@nikhefh.UUCP (Jona Oberski) writes: > Question: Which things - common instruments, consumergoods, etc. - would not > exist if we would not have Einstein's Theory of Relativity: "ETR"? It's hard to separate any development that came after relativity from the influence of relativity. Quantum mechanics, for example, is not directly dependent on relativity, but I believe the prime developers were greatly influenced by Einstein's approach. However, I'll assume that your question means what if the Schroedinger equation were known but not the Dirac equation. (If the Schroedinger equation goes away, so do transistors and integrated circuits, among other things.) Without the Dirac equation, I don't believe we would understand nuclear magnetic resonance (NMR) or be able to use the phenomenon in analysis. (I'm not very knowledgeable in this field, so experts please correct these comments.) NMR has been used for many years in organic chemistry and more recently in biochemistry to determine molecular structures. While we would certainly have some sorts of plastics without NMR, I doubt we would have anything like the vast number and variety tailored for specific properties that we have today. Nor would we have most of the synthetic fibers or products like Teflon, Tyvek, and lots of others. I'm not sure about application to pharmaceuticals, but I suspect that many drugs would not exist and the biochemical actions of others would not be understood. NMR has also been used for a few years now for medical imaging. (It's referred to as "magnetic resonance imaging" or "MRI" to avoid negative public reaction to the word "nuclear"). It probably saved my brother's life a couple of years ago, when doctors were able to use MRI to find soft tissue problems that didn't show up on X-rays or CAT scans. Another application that comes to mind is X-ray diffraction analysis, which is widely used for studying crystals of all kinds. Studies of semiconductors and viruses probably have had the greatest practical effects, but I'm not really sure how important the relativistic corrections are. Finally, if you are willing to accept intangibles, how about the reassurance that the Sun will not become a nova or supernova? Relativity is crucial in understanding the processes that actually cause novae and supernovae, and we now know that these processes are not important in the Sun. > By the way, do you like the idea: > "The only commonly-known physicist's theory is without practical value". No. -- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa2 60 Garden St. FTS: 830-7123 UUCP: willner@cfa Cambridge, MA 02138 USA ARPA: willner@cfa.harvard.edu