From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,60e2922351e0e780 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-11-20 18:43:19 PST Path: archiver1.google.com!news2.google.com!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!proxad.net!usenet-fr.net!enst.fr!melchior!cuivre.fr.eu.org!melchior.frmug.org!not-for-mail From: "Alexandre E. Kopilovitch" Newsgroups: comp.lang.ada Subject: Re: OT: Nuclear Waste (Was Re-Marketing Ada) Date: Fri, 21 Nov 2003 05:51:53 +0300 (MSK) Organization: Cuivre, Argent, Or Message-ID: References: NNTP-Posting-Host: lovelace.ada-france.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: melchior.cuivre.fr.eu.org 1069382485 6005 80.67.180.195 (21 Nov 2003 02:41:25 GMT) X-Complaints-To: usenet@melchior.cuivre.fr.eu.org NNTP-Posting-Date: Fri, 21 Nov 2003 02:41:25 +0000 (UTC) To: comp.lang.ada@ada-france.org Return-Path: In-Reply-To: ; from "Robert I. Eachus" at Thu, 20 Nov 2003 18:47:05 -0500 X-Mailer: Mail/@ [v2.44 MSDOS] X-Virus-Scanned: by amavisd-new-20030616-p5 (Debian) at ada-france.org X-BeenThere: comp.lang.ada@ada-france.org X-Mailman-Version: 2.1.3 Precedence: list List-Id: Gateway to the comp.lang.ada Usenet newsgroup List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Xref: archiver1.google.com comp.lang.ada:2777 Date: 2003-11-21T05:51:53+03:00 Robert I. Eachus wrote: > > But what those result *mean*? Are the *words* appropriate? Do those words > > carry proper, familiar associations in this case? To which degree? > > I can't say for you, which is why I recommend the math. Followning the > formal math in quantum mechanics is tough, but it tells you things. Unfortunately, I graduated from Moscow University (long ago) as mathematician, and even worse, my specialization was infinitedimensional representations of Lie groups - too close to quantum mechanics, you know. So, for me mathematics can't say anything definite about physics in particular as well as about any reality in general. Mathematics says only "if we believe in X then we should believe also in Y... provided that our notions of X and Y are well-established and that we did not violate many our silent assumptions, which are standard for this domain". Certainly I know also the thesis, which claims that any correct and beautiful mathematical model should represent some fact/law of reality - well, I tend to agree with that, but even that thesis says nothing about correspondence to particular interpretation. > > What does it mean - teleportation of a single photon? How can one identify > > a single photon? (And it is just the first question). > > You really need to study QM a lot to be able to answer those questions. So what is the use of that public claim? How many people studied QM enough for that? Basic QM (that is, before QED) is most probably not enough, and even that is taught for physisists and chemists only, I think. I guess that I may be able to read that article, spending several weeks or even months for that (I certainly need to recall many things and retrain myself... I did similar things several times, so I know how much time and effort it takes). Then, to evaluate the result, that is, to develop my own opinion about it, I should spend on it several months more. Naturally, I will not spend that much time for a result of very doubtful worthiness. And the vast majority of educated people are in much worse position for this case. So why that result should be broadcasted outside of the proper community of physisists? We want people to lose a sense of difference between a reality and a movie - just to keep them optimistic about Our Mighty Science? > But not only can you identify a single photon you can create a pair of > "entangled" photons, such that you can only measure one of two > properties for the pair. If you measure the polarization of one photon > that is entangled, in one plane, the entangled photon will have the > opposite polarization in that plane. Try to measure the two > polarizations at right angles, and you won't succeed. This is standard QM. > > What happens in the teleportation experiment is that the entangled state > is teleported. After the teleportation of one of the members of a pair, > the NEW photon is entangled with the other member of the pair. The > original photon is no longer entangled with anything. So quantum > teleportation makes one photon or other particle (at a distance) into a > copy of another. Well, I can honestly say that I did not understand almost anything - I got just very vague glimpse of some part of the deal. And I didn't hope to get more, of course. Please, get me right: I do not say that the experiment was somehow incorrect or the result is unbelievable or unimportant - I just say that this is wrong to broadcast it to general public as an important achievement in teleportation, because the public (and even educated public) will interpet these words another way, nothing similar to physisist's understanding of the event. > Similarly, the Alcubierre warp drive when first proposed, was completely > impractical. Now there are lots of papers published on the subject and > the amount of negative energy required is becoming quite modest. See: > http://lanl.arxiv.org/abs/gr-qc/9905084 and > http://xxx.lanl.gov/PS_cache/gr-qc/pdf/0207/0207109.pdf No, never more! -;) I followed that gr-qc several years in the mid of 90th, and dropped that wrong habit with big relief. > That doesn't > mean the human race can start building warp drive spaceships next week. Well, I'll better wait until the people responsible for that succeed to build something useful. > But the Alcubierre geometry is now getting to be close to reasonable. Although I saw enough various geometries, I don't recall that name... well, one geometry more, one toy more. Grants should be received, of course. > (Now all we need is a way to make a few kilograms of negative mass.) Hm, are you sure that they will not annihilate all us? -;) Oh, I just guessed what is the famous Big Bang - it happens every time when some civilization in Universe accumulates critical negative mass -;) . Alexander Kopilovitch aek@vib.usr.pu.ru Saint-Petersburg Russia