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=0.1 required=5.0 tests=BAYES_05,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1042f393323e22da X-Google-Attributes: gid103376,public X-Google-Thread: 1014db,1042f393323e22da X-Google-Attributes: gid1014db,public X-Google-Thread: 109fba,1042f393323e22da X-Google-Attributes: gid109fba,public From: Jonathan Guthrie Subject: Re: Software Engineering and Dreamers Date: 1997/06/11 Message-ID: <5nl4ck$ahj$1@news.hal-pc.org>#1/1 X-Deja-AN: 247593022 Distribution: world References: <19970602.562B58.2B32@ai110.du.pipex.com> <5n1261$qj6@polo.demon.co.uk> <19970602.433020.144E5@ai078.du.pipex.com> <33983ABE.26B2@sni.de> <19970606.49CA70.12B91@ae124.du.pipex.com> <5nh0th$dam$1@news.hal-pc.org> <19970609.5A1DA0.14F78@an194.du.pipex.com> Organization: Houston Area League of PC Users Newsgroups: comp.lang.c++,comp.lang.c,comp.lang.ada Date: 1997-06-11T00:00:00+00:00 List-Id: Okay, the "personal attacks" (calling you a "fool" in public hardly qualifies as a personal attack on Usenet, referencing the brouhaha on various newsgroups over an article by Ousterhout as an example of what I'm thinking of) are uncalled for, so here's what I really think. In comp.lang.ada Mathew Hendry wrote: > : However, crocodiles moving planets around in some unstated arbitrary way > : is useless to make predictions from. Therefore, the theory makes no > : predictions at all about planetary "behavior" (one could argue that it > : cannot---after all, what happens if the crocodiles change their mind > : about how to move the planets?) > The predictions of the theory are the same, whether you accept it or not. Its > predictions follow directly from its stated assumptions, as with any other > theory, valid or not. You don't seem to understand. I will attempt to explain better. The positions of the planets, which is all you seem to be talking about, can be determined by Kepler's laws. Those laws can be derived from Newtonian dynamics while it is a postulate with this "crocodile theory." While it is possible to make other predictions than the future positions of the planets from Newtonian dynamics, it is not possible to predict ANYTHING using the theory that crocodiles move the planets by whim and their knowledge of Kepler's laws EXCEPT the future positions of the planets, This is true "whether you accept it or not." Therefore, your "crocodile theory" is inferior in predictive power to Newton's theory of universal gravitation, which is what you seem to be comparing it to. Now, if you were to expand your "crocodile theory" to be something like a "theory of universal crocodiles", I would point out that A) Newton doesn't attempt to explain where gravity comes from or how it works so I'm as willing to accept your theory of gravitation as any other that I've seen and B) Changing the name isn't an explanation. > Obviously, you would be a fool if you did accept the theory, but that's hardly > the point. My intention was to illustrate the fact that theories are not > simply blind prediction engines. I know what you're point is. That's why I started with a statement that Ockham's razor isn't needed. Ockham's razor is needed to select which theory is preferred when you have theories of equal predictive power. To invoke it is to concede your point. However, you have not demonstrated to my satisfaction that your theory is equal in predictive power to the laws of Newtonian mechanics (simply stating that it is won't fly---I'd just as soon believe that someone always tells you the truth because they say they do) and I am attempting to explain WHY that I'm not satisfied with your "proof." In a nutshell, it's because the "crocodile theory" only explains the motions of the planets, while Newtonian mechanics governs EVERYTHING. Well, okay, there is one other reason I don't like your example. It's really bogus to wave your hands by saying "you get the same answers, okay?" How do you know? Are you psychically linked to these crocodiles, or what? What RAW DATA are you using to create your theory with? Where does it come from? (This IS what you're trying to demonstrate, which is why it's the "other reason.") With all the competing theories out there, and all the very real examples you could make of competing theories making identical predictions with one being favored for emotional reasons, you came up with a hypothetical one. It just so happens that I agree with you: The value of theories is based upon more than their predictive power. Ockham's razor, for better or for worse, makes that sort of selection a formal part of science. However, I could come up with a better example with my eyes closed. In fact, you seem to be so attached to the hypothesis that I have an emotional attachment to Newtonian mechanics that I might use your posts to ME as an example of what you're trying to demonstrate. Further deponant sayeth not. -- Jonathan Guthrie (jguthrie@brokersys.com) Information Broker Systems +281-895-8101 http://www.brokersys.com/ 12703 Veterans Memorial #106, Houston, TX 77014, USA We sell Internet access and commercial Web space. We also are general network consultants in the greater Houston area.