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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,f039470e8f537101 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-07-21 13:49:00 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.uchicago.edu!yellow.newsread.com!netaxs.com!newsread.com!newsfeed.stueberl.de!fu-berlin.de!uni-berlin.de!adsl-213-200-246-247.cybernet.CH!not-for-mail From: Vinzent Hoefler Newsgroups: comp.lang.ada Subject: Re: Ariane5 FAQ Date: Mon, 21 Jul 2003 22:46:52 +0200 Organization: JeLlyFish software Message-ID: References: <1058799152.775376@master.nyc.kbcfp.com> <1058810510.375902@master.nyc.kbcfp.com> <1058813341.841940@master.nyc.kbcfp.com> <1058816605.566685@master.nyc.kbcfp.com> Reply-To: v.hoefler@acm.org NNTP-Posting-Host: adsl-213-200-246-247.cybernet.ch (213.200.246.247) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable X-Trace: news.uni-berlin.de 1058820539 15201985 213.200.246.247 (16 [175126]) X-Newsreader: Forte Agent 1.8/32.548 Xref: archiver1.google.com comp.lang.ada:40584 Date: 2003-07-21T22:46:52+02:00 List-Id: Hyman Rosen wrote: >Vinzent Hoefler wrote: >> Well, so I ask again, *which* reasons were that? I see none, besides >> the good belief, it won't go wrong. > >They took a piece of self-contained hardware and moved it >from one rocket to another. They thought the software would >work. Well, one way or another - it did. It did exactly what is was supposed to do. >We have to assume that the Ariane 5 folks were not >complete blithering idiots, Dangerous assumption. ;) >so they must have has readsons >to assume it would work. So what you're trying to say is that they must have reasons just because they did it? Sorry, but I wouldn't consider this a strong argument. Alas, people do a lot of things for no apparent reason. This is sometimes ok if we are talking about "normal" life, but if there is a technical background, doing so can become very dangerous. In that area we should usually try to prove our beliefs (and obviously, this wasn't done in the Ariane 5 case). This proving process usually involves some reasons for this or that. So what reasons had they and could they prove the correctness? Obviously the answer is "No, they couldn't, because they didn't.". A reason like "it worked on the Ariane 4" is not really a reason, as I have already tried to point out. Personally for me it looks like they just *assumed* the IRS would work. This might have been the reason for the decision to just reuse it, right. But if you look deeper, they didn't seem have a reason for assuming that, they simply just believed it. What I mean is, you can probably not prove that somebody really loves his wife (BTW, does he have a reason for doing so?[0]) but you can tell that the candle on the table will shed some fancy light on her, because there is a reason for that it is doing so (something with high temperature, gases, electrons, molecular movements and photons and such stuff, I guess ;). Well, bad example, try to go into detail and predict the exact movement of the flame... Vinzent. [0] Because he just does? :-)