Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!columbia!heathcliff.columbia.edu!zdenek From: zdenek@heathcliff.columbia.edu (Zdenek Radouch) Newsgroups: sci.physics Subject: Re: Analog models of computation Message-ID: <3505@columbia.UUCP> Date: Wed, 15-Oct-86 22:38:28 EDT Article-I.D.: columbia.3505 Posted: Wed Oct 15 22:38:28 1986 Date-Received: Thu, 16-Oct-86 02:03:27 EDT References: <8195@watrose.UUCP> Sender: nobody@columbia.UUCP Reply-To: zdenek@heathcliff.columbia.edu.UUCP (Zdenek Radouch) Followup-To: sci.physics Distribution: net Organization: Columbia University CS Department Lines: 28 There are many problems with "analog type solutions". In some cases we are interested only in the character of the solution (is the system stable? will it oscillate? is the output linear or exponential? etc.). There are other applications where "analog" solution gives us required precision. Many of these problems are too complex for digital computers and can be quite satisfactorily solved on devices known as "analog computers". I won't go into details, describing an analog computer, because everybody knows or can look at a representative - analog musical synthesiser. Similar devices are used in simulations of complex mechanical systems. If you ever tried to solve differential equation, compute a sine wave or exponential curve, you know, how difficult that is on a digital computer. But if you use a capacitor and an inductor (or mass and spring) you get second order differential equations, sine waves or exponentials with no difficulties at all! zdenek ------------------------------------------------------------------------- Men are four: He who knows and knows that he knows, he is wise - follow him; He who knows and knows not that he knows, he is asleep - wake him; He who knows not and knows that he knows not, he is simple - teach him; He who knows not and knows not that he knows not, he is a fool - shun him! zdenek@CS.COLUMBIA.EDU or ...!seismo!columbia!cs!zdenek Zdenek Radouch, 457 Computer Science, Columbia University, 500 West 120th St., New York, NY 10027