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From: JGA%MIT-MC@sri-unix.UUCP
Newsgroups: net.physics
Subject: Dean Drive Possible?
Message-ID: <12364@sri-arpa.UUCP>
Date: Tue, 17-Apr-84 12:57:00 EST
Article-I.D.: sri-arpa.12364
Posted: Tue Apr 17 12:57:00 1984
Date-Received: Mon, 23-Apr-84 01:12:57 EST
Lines: 47

From:  John G. Aspinall <JGA @ MIT-MC>

The Dean Drive came up in a discussion on the SPACE and SF-Lovers
digests a while ago.  Marvin Minsky submitted an amusing anecdote
about the subject to the lists.  With his permission, here is his
story.

  From: Marvin Minsky@MIT-AI (Sent by MINSKY@MIT-AI)
  Date: 01/17/82 00:25:30
  Subject: Dean Machine History

  Shortly after the Dean drive was described in Astounding, John Campbell
  published a picture of it.  I examined the picture with a lens and
  managed to read the brand name of the bathroom scale used to measure the
  loss of weight of the machine.  My college roommate, Roland Silver, and
  I conjectured correctly that this scale had a "diode" in it that coupled
  the platform and the reading device.  So we went to Sears Roebuck in
  Porter Square, Cambridge and bought that very scale.

  When you stand on it it reads your weight fine, but if you pump your
  arms up and down -- just as did the dean machine itself -- then the
  weight fluctuates a lot -- with the mean weight (and even the maximum)
  far below the real weight.

  So then Clause Shannon and John Pierce and I wrote a sharp detailed
  letter to Campbell about this.

  John Campbell didn't print our letter, but he sent me (knowing I was the
  instigator) a long letter that I still have here, denouncing
  establishment scientists for their reactionary and unimaginative
  rigidity and general intolerance.

  Suitably chastened, I dropped the matter and continued with my
  reactionary, establishment-bound studies.

  Anyway, this incident jibes with Pournelle's account about Cambell
  seeing the machine which "jumped around a lot" on a bathroom scale.  I
  checked out all the other scales, too, and finally found one that reads
  high when you bounce.  But these were much less common.  So, possibly,
  Dean was hoist by this pitiful petard.  But I maintained that this was
  extremely unlikely since, obviously, he was all too familiar with
  flakey, vibrating, weighing mechanisms.

    -- marvin

  P.S..  I should add that much as we hated him, we loved him greatly too,
  and for all he did for all of us.  And same for G. Harry Stine.