Re: Significant digits in a float?

References	(2 earlier) <roy-DA9493.09383329042014@news.panix.com> <8td53bxud5.ln2@news.ducksburg.com> <ljp9sp$h22$1@ger.gmane.org> <CAPTjJmqya7paQowEkY7-pfsSynybEYTVgC2QTbviX5DWc8VHUg@mail.gmail.com> <53606083.4000509@stoneleaf.us>
Date	2014-04-30 13:03 +1000
Subject	Re: Significant digits in a float?
From	Chris Angelico <rosuav@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.9603.1398833574.18130.python-list@python.org> (permalink)

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On Wed, Apr 30, 2014 at 12:31 PM, Ethan Furman <ethan@stoneleaf.us> wrote:
> On 04/29/2014 03:51 PM, Chris Angelico wrote:
>> Any point where the mile east takes you an exact number of times
>> around the globe. So, anywhere exactly one mile north of that, which
>> is a number of circles not far from the south pole.
>
> Perhaps my geography is rusty, but I was under the impression that one
> cannot travel south if one is at the South Pole (axial, not magnetic).

Correct, but there's a place not far from the South Pole where the
circumference of the earth (travelling east) will be exactly one mile.
I could calculate where that would be on a perfect sphere, but earth
isn't, so I'll just say "near the South Pole". If you start exactly
one mile north of that circle, then you can accomplish the original
challenge. Also, if your mile east takes you exactly twice around the
circumference, you still achieve the same thing, so there's another
circle (one mile north of *that* circle), and another at the
three-times-around circle, etc.

But I think a better answer is New York City. You start out lost, you
go a mile south, a mile east, a mile north, and you are again lost.

ChrisA

Thread

Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-28 12:00 -0400
  Re: Significant digits in a float? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-04-29 02:34 +0000
    Re: Significant digits in a float? Ben Finney <ben@benfinney.id.au> - 2014-04-29 13:23 +1000
      Re: Significant digits in a float? Steven D'Aprano <steve@pearwood.info> - 2014-04-29 05:43 +0000
        Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-04-29 20:33 -0400
          Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 20:42 -0400
            Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-04-30 20:02 -0400
              Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-04-30 22:54 -0500
                Re: Significant digits in a float? Paul Rubin <no.email@nospam.invalid> - 2014-04-30 20:56 -0700
                Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-04-30 23:16 -0500
                Re: Significant digits in a float? William Ray Wing <wrw@mac.com> - 2014-05-01 11:53 -0400
                Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-05-06 11:29 -0500
                Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-01 22:06 -0400
                Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-05-06 09:51 -0500
                Re: Significant digits in a float? alister <alister.nospam.ware@ntlworld.com> - 2014-05-06 15:18 +0000
                Re: Significant digits in a float? Joel Goldstick <joel.goldstick@gmail.com> - 2014-05-06 12:14 -0400
                Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-06 19:48 -0400
                Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-05-01 08:56 -0400
                Re: Significant digits in a float? Larry Hudson <orgnut@yahoo.com> - 2014-05-01 12:51 -0700
                Re: Significant digits in a float? Adam Funk <a24061@ducksburg.com> - 2014-05-01 22:05 +0100
                Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-01 21:47 -0400
                Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-05-06 09:59 -0500
                [OT] Silde rules [was Re: Significant digits in a float?] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-06 16:10 +0000
                Re: [OT] Silde rules Ben Finney <ben@benfinney.id.au> - 2014-05-07 10:01 +1000
              Re: Significant digits in a float? Adam Funk <a24061@ducksburg.com> - 2014-05-01 21:55 +0100
                Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-01 22:26 -0400
                Re: Significant digits in a float? Adam Funk <a24061@ducksburg.com> - 2014-05-08 20:58 +0100
    Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 09:38 -0400
      Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 02:30 +1000
        Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 19:53 -0400
          Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 10:13 +1000
          Re: Significant digits in a float? Ben Finney <ben@benfinney.id.au> - 2014-04-30 10:13 +1000
          Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 10:17 +1000
          Re: Significant digits in a float? Ben Finney <ben@benfinney.id.au> - 2014-04-30 10:20 +1000
          Re: Significant digits in a float? Grant Edwards <invalid@invalid.invalid> - 2014-04-30 18:19 +0000
      Re: Significant digits in a float? Ned Batchelder <ned@nedbatchelder.com> - 2014-04-29 12:47 -0400
        Re: Significant digits in a float? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-04-30 09:45 +1200
      Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 02:59 +1000
      Re: Significant digits in a float? Adam Funk <a24061@ducksburg.com> - 2014-04-29 21:16 +0100
        Re: Significant digits in a float? Mark H Harris <harrismh777@gmail.com> - 2014-04-29 15:39 -0500
          Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 07:15 +1000
        Re: Significant digits in a float? Ryan Hiebert <ryan@ryanhiebert.com> - 2014-04-29 15:42 -0500
        Re: Significant digits in a float? emile <emile@fenx.com> - 2014-04-29 15:42 -0700
          Re: Significant digits in a float? alister <alister.nospam.ware@ntlworld.com> - 2014-04-30 09:03 +0000
          Re: Significant digits in a float? Grant Edwards <invalid@invalid.invalid> - 2014-04-30 18:21 +0000
            Re: Significant digits in a float? emile <emile@fenx.com> - 2014-05-01 09:34 -0700
              Re: Significant digits in a float? alister <alister.nospam.ware@ntlworld.com> - 2014-05-01 17:13 +0000
        Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 08:51 +1000
          Re: Significant digits in a float? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-04-30 20:14 +1200
            Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 18:27 +1000
            Re: Significant digits in a float? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-04-30 14:05 +0100
        Re: Significant digits in a float? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-04-30 00:34 +0100
        Re: Significant digits in a float? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-04-29 20:37 -0400
        Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 20:45 -0400
        Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 10:45 +1000
          Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 20:48 -0400
        Re: Significant digits in a float? Ethan Furman <ethan@stoneleaf.us> - 2014-04-29 19:31 -0700
          Re: Significant digits in a float? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-04-30 02:59 +0000
            Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-29 23:30 -0400
              Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 13:40 +1000
        Re: Significant digits in a float? Chris Angelico <rosuav@gmail.com> - 2014-04-30 13:03 +1000
          Re: Significant digits in a float? Roy Smith <roy@panix.com> - 2014-04-30 08:01 -0400
        Off-topic  circumnavigating the earth in a mile or less  [was Re: Significant digits in a float?] Ethan Furman <ethan@stoneleaf.us> - 2014-04-30 06:14 -0700
        Re: Off-topic  circumnavigating the earth in a mile or less  [was Re: Significant digits in a float?] Ethan Furman <ethan@stoneleaf.us> - 2014-04-30 07:02 -0700
          Re: Off-topic  circumnavigating the earth in a mile or less Adam Funk <a24061@ducksburg.com> - 2014-05-01 21:52 +0100
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Chris Angelico <rosuav@gmail.com> - 2014-05-01 00:27 +1000
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Chris Angelico <rosuav@gmail.com> - 2014-05-01 05:10 +1000
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Ryan Hiebert <ryan@ryanhiebert.com> - 2014-04-30 10:24 -0500
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Ian Kelly <ian.g.kelly@gmail.com> - 2014-04-30 17:46 -0600
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Terry Reedy <tjreedy@udel.edu> - 2014-04-30 22:20 -0400
          Re: Off-topic circumnavigating the earth in a mile or less [was Re:   Significant digits in a float?] Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-05-01 18:16 +1200
          Re: Off-topic circumnavigating the earth in a mile or less Adam Funk <a24061@ducksburg.com> - 2014-05-01 21:57 +0100
            Re: Off-topic circumnavigating the earth in a mile or less Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-01 22:49 +0100
            Re: Off-topic circumnavigating the earth in a mile or less alister <alister.nospam.ware@ntlworld.com> - 2014-05-02 08:49 +0000
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Chris Angelico <rosuav@gmail.com> - 2014-05-01 11:57 +1000
        Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?] Vlastimil Brom <vlastimil.brom@gmail.com> - 2014-05-01 09:49 +0200
      Re: Significant digits in a float? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-04-30 02:50 +0000
      Re: Significant digits in a float? Grant Edwards <invalid@invalid.invalid> - 2014-04-30 18:18 +0000

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