Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Ian Kelly <ian.g.kelly@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: What exactly is "exact" (was Clean Singleton Docstrings)
Date: Mon, 18 Jul 2016 09:25:25 -0600
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On Mon, Jul 18, 2016 at 3:29 AM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Monday 18 July 2016 14:16, Rustom Mody wrote:
>> In short one could think of inexact and exact =E2=80=94 in scheme's inte=
nded
>> semantics =E2=80=94 as better called scientific (or science-ic) and math=
ematic
>> numbers.
>
> I don't think so. "Science" uses both experimentally-derived numbers (e.g=
. G,
> c, the mass of the electron) and numbers known exactly (=E2=88=9A2, e, =
=CF=80).

Off-topic, c being a fundamental constant is actually in the latter
category. Its *exact* value is 299792458 m/s.

The length of the meter, on the other hand, is defined as the distance
traveled by light in a vacuum in 1/299792458 seconds and is subject to
the precision of measurements.