Article View: sci.physics
Article #4500Re: What's a manifold?
From: Bruce Scott
Date: Tue, 10 Nov 1992 00:02
Date: Tue, 10 Nov 1992 00:02
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1724 bytes
asimov@wk223.nas.nasa.gov (Daniel A. Asimov) writes:
>As has been mentioned, it *is* a theorem that all manifolds do occur
>as subspaces of some Euclidean space: in fact, any n-manifold embeds in R^(2n).
>
>This is a pleasant theorem, but it would be inappropriate to take this as a
>definition.
What about the one-dimensional helix embedded in R^3. Is the helix not a
1-manifold? Note that if you compact it along its axis you get a circle
(also a 1-manifold--is this S^1?) embedded in R^2. But a circle is a
degenerate case of a helix ("stretching" along the axis having vanished)
and is not in general a helix.
Someone educate me on this.
Gruss,
Dr Bruce Scott The deadliest bullshit is
Max-Planck-Institut fuer Plasmaphysik odorless and transparent
bds at spl6n1.aug.ipp-garching.mpg.de -- W Gibson
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Newsgroups: sci.physics,sci.math Path: arc1-ca.pugleaf.net!sparky!uunet!think.com!sdd.hp.com!decwrl!concert!samba!usenet From: Bruce.Scott@launchpad.unc.edu (Bruce Scott) Subject: Re: What's a manifold? Message-ID: <1992Nov10.000228.14551@samba.oit.unc.edu> Sender: usenet@samba.oit.unc.edu Nntp-Posting-Host: lambada.oit.unc.edu Organization: University of North Carolina Extended Bulletin Board Service References: <SMITH.92Nov5132141@gramian.harvard.edu> <1992Nov6.024142.6758@galois.mit.edu> <1992Nov6.190913.18507@nas.nasa.gov> Date: Tue, 10 Nov 1992 00:02:28 GMT Lines: 27