Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Skepticism, mysticism, Jewish mathematics
Replies: 115   Last Post: Aug 7, 2006 1:30 AM

 Messages: [ Previous | Next ]
 R. Srinivasan Posts: 252 Registered: 12/13/04
Re: Skepticism, mysticism, Jewish mathematics
Posted: Aug 5, 2006 2:05 AM

Mike Kelly wrote:
> R. Srinivasan wrote:
> > Mike Kelly wrote:
>>> [...]
> > >
> > > But the sequence of nested intervals does get "as close as you like" to
> > > zero, if you wait long enough. Any point other than zero will be
> > > "passed" eventually.

> You are considering a process in time, where you are at a particular
> > interval, and then pass on to the next smaller nested interval, and so
> > on. If you asked the Greeks, they would have probably told you that
> > this infinite process of sub-diviision can never be "completed" and
> > you will "always" be an interval's length away from zero. Whereas you
> > have assumed that you can somehow complete this process, and after
> > completion, only the point zero is never passed. That precisely is the
> > issue in Zeno's paradox.

> > >
> > Note carefully the difference between your approach and mine. I am
> > considering the *totality* of nested intervals (which classical
> > standard real analysis permits) and saying that not one interval in
> > this totality has end-points "infinitely close" to zero.

>
> It is not necessary for any interval to have end-points "infinite
> close" to zero (whatever that means) to decide what is in the
> intersection. You're considering which real numbers are in every one of
> the nested intervals. If you pick any real number other than zero, then
> some intervals don't contain it, so they aren't in the intersection. So
> zero is the only real number in the intersection.
>
> "intersection" has nothing to do with "end-point infinitely close" to
> something.

I don't deny that there is a proof that zero is the only point in the
intersection. And there is also a simple proof-by-contradiction that
would rule out the possibilty of an interval being in the intersection.
All I am saying is that there is another paradoxical way of arguing
that an interval has to be in the intersection. And as Herb has pointed
out in another post, there may well be another way of arguing that
there should be nothing in the intersection -- I am personally not able
to get this intuition yet (will have to study the theorems he has
mentioned). You can deny these paradoxical intuitions and see no
paradox -- then there would be no way of contradicting you within
classical real analysis. Or you can look for an alternative logic where
there may be a different way of eliminating these paradoxes at the cost
of some restrictions, and yet do much of practically useful real
analysis. I am pursuing this latter route.

Regards, RS

Date Subject Author
7/25/06 David Petry
7/25/06 fishfry
7/25/06 Dr. David Kirkby
7/25/06 Dr. David Kirkby
7/25/06 lloyd
7/25/06 Doug Schwarz
7/25/06 Virgil
7/26/06 Mike Kelly
7/26/06 David Petry
7/26/06 Gene Ward Smith
7/26/06 Brian Quincy Hutchings
7/26/06 dkfjdklj@yahoo.com
7/26/06 herbzet
7/26/06 David Petry
7/28/06 herbzet
7/26/06 herbzet
7/26/06 lloyd
7/26/06 herbzet
7/26/06 dkfjdklj@yahoo.com
7/26/06 herbzet
7/26/06 Gene Ward Smith
7/26/06 Gerry Myerson
7/26/06 David Petry
7/26/06 Randy Poe
7/26/06 mensanator
7/27/06 Richard Herring
7/27/06 mensanator
7/27/06 Richard Herring
7/26/06 Gene Ward Smith
7/26/06 David Petry
7/26/06 Patricia Shanahan
7/26/06 Gene Ward Smith
7/28/06 herbzet
7/26/06 Dr. David Kirkby
7/26/06 Randy Poe
7/27/06 Rotwang
7/28/06 herbzet
7/30/06 Han de Bruijn
7/30/06 Barb Knox
7/30/06 zr
7/30/06 Virgil
7/30/06 Gene Ward Smith
7/30/06 zr
8/1/06 Virgil
7/30/06 T.H. Ray
7/31/06 Brian Quincy Hutchings
7/31/06 T.H. Ray
8/1/06 Brian Quincy Hutchings
8/1/06 David R Tribble
7/30/06 Gene Ward Smith
7/30/06 Ioannis
7/30/06 Dr. David Kirkby
7/30/06 zr
7/30/06 Dave Rusin
8/1/06 David Bernier
8/1/06 David R Tribble
8/2/06 Ioannis
7/31/06 Han de Bruijn
8/2/06 R. Srinivasan
8/3/06 Rupert
8/4/06 R. Srinivasan
8/4/06 R. Srinivasan
8/4/06 Rupert
8/4/06 R. Srinivasan
8/4/06 Rupert
8/4/06 R. Srinivasan
8/4/06 Mike Kelly
8/4/06 R. Srinivasan
8/4/06 Mike Kelly
8/4/06 R. Srinivasan
8/4/06 R. Srinivasan
8/4/06 Mike Kelly
8/4/06 R. Srinivasan
8/4/06 herbzet@cox.net
8/4/06 R. Srinivasan
8/6/06 Newberry
8/4/06 Jack Markan
8/4/06 Brian Quincy Hutchings
8/7/06 R. Srinivasan
8/4/06 Mike Kelly
8/5/06 R. Srinivasan
7/28/06 herbzet
7/28/06 Gene Ward Smith
7/28/06 herbzet
7/28/06 mensanator
7/28/06 herbzet
7/27/06 T.H. Ray
7/28/06 herbzet
7/29/06 David Petry
7/30/06 herbzet@cox.net
8/4/06 Jack Markan
8/4/06 T.H. Ray
7/26/06 David R Tribble
7/26/06 Gene Ward Smith
7/26/06 T.H. Ray
7/26/06 toni.lassila@gmail.com
7/26/06 Bennett Standeven
7/26/06 Brian Quincy Hutchings
7/27/06 Rotwang
7/27/06 Craig Feinstein
7/27/06 Toni Lassila
7/27/06 Craig Feinstein
7/27/06 Brian Quincy Hutchings
7/27/06 Rupert
7/28/06 zr
7/28/06 herbzet
7/28/06 T.H. Ray
7/29/06 zr
7/29/06 Virgil
7/29/06 zr
7/29/06 Virgil
7/30/06 herbzet@cox.net
7/30/06 T.H. Ray
7/30/06 LauLuna
7/30/06 LauLuna