The Math Forum

Search All of the Math Forum:

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

Math Forum » Discussions » sci.math.* » sci.math

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

Topic: the real tube
Replies: 2   Last Post: Feb 15, 2013 8:46 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 351
Registered: 10/27/06
the real tube
Posted: Feb 10, 2013 1:14 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Instead of the real line, consider the real tube,
where at each position p along the tube is a disc
of no thickness, at distance p from the zero
disc, and at a right angle to the central line of
the tube. This is not a hollow tube, so each real
number is represented by a disc, not a ring.

Now say that the tube is one centimeter thick
and one meter long, and that it contains the
zero meter disc, 0, but does not contain the one
meter disc, 1.

Now hold up the tube in front of your eye, as you
would hold a telescope, looking toward the zero
meter end. You see the disc 0, face on. Now
turn the tube around and look toward the one
meter end. What do you see?

Date Subject Author
Read the real tube
Read Re: the real tube
Read Re: the real tube

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.