Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

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


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

Topic: This Week's Finds in Mathematical Physics (Week 140)
Replies: 10   Last Post: Oct 27, 1999 9:53 PM

Advanced Search

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

Posts: 40
Registered: 12/12/04
Re: Flies, trains, and series summation
Posted: Oct 27, 1999 9:53 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply





Kresimir Kumericki wrote:
>
> [sci.physics.research removed]
>
> In sci.physics Chris Hillman <hillman@math.washington.edu> wrote:

> > On 22 Oct 1999, Phillip Helbig wrote:
> >> The problem being: Two trains are 60 miles apart and approaching each
> >> other at 30 miles per hour. There is a fly flying between the
> >> cowcatchers of each train, at 60 miles per hour, back and forth, turning
> >> around immediately. What is the total distance covered by the fly


The poster is insufficiently lazy. Draw a Feynman-type diagram;
space horizontal, time vertical. The trains' trajectories form a V and
the fly travels a shrinking zigzag (limited by the length of the
fly!). Measure the path length!

Mark L. Fergerson







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

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.