What is the Staircase Line in a Unit Square?

  • Context: High School 
  • Thread starter Thread starter fourier jr
  • Start date Start date
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
5 replies · 4K views
fourier jr
Messages
764
Reaction score
13
Take the unit square & make a zig-zag line like a staircase from one corner to the opposite one. Then the total distance if you add up the vertical parts & & horizontal parts is 2. Even if you make trillions & trillions of 'stairs' the sum of all the vertical parts & horizontal parts is still 2 even though the graph would look more & more like a diagonal line, whose length of course is [tex]\sqrt{2}[/tex]. Someone mentioned this example before & put up a link to the mathworld page on it but I couldn't find it & nothing I searched for seemed to work. :confused:
 
Mathematics news on Phys.org
Hummm... fractals?
 
The diagonal paradox, again. Use the search button. :smile:
 
Minkowski's L1 distance

Taxicab metric?
 
Weyl Tile argument

fourier jr said:
Take the unit square & make a zig-zag line like a staircase from one corner to the opposite one. Then the total distance if you add up the vertical parts & & horizontal parts is 2. Even if you make trillions & trillions of 'stairs' the sum of all the vertical parts & horizontal parts is still 2 even though the graph would look more & more like a diagonal line, whose length of course is [tex]\sqrt{2}[/tex]. Someone mentioned this example before & put up a link to the mathworld page on it but I couldn't find it & nothing I searched for seemed to work. :confused:

It's related to the "Weyl Tile argument", which is discussed in some books on philosophy of mathematics, and even some web pages:
http://faculty.washington.edu/smcohen/320/atomism.htm
The argument as stated there isn't serious, but this has serious applications to why naive "quantization" of space won't work. See spin networks for a more sophisticated approach: http://math.ucr.edu/home/baez/penrose/

It's also related to a "paradox" in geometric measure theory, which is probably closer to the applications you have in mind, huh? See p. 129 of Spivak, Calculus on Manifolds.
 
Last edited: