Refuting the Anti-Cantor Cranks

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SUMMARY

This discussion centers on the challenges of engaging with anti-Cantor cranks who dispute the validity of Cantor's diagonalization proof, which demonstrates the uncountability of real numbers. Participants share their experiences and strategies for addressing common arguments, emphasizing that many cranks are resistant to logical reasoning. The consensus is that while some individuals may eventually understand Cantor's proof, many are entrenched in their misconceptions and unlikely to change their views. The discussion highlights the futility of trying to convince those who are not open to reasoned dialogue.

PREREQUISITES
  • Understanding of Cantor's diagonalization proof
  • Familiarity with the concept of uncountability in set theory
  • Basic knowledge of real numbers and their properties
  • Awareness of logical fallacies and argumentation techniques
NEXT STEPS
  • Study Cantor's diagonalization proof in detail
  • Explore the concept of uncountability in set theory
  • Learn about common logical fallacies to better counter arguments
  • Research effective communication strategies for discussing mathematical concepts
USEFUL FOR

Mathematicians, educators, and anyone interested in understanding or debating the implications of Cantor's work and the nature of mathematical arguments.

  • #91
micromass said:
It can be proven that the only numbers which have multiple decimal representation are numbers which end in 00000... or 9999...

It's a good thing there are only a handful of such numbers and not an infinite number of them.

If we take the diagonal in Cantor's prove and change all numbers not equal to 5 to 5, and furthermore change all 5's to 6, then we get a number not on the list and the problem will not show up. That is: a number like 0.55555555... has a unique decimal representation.
It's a good thing Cantor didn't use base 6 in his proof.

Furthermore, there are versions of Cantor's proof which do not work with decimal representation at all!

Some versions work in base 10 and some don't? I may have underestimated the flexibility of this proof!
 
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  • #92
Antiphon said:
It's a good thing there are only a handful of such numbers and not an infinite number of them.

There are an infinite number of them.
 
  • #93
micromass said:
There are an infinite number of them.

I feel guilty- you took the bait!
 
  • #94
micromass said:
There are an infinite number of them.

Infinite, but most certainly countable. After all, such numbers are, trivially, rational.
 

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