The Smallest Non-Computable Busy Beaver Number: Is it Knowable?

  • Context: Undergrad 
  • Thread starter Thread starter johnkclark
  • Start date Start date
  • Tags Tags
    Function
Click For Summary

Discussion Overview

The discussion centers on the nature of Busy Beaver numbers, particularly the smallest non-computable Busy Beaver number. Participants explore the implications of computability, the existence of certain Busy Beaver numbers, and the challenges in determining their values. The conversation touches on theoretical aspects, logical frameworks, and the limits of current understanding in this area of mathematics and computer science.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants assert that the first four Busy Beaver numbers are finite and computable, while the 7918th is finite but not computable, as established by Scot Aaronson.
  • There is a discussion about the meaningfulness of stating that a number is not computable, with some arguing that it is relevant only in the context of finite algorithms.
  • One participant expresses uncertainty about whether the fifth Busy Beaver number is computable, suggesting it might also be non-computable.
  • Another participant elaborates on the implications of incompleteness in reasoning systems, indicating that certain Busy Beaver numbers may elude proof within established mathematical frameworks.
  • There is mention of the independence of the question regarding the 7918th Busy Beaver number from Zermelo-Frankel set theory, suggesting that stronger axioms might allow for its determination.
  • Participants discuss the potential for reducing the upper bound of Busy Beaver numbers and the complexities involved in encoding independence statements to further this goal.
  • One participant notes that while a given Turing machine will either halt or not, the challenge lies in knowing the exact value of the Busy Beaver number, particularly for BB(5).

Areas of Agreement / Disagreement

Participants express a range of views on the computability of Busy Beaver numbers, with some agreeing on the established values of the first few numbers while others question the computability of higher numbers. The discussion remains unresolved regarding the smallest non-computable Busy Beaver number and the implications of various logical systems.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about computability and the definitions of the Busy Beaver function. The implications of incompleteness and the independence of certain statements from established axiomatic systems are also noted but not fully resolved.

  • #31
stevendaryl said:
I don't know why you keep saying it. ... If you reject set theory and logic, then I don't see the point in your posting in this forum.
There is nothing to add.

As long as there is no common base, which has to be first-order logic unless stated otherwise, I can prove that a discussion is meaningless. Repeating false statements doesn't add facts. Furthermore a distinction like
johnkclark said:
But I tend to think truth is more important than proof.
doesn't make sense in mathematics, because mathematics doesn't search truth, only logical consistent conclusions, which we call proofs, and is philosophically highly undetermined here. For those interested in truth, I refer to https://en.wikipedia.org/wiki/Truth and the links therein - some of which led to other logical systems like constructivism.

Thread remains closed.
 

Similar threads

  • · Replies 15 ·
Replies
15
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
5K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 80 ·
3
Replies
80
Views
69K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 25 ·
Replies
25
Views
8K