Question about the natural numbers.

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Discussion Overview

The discussion revolves around the properties of the set of natural numbers, particularly whether it is the only infinite set that is not a power set of another set. Participants explore foundational concepts in set theory and the implications of different starting points for constructing numbers.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants assert that the natural numbers serve as a fundamental building block for numbers.
  • One participant questions the necessity of starting with natural numbers, suggesting alternatives like starting with 0 and 1 and adding 1 repeatedly.
  • Another participant proposes that nearly every set is not a power set of another set, prompting a clarification about the nature of infinite sets and bijections.
  • A later reply connects the original question to the Generalized Continuum Hypothesis, indicating a deeper theoretical context.
  • There is a suggestion that starting with 0 and adding larger increments, such as 1,000,000, leads to a set of the same cardinality as adding 1 repeatedly.

Areas of Agreement / Disagreement

Participants express differing views on the foundational aspects of natural numbers and their relation to power sets, indicating that multiple competing views remain without a consensus.

Contextual Notes

Some assumptions about the definitions of infinite sets and cardinalities are not explicitly stated, which may affect the clarity of the discussion.

cragar
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Is the set of natural numbers the only infinite set that is not a power set of another set?
 
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cragar said:
Is the set of natural numbers the only infinite set that is not a power set of another set?

Hey cragar.

Well you need to have a building block for numbers in the simplest manner and the natural numbers are that block.

Do you have any thoughts about a building block that is a subset or rather something simpler than the natural numbers?

It is a very good question to ask, because these kinds of things get people thinking and understanding and that's always good.
 
why can't we just start with 0 and 1 . and just add 1 to 1 as many times as we want
 
cragar said:
Is the set of natural numbers the only infinite set that is not a power set of another set?
Nearly every set is not the power set of another set.

Did you instead mean
the only infinite sets for which there is not a bijection from X to a power set of another set are sets for which there is a bijection to the natural numbers​
or maybe
the cardinality of the natural numbers is the only infinite cardinal number that is not the cardinality of a power set​
?

If so, then your question is essentially the Generalized Continuum Hypothesis.
 
cragar said:
why can't we just start with 0 and 1 . and just add 1 to 1 as many times as we want

You might just as well start with 0 and add 1,000,000 and keep adding 1,000,000. You'll end up with a set that is the same size as if you had added 1 each time
 

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