- Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ] [ by messages with attachments ]

From: Torgny Tholerus <torgny.domain.name.hidden>

Date: Thu, 04 Jun 2009 17:27:52 +0200

Brian Tenneson skrev:

*>
*

*>
*

*> Torgny Tholerus wrote:
*

*>> It is impossible to create a set where the successor of every element is
*

*>> inside the set, there must always be an element where the successor of
*

*>> that element is outside the set.
*

*>>
*

*> I disagree. Can you prove this?
*

*> Once again, I think the debate ultimately is about whether or not to
*

*> adopt the axiom of infinity.
*

*> I think everyone can agree without that axiom, you cannot "build" or
*

*> "construct" an infinite set.
*

*> There's nothing right or wrong with adopting any axioms. What results
*

*> is either interesting or not, relevant or not.
*

How do you handle the Russell paradox with the set of all sets that does

not contain itself? Does that set contain itself or not?

My answer is that that set does not contain itself, because no set can

contain itself. So the set of all sets that does not contain itself, is

the same as the set of all sets. And that set does not contain itself.

This set is a set, but it does not contain itself. It is exactly the

same with the natural numbers, BIGGEST+1 is a natural number, but it

does not belong to the set of all natural numbers. The set of all sets

is a set, but it does not belong to the set of all sets.

*>
*

*>> What the largest number is depends on how you define "natural number".
*

*>> One possible definition is that N contains all explicit numbers
*

*>> expressed by a human being, or will be expressed by a human being in the
*

*>> future. Amongst all those explicit numbers there will be one that is
*

*>> the largest. But this "largest number" is not an explicit number.
*

*>>
*

*>>
*

*> This raises a deeper question which is this: is mathematics dependent
*

*> on humanity or is mathematics independent of humanity?
*

*> I wonder what would happen to that human being who finally expresses
*

*> the largest number in the future. What happens to him when he wakes
*

*> up the next day and considers adding one to yesterday's number?
*

This is no problem. If he adds one to the explicit number he expressed

yesterday, then this new number is an explicit number, and the number

expressed yesterday was not the largest number. Both 17 and 17+1 are

explicit numbers.

Date: Thu, 04 Jun 2009 17:27:52 +0200

Brian Tenneson skrev:

How do you handle the Russell paradox with the set of all sets that does

not contain itself? Does that set contain itself or not?

My answer is that that set does not contain itself, because no set can

contain itself. So the set of all sets that does not contain itself, is

the same as the set of all sets. And that set does not contain itself.

This set is a set, but it does not contain itself. It is exactly the

same with the natural numbers, BIGGEST+1 is a natural number, but it

does not belong to the set of all natural numbers. The set of all sets

is a set, but it does not belong to the set of all sets.

This is no problem. If he adds one to the explicit number he expressed

yesterday, then this new number is an explicit number, and the number

expressed yesterday was not the largest number. Both 17 and 17+1 are

explicit numbers.

-- Torgny Tholerus --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list.domain.name.hidden To unsubscribe from this group, send email to everything-list+unsubscribe.domain.name.hidden For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---Received on Thu Jun 04 2009 - 17:27:52 PDT

*
This archive was generated by hypermail 2.3.0
: Fri Feb 16 2018 - 13:20:16 PST
*