On 19 Jan 2014, at 04:05, meekerdb wrote:
On 1/18/2014 1:09 AM, LizR wrote:
On 18 January 2014 19:51, meekerdb <[email protected]> wrote:
On 1/17/2014 10:18 PM, LizR wrote:
On 18 January 2014 19:12, meekerdb <[email protected]> wrote:
But where does it exist? X has to be conscious of a location, a
physics, etc. If all this is the same as where I exist, then it
is just a translation of this world into arithmetic. It's the
flip side of "A perfect description of X is the same as X", i.e.
"X is the perfect description of X". If every perfect description
is realized somewhere in arithmetic (and I think it probably is)
nothing is gained by saying we may be in arithmetic.
Don't we gain less entities, making Occam a bit happier? If we can
get the appearance of a universe without having to actually have
one, can't we "retire the universe" and just stick with the
"appearance-of-one-with-equal-explanatory-value" ? (Not an
original idea, of course, I'm fairly sure Max Tegmark said
something along those lines regarding his mathematical universe
hypothesis -- that if the maths was isomorphic to the universe,
why bother to assume the universe was physically there?).
I'm asking why have the maths?
Well (putting on my AR hat) we have it because the maths is
necessarily existent, while the universe isn't.
I disagree. The maths are necessarily true, i.e. "axioms imply
theorems" is true.
OK.
But why should that imply *existence*.
It does not. Unless we believe in the axioms, which is the case for
elementary arithmetic. But then we believe in the existence of prime
numbers, and in the many relative computational states.
We know we can invent all kinds of maths by just changing the axioms
or even changing the rules of inference.
OK. But note that we don't do that for arithmetic, except by adding
axioms, or using another theory.
Sometimes people on this list post the semi-mystic opinion that
everything=nothing, pointing to the need for discrimination. I look
at this as saying positing everything is the same as saying nothing.
I agree. But searching a theory, we have to define the things first.
then in some theory the "nothing" can appear to be already Turing
complete, so that in that frame, the nothing theory get incarnated.
In classical physics you need at least three bodies to get Turing
universality.
In quantum mechanics the vacuum is already Turing complete. For example.
Of course there's an answer - we can manipulate the maths - but
then doesn't that proves that the maths aren't the universe. They
wouldn't be any use as predictive and descriptive tools if they
WERE the things described. They are only useful because they are
abstractions, i.e. they leave stuff out (like existence?).
Well .... the maths does have that "unreasonable
effectiveness" (that you're probably bored to death hearing about).
And one reason for that could be because it is - in the guise of
some yet-to-be-discovered TOE - isomorphic to the universe.
Or it could be because we, denizens of this physics/universe, invent
them.
But that's the case we have to explained why they work or seem top
work, it seems to me.
Bruno
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/groups/opt_out.
