On 6/5/2015 4:29 PM, Bruce Kellett wrote:
meekerdb wrote:
On 6/5/2015 12:22 PM, John Clark wrote:
On Fri, Jun 5, 2015 , meekerdb <[email protected] <mailto:[email protected]>>
wrote:
>> It's very relevant if you want to know what is a simplified
approximation of what. And we both agree that a electronic
computer is vastly more complex than it's logical schematic,
so why can we make a working model of the complex thing but
not make a working model of the simple thing when usually it's
easier to make a simple thing than a complex thing? The only
answer that comes to mind is that particular simplified
approximation is just too simplified and just too approximate
to actually do anything. That simplification must be missing
something important, matter that obeys the laws of physics.
> The trouble with this argument is that the laws of physics are
mathematical abstractions.
Mathematicians are always saying that mathematics is a language, but what would be the
consequences if that were really true? The best way known to describe the laws of
physics is to write then in the language of mathematics, but a language is not the
thing the language is describing.
I agree the laws of physics are descriptions we invent; but even so they are
abstractions and not material and what they define is only an approximation to what
happens in the world. That's what makes them useful - they let us make predictions
while leaving out a lot of stuff.
So what is this "lot of stuff" that the mathematical abstractions leave out? In response
you your initial point that "the laws of physics are mathematical abstractions", the
obvious questions is "Abstractions from what?"
Abstractions from physical events. We find we can leave out stuff like the location (and
so conserve momentum) and the position of distant galaxies and the name of the
experimenter and which god he prays to etc. Of course what we can leave out and what we
must include is part of applying the theory. Physicists work by considering simple
experiments in which they can leave out as much stuff they're not interested in as
possible in order to test their theory. Engineers don't get to be so choosy about what's
left out; they have to consider what events may obtain. But they also get to throw in
"safety factors" to mitigate their ignorance.
Brent
Bruce
--
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/d/optout.
