On 2/17/2014 8:58 PM, Russell Standish wrote:
On Mon, Feb 17, 2014 at 07:30:23PM -0800, meekerdb wrote:
On 2/17/2014 7:09 PM, Russell Standish wrote:
On Mon, Feb 17, 2014 at 06:32:35PM -0800, meekerdb wrote:
On 2/17/2014 5:21 PM, Russell Standish wrote:
On Mon, Feb 17, 2014 at 02:03:49PM -0800, meekerdb wrote:
On 2/17/2014 1:55 PM, Russell Standish wrote:
On Mon, Feb 17, 2014 at 05:33:48AM -0800, Edgar L. Owen wrote:
Russell,
All of science assumes an external reality independent of human
observation.
Who says? I must have been asleep when they announced this in Physics
101! Actually, I'm pretty sure they never did.
I'd say science assumes that we can agree on observations. The
success of this hypothesis is generally taken as evidence for a
reality independent of human observation.
By whom?
Vic Stenger for one. Me for two.
and David Deutsch, for three, IIUHC. To which we can add Bruno Marchal and
myself against the obviousness of that idea.
But these are all rather unusual individuals, in a way.
That is a serious question. Of course, some scientists might
speculate about this down at the pub, and certainly there has been
some discussion along these lines on this list, but in everyday
science, everyone is trained as a positivist, and tends to act as
such, which is probably a worse syndrome than naive Aristotelianism.
The notion that there is a real reality there, with solid things like
tables and stones to stub your toes on has taken such a drubbing since
the beginning of the 20th century,
I'd say positivism has taken a lot more of a drubbing since Mach than realism.
Hmm - I'm not so sure. It was certainly the prevailing opinion back
when I was closer to fundamental physics research. The sort of stuff I
deal with now is much less abstract, though, so things like tables and
stones (or people and dollars) are fundamental objects of
analysis. Are people doing string theory utterly realist about the
stuff they do? Seems hard to imagine it.
There's a strong form of realism which says the real is whatever is
in the ontology of our best theory. I think that is a mistake and I
doubt anyone really holds that view. Of course it is our working
assumption at any given time, but that is true even when we're
pretty sure the theory is false. GR is our best theory of spacetime
and so we think gravity waves exist, but we don't think
singularities exist and consider GR almost certainly wrong. I think
scientific realists are all falibilists.
But there is a weaker form. However unlikely one thinks strings or
singularities or multiple-worlds are, one may still hypothesize that
there is *some* reality as the explanation for the intersubjective
agreement that is consistently observed.
Sure - one may hypothesise so. But does it assist in any scientific
experiment to do so? And is there any evidence to support the
hypothesis, or is it simply like pre-classical physics - good enough
to get the next meal.
The same kind of evidence as for any scientific theory. It not only assists, the
repeatability of experiments by persons with different minds tests it.
Just consider the contrast
with religions in which there is NOT intersubjective agreement about
visions and revelations.
The replacement of tables and chairs by atoms and then by wave
functions is just changing our best guess about ontology - it's not
evidence that there is no mind independent ontology. The fact that
there is intersubjective agreement on observations is still evidence
for a mutual reality.
Yes a mutual reality, but not a mind independent one.
Certainly independent of any single mind. And the science
formulated so far is independent of mind - which is why Liz supposed
that the past existed before it was observed (and constitutes a
block universe past).
Supposed, maybe, but certainly not evidence of it. Whose to say that
"our" past is not simply hewn out of the primordial Multiverse by our
observations, which progressively fix which world (and history) we inhabit?
Why "our" then; why not "my" and why not a brain is a vat? Why not nothing but a
momentary dream? Some hypotheses are more fruitful than others, lead to more predictions,
provide a more succinct model of the world.
that most everyday scientists usually
just focus on mathematical descriptions of phenomena, and leave it at that.
But if you ask them why mathematical descriptions are so successful?
Wouldn't they just point at Occam's razor, if they've thought about it
at all, that is? Or even go with Max Tegmark and say its all mathematics.
Mathematics is just a different substrate, a different but still
mind indpendent reality. Notice that the main argument given for
the reality of mathematics is the intersubjective agreement on the
truths of mathematics; which gives the feeling it is discovered
rather than invented.
Yes - but I really don't think this is Vic's, or David's view of a
mind-independent reality. But also see my comment below re COMP.
Or why do we all agree that's a chair over there?
That one is obviously convention. Someone from remote Amazonia who's
never seen a chair before wouldn't agree.
They might not agree on the name, but they would agree there was an
object there. The possibility of having a useable convention would
seem to be a miracle if there is nothing mind-indpendent that
correlates the perceptions of different persons.
The English language? Its clearly mind dependent, as there are minds
to whom English is complete gibberish.
?? I don't understand the point of this remark.
The existence of
some mind independent reality is always the working assumption.
Really? I don't think working scientists need to think about the issue
much at all.
Because it's an assumption so common they only question it unusual
experiments - like tests of psychics.
Assuming the assumption is common for the sake of argument, can you
think of a situation where that assumption has any bearing on the
experiment being performed?
Sure. The experimenters don't try to think special thoughts about or during the experiment
to influence the result - contrast prayer.
Whether they assume there is some kind of
mind-independent reality, or are outrageous solipsists would not
affect their ability to conduct experiments or do theory.
One could still assume a mind-independent reality while assuming
that one was the only mind. But they could not do either
experiments or theory if they assumed the result depended on what
they hoped or wished or expected.
I certainly have never asserted that. The reality we observe must be
compatible with our existence. Any observed reality must be compatible
with the existence of an observer. But we suppose that there are many
different possible observed worlds.
Real ones?
Some features of those worlds are
accidental ("mere geography"), and only shared by some worlds. Other
features are shared by all observable worlds (what we call
"physics"). The question is whether any feature shared by all possible
observed worlds
Is that possible worlds that are observed or worlds that might possibly be
observed?
is due to some reason other than the fact that
observers necessarily exist in those worlds. For there to be a mind
independent reality, there needs to be such a facts.
So a world must have physics that *permits* observers in order that it be our world. But
worlds don't have to have *geography* that permits observers, e.g. this universe between
inflation and the recombination. So they can be mind independent.
It is my position
that no such fact exists - but I'd love to be proved wrong, it would
make things "interesting".
I could believe that mathematical facts (about say the integers) could
fit that category, and thus be the basis of a fundamental
ontology. But even in COMP, we cannot distinguish between an ontology
of Peano arithmetic, or of Curry combinators, say. Once your ontology has
the property of Turing completeness, you could choose any such
ontology and be none the wiser. Doesn't this make the whole notion of
an ontological reality rather meaningless?
Then you would have structural realism.
Anyway, given some fact of our reality about which it is not known
whether it is necessary for the existence of an observer, how do we
distinguish between mind dependence (perhaps we may discover it to be
important later on when we have a better theory of consciousness),
mind independent physics or just mere geography?
You seem dismissive of geography, even though it includes us. It seems like a too
convenient move to deny realism.
Brent
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