Bill Hobba wrote:


Basically we still do not really know.

But this we do know: The notion of algorithm (computable functions on
integers) on the integers is well defined. Refer to any text book on
computable functions.

Bob Kolker

Bjoern Feuerbacher wrote in message ...
Donald Hamilton wrote:
"robert j. kolker" wrote in message ...

Donald Hamilton wrote:

Do you think the "laws of nature" change over time? I'm talking about
the laws not the conditions. It would have been a very different
universe without inertia, gravity & electromagnetic energy to guide
matter.

See -The Life of the Cosmos- by Lee Smolin. He conjectures that the
kosmos is evolving and that the "laws of physics" change over time.

Bob Kolker


My idea of the "physical laws of nature" are - it is the framework of
the universe that creates and guides all matter and energy. It is the
timeless, invariant phenomena that creates space and gives the
universe its personality.

Well, you might consider that these same, unchanging physical laws
might *look* quite differently under different circumstances.

Compare e.g. the time before the electroweak symmetry breaking with
the situation today... One can argue that both are governed by the same
laws - but due to the different circumstances (he different
temperature), the outcome is quite different!


Bye,
Bjoern

I said in a previous post that the conditions may change but
the "laws" never do. Everything operates within the framework of these
invariant laws of nature. Physicists are restricted to discovering and
working within the physical laws whereas philosophers can go beyond
into the realm of metaphysics.

donham
http://novan.com

"robert j. kolker" wrote in message
...


Bill Hobba wrote:


Basically we still do not really know.

But this we do know: The notion of algorithm (computable functions on
integers) on the integers is well defined. Refer to any text book on
computable functions.

Agreed - but that was not my point. My point was that algorithm in a
general sense still has issues with a 'bulletproof' definition. But it is
not the only thing - simply and example of many things like that,
specifically, in the context of my post, I was pointing out laws of nature
are like that.

Thanks
Bill


Bob Kolker

Bill Hobba:

'And there is more, much more to an algorithm than the function it computes.
The thesis was a great step toward understanding algorithms, but it did not
solve the problem what an algorithm is.'


Here's what I have (from vitanyi and li) as church's thesis:

``The class of algorithmically computable functions (in the intuitive
sense) coincides with the class of partial recursive functions.''

"Bilge" wrote in message
...
Bill Hobba:

'And there is more, much more to an algorithm than the function it
computes.
The thesis was a great step toward understanding algorithms, but it did
not
solve the problem what an algorithm is.'


Here's what I have (from vitanyi and li) as church's thesis:

``The class of algorithmically computable functions (in the intuitive
sense) coincides with the class of partial recursive functions.''


A few years ago did some work on data mining and read about adaptive
compression algorithms that led me to Kolmogorov Complexity by Vitanyi and
Li. Do not quite remember the above but then again I found it a bit heavy
going. Still nice quote - very nice.

Thanks
Bill

"Donald Hamilton" wrote in message
om...
Bjoern Feuerbacher wrote in message
...
Donald Hamilton wrote:
"robert j. kolker" wrote in message
...

Donald Hamilton wrote:

Do you think the "laws of nature" change over time? I'm talking about
the laws not the conditions. It would have been a very different
universe without inertia, gravity & electromagnetic energy to guide
matter.

See -The Life of the Cosmos- by Lee Smolin. He conjectures that the
kosmos is evolving and that the "laws of physics" change over time.

Bob Kolker


My idea of the "physical laws of nature" are - it is the framework of
the universe that creates and guides all matter and energy. It is the
timeless, invariant phenomena that creates space and gives the
universe its personality.

Well, you might consider that these same, unchanging physical laws
might *look* quite differently under different circumstances.

Compare e.g. the time before the electroweak symmetry breaking with
the situation today... One can argue that both are governed by the same
laws - but due to the different circumstances (he different
temperature), the outcome is quite different!


Bye,
Bjoern

I said in a previous post that the conditions may change but
the "laws" never do.

Hmmmm. Let us look at Ohms law. Does it change - well a diode does not
obey it. But wait - a diode is not a resistor - so Ohms law only apples to
resistors. But what is a resistor - why something that obeys ohms law.

What about Newton's first law - An object at rest tends to stay at rest and
an object in motion tends to stay in motion with the same speed and in the
same direction unless acted upon by a force. But wait a minute does it not
follow from Newton's second law? But is that not a definition anyway so
what is the physical content of the first law? Well to cut a long story
short its content is that frames exist in which particles obey Newtons first
law - these are called inertial frames. But wait a minute - have we ever
found one that is strictly inertial - no. So how can nature be determined
by the existence of things that do not actually exist and how can such gain
the status of law? Indeed from QM how can we know that a particle has
constant velocity anyway?

Everything operates within the framework of these invariant laws of
nature.

Like Ohms law and Newton's first law right?

Physicists are restricted to discovering and working within the physical
laws

Physicists are restricted to the scientific method - end of story. If that
coincides with your idea of 'physical law' or not is an irrelevancy.

whereas philosophers can go beyond into the realm of metaphysics.

You mean like Hegel who said;

'But what is Spirit? It is the one immutably homogeneous Infinite - pure
Identity - which in its second phrase separates itself from itself and makes
this second aspect its own polar opposite, namely as existence for and in
Self as contrasted with the Universal. '

Philosophy often looks a lot like unintelligible bull.

Bill


donham
http://novan.com

wrote in message ...
| Gerry Quinn wrote:
|
| In article , says...
| Donald Hamilton wrote:
|
| Since the BB was a physical event there must have been some physical
| laws in place before, for the event to occur - don't you think.
|
| The big bang is a singularity in non-quantum physics. There
| don't have to be any laws in place since the theory predicts
| a singularity.
|
| Theories that predict singularities need to be replaced by non-broken
| theories. After this is done, the range of matters discussable in
| available theory extends into (and maybe past) the regions previously
| described as singularities.
|
| Some day, likely enough, there will be a consensus on matters pertaining
| to the time now referred to as the Big Bang singularity.
|
| Depending on how that theory considers time, it may or may not have
| something to say about what happened before.
|
|
| No problem. But us show/or not such a theory.
|
| Telling us that there may or may not be such a theory
| is telling us nothing.
|
| My point in responding to the original poster is
| that his question is meaningless in the context
| of the theory that predicted the singularity in
| the first place.
|
| Next time you want to post, post something
| that makes sense, please!
|
| John Anderson
You wouldn't know sense if it bit you in the arse.


The Seven Deadly Sins of Special Relativity.

For quotations following, reference:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
("On the Electrodynamics of Moving Bodies" by Albert Einstein)

1) "light is always propagated in empty space with a definite velocity c
which is independent of the state of motion of the emitting body",
a totally unproven assumption without any evidence to support it.

2) "In agreement with experience we further assume the quantity
2AB/(t'A-tA) = c to be a universal constant- the velocity of light in empty
space.",
an admitted assumption that is quite worthless when there is any
relative motion between A and B, yet essential to the derivation of the
remainder of Einstein's nonsense.

3) The equation
½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)) ,
the ½ of which is derived from 2) above and is tantamount to saying
(1/3 + 2/3)/2 = 1/3.

4) The missing 0' from that equation, since x' = x-vt, hence 0' = 0-vt,
and the equation should be
½[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v))
at the very least.

5) The further assumption "IF we place x' = x-vt ... " without considering
IF we place x' = x+vt, from which we derive (using Einstein's method)
tau = (t+xv/c^2)/sqrt(1-v^2/c^2)
xi = (x + vt)/sqrt(1-v^2/c^2)" -Paul B. Andersen

6) The statements
"But the ray moves relatively to the initial point of k,
when measured in the stationary system, with the velocity c-v..."
and
"It follows, further, that the velocity of light c cannot be altered by
composition with a velocity less than that of light. For this case we obtain
V = (c+w)/(1+w/c) = c."
which are contradictory, the first being Galilean, the second being
contrary to the vector addition of velocities, an axiom of a vector space.

7) The lack of a check to verify the theory is self-consistent by feeding
the new PoR given in 6) into the equation given in 3) and finding a total
failure.
Check:
(t1-t)/(t2-t)*[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/V+x'/V)] = tau(x',0,0,t+x'/V)

Androcles.