On Mon, 28 May 2012 20:39:42 +0100, Peter Duncanson
wrote:

On Mon, 28 May 2012 19:37:23 +0100, Java Jive
wrote:

In my own words, I
would describe the problem thus:

A Big Bang universe must in some sense be finite, because it begins
with all the matter at a single point before it was flung out by the
explosion, and although it was flung out immensely fast, and even
allowing for the alteration of time under General Relativity, it must
have been with a finite velocity, and a finite amount of time has
elapsed since,

Is it not now considered that rather then matter being flung out
explosively it is space that has expanded taking fragmented matter with
it?

and therefore it can only have expanded by a finite
amount. So what happens at the 'edge' of it and beyond?

Yes. Note "in my own words", the use of the general word 'matter'
(though perhaps 'material' or 'fabric' would have been even better),
rather than specifically 'mass', and the quoting of the word 'edge'!
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Tim Streater wrote
(Richard Tobin) wrote
J G Miller wrote

Big Bang Theory is very definitely a full theory supported by hard
observational evidence no matter what Young Earth Creationist's and
other delusional religious nutters might have you believe.

Such as the life long atheist and Darwinist Fred Hoyle, FRS?

That would be the late Fred Hoyle, who developed his theories on the
subject before the compelling evidence we now have was available.

His Steady State hypothesis was reasonable for its time.

But he demonstrated the problem between his ears very graphically indeed
when he wasnt prepared to accept what the evidence later showed.

Richard Tobin wrote:

I don't think it's unusual for a aging scientist to remain attached to
one of their theories even once the evidence against is overwhelming.

I suppose that will happen with the global warming people once the truth
comes out.

Bill

Tim Streater wrote
Rod Speed wrote
J G Miller wrote
Martin Brown wrote

Big Bang Theory is very definitely a full theory supported by hard
observational evidence no matter what Young Earth Creationist's
and other delusional religious nutters might have you believe.

Such as the life long atheist and Darwinist Fred Hoyle, FRS?

He's notorious for some VERY nutty stuff.

OTOH he worked out how stars do fusion. And that the nucleus of the
carbon atom must have a resonance at a certain energy, to permit the
fusion process to work. When he asked some particle physicists to verify
this, they laughed at him first of all, until they did the experiment
and showed him to be correct.

http://en.wikipedia.org/wiki/Triple-alpha_process

Which just shows that those arent necessarily mutually exclusive.

Rutherford also did some very useful stuff and then made a
complete fool of himself when he proclaimed that nothing of
any practical value would ever come out of nuclear physics, just
before the atom bomb and modern semiconductors showed up.

And Einstein proclaimed that god does not play dice with the universe.
Pity about radioactive decay.

Peter Duncanson wrote:
On Mon, 28 May 2012 19:37:23 +0100, Java Jive
wrote:

Very interesting. Thanks for the following.

I've interpolated a question further down.

As it happens, I met Prof Hoyle, I think it would have been in the
60s. He came to tea and/or dinner at our house. Although, from this
brief meeting and even now that we know he was wrong, I wouldn't
presume to speak for him, paraphrase him, or put words in his mouth -
people should read his own work if they want to understand his
reasoning - as I was then, as now, interested in Astronomy, he and I
talked for a while about the two opposing theories, for which, at that
time, there was considered insufficient evidence to confirm or reject
either.

AIUI, one of Hoyle's criticisms of the Big Bang Theory was a
philosophical one, based on its incompleteness. In my own words, I
would describe the problem thus:

A Big Bang universe must in some sense be finite, because it begins
with all the matter at a single point before it was flung out by the
explosion, and although it was flung out immensely fast, and even
allowing for the alteration of time under General Relativity, it must
have been with a finite velocity, and a finite amount of time has
elapsed since,

Is it not now considered that rather then matter being flung out
explosively it is space that has expanded taking fragmented matter with
it?


make little difference really.

and therefore it can only have expanded by a finite
amount. So what happens at the 'edge' of it and beyond? The theory
can tell us nothing about that, and for many opponents of it, I
believe including Hoyle, this was profoundly dissatisfying and a major
objection to it.

To me then and since, one possible answer has always seemed 'obvious',
that our universe is just one among possibly infinitely many others,
and, although I dare say that many others possibly before and
certainly since have come up with this idea, as far as I was concerned
then, it was an original idea of my own, and therefore I mentioned it.
He seemed genuinely surprised at this turn in the conversation, as if
that possibility had never occurred to him, and then clammed up
rather, as if unwilling to discuss the subject further. Perhaps he
thought I was just a young smart-arse trying to catch him out, and/or
that it was beneath his dignity to discuss something with someone who
didn't have sufficient in depth knowledge of the facts of the subject,
or perhaps he had no interest in debating what was mostly a
philosophical point - it is difficult to see how one could test for
other universes beyond the limits of our own - but in truth I really
don't know why.

At any rate, we do know now that the Steady State Theory was wrong.


Well we know that the best fit story we can tell about the (physical)
universe starts with a bang.

As far as we can conjectu whether space and time came into being then
or not is a moot question.






--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On 29/05/2012 00:05, The Natural Philosopher wrote:
Peter Duncanson wrote:
On Mon, 28 May 2012 19:37:23 +0100, Java Jive
wrote:

A Big Bang universe must in some sense be finite, because it begins
with all the matter at a single point before it was flung out by the
explosion, and although it was flung out immensely fast, and even
allowing for the alteration of time under General Relativity, it must
have been with a finite velocity, and a finite amount of time has
elapsed since,

Is it not now considered that rather then matter being flung out
explosively it is space that has expanded taking fragmented matter with
it?

make little difference really.

Actually it makes quite a big difference. Most people imagine before the
big bang as space with nothing in it. The reality of our equations are
correct is a void of no space or time with spacetime still as yet
undefined at a singularity. We can go back to miniscule fractions of a
second after the event, but never quite to zero as the energies then
become so great that our knowledge of the physics breaks down.

and therefore it can only have expanded by a finite
amount. So what happens at the 'edge' of it and beyond? The theory
can tell us nothing about that, and for many opponents of it, I
believe including Hoyle, this was profoundly dissatisfying and a major
objection to it.

To me then and since, one possible answer has always seemed 'obvious',
that our universe is just one among possibly infinitely many others,
and, although I dare say that many others possibly before and
certainly since have come up with this idea, as far as I was concerned
then, it was an original idea of my own, and therefore I mentioned it.
He seemed genuinely surprised at this turn in the conversation, as if
that possibility had never occurred to him, and then clammed up
rather, as if unwilling to discuss the subject further. Perhaps he
thought I was just a young smart-arse trying to catch him out, and/or
that it was beneath his dignity to discuss something with someone who
didn't have sufficient in depth knowledge of the facts of the subject,
or perhaps he had no interest in debating what was mostly a
philosophical point - it is difficult to see how one could test for
other universes beyond the limits of our own - but in truth I really
don't know why.

At any rate, we do know now that the Steady State Theory was wrong.


Well we know that the best fit story we can tell about the (physical)
universe starts with a bang.

As far as we can conjectu whether space and time came into being then
or not is a moot question.

Whilst string theory holds out the possiblity that our +++- signature
observable universe is the result of a collision between two higher
dimensional entities its predictive power is somewhat limited. And any
new more complete theory would still have to explain all the existing
observational data about the evolution of the universe with time.

http://www.edge.org/3rd_culture/turo...k07_index.html

The first thing that really made the astronomical community realise that
the early universe was a much more violent place as radio astronomy then
in its infancy could see very much further than optical astronomers.
Ironically an experiment that Hoyle himself suggested doing to
distinguish between the two competing theories. Cygnus A is one of the
brightest and largest objects in the radio sky after the sun and yet it
has a puny looking optical component in the middle. It is our nearest
extremely violent active radio galaxy.

A nice history of this period is online at the Chandra website:
http://chandra.harvard.edu/chronicle/0101/cyga1.html


--
Regards,
Martin Brown

"The Natural Philosopher" wrote in message
...
J G Miller wrote:
On Monday, May 28th, 2012, at 09:40:30h +0100, Martin Brown wrote:

Big Bang Theory is very definitely a full theory supported by hard
observational evidence no matter what Young Earth Creationist's and
other delusional religious nutters might have you believe.

Such as the life long atheist and Darwinist Fred Hoyle, FRS?
Well yes and no..

The big bang is a theory which is not refuted by the evidence, that's all.

So actually is Creationism. God could as easily created a universe
complete with a fake fossil record and all conditions just right to LOOK
as though it was much older etc. etc.

William of Occam might have had something to say about that...

The problem is that is an irrefutable theory* and hence according to
Popper, metaphysical, not scientific. And its not actually a useful
theory either - it makes no predictions at all.

--
Max Demian

Max Demian wrote:
"The Natural Philosopher" wrote in message
...
J G Miller wrote:
On Monday, May 28th, 2012, at 09:40:30h +0100, Martin Brown wrote:

Big Bang Theory is very definitely a full theory supported by hard
observational evidence no matter what Young Earth Creationist's and
other delusional religious nutters might have you believe.
Such as the life long atheist and Darwinist Fred Hoyle, FRS?
Well yes and no..

The big bang is a theory which is not refuted by the evidence, that's all.

So actually is Creationism. God could as easily created a universe
complete with a fake fossil record and all conditions just right to LOOK
as though it was much older etc. etc.

William of Occam might have had something to say about that...


A much misquoted man. From a time when science was called Natural
Philosophy and people actually understood what it was and what they were
doing with it.

Occams razor implies that no theory has truth content. It tacitly
accepts that all theories are just conjecture, and therefore the
pragmatic thing to do is select the one that is easiest to use.


And Occam's razor itself is context sensitive: In the context of some
peoples worldview, the thought of a massive explosion that set time and
space ticking is far far more preposterous and unnecessary than a
supernatural being who sat there with his PC and designed a universe as
an act of pure love and creativity...

Metaphysical theories are free issue: everybody has to have one, in
order to put structure into their experience. It is the assumption of
the Material Realist that Natural Laws exist, but are blind and
mechanical. And that the overarching principle of the Universe is
causality expressed through time varying development

There is as little reason to believe that is true as there is for a sky
fairy.

One merely notes that it has better predictive results. But one also
notes that its predictions apply to the metaphysical structure it itself
defines: That is, if you believe it, and use it, it works, but that may
be no more than a self fulfilling prophecy.






The problem is that is an irrefutable theory* and hence according to
Popper, metaphysical, not scientific. And its not actually a useful
theory either - it makes no predictions at all.



--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

dennis@home wrote:


"The Natural Philosopher" wrote in message
...

Ideas about the world are not the same as the world-in-itself**.

I hope you remember that the next time you try arguing with me about the
*theory* of relativity.

Dennis, a different rule ap[plies when talking to you.
"Ideas about a theory are not the same as understanding what the theory
itself says"

If the theory is one step removed from the reality, the dennis view of
the theory is several steps beyond that.




--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.