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PostPosted: Sat Jun 26, 2010 8:34 am 
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Everett's "many worlds theory" (or should that be hypothesis?) is supposed to account for why a single particle can pass through two slits at the same time.
When you rise from your armchair, you divide into two Cliffs, but neither of you are aware of the other's existence. Both Cliffs are grumpy old codgers, so nothing changes in that respect.
One Cliff grumbles: "Don't tell me about football!"; the other Cliff grumbles: "Don't tell me about astronomy!" :wink:

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Last edited by brian livesey on Mon Jun 28, 2010 3:37 pm, edited 1 time in total.

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PostPosted: Sun Jun 27, 2010 1:39 pm 
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Dear Brian
I think you are at least partly right !
These days when I try to sit back down again, me now being a bit slower, I suspect the other me gets down on the armchair a bit more quickly which is the problem. When I was younger I probably got down a bit quicker and so it was the other me that had the problem.
As regards astronomy I think if you take cosmology out of it I have no big problem.
Astronomy and cosmology seem to equate to matter and antimatter.
When I first got interested in astronomy I never heard of anti-matter (although I'm sure those more knowledgable and less naive knew something about it).
Nowadays antimatter seems to be taken for granted. They tell us that for some not as yet fully understood reasons - matter seems slightly more domminant (or at least usually).
With regards to football, I do have one claim to footballing fame.
Not being a very good footballer I was only a second choice player for my school house team. However, I got picked for a crunch match when
we played the favourites to win the house championship. The other team had several star players included one who eventually played for Man Utd and even got capped for England. They were all over us for 85 minutes but despite my efforts we won 1 - nil.
We were the champions - as the well known pop song says.
I sometimes think cosmological theory is a bit analagous to football.
There was a time when shirt pulling would not have been
acceptable in British football, Nat Lofthouse would have just knocked 'em flying,but now our footballers pull their opponents shirts with gusto with
the best of 'em.
Plug a cosmological theory enough and everybody thinks its wonderful.
Next thing you know cosmologists will start playing with a new ball, that'll really mess things up again.
Best wishes from Cliff
PS They're just out on the field about now.... Engerland ! ENGERLAND !!!!


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PostPosted: Mon Jun 28, 2010 9:03 am 
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You know more about football than I do, Cliff. Frankly, I don't find it very edifying to watch millionaires kicking a ball round a field. :wink:

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PostPosted: Mon Jun 28, 2010 8:28 pm 
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Dear Brian
Neither do I !
I think football's a good game but that's as far as it goes.
One of my old bosses was friends at University with a chap who became a TV football pundit. My old boss an amateur footballer and club secretary asked his old university "friend" to give an after dinner speach at the amateur clubs annual dinner.
"How much will the club pay me ?"
"We don't pay our after dinner speakers."
That was the end of their friendship.
The TV pundit went on to be a big noise in the FA. He was on telly yesterday making excuses for Engerland's poor performance.
I rate UK (professional) football much lower than cosmology.
Best wishes from Cliff


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PostPosted: Tue Jun 29, 2010 9:48 am 
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To cap it all, Cliff, now we have hard-nosed, industrial, tennis to cope with.
One of Everett's other worlds would be better for the likes of you and me: where the losers are the winners. :wink:

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PostPosted: Tue Jun 29, 2010 10:43 am 
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Is there any point in me suggesting you move back on topic? :?

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PostPosted: Tue Jun 29, 2010 12:52 pm 
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Maybe we've run out of contributors, Joe. How do you feel about the comments made by Martin Rees?
Do you think that human comprehensibility has reached it's limits? Or do you take the view held by some of us that it's still early days?

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PostPosted: Wed Jun 30, 2010 11:59 am 
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Hi,
I'm in no position to slight anyone (esp. scientists, cosmologists, etc., I've just got my own seat on the fence ).
Now I have got the most respect for Lord Rees but reading some of the posts ('defeatist' comes to mind, M54's post), it makes one think and could open up a whole new debate.
Whilst I have been 'laid up' with health problems (can manage to hobble outside for sat. observations) I have been doing a lot of reading about Lord Rees and I came across this item from several years ago.

http://news.bbc.co.uk/1/hi/in_depth/uk/ ... 976279.stm

All the best.
Dave

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PostPosted: Thu Jul 01, 2010 9:53 am 
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brian livesey wrote:
Do you think that human comprehensibility has reached it's limits? Or do you take the view held by some of us that it's still early days?

I can't believe it has reached its limits but I really haven't thought long and hard about it. I have great respect for Rees and I wouldn't write off any of his opinions (in cosmology).

I haven't seen or read the interview but will there come a time when we do reach our limits? If so, why not now or in the very near future?

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PostPosted: Thu Jul 01, 2010 12:52 pm 
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There is a sense in which we can never have complete knowledge, but not in the way that Rees means it. For him, the limit seems to be set by the physical nature of the brain, but he would need to produce evidence to show this limitation.
On the other hand, knowledge can never be complete because we live in an evolving universe, so there are always new phenomena to discover.
By the way, Joe, were is Dave (ep) these days? This is the sort of debate that would appeal to him.

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PostPosted: Thu Jul 01, 2010 1:02 pm 
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brian livesey wrote:
On the other hand, knowledge can never be complete because we live in an evolving universe, so there are always new phenomena to discover.
By the way,Joe, were is Dave (ep) these days? This is the sort of debate that would appeal to him.

There is always something else to discover but will it always push the limits? Will new discoveries add a new chapter to our knowledge or just bloat the same old chapters already written?

brian livesey wrote:
By the way,Joe, were is Dave (ep) these days? This is the sort of debate that would appeal to him.

D'you mean davep? I haven't noticed him around much but he may be popping back every now and then. I think he has demands on his time elsewhere, but I don't really know.

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PostPosted: Thu Jul 01, 2010 1:23 pm 
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Modern science takes a dialectical view of nature: that everything is in the process of becoming something else. This means that the "old chapters"of knowledge eventually fall away like the dead branches of a tree, while new branches represent new chapters of knowledge amounting, in effect, to new books.
Martin Rees isn't the only scientific notable to preach a doomsday scenario for humanity.
In fact, a growing doomsday mentality has sometimes signalled the more-or-less rapid decline of a civilisation and the emergence of a new one in its place; as with the Late Roman Empire, when its citizens literally thought the end of the world was nigh, until they stepped into feudalism.
Yes, Joe, I do mean davep. I was under the impression that you were personal friends. He might still be on DU. :wink:

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PostPosted: Thu Jul 01, 2010 2:06 pm 
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brian livesey wrote:
Yes, Joe, I do mean davep. I was under the impression that you were personal friends. He might still be on DU. :wink:

We were "virtual friends", but he has cut back on visits here and I have cut back on visits to DU. We don't bump into each other much these days. It's nothing personal. :D

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PostPosted: Fri Jul 02, 2010 8:00 pm 
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Dear al(L)
This may be a silly question.
However, it occurs to me that light supposedly travels at 300,000 km\sec in a vacuum. However, I think true vacuums are pretty rare and I gather no one has succeeded in producing a true vacuum in any laboratory but I also gather that some gas\dust clouds observed in space (indeed perhaps most of them are more tenuous than our laboratory vacuums.
That being so I suppose space though not a true vacuum is "thin" enough not to affect the speed of light much.
That said though there is now another possible additional factor that might affect the speed of light on its journey through space ie dark matter.
If I recall correctly ordinary matter accounts for less than 5% of stuff in the universe, Dark Matter accounts for roughly 25% of the rest. So I wonder if the speed of light travelling in the vicinity of dark matter is affected in any way.
Then there's that other thing Dark Energy, I wonder what if any affect that might have on the speed of light.
Even if the speed of light is altered by these things - does it mater ?
Or does it result in us getting a totally distorted view of what the universe is really like ?
If ordinary matter only accounts for a few percent of the universes stuff then perhaps our current understanding of cosmology is way off target ?
Best wishes from Cliff
Best of luck from Cliff


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PostPosted: Mon Jul 05, 2010 9:55 am 
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As you know, Cliff, results in cosmology depend on an accumulation of data. Orbiting observatories are doing good service in this respect.
I don't see why we should describe baryonic matter as "ordinary" matter, as if to downgrade it.
Maybe we should call baryonic matter "super-matter", seeing that Nature's most complex creations are made of it, including grumpy old codgers. :lol:

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