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RE: The universe appears "old", but it is still less than 10,000 years old
February 19, 2014 at 9:17 am
(This post was last modified: February 19, 2014 at 9:27 am by Alex K.)
(February 19, 2014 at 9:13 am)Zen Badger Wrote: (February 19, 2014 at 9:07 am)Alex K Wrote: Well, all I can say is what I say above 
The trouble with special relativity is that for two events in spacetime which are too far apart to be connected causally, there is no unique notion of which happened before or after the other. In standard SRT synchronization, it depends only on the relative speed of the observer (not on relative position) which of the two events happens first. This ambiguity in temporal order of causally disconnected events can be exploited to further drop the shared timeframe which is usually assumed at least for observers at rest to each other.
To summarize the whole thing: if you strip away the mathematical shenanigans, what Waldorf wants us to do is the following: you observe light from Andromeda tonight - let's call the moment in time on Andromeda when it left there "now" rather than "3 million years ago", and act as if no further time had passed on Andromeda after the departure of this light - this is in principle a completely skewed, but consistent way to view the world because nothing that happened after that on Andromeda is causally connected to us yet.
I understand all of that.
But that is simply a case of perception. It's doesn't mean that it is what is actually happening.
And it doesn't mean that the light from Andromeda got here instantly.
It still took it 2.2 million years to complete the journey, no matter how we wish to view it.
There is no concept of "what is actually happening" with any grounding in evidence beyond what is expressed by our scientific models. It seems to me like you desperately want to remain in a baroque era intuition of reality onto which all the new stuff is just grafted on, but with an actual absolute space and time and deterministic reality lurking beneath Relativity and Quantum Theory. That's not how it is, if you want to say "it took 2.2 million years", you have to put a little imaginary footnote which specifies within which theoretical framework and for which observer this statement is to be interpreted. This is already the case without nonisotropic synchronization nonsense: in general relativity, someone sitting on the surface of jupiter will measure a different time passing than someone floating in space. This difference will be rather minuscule, but that's not the point.
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RE: The universe appears "old", but it is still less than 10,000 years old
February 19, 2014 at 8:38 pm
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RE: The universe appears "old", but it is still less than 10,000 years old
February 19, 2014 at 8:53 pm
Not to put the gentlemen on the spot, but I for one would enjoy seeing a formal debate between Alex K and Statler, if only to keep the discussion entirely on topic and without distractions. I admit that I am completely out of my element when it comes to relativistic physics, but I think the discussion would be fascinating and fruitful.
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RE: The universe appears "old", but it is still less than 10,000 years old
February 19, 2014 at 11:50 pm
(February 19, 2014 at 8:53 pm)Crossless1 Wrote: Not to put the gentlemen on the spot, but I for one would enjoy seeing a formal debate between Alex K and Statler, if only to keep the discussion entirely on topic and without distractions. I admit that I am completely out of my element when it comes to relativistic physics, but I think the discussion would be fascinating and fruitful.
That’s a great idea and I’d be open to doing something like that on a bit broader subject since this is not my area of study and work. My expertise is in Environmental Science and Geospatial Science so I am certainly no expert on relativistic physics. I did have a few courses on it in University and taught General Physics it at the High School level but I think Alex definitely possesses more knowledge on the subject matter.
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RE: The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 1:04 am
the yec attempt to misuse the genesis genealogies as a time-keeping, age dating device to establish adam and eve appearance and arrive at 6000 years and their hyper-literalism scripture interpretation of the six days of creation prevents them from harmonizing the biblical account with unequivocal proven scientific data putting the earth's age around 4.6 billion years.
Atheist Credo: A universe by chance that also just happened to admit the observer by chance.
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The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 1:13 am
(February 19, 2014 at 11:50 pm)Statler Waldorf Wrote: (February 19, 2014 at 8:53 pm)Crossless1 Wrote: Not to put the gentlemen on the spot, but I for one would enjoy seeing a formal debate between Alex K and Statler, if only to keep the discussion entirely on topic and without distractions. I admit that I am completely out of my element when it comes to relativistic physics, but I think the discussion would be fascinating and fruitful.
That’s a great idea and I’d be open to doing something like that on a bit broader subject since this is not my area of study and work. My expertise is in Environmental Science and Geospatial Science so I am certainly no expert on relativistic physics. I did have a few courses on it in University and taught General Physics it at the High School level but I think Alex definitely possesses more knowledge on the subject matter. :angel:
What university? Brigham Young?
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RE: The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 4:49 am
(This post was last modified: February 20, 2014 at 5:15 am by Alex K.)
(February 19, 2014 at 8:53 pm)Crossless1 Wrote: Not to put the gentlemen on the spot, but I for one would enjoy seeing a formal debate between Alex K and Statler, if only to keep the discussion entirely on topic and without distractions. I admit that I am completely out of my element when it comes to relativistic physics, but I think the discussion would be fascinating and fruitful.
Sounds like fun, but I'd like to prepare somewhat for such an endeavour, and work doesn't allow that currently, maybe next week.
Can you in the meantime propose a topic? It's not obvious to me what the topic of a debate would be. "Is the universe less than 10000 years old"?
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RE: The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 5:26 am
(February 19, 2014 at 9:17 am)Alex K Wrote: (February 19, 2014 at 9:13 am)Zen Badger Wrote: I understand all of that.
But that is simply a case of perception. It's doesn't mean that it is what is actually happening.
And it doesn't mean that the light from Andromeda got here instantly.
It still took it 2.2 million years to complete the journey, no matter how we wish to view it.
There is no concept of "what is actually happening" with any grounding in evidence beyond what is expressed by our scientific models. It seems to me like you desperately want to remain in a baroque era intuition of reality onto which all the new stuff is just grafted on, but with an actual absolute space and time and deterministic reality lurking beneath Relativity and Quantum Theory. That's not how it is, if you want to say "it took 2.2 million years", you have to put a little imaginary footnote which specifies within which theoretical framework and for which observer this statement is to be interpreted. This is already the case without nonisotropic synchronization nonsense: in general relativity, someone sitting on the surface of jupiter will measure a different time passing than someone floating in space. This difference will be rather minuscule, but that's not the point.
Hmmm, let me try this another way.
Light speed in not instantaneous.
Are we agreed on that point?
![[Image: mybannerglitter06eee094.gif]](https://images.weserv.nl/?url=i118.photobucket.com%2Falbums%2Fo112%2Fpussinboots_photos%2FBikes%2Fmybannerglitter06eee094.gif)
If you're not supposed to ride faster than your guardian angel can fly then mine had better get a bloody SR-71.
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RE: The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 5:47 am
(This post was last modified: February 20, 2014 at 7:23 am by Alex K.)
(February 19, 2014 at 8:38 pm)Statler Waldorf Wrote: Quote:We can for example indirectly measure the temperature of the cosmic microwave background as seen by gas millions - billions of lightyears away, and can directly see that the universe is warmer by the expected amount. And so on and so forth. There is no way around the big bang 
More reluctance to give specifics; how is something being “warmer by the expected amount” support for the big bang? Sounds like hand waiving to me.
Hand waiving? That's a new debate tactic I was not aware of. I wash my hands of it, though.
Anyhow, don't try to accuse me of shying away from specifics if your argument relies on me actually doing so.
In an expanding universe a la FLRW, the temperature of the cosmic microwave background ist inversely proportional to the scale factor due to redshift by expansion. At the same time, the redshift we observe from distant objects is the difference between the scale factor now and at the time and place of light emission.
So, if we would find a way to measure the temperature of the cosmic microwave background as seen by the distant galaxy at the time the observed light left there, we can compare it to the temperature we see now locally. The relative cooling between the CMB we observe now locally and the CMB as seen by this galaxy when it gave off the observed light should be proportional to the redshift of the light emitted from this Galaxy on the way to us.
This is an important consistency check. Silly creation models make no prediction concerning this whatsoever.
How do you measure the CMB temperature as seen by Galaxies far away? You compare occupations of different energy levels of molecules and emission lines. It's an extremely ingenious method, because it basically uses the molecules of far away galaxies as a measurement apparatus.
Here's an older paper where they first measure it:
http://www.uam.es/personal_pas/txrf/frm/...2000_1.pdf
They consider galaxies with a redshift z=2.34. Now the CMB temperature is 2.73K, so the expected temperature of the microwave radiation bath in which Galaxies of redshift z=2.34 are embedded is 2.73 * (1+2.34) = 9.1 K. They measure 10 +/- 4. For more current data of different redshifts see http://arxiv.org/pdf/0909.2815.pdf , in particular Figure 1. The discussion right now is whether certain physics effects could alter this relation subtly, see e.g. http://arxiv.org/pdf/1007.2325.pdf . The discussion is not whether this redshift has taken place
Why is there a distance dependent redshift again in silly creation models, and why is there a CMB throughout the universe which follows the expected scaling relations derived from this redshift? I'm sure if you phantasize long enough about it, you'll find a convincing answer, like god did it or so
(February 19, 2014 at 11:50 pm)Statler Waldorf Wrote: That’s a great idea and I’d be open to doing something like that on a bit broader subject since this is not my area of study and work. My expertise is in Environmental Science and Geospatial Science so I am certainly no expert on relativistic physics.
The problem is that if you don't fix a narrow question/topic for a debate, it becomes completely intractable. What would your topic of choice be?
As a little inspirational aside: every dot on this picture is an observed galaxy. I'm sure it was all made just for us. The bubble structure which you can see at scales of hundreds of millions of light years nicely fits a simultaneously cooling thermal bath collapsing under its own gravity with a dark matter component of 70% or so.
Observation:
Simulation of collapsing dark matter:
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RE: The universe appears "old", but it is still less than 10,000 years old
February 20, 2014 at 7:20 am
(This post was last modified: February 20, 2014 at 7:22 am by Alex K.)
(February 20, 2014 at 5:26 am)Zen Badger Wrote: Hmmm, let me try this another way.
Light speed in not instantaneous.
Are we agreed on that point?
I honestly don't do this to annoy you 
But I'm going to be anal retentive now - It's really important to clarify concepts here, or our discussion will be meaningless.
So I don't know what you mean by instantaneous, please elaborate.
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