Light from stars

[TheGreenMan]

I was reading AiG when I came across this feedback article where Dr. Jason Lisle (Ph.D. in astrophysics) and Matthew D’Orazio (no clue if he has anything) address a letter written to AiG. Find the article here.
The section I am curiouse about is the section dealing with light travel time from distant stars.

AiG

Second, you have assumed that the effects of gravitational time dilation are insignificant. Einstein tells us that time can flow at different rates under different circumstances. Under the right conditions, light from the most distant galaxies could have arrived at Earth in very short amounts of time. Yet you seem to have totally ignored this important principle of physics.

© source where applicable

I do not get what the authors are driving at. Would time dialation have any effect on the light? Would it have the correct effect (getting the light here sooner)? If it did get here sooner wouldn't the light be blue shifted instead of red shifted?

[oxmixmudd]

I was reading AiG when I came across this feedback article where Dr. Jason Lisle (Ph.D. in astrophysics) and Matthew D’Orazio (no clue if he has anything) address a letter written to AiG. Find the article here.
The section I am curiouse about is the section dealing with light travel time from distant stars.

AiG

Second, you have assumed that the effects of gravitational time dilation are insignificant. Einstein tells us that time can flow at different rates under different circumstances. Under the right conditions, light from the most distant galaxies could have arrived at Earth in very short amounts of time. Yet you seem to have totally ignored this important principle of physics.

© source where applicable

I do not get what the authors are driving at. Would time dialation have any effect on the light? Would it have the correct effect (getting the light here sooner)? If it did get here sooner wouldn't the light be blue shifted instead of red shifted?

Since he is not specific, we have to guess. My guess is that it involves Humphreys' White Hole Cosmology, where the Earth sits in a time dilated state while the rest of the universe evolves naturally. His reference to 'arrived at Earth in very short amounts of time' is relative to the Earth itself (time as measured on Earth). The initial form of the theory assumed an assymetric relationship where the clocks on Earth ticked (and tick) slower than elsewhere in the universe due to the gravitational well of the Universe being centered on the Earth. He was called on that due to problems (such a situation is contrary to observation and theory) and he returned with a response that placed the Earth not in a time dilated state but an area of Euclidean time (no time) during the 'evolution' of the Universe proper. This also has problems based on how he is interpreting the metric he uses, but I am not qualified to define why beyond what I have been told by those who do know.

The upshot: Humphreys' theory does not allow for old objects to form naturally 'nearby'. As there are a great many very old objects nearby, his theory does not conform to observation without several "Insert miracle here" operations. Further, this time dilation can't still be in place as events in the distant* universe follow the same timeline as events here on Earth (a la SN1987a).


Jim

*to many millions, even billions of light years. There is some dilation at distances in the many billions of light years, but this is expected in the BB model and is due to the expansion of space.

[Minnesota]

From my understand of time dilation, it has absolutely nothing to do with the time it takes an object, including light to get from A to B. It refers to the difference in the passage of time between two frames of reference (observers) who are not stationary in respect to each other: one or both are moving. In a single coordinate system time dilation does not affect the time it takes an object to get from A to B. If we perceive a bunch of photons taking 2 million years to get us, as measured by the red shift in the resulting spectrum, it is only because such a shift is produced by the velocity of the expanding universe and the loss of energy in those photons as they escape the gravity of their source (gravitation redshift--the Einstein effect) . Could this red shift be produced by the gravitational time dilation? No. GTD is strictly an effect in one frame of reference as measured in another frame of reference. In looking at the light from a galaxy both the light and we are in the same frame of reference, so time dilation does not enter into our measurement of its distance.
As I understand it all

From what I can tell, the author is blowing smoke up the pants of his readers. Misusing the jargon of science to snow the reader.

[rogue06]

YECs have been coming up with ever-more creative ways to explain light from stars located more than 10,000 light-years away. Some claimed an "appearance of age" argument, saying that the light was created in transit so it only "appears" to be old. Fortunately most YECs saw the theological folly of embracing the concept of Last Thursdayism and abandoned it. Others talked about varying speeds of light totally ignoring the full consequences of their ad hoc solution.
Then in 1987 we witnessed a supernova (SN1987) event! The light from it spread out and lit up the surrounding gas and various nuclear products decayed giving off their characteristic light colors as expected. This became a real problem for YEC astronomers for the Hubble telescope could measure the distance from the lighted dust to the supernova, and using nothing more than high school trigonometry, computed its distance as approximately 169,000 light years away.
Now, it seems that the straws that they grasp on are "White Holes" and such.

[grmorton]

From my understand of time dilation, it has absolutely nothing to do with the time it takes an object, including light to get from A to B. It refers to the difference in the passage of time between two frames of reference (observers) who are not stationary in respect to each other: one or both are moving. In a single coordinate system time dilation does not affect the time it takes an object to get from A to B. If we perceive a bunch of photons taking 2 million years to get us, as measured by the red shift in the resulting spectrum, it is only because such a shift is produced by the velocity of the expanding universe and the loss of energy in those photons as they escape the gravity of their source (gravitation redshift--the Einstein effect) . Could this red shift be produced by the gravitational time dilation? No. GTD is strictly an effect in one frame of reference as measured in another frame of reference. In looking at the light from a galaxy both the light and we are in the same frame of reference, so time dilation does not enter into our measurement of its distance.
As I understand it all

From what I can tell, the author is blowing smoke up the pants of his readers. Misusing the jargon of science to snow the reader.

Not only are they blowing smoke, the smoke is of an illegal variety. For someone with a Ph. D. in astronomy to write such nonsense is amazing. Where did this guy get his Ph. D.? I wouldn't want my children educated there.

Gravitational time dilation has zero to do with light travel time. If you go near a black hole, your time feels normal to you. But you seem to slow down tremendously to any observer watching you from far away. Your heatbeats will take centuries to that external observer if you are close enough to the event horizon. You have traveled no where. When you come back from your close encounter with the black hole, it could be millennia later. That doesn't solve the light travel time.

The only time gravitational time dilation takes place is next to a very very large mass. In interstellar space there is almost ZERO matter and that means the gravitational field is very very small and there is effectively NO gravitational time dilation. What happens to light trying to climb out from the black hole is that effectively it travels slower (which is observed as lengthening of the wavelengths)

This describes the situation from the event horizon inward. Above I mentioned that just above the event horizon, light travels slowly outward because the local space is flowing into the black hole at nearly the speed of light.

Edward R. Harrison, Cosmology, (Cambridge:
Cambridge University Press, 1981), p. 191-192

"The surface of a black hole where space in effect falls inward at the
speed of light is known as the event horizon: Events inside the horizon can
never communicate with the events outside the horizon, because light signals
cannot travel faster than the speed of light in local space (see Figure 9.8).
A signal traveling outward at the speed of light remains static at the event
horizon. Inside the horizon space flows inward faster than the speed of light,
and outward-moving signals, traveling through space at the speed of light, are
dragged in and cannot reach the horizon. Special relativity is still valid in
small local regions; for instance, the local speed of light is the speed that
we use, and nothing can move through space faster than light. But on the large
scale, space is so deformed that we can regard it as flowing inward with a
speed that has no limit, and small local regions - in which special relativity
is valid - are carried along with it. If we were in a spaceship that fell into
a black hole, we could never escape; no matter how strong the thrust of the
rocket engines, we could not exceed the speed of light in local space and would
therefore be carried to our doom."

© source where applicable

But, gullible YECs will once again make Christianity look stupid by parrotting this around the internet as if it is some divinely inspired truth.

[johnmartin]

Hello all

Has there been any real science experiments done that verify time dilation theory or is it still all theoretical? If so, how closely did the experiments relate to the theory? Can some examples be given that are conclusive. If so, please reference them for comment.

JM

[supersport]

strange...I was just reading about this tonight.

http://www.answersingenesis.org/docs...cdk_davies.asp

this is a good read. AIG puts it in perspective pretty well.

[Minnesota]

Has there been any real science experiments done that verify time dilation theory or is it still all theoretical?

Numerous experiments have confirmed it. A Google search should turn them up.

[JonF]

[size=2]Has there been any real science experiments done that verify time dilation theory or is it still all theoretical?

Billions and billions. Every time a physicist smashes particles in a particle accelerator time dilation is tested. Every time anyone reads their position with GPS time dilation is tested.

If so, how closely did the experiments relate to the theory?

Nearly perfectly, within the limitations of our measuring instruments.

[quote[Can some examples be given that are conclusive. If so, please reference them for comment.[/quote]
Real-World Relativity: The GPS Navigation System
Special Relativity (see the Peculiar Relativistic Effects heading).
And one of my personal favorites: Hafele and Keating Experiment.

There are lots and lots and lots more.

[Jorge]

strange...I was just reading about this tonight.

http://www.answersingenesis.org/docs...cdk_davies.asp

this is a good read. AIG puts it in perspective pretty well.

An observation to keep in mind is that when Setterfield (a Christian YEC) advanced the notion of a variable c the airwaves were filled with ridicule and catcalls. But when Davies and others (all secular Humanists) advanced the same idea, they received "scientific" attention and even got published in the 'prestigious' Nature.

It's a self-fulfilling prophesy and hypocrisy elevated to astronomical levels.

Jorge

[aniso]

An observation to keep in mind is that when Setterfield (a Christian YEC) advanced the notion of a variable c the airwaves were filled with ridicule and catcalls. But when Davies and others (all secular Humanists) advanced the same idea, they received "scientific" attention and even got published in the 'prestigious' Nature.

It's a self-fulfilling prophesy and hypocrisy elevated to astronomical levels.

Jorge

Umm, no, Jorge. There is a major difference between Setterfield cdk and Davies cdk. You will note that Davies says c has declined since the beginning of the universe. Setterfield is effectively saying that it has declined since the beginning of the human species. You will also note that There is little discussion of the magnitude of this decay since the flood. For Setterfield, it is something like 6 or 7(?) orders of magnitude. The AIG article avoids this issue.

In addition, the comment by Wise is telling:

"Paul Davies’ Nature article itself falls far short of the hype, which is much ado about nearly nothing."

As he points out, this has been known since 1917.

[oxmixmudd]

An observation to keep in mind is that when Setterfield (a Christian YEC) advanced the notion of a variable c the airwaves were filled with ridicule and catcalls. But when Davies and others (all secular Humanists) advanced the same idea, they received "scientific" attention and even got published in the 'prestigious' Nature.

It's a self-fulfilling prophesy and hypocrisy elevated to astronomical levels.

Jorge

Aniso is correct Jorge. You are equating apples and steel balls. The kind of 'cdk' proposed in the mainstream has not even the slightest analogy in the Setterfield fantasy. For you to equate the two can only be ignorance or willfull deception. Either way, it doesn't speak well of you. The equivalent in this thread would be like equating a trip to mars with a trip to Alpha Centauri or even Sirus (magnitude based comparison only). Keeping in mind a 6 or 7 order of magnitude change in the SOL would drastially change nearly every property of physics in the known universe, it's real equivalent would be equating a trip to mars with a trip to the visible edge of the Universe!

Jim

[HRG_new]

[size=2]Hello all

Has there been any real science experiments done that verify time dilation theory or is it still all theoretical?

Yes. That GPS works is the most impressive experiment. A GPS system has to take into account both special-relativistic time dilation (due to the motion of the GPS satellite) and general-relativistic time dilation (the satellite is higher up in Earth's gravity well).

This should satisfy even Thomists.

[Jorge]

Aniso is correct Jorge. You are equating apples and steel balls. The kind of 'cdk' proposed in the mainstream has not even the slightest analogy in the Setterfield fantasy. For you to equate the two can only be ignorance or willfull deception. Either way, it doesn't speak well of you. The equivalent in this thread would be like equating a trip to mars with a trip to Alpha Centauri or even Sirus (magnitude based comparison only). Keeping in mind a 6 or 7 order of magnitude change in the SOL would drastially change nearly every property of physics in the known universe, it's real equivalent would be equating a trip to mars with a trip to the visible edge of the Universe!

Jim

Thanks for the unnecessary lesson from both of you. I know very well the difference between Setterfield's proposal and that of Davies, Magueijo and others . If you read my post again - this time keeping the concept of 'reading comprehension' in mind - you will note that I referred to the notion, the idea, of a variable c.

But I'm used to seeing this type of reaction. Not long ago I talked about the grave injustice regarding Damadian and MRI. YECs can't get a fair shake -- nor should they expect to get a fair shake -- in a system controlled by secular Humanism and with liberal-minded Christians as allies. That's exactly what we see.

Jorge

[Barry Desborough]

Thanks for the unnecessary lesson from both of you. I know very well the difference between Setterfield's proposal and that of Davies, Magueijo and others . If you read my post again - this time keeping the concept of 'reading comprehension' in mind - you will note that I referred to the notion, the idea, of a variable c.

But I'm used to seeing this type of reaction. Not long ago I talked about the grave injustice regarding Damadian and MRI. YECs can't get a fair shake -- nor should they expect to get a fair shake -- in a system controlled by secular Humanism and with liberal-minded Christians as allies. That's exactly what we see.

Jorge

It's a pretty simple thing to understand, Jorge. One 'theory' is, in technical parlance, crap, and the other is not.