Speed of Light and Age of Universe

Originally posted by KellyJay
You believe that when you look down the street
that you are peering into the past too? Telescopes are not time
machines they are telescopes; you think if you look far away you are
looking into the past?

That's exactly the nature of sight. Light is a non-instantaneous medium of information, so everything that is seen happened in the past, whether it be a fraction of a second or millennia in the past.

Do you believe that when you look through a telescope at a distand star, you are seeing the star as it actually is at the moment the light hits your eye?

Whose belief is more foolish?

Originally posted by no1marauder
Here's one with dj2becker (starting on page 7) and Darfius (earlier) making the claim that the speed of light might have changed (CalJust does, too citing Humphries' crackpot book): http://www.timeforchess.com/board/showthread.php?threadid=20050&page=1

I'm sure there's others.

Have you read Humphries book so you could label it "crackpot"? I recall it having a useful (or at least tenable) explanation for how a young universe (from earth’s perspective) would allow for earth-dwellers to see distant stars.

I don’t have it on hand, so I hope I don’t butcher my recollections of his claims.

According to Einstein's general theory of relativity it is possible for time dilation due to gravity. Time dilation becomes dramatically huge near the event horison of a black or white hole. In the case of a white hole, nothing can remain inside its event horison; everything is ejected. As matter and energy are ejected, the event horizon shrinks and eventually becomes zero, leaving a core of matter of normal density (unlike a black hole which compacts the matter into an extremely high density). Assuming the universe is finite, Humphreys deduces that the entire observable universe at one stage existed inside such an event horizon.

Humphreys argues that at the time earth was on the event horizon, the time dilation would have been such that millions of years could have passed in outer space (billions, depending on their distance to the earth) during only a matter of hours (or days) of earth-time.

The theory is basically one where time runs at different speeds in different places -- quite plausible given the conditions proposed in the Big Bang.

The speed of light can be observed and measured in cirtain types of stars. The Distance to the said star can be be determined independant of the speed of light. If the distance to a given star is say 100,000 light years and we can measure the speed of light at the star as being no more than 2 times the speed of light, then either the time it took the light to reach us was >50,000 years or light was normal speed at the star, speeded up to get here real quick then slowed down again just in time to reach us.
Many aspects of physics also depend on relativity and a different speed of light would result in different physics and different stars. If the speed of light was significantly different when the light left the stars then we would expect to see different stars than we do. In fact we would expect to see types of stars directly proportional to thier distance from us and not the uniform physics we observe.
As Kelly points out we have no way of knowing what happened yesterday, all we can do is look at our observations. However if there are so many observations confirming one thing then we can conclude that either it did happen or God made it look like it happened, it is not just us misunderstanding the observations as Kelly keeps implying.

Originally posted by twhitehead
The speed of light can be observed and measured in cirtain types of stars. The Distance to the said star can be be determined independant of the speed of light. If the distance to a given star is say 100,000 light years and we can measure the speed of light at the star as being no more than 2 times the speed of light, then either the time it took the ligh ...[text shortened]... k like it happened, it is not just us misunderstanding the observations as Kelly keeps implying.

Wow!!! How do you measure the light at the star?!

Originally posted by Halitose
Wow!!! How do you measure the light [b]at the star?![/b]

When a star explodes or some similar phenomena with radiation exiting the star at the speed of light, it interacts with material around the star, the interaction can be observed and the time from the initial explosion to the later interaction can be measured, and the speed of light estimated.

Originally posted by twhitehead
When a star explodes or some similar phenomena with radiation exiting the star at the speed of light, it interacts with material around the star, the interaction can be observed and the time from the initial explosion to the later interaction can be measured, and the speed of light estimated.

Rather vague. Should I apply this vagueness to the estimated speed of light?

Originally posted by Halitose
Rather vague. Should I apply this vagueness to the estimated speed of light?

When I have time I will try to look up some examples/ links etc on the subject.

Originally posted by DoctorScribbles
That's exactly the nature of sight. Light is a non-instantaneous medium of information, so everything that is seen happened in the past, whether it be a fraction of a second or millennia in the past.

Do you believe that when you look through a telescope at a distand star, you are seeing the star as it actually is at the moment the light hits your eye?

Whose belief is more foolish?

I understand your point you I do not believe you understand mine.

You are relating distance and time to get age for the reasons you
gave to know the age, the distance + rate gives age is faith it isn’t
a valid means of knowing the age. All you really know is the
distance and rate, but are you getting them right, let alone what
it is you think it means?

I agree what a light year represents; however, that is still just
a rate. It is no different seeing a car moving 45 mph as you
monitor it with a speed gun! Was the car 45 miles away an
hour ago, or did it start its journey 2 miles back? You need
to know how and when it was started, to know how old it is
rate and distance don't give that information alone!
Kelly

Originally posted by twhitehead
The speed of light can be observed and measured in cirtain types of stars. The Distance to the said star can be be determined independant of the speed of light. If the distance to a given star is say 100,000 light years and we can measure the speed of light at the star as being no more than 2 times the speed of light, then either the time it took the ligh ...[text shortened]... k like it happened, it is not just us misunderstanding the observations as Kelly keeps implying.

There can be a lot of things that come into play, but knowing
the speed of light isn't even on the table when it comes to the
age of the universe as far I'm concern for reasons I've already
given.

I am interested in how you measure light's speed, is it is
calculation from other measurements, or do we have something
quick enough to react to capture the rate of how fast light travels?
Kelly

Originally posted by KellyJay
I understand your point you I do not believe you understand mine.

You are relating distance and time to get age for the reasons you
gave to know the age, the distance + rate gives age is faith it isn’t
a valid means of knowing the age. All you really know is the
distance and rate, but are you getting them right, let alone what
it is you think it mean ...[text shortened]... was started, to know how old it is
rate and distance don't give that information alone!
Kelly

These are purely skeptical objections to the evidence.

Every measurement of the speed of light indicates that it has a constant value.

This is in contrast to the speed of cars, the measurements of which indicate that it is not constant.

Originally posted by KellyJay


I am interested in how you measure light's speed, is it is
calculation from other measurements, or do we have something
quick enough to react to capture the rate of how fast light travels?
Kelly

Here is a good cartoon-based explanation, suitable for those used to reading Dr. Dino's website.

http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html

Originally posted by DoctorScribbles
These are purely skeptical objections to the evidence.

Every measurement of the speed of light indicates that it has a constant value.

This is in contrast to the speed of cars, the measurements of which indicate that it is not constant.

ROFL really, you think if that the universe was created 7K ago
your readings of rate would still be the same, or different?
I believe it would be the same, but it really doesn’t matter! I am
giving you light is constant and that you are getting the speed
of light correct, it is just what you think it is, but all of that does
not mean that you know the age!

The rate has nothing to do with my objections, and if you are
honest you have to agree! You only know rate and distance not,
age! The rate of cars can change, the rate of stars can be the
same, the question on how long light was traveling or how long
the car was traveling had nothing to do with the ability to
change speeds! In my question how long each was traveling is
the real question, when did the journey of light begin, and when
did the journey of the car begin? You cannot get that from just
how fast or slow the rate of travel is.
Kelly

Originally posted by KellyJay
ROFL really, you think if that the universe was created 7K ago
your readings of rate would still be the same, or different?
I believe it would be the same, but it really doesn’t matter! I am
giving you light is constant and that you are getting the speed
of light correct, it is just what you think it is, but all of that does
not mean that you know the age!

ROFL, really, you think the universe was created 7K years ago? I don't, so I don't subject my conclusions to being consistent with that premise.

I am giving you light is constant and that you are getting the speed
of light correct, it is just what you think it is, but all of that does
not mean that you know the age!

This is purely skeptical. If I know the distance of the star, and I know that I am receiving light that originated at the star, I know a lower bound on the star's age, given that you grant that my assessment of the speed of light is correct. Your objections to my conclusion about the lower bound on the star's age must either be:
1) I don't actually know the distance of the star, or
2) The light I am receiving did not originate at the star.

I have evidence to support that neither of (1) or (2) hold. Can you give me any non-skeptical argument that they do hold?

Originally posted by KellyJay
ROFL really, you think if that the universe was created 7K ago
your readings of rate would still be the same, or different?
I believe it would be the same, but it really doesn’t matter! I am
giving you light is constant and that you are getting the speed
of light correct, it is just what you think it is, but all of that does
not mean that you know the ...[text shortened]... of the car begin? You cannot get that from just
how fast or slow the rate of travel is.
Kelly

well, if a star is 50,000 light years away, and we see the light today then either the universe is at least 50,000 years old, or god's up to his old tricks of faking the evidence again. Why Kelly, when we've got observations about the distance of stars, convergent radiodating estimates for the age of the earth etc, do you still maintain a 7,000 year old universe??

Originally posted by scottishinnz
well, if a star is 50,000 light years away, and we see the light today then either the universe is at least 50,000 years old, or god's up to his old tricks of faking the evidence again. Why Kelly, when we've got observations about the distance of stars, convergent radiodating estimates for the age of the earth etc, do you still maintain a 7,000 year old universe??

Does having a mind so closed nothing new will ever sink in have anything to do with it?