• Starting today August 7th, 2024, in order to post in the Married Couples, Courting Couples, or Singles forums, you will not be allowed to post if you have your Marital status designated as private. Announcements will be made in the respective forums as well but please note that if yours is currently listed as Private, you will need to submit a ticket in the Support Area to have yours changed.

light years

USincognito

a post by Alan Smithee
Site Supporter
Dec 25, 2003
42,070
16,820
Dallas
✟918,891.00
Country
United States
Gender
Male
Faith
Atheist
Marital Status
Private
shinbits said:
So if the universe was created, the light could've taken only a few weeks to reach, as it moved away from earth, with the spreading of the galaxy.

I thought you said there would be no changes between what we observe now and during the Creation with regard to physics. But you want to suggest that shortly after Creation the visible Univserse (not just the galaxy, we can see several other galaxies with the bare eye - plus if they were all "light weeks" away we would have seen many more) were all compressed down to be "light weeks away"?

Also, you keep suggesting this flashlight anaology. How is a star supposed to move away from the Earth either at, or faster than the speed of light in order to move millions of light years away in 6,000 years?
 
Upvote 0

notto

Legend
May 31, 2002
11,130
664
55
Visit site
✟29,869.00
Faith
United Ch. of Christ
shinbits said:
That's only if the light is just reaching us. But like in the example of the "flashlight", the light could have always been hitting us, starting from when it was first created, and continued moving back.

You are completely wrong and don't even understand why. You are a great creationist.

If the light that was hitting us was emitted when the star was closer as you suggest, the star would LOOK CLOSER THAN IT DOES NOW, just like the flashlight would.

You need to take a few physics classes and get back to us.
 
Upvote 0

Donkeytron

Veteran
Oct 24, 2005
1,443
139
45
✟24,874.00
Faith
Non-Denom
Dannager said:
Could you please identify for us the changes that need to be made to currently existing theory so that we can recalculate our measurements based on your new proposal?

yes. I am always excited by the actual astrophysicist vs YEC on the subject of astrophysics threads.
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
USincognito said:
I thought you said there would be no changes between what we observe now and during the Creation with regard to physics. But you want to suggest that shortly after Creation the visible Univserse (not just the galaxy, we can see several other galaxies with the bare eye - plus if they were all "light weeks" away we would have seen many more) were all compressed down to be "light weeks away"?

Also, you keep suggesting this flashlight anaology. How is a star supposed to move away from the Earth either at, or faster than the speed of light in order to move millions of light years away in 6,000 years?
Thnk you all for participating in this debate. This was the crunch for me no longer identifying myself as a creationist. As Gould and others have commented, science and religion are two differnt constructs, and I have a view of evolution that does not conflict with my beliefs, however I do not take things so literally now.

It makes sense to me that the universe is billions of years old, but I am basing this belief on scientific assumptions. Its not about being right, I just want to be able to support my argument with a logical argument. I think I need to take an online course in physics.

The way we perceive the world shapes our interactions with it.
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
dad said:
You don't understand material on this topic. Guess you think you are clever being short with people, and not backing up your contentions. It matters not, what surprises me is a christian having such strong delusion.
Please don't hush, I appreciate your viewpoint.

We are dealing with assumptions, but empirical science requires that a set of assumptions be met before a conclusion is drawn, and that the conclusion be falsifiable. What I'm interested in are the what the set of assumptions are that provide scientists with the confidence that what is seen in a telescope is billions of light years away.
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
KerrMetric said:
But the light isn't - it is still coming towards us and being stretched in the process hence the cosmological redshift.

This is all handled in the calculations, it isn't forgotten about.
Could you explain more about redshift and the doppler effect?

Is part of it that the frequency increases the closer an object is to earth?
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
KerrMetric said:
Whe you form the star (naturally) the material even if varying in fuel content from star to star (and that is very difficult to conceive how that came to be) the star takes a long time to adjust itself to what we see because it is so big. You can't natually make it in the internal stratification we know exists. So it has to adjust to this. But adjustments take a long time

For example if you turned off the nuclear reactions in the core by magic it would take the Sun millions of years to exhibit this change at the surface. This is called the Kelvin - Helmholtz timescale and is equal to GM^2/RL which is about 10 million years for the Sun.

The only way to avoid this is to have a totally supernatural formation but then why not do that yesterday?




NO. The ag of the universe has no bearing on this. Stellar ages are from the physics of ionised gases, nuclear physics, fluid dynamics and thermodynamics. This is tried and tested physics.






No it implies the stars formed at approximately coevally and nothing more.





Yes it is crazy. The expansion effects are INCLUDED in the calculation.
If the stars formed coveally is this why the theory of the strecthing of the universe makes sense?
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
KerrMetric said:
But the light isn't - it is still coming towards us and being stretched in the process hence the cosmological redshift.

This is all handled in the calculations, it isn't forgotten about.
If light is being stretched does it affect the speed that it travels at? I thought that the speed of light was constant.
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
KerrMetric said:
Nope, you have it wrong.





Nope, poor analogy.





Nope. If you magically made them this way they wouldn't appear as they do.






But the fact we see things a great distance puts a lower limit on the age of the universe. This has nothing to do with a single object but it does put a lower bound on the age of the universe.
How does this provide us with a lower limit?
 
Upvote 0

devotee

Active Member
Mar 15, 2006
78
1
✟22,708.00
Faith
Other Religion
Dannager said:
shinbits, you are half correct in your assumptions. We won't be able to tell exactly how old a star is based on light-years away. That's fine. Science isn't big on certainty anyway. But what we can be certain of is that the objects we view, based on their distance, must be at least a certain age. We don't know how old they are, but we know how the minimum amount of time they could have been around for.
How can we be confident about that at least age?
 
Upvote 0

Dal M.

...more things in heaven and earth, Horatio...
Jan 28, 2004
1,144
177
43
Ohio
✟17,258.00
Faith
Agnostic
Marital Status
Married
devotee said:
How can we be confident about that at least age?

Because the speed of light in a vacuum is a constant. If we see an object fifty light years away, then it must be at least fifty years old, or else the light wouldn't have had the time to reach us yet. If we see an object fifty thousand light years away, then it must be at least fifty thousand years old.

The Hubble telescope has spotted galaxies twelve billion light years away.
 
Upvote 0

dad

Undefeated!
Site Supporter
Jan 17, 2005
44,905
1,259
✟25,524.00
Country
Canada
Gender
Male
Faith
Christian
Marital Status
Private
devotee said:
Please don't hush, I appreciate your viewpoint.

We are dealing with assumptions, but empirical science requires that a set of assumptions be met before a conclusion is drawn, and that the conclusion be falsifiable. What I'm interested in are the what the set of assumptions are that provide scientists with the confidence that what is seen in a telescope is billions of light years away.
The main assumption underlying all, including light, and decay, is that all things were the same as they are now in the past, -constant. Also, that things are constant all through the universe as well at the moment, and will be in the future.
If all things were the same in the past, I am afraid that the timeframe of the bible seems wrong, but I am confident things were different in a big way. So different that it boggles the mind, as bible believers will see that the future will be when this temporary universe passes away. Of course the fabric of the universe, and matter must be totally different in a future where earth is not going to crash into anything, or decay away like the sun in present conditions.
 
Upvote 0

dad

Undefeated!
Site Supporter
Jan 17, 2005
44,905
1,259
✟25,524.00
Country
Canada
Gender
Male
Faith
Christian
Marital Status
Private
KerrMetric said:
You can't even talk the lingo. "provable"??? LOL.

You took some article and then said these things were assumptions. I told you they were not. You actually shock us all and do some checking. Instead of playing peanut gallery boy actually do some leg work. I personally doubt the chances of you following the arguments necessary but I'd be happy if you could prove me wrong on that point. I'm rooting for you dad.
All that to say you can't support the claims, OK. The stars are assumed old if they are a certain size, basically, and the big bang is assumed, rather than creation. (Can't have both and the bible cause the earth was made before the stars, not vica versa, regardless of time arguements). No wonder proof isn't in your vocabulary!
 
Upvote 0

dad

Undefeated!
Site Supporter
Jan 17, 2005
44,905
1,259
✟25,524.00
Country
Canada
Gender
Male
Faith
Christian
Marital Status
Private
Dal M. said:
Because the speed of light in a vacuum is a constant. If we see an object fifty light years away, then it must be at least fifty years old, or else the light wouldn't have had the time to reach us yet. If we see an object fifty thousand light years away, then it must be at least fifty thousand years old.
....
Only assuming that it was always the same light, and speed, and laws, of course. Assumptions can be funny things.
 
Upvote 0

Physics_guy

Well-Known Member
Dec 11, 2003
1,208
66
✟1,687.00
Shinbits, you are missing something rather obvious in your example. Even if you were somehow able to magically move at millions of times the speed of light backwards away from the Earth, the photons leaving your flashlight can't. Therefore, there wouldn't be a continuous stream hitting the earth if you recessed at greater than the speed of light, because those photons cannot move faster than 3 million m/s (you can't either, but assuming your hypothetical for a second we will allow it).

Also, you said that light was good at measuring distance, but not age. This is fundamentally wrong. It isn't great at measuring either actually. We can however know how old light is by knowing how far it has traveled and we can estimate distances by other methods (parallax measurement for example).
 
Upvote 0

KerrMetric

Well-Known Member
Oct 2, 2005
5,171
226
64
Pasadena, CA
✟6,671.00
Faith
Non-Denom
Marital Status
Married
Politics
US-Libertarian
shinbits said:
Okay. What basic law of physics says that stars need time to "adjust" after being created? And how much time would they need, according to physics?[/

The answer to this question would basically prove your point, at least on the question of stars needing time to adjust. :)
Of course, that's after some logical follow up questions, if there are any to be asked.


Lets be clear here - if God did this in some supernatural manner that violated standard physics then this question is meaningless.

But if you want stars to form a few thousand years ago "naturally" then they would not be in thermal equilibrium. They would then have to adjust their structure in accord to thermodynamics and fluid dynamics. This is straightforward to calculate. I even gave the approx. formula earlier. For the Sun this thermal adjustment timescale is about 10 million years or so.

Now the Sun appears as a body in hydrostatic, thermal and nuclear equilibrium. Thus it appears as it should if it is very old. The only way you could have made it a few thousand years ago and have it appear as it does is to do it all outside of physics (supernaturally.)

But this means God created the stars to appear old but in your reality they are not. This is the fake history problem.



It's not a false history or bad theology. If God made the universe only a few thousand years ago, wouldn't He want man to enjoy His creation? Wouldn't He want to show off His Glory and the work of His hands? Why would God want to wait millions of years for this to happen?

Why didn't he do it last Thursday? This is terrible theology the creating of false hstories which deceive us. That is not God but the work of the devil.


A universe only a few thousand years old wouldn't a change in the current physics of stars.

Poorly written so I don't get the question.



Well, as mentioned before, the light could've started reaching earth at a much closer distance, then moved away from the earth as the universe expanding, making more space between celestial systems. It could've started out taking only a few weeks to reach earth at first, and as it reached earth, and moving away as the universe expanded.

How can the light move backwards? You also are implying a known incorrect expansion rate.


If I had a powerful flashlight pointed at a wall, kept the light from it steadily pointing at the wall, and drove away in a car with someone at the wheel---
If someone tried to measure how old that light was and started first by measuring the distance of the source, then calculating the speed of light, they would come up with the wrong age. That's because it did not take however many seconds for the light to get there; there light was always there.


You cannot measure how "old" light is. You measure the distance by some other method and then infer how long ago the light was emitted.

You are hopelessly confused here. When you see the light on the ground it isn't the same photons stuck on the ground which is what you seem to be saying. This is just bizarre.



So if the universe was created, the light could've taken only a few weeks to reach, as it moved away from earth, with the spreading of the galaxy.

The expansion really oly takes affect on large length scales. The galaxy is a gravitationally bound system and effectively does not take part in the expansion within itself. This is a common misconception.

And if earth is only a few thousand years old, and it only took, say a few weeks for the light to initially reach it, that means that the stars would only be a few thousand years old also.

No it doesn't. Again you are really really confused here.


As mentioned, no one knows how fast the universe was initially moving at creation. And if it's believable that the Big Bang's "explosion" made the universe move at many times the spead of light, initially, then it is believable, that the universe could've moved that fast initially, at creation.

Does that make sense? :)


No it doesn't. Your question is about as sensible as asking what is the colour of smell.
 
Upvote 0

KerrMetric

Well-Known Member
Oct 2, 2005
5,171
226
64
Pasadena, CA
✟6,671.00
Faith
Non-Denom
Marital Status
Married
Politics
US-Libertarian
devotee said:
Could you explain more about redshift and the doppler effect?

Is part of it that the frequency increases the closer an object is to earth?

Please Google this. There are many websites with diagrams that explain this better than I can write a sentence or two about it.

Your frequency question makes no sense.
 
Upvote 0