Easy arguments against the Bible, and religion as a whole

[TheDarkestOfAngels]

If I stopped, I'd have to actually be productive with my life.
That obviously can't happen.

[Jackalope]

yes, many theories based on the fact that the universe is how it always was. what if light was once faster than it was now? what if it's speed is slowing down? if any of these arguements are true then those arguements don't hold water

Do you have any evidence that these arguments are plausible? If so, we can discuss them here. There are proponents of these arguments, to be sure. I believe we have a thread that has addressed this topic in some detail.

If I recall correctly, the observational evidence doesn't support those arguments. I'm not satisfied with the sources I have immediately available, and I don't have the time right this second to investigate further. I will later if you're earnestly interested in the information. You are free of course to investigate on your own.

[chi pan]

yes, many theories based on the fact that the universe is how it always was. what if light was once faster than it was now? what if it's speed is slowing down? if any of these arguements are true then those arguements don't hold water

Do you have any evidence that these arguments are plausible? If so, we can discuss them here. There are proponents of these arguments, to be sure. I believe we have a thread that has addressed this topic in some detail.

If I recall correctly, the observational evidence doesn't support those arguments. I'm not satisfied with the sources I have immediately available, and I don't have the time right this second to investigate further. I will later if you're earnestly interested in the information. You are free of course to investigate on your own.

well this is really a tangent off the main topic but i suppose i'll support some evidence. not looking very far but here.

http://opfocus.org/index.php?topic=story&v=8&s=4

Light, which normally travels the 240,000 miles from the Moon to Earth in less than two seconds, has been slowed to the speed of a minivan in rush-hour traffic -- 38 miles an hour.

http://news.harvard.edu/gazette/1999/02.18/light.html

http://en.wikipedia.org/wiki/Slow_light

[Jackalope]

Light, which normally travels the 240,000 miles from the Moon to Earth in less than two seconds, has been slowed to the speed of a minivan in rush-hour traffic -- 38 miles an hour.

http://news.harvard.edu/gazette/1999/02.18/light.html

http://en.wikipedia.org/wiki/Slow_light

Yes, those are special cases where light has shown to slow. Any evidence that it has increased in speed (as would be required for the young-earth argument to hold water)?

Also - if you're making a young-earth argument, there's other evidence you'll need to deal with aside from the speed of light. We even have a thread for it.

I looked at your first link (the one from Optics and Photonics) and it's pretty thin on details. Before I could seriously consider this line of evidence, I'd need to see a bit more detail. Sanejouand's speculation (if true) that 'c' has slowed over time would turn modern physics on it's head, and so I think it's reasonable to expect more detail. I note that while the article does have references, none of them are from the person making the claim. Has this been published in a peer-reviewed journal? Without peer review, all I see is a vacuous claim that can't be taken seriously as scientific evidence. If there's more, by all means present it.

[TheDarkestOfAngels]

well this is really a tangent off the main topic but i suppose i'll support some evidence. not looking very far but here.

http://opfocus.org/index.php?topic=story&v=8&s=4

Light, which normally travels the 240,000 miles from the Moon to Earth in less than two seconds, has been slowed to the speed of a minivan in rush-hour traffic -- 38 miles an hour.

http://news.harvard.edu/gazette/1999/02.18/light.html

http://en.wikipedia.org/wiki/Slow_light

The first link is interesting but...

It is clear now that the speed of light must be constant regardless of the propagation direction or the motion of the source or observer — indeed this is one of the postulates of Einstein’s relativity. The constancy of the speed of light is so fundamental and accepted now that in 1983 the 17th Conférence Générale des Poids et Mesures decreed that "The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second." At this point c cannot change by definition.

So there you have it - C is always equal to C.
As to your other two links - note that light is always passing through a medium to do that, which involves physical processes that don't technically slow down light because of the way that photons pass through various materials.

[Jackalope]

As to your other two links - note that light is always passing through a medium to do that, which involves physical processes that don't technically slow down light because of the way that photons pass through various materials.

Regardless of that, they don't support his speculation that light might have traveled faster in the past - unless he's further implying that there's something fundamentally different about the matter in interstellar/intergalactic space now vs. then.

---

Also - it's worth noting that the scientific consensus on the age of the universe rest on the speed of light. There is a lower constraint of 12-13 billion years based on the cooling rate of white dwarf stars (Chaboyer, Brian, Pierre Demarque, Peter J. Kernan, and Lawrence M. Krauss. 1996. A lower limit on the age of the universe. Science 271: 957-961).

That is, unless one wants to argue against the laws of thermodynamics as well.

[TheDarkestOfAngels]

Regardless of that, they don't support his speculation that light might have traveled faster in the past - unless he's further implying that there's something fundamentally different about the matter in interstellar/intergalactic space now vs. then.

Precisely - I poitned out elsewhere that the speed of light is also used in the equation of E=MC^2 - so if the speed of light is variable over time, then the nature of all matter of energy changes over time - which means that the universe could not have formed as it did and all of physics both of the very small and very large (quantum and astro) would be meaningless given that our calculations of the history of the earth and the universe all involve E=MC^2 in some form or another.

That equation alone is practically the difference between now and 19th century science, technology, and understanding.
Even if things like tacheyons exist in the universe (imporbable but not impossible), then that doesn't change the fact that light not only must be constant for our sake, but it is foundational to the underlying mechanics of all matter and energy.

A universe in which C can be variable cannot be our universe.

[Jackalope]

A universe in which C can be variable cannot be our universe.

Unless we are fundamentally wrong about a great many things, yes, it would appear to be the case.

[chi pan]

well if it is constant, then how come you can see 40 billion lightyears of the observable universe when it's supposedly only almost 14 billion years old?

[Jackalope]

well if it is constant, then how come you can see 40 billion lightyears of the observable universe when it's supposedly only almost 14 billion years old?

Inflation and the Big Bang.