Speed of light not constant = young universe

[Heywood]

Reminds me of a discussion in metaphysics class beginning the the premise that space was stretched out in one direction causing objects and space the lengthen as you turned into the stretched direction. Once someone proposed light and sound and other things would travel proportionally faster in the elongated direction we gave it up as an untestable, and ultimately unimportant idea. No difference could be demonstrated even it it were true.

In your metaphysics class light would only travel proportionally faster in the elongated direction if the permittivity and permeability of space in that elongated direction also changed proportionally. You think of light as a constant. It is not. In actuality what appears to be constant speed of light are actually the product of constant factors.....factors which determine the speed of light.....those factors are the permittivity and permeability of space.

Elongate space but keep the permittivity and permeability of space constant and see what happens in your thought experiment.

[Jenny A]

Do you have a link for this nonsense? Sounds kinda like the arguement that god made the stars with their light already reaching the earth.

http://www.christianforumsite.com/index....ads/38966/

It started out about when jebus was coming back.

Thanks. I think one could go mad on that forum.

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In your metaphysics class light would only travel proportionally faster in the elongated direction if the permittivity and permeability of space in that elongated direction also changed proportionally. You think of light as a constant. It is not. In actuality what appears to be constant speed of light are actually the product of constant factors.....factors which determine the speed of light.....those factors are the permittivity and permeability of space.

Elongate space but keep the permittivity and permeability of space constant and see what happens in your thought experiment.

Yes light is actually a constant. It can appear slower as it travels through dense material like glass or water because it is refracting off the material as it travels through it.

The thought experiment presumed that atoms and light itself would stretch. Thus light would appear constant.

My point however, is that suggesting that light is slowing down without evidence to support it is about as useless an idea as the one proposed in metaphysics class.

[KUSA]

Thanks. I think one could go mad on that forum.

It's full of madness. I have been reading a lot there to observe the xtian in its natural habitat.

[Jackalope]

Is that contradictory to what I said? It appears to be constant through a homogenous medium. Those that make positive claims otherwise need to show their work - and they'll need to propose a falsifiable mechanism by which it could be so.

To show their work requires a vast amount of time. We simply haven't had enough time in which we knew how to measure the speed of light to make such a determination. 100,000 years from now we will be in a much better position to claim the speed of light is constant over time(if it turns out that it is).

I would submit, that this being the case, that one should not make truth claims regarding said incomplete information.

And really, by "show their work", what I mean is to show what led them to prefer a particular interpretation of the evidence over another, besides wish-thinking. In the absence of observation the suggest that the speed of light is not isotropic, I believe that the principle of parsimony suggests that a constant speed of light is the only reasonable assumption to make. Should we remain open to alternative explanations? If and when there is observational data to support them, yes, we should be open to examine such data.

However, I will also say this - though my mind remains open, the concept of a very young universe (and earth) as put forth by young earthers remains ludicrous.

[LostLocke]

You think of light as a constant. It is not.

To the observer, it is. That's where the 'constant' comes from, not the actual speed being constant.

If I'm on a train going 50mph, and I throw a ball at 50mph, how fast is the ball going?
If you answered 100mph or 50mph or 0mph, you are correct.
The relative speed of the ball will vary depending on whether you are on the ground or on the train, and what direction I throw the ball (if you are on the ground).

With light, there's only one correct answer. It makes no difference how fast the train is going, how fast I throw the light, what direction I throw it, if you're on the ground or on the train, etc. Everyone will see the light moving at the same speed.

[TubbyTubby]

Thanks. I think one could go mad on that forum.

It's full of madness. I have been reading a lot there to observe the xtian in its natural habitat.

I used to hang around there for amusement until the inevitable ban, although I was an accepted atheist for a while.

Off the same thread;

"Well, evolution is not true scientifically either, because first of all, the new change (evolutionary) happens in only few beings, like about 5 in the whole world, and then they will reproduce with the original beings, and then the species won't be like evolved, it will be just half the new changed being and half the original being. We didn't come from apes, but Adam and Eve were probably black because the Eden is somewhere in East Africa and the earth or clay what God used to make Adam was probably dark brown. If we came from apes, then we are not evolved, we are just half ape and half human. Because again, only few apes in the world get the change, and then they reproduce with the original apes, and then we are half human half ape. So evolution is not possible. But the creationism took few billion years. Adam and Eve came about 200,000 years."

In all seriousness, someone writing stuff like this needs professional help.

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To be fair Polly is a special case there - just been reading the latest polar bear thread, you could make good comedy sketches from that forums content.
http://www.christianforumsite.com/index....ads/38988/
What Does The Polar Bear Symbolize?

[Jenny A]

It's full of madness. I have been reading a lot there to observe the xtian in its natural habitat.

I used to hang around there for amusement until the inevitable ban, although I was an accepted atheist for a while.

Off the same thread;

"Well, evolution is not true scientifically either, because first of all, the new change (evolutionary) happens in only few beings, like about 5 in the whole world, and then they will reproduce with the original beings, and then the species won't be like evolved, it will be just half the new changed being and half the original being. We didn't come from apes, but Adam and Eve were probably black because the Eden is somewhere in East Africa and the earth or clay what God used to make Adam was probably dark brown. If we came from apes, then we are not evolved, we are just half ape and half human. Because again, only few apes in the world get the change, and then they reproduce with the original apes, and then we are half human half ape. So evolution is not possible. But the creationism took few billion years. Adam and Eve came about 200,000 years."

In all seriousness, someone writing stuff like this needs professional help.

If you never crack open an actual science book, and you read creationism, that's exactly where you get. Even bright kids can get there. A high school friend of my daughter's is a couple years ahead in math, does very well in science courses, but was for some time convinced that the great flood of Genesis, not continental drift, broke up the continents. One geology class and she changed her mind though.

It's not psychotic unless you already know the science and then descend into this stuff.

[KUSA]

It's amazing to me how they hold on to retarded shit just because they can't accept anything that might not fit in their theistic views.

Not so... it's been cropping up for over 300 years and no one can put it to rest. Even the scientific community is accepting it as fact now because the data cannot be refuted:

http://math.ucr.edu/home/baez/physics/Re...light.html
http://www.livescience.com/29111-speed-o...stant.html
http://news.discovery.com/space/speed-of...130428.htm
http://www.huffingtonpost.com/2013/04/29...75487.html

God wins again!

[TubbyTubby]

It's amazing to me how they hold on to retarded shit just because they can't accept anything that might not fit in their theistic views.

Perhaps because the truth is really fucking scary. The mind is very powerful and rejecting the comfort of god after it has been your whole life must be an immense leap.
There are plenty here who have done so and I salute them. I never had to make that leap.

[pocaracas]

When Einstein was doing the math to arrive at the laws of relative motion of electro-magnetic waves, starting from the famous Maxwell equations of electromagnetism, he came across a constant. He called it 'c', for constant.
Later, he noted this constant had units of speed (length/time) and, since he was dealing with electromagnetic waves, he interpreted it as the speed of these waves.

This constant has been measured by university students ever since, multiples times per year and in multiple locations all over the planet.
They have all arrived at the same value, with variable degree of certainty, of course.
None of them have observed a constant shifting of this speed towards a lower speed.... in 100 years, it's always been the same.


Also, a few dedicated teams have been measuring it with increasing accuracy. The presently accepted value can be found at http://physics.nist.gov/cgi-bin/cuu/Value?c

It is considered exact there, because... this is great!...

The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is exactly 299,792,458 metres per second, a figure that is exact because the length of the metre is defined from this constant and the international standard for time.[1]

Not too long ago, the metre was redefined into the length that light spans in 1/299,792,458 seconds.

So, if anyone is willing to claim that the speed of light is changing, then that person will have to acknowledge that the metre is changing, too... O.o