# Is there evidence (or not) that c has changed over time?

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Hi my name is Chris and I’m a noob!

Well I’m a noob here but I’m a Forum Moderator (CJ) on the Forum at Richard Dawkins Net. We often get fundy nut jobs visiting our site and we have a particularly irritating version currently bugging the other members. So I have come here to ask for some help.

The question I would like answered is where on the web should I direct this person to that would show him that c has not changed since the big bang?

This person is fairly obviously trying the old “light has changed speed since the universe formed” argument to expound a theory that God did it! It’s quite a common tactic of these people to ask ridiculous questions and then when they can’t be answered claim all of science is rubbish.

Any suggestions would be appreciated.

Regards

Chris

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The question I would like answered is where on the web should I direct this person to that would show him that c has not changed since the big bang?

I think it should be the other way around! Ask him where to direct you so you can see for yourself what does he mean by saying "the speed of light has changed".

Speed Limit

And you're not supposed to convince him (or anyone) with all costs about anything. Just tell him scientific experiments that deny him and if he doesn't want to accept that, well it's his problem. Ignorance is growing these days:rolleyes: !

Light speed has changed! What a thought man!!! :doh:

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I'd take a look at TalkOrigins.

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This person is fairly obviously trying the old “light has changed speed since the universe formed” argument to expound a theory that God did it!

God changed the speed of light???

This guy is not even a creationist or a materialist! Because creationists strongly support the idea that fundamental laws have not changed. And on the other hand he's not even a materialist because they don't believe that there is a God!

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I think it should be the other way around! Ask him where to direct you so you can see for yourself what does he mean by saying "the speed of light has changed".

Tried that but obvously that has yet to work! In practice I'm not so much interested in showing him what the problems is (he is far beyond help) however I am interested in showing the less scientifically literate members just what a bunch of tommy rot this guy is talking!

Thanks for the Wiki link thedarkshade I'll stick that in the melting pot at our end. Do you know of any other links one could add to continue the

Regards

Chris

I'd take a look at TalkOrigins.

Excellent that one goes in as well!

Edit

Actually the Talk Origins link does not refute the specific BS proposed by our little visitor. His request is that we prove that c has not changed. If I am reading it right the TO link cites research that does not show this. The stated experimental data only says that a constant speed could fall within the experimental data. I understand this but our little creotard friend will just use it as a wriggle hole.

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OK, try these:

History of speed of light

another evidence

this last one contains a detailed mathematical explanation of that guy seems to need!

These are quiet detailed links so I hope you manage to go through them! Cheers

Has speed of light changed?

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OK, try these:

History of speed of light

another evidence

this last one contains a detailed mathematical explanation of that guy seems to need!

These are quiet detailed links so I hope you manage to go through them! Cheers

Has speed of light changed?

After a very brief look the New Scientist article looks facinating I'll have a cloaser look tomorrow as it's 01:12 in the morning here so I'm off to

Thanks for helping the noob; much appretiated.

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The question I would like answered is where on the web should I direct this person to that would show him that c has not changed since the big bang?

Hi Chris - I've not visited your forums, but I like the Dawkins.net site as a whole, and tend frequently to watch the videos of talks and lectures. They're very thought provoking, and it's nice knowing there are others approaching these issues with a similar approach to my own.

To your problem poster, you must start by knowing that no evidence you share will ever overcome their blind faith, so let's both hope that other readers approach the discussion with open eyes and ears (you may not be able to change the mind of your opponent, but you can change the minds of spectators).

I am, by no means whatsoever, an expert on this material, but I do have an amateur level interest and I'm also a decent googler.

Maybe this will help:

The "has the speed of light remained constant since the beginning of time" question/issue appears to have begun when an article was published in the journal Nature (the August 8, 2002 edition). Here is the abstract for that article:

http://www.nature.com/nature/journal/v418/n6898/full/418602a.html

There is evidence to suggest that the fine-structure constant, $\alpha$ — a measure of the strength of the electromagnetic interaction between photons and electrons — is slowly increasing over cosmological timescales.

As $\alpha$ = $\frac{e^2}{\hbar c}$ (where e is the electronic charge, $\hbar$ (pronounced H-bar) is Planck's constant and c is the speed of light), this would call into question which of these fundamental quantities are truly constant.

Here we consider black-hole thermodynamics as a test of which constants might actually be variable, discounting those that could lead to a violation of the generalized second law of thermodynamics.

Then, I found a question about that paper in the journal Nature at the Cornell University "Ask an Astronomer" site, which says the following:

http://curious.astro.cornell.edu/question.php?number=606

The article in Nature talks about the possibility of the speed of light changing over the history of the universe. Where this stems from is observational evidence that the "fine structure constant" has changed. The fine structure constant determines the exact wavelength of fine structure lines in the spectra of atoms, and measurements of the spectra of quasars suggest that it many have decreased by 0.00072 +/- 0.00018 % over the past 6-10 billion years (ref in the Nature article).

The authors of the paper argue that since the fine structure constant is equal to the charge on an electron squared divided by Planck's constant times c (speed of light), then for the fine structure constant to change one of these must also change. They go on to provide an arguement as to why they think it must be the speed of light, and that's what caught the eyes of the popular press.

However this article out today on the LANL preprint server argues why dimensionful constants (like c) cannot change, since we can just define them to be whatever we want by changing units. For example if we define units in which the speed of light and Planck's constant are both exactly equal to one (which is commonly done in theoretical Physics), then the fine structure constant is just equal to the charge on an electron squared, and the question has no meaning.

Toward the end of the above response the author (Karen Masters) referred to an article that argued those conclusions (which suggests that dimensional constants (like c) change), and that article arguing the conclusions is available at the link below (as a .pdf). I've included only brief comments from this paper, but it goes into much more detail and should serve as the evidence you need:

http://lanl.arxiv.org/pdf/hep-th/0208093

In our opinion, however, this debate has been marred by a failure to distinguish between dimensionless constants such as $\alpha$, which may indeed be fundamental, and dimensional constants such as the speed of light c, the charge on the electron e, Planck’s constant $\hbar$, Newton’s constant G, Boltzmann’s constant k etc, which are merely human constructs whose number and values differ from one choice of units to the next and which have no intrinsic physical significance.

An example of this confusion is provided by a recent paper, where it is claimed that “$\alpha$ = $\frac{e^2}{\hbar c}$, this would call into question which of these fundamental quantities are truly constant”.

By consideration of black hole thermodynamics, the authors conclude that theories with decreasing c are different from (and may be favored over) those with increasing e. Here we argue that this claim is operationally meaningless, in the sense that no experiment could tell the difference, and we replace it by a meaningful one involving just dimensionless parameters.

To reiterate: assigning a change in $\alpha$ to a change in e (Planck) or a change in $\hbar$ (Stoney) or a change in c (Schrodinger) is entirely a matter of units, not physics.

Just as no experiment can determine that MKS units are superior to CGS units, or that degrees Fahrenheit are superior to degrees Centigrade, so no experiment can determine that changing c is superior to changing e, contrary to the main claim of Davies et al.

In summary, it is operationally meaningless and confusing to talk about time variation of arbitrary unit-dependent constants whose only role is to act as conversion factors. For example, aside from saying that c is finite, the statement that $c = 3 \times 10^8 m/s$, has no more content than saying how we convert from one human construct (the meter) to another (the second).

Asking whether c has varied over cosmic history (a question unfortunately appearing on the front page of the New York Times, in Physics World, in New Scientist, in Nature and on CNN) is like asking whether the number of liters to the gallon has varied.

The "Response to Criticisms" section in the above rebuttal article is especially useful, but overall it's a very well presented paper that answers your question (or, more specifically, the question of your "God did it so you're wrong" problem poster).

I particularly like the final sentence in the quote above from the rebuttal article, so am repeating it below for emphasis:

Asking whether c has varied over cosmic history is like asking whether the number of liters to the gallon has varied.

I hope I was able to present this in a way that is approachable. Feel free to use any or all of this in your response on your own forum. There are many here at SFN who really grasp this at a much more fundamental level than me, so don't hesitate to ask further questions if you have them and I'm sure someone will be able to point you in the right direction.

Go get 'em!

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INow

There is a lot to get through and I really appretiate the time and effort you put into that post.

Thanks

Chris

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Absolutely my pleasure. It's helping people with questions like that which makes me enjoy my membership at SFN so much. Hopefully I can do my part to help increase the constituency of rationality, while learning something myself in the process.

Cheers.

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Any luck on convincing that guy CLJ?

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Well at this point he has not responded but you can see the thread here if you like here

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Well at this point he has not responded but you can see the thread here if you like here

Ok, thanks for the link. I requires a username and a password. I guess I'm gonna be a new memer;) !

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Evolutionists like to jump with both feet on Creationists, and there is certainly a lot of hostility between the two camps. This is not entirely a good thing. Men of science should be impartial, objective and open to differences of ideas and opinions. They should be, anyway. The reality is, smart people in general have extremely large egos and like to crush other people's. If someone on the street were to tell you that heavier objects fall faster than lighter objects, you shouldn't take this as a chance to make that person feel inferior to you.

The idea that c, the velocity of light, may have changed over time is not "tommyrot," any more than any other idea that has to be tested and confirmed or denied. Back in 1990 or so, this was a serious enough question for many scientists, whether they believed in evolution and an old universe or not, to put in significant effort to confirm or deny the idea. Rightly so; science is supposed to do that, not just sit up high and mighty and say, "You prove it to me." In a few years, the general concensus, even among young Earthers, is that the velocity of light has not changed significantly over the age of the Universe. But, don't act smug if some layman doesn't know about that work. I guarantee, there are many ideas that laymen--and probably many of you--believe to be true, but aren't.

Creation scientists have moved on to other ideas. D. Russell Humphreys offers an hypothesis in his book, "Starlight and Time: Solving the Puzzle of Distant Starlight in a Young Universe," in which he proposes that relativistic expansion of the Universe has resulted in objects distant from Earth experiencing time at a different rate than Earth does. Rather than dismissing this hypothesis as "nonsense," the scientific response is to test its predictions.

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Take your creationist crap elsewhere. This thread is about the consistency of the speed of light. If you want to discuss natural selection or science itself, open your own thread in the proper forum.

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Take your creationist crap elsewhere. This thread is about the consistency of the speed of light. If you want to discuss natural selection or science itself, open your own thread in the proper forum.

I may be new here, but I have known people like you for several decades. It's people like you who give science and scientists a bad name.

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I may be new here, but I have known people like you for several decades. It's people like you who give science and scientists a bad name.

You've read maybe three or four of my posts, and yet you claim to know me. Further, you lump me into some group, and suggest I'm giving that group a bad name. That's an opinion, though... not a fact.

Science is a process... a method. Scientists are people who engage in that method, and they each have their own personalities. I can be the biggest jerk and offensive son of a bitch in the world, but if my data is accurate and reproducible, then I am right regardless of how much you don't like it.

Btw... you should look up the concept of an ad hominem and how it's an argumentative fallacy.

Back in 1990 or so, this was a serious enough question for many scientists, whether they believed in evolution and an old universe or not, to put in significant effort to confirm or deny the idea.

Can you please name two of these "many" scientists, and point us in the direction of their work so we can review it for ourselves? What were their findings?

Rightly so; science is supposed to do that, not just sit up high and mighty and say, "You prove it to me."

This is known as an "appeal to shame," and is not useful (nor generally allowed) in a scientific discussion. Regardless, let me give an example of why your suggestion that this is an invalid approach fails.

If I told you that a purple unicorn washed my spaceship every Thursday, and I EXPECTED you to take me seriously, wouldn't you ask me to prove it first?

Of course you would.

But, don't act smug if some layman doesn't know about that work.

This is another appeal to shame.

I guarantee, there are many ideas that laymen--and probably many of you--believe to be true, but aren't.

And this is a strawman. How is this relevant to determining the constancy of the speed of light since t0?

Creation scientists have moved on to other ideas. D. Russell Humphreys offers an hypothesis in his book, "Starlight and Time: Solving the Puzzle of Distant Starlight in a Young Universe," in which he proposes that relativistic expansion of the Universe has resulted in objects distant from Earth experiencing time at a different rate than Earth does.

Relative to which observers? This different rate at which time passes to which you've referred above has already been described and formulated by relativity, so I'm curious how/why you think Humphrey's book is different. Please note, I am curious, and I have my eyes open, but I'm asking you to show me why it's important, not just tell me.

Rather than dismissing this hypothesis as "nonsense," the scientific response is to test its predictions.

What predictions would those be, and how can they be tested?

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Well I’m a noob here but I’m a Forum Moderator (CJ) on the Forum at Richard Dawkins Net. We often get fundy nut jobs visiting our site and we have a particularly irritating version currently bugging the other members. So I have come here to ask for some help.

Hey, what do you know, I'm a member of that forum too by the same user name (though I don't post there nearly as often as I do here )

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You've read maybe three or four of my posts, and yet you claim to know me.

Your initial reply to me was sufficiently illustrative of what is wrong with people in science.

Further, you lump me into some group, and suggest I'm giving that group a bad name. That's an opinion, though... not a fact.

You don't seem to mind opinion when it is used to attack Creationists.

Science is a process... a method.

Science is a body of knowledge. The method used to verify this knowledge is the scientific process. So, what?

Scientists are people who engage in that method, and they each have their own personalities.

Many of them are jerks, too.

I can be the biggest jerk and offensive son of a bitch in the world, but if my data is accurate and reproducible, then I am right regardless of how much you don't like it.

Yes, you could be a wretched excuse of a human being and still make excellent science discoveries. That really doesn't justify one's existence, though, and it certainly doesn't justify abusive treatment of other people. A Nobel Prize winner who violates the law still may go to prison. I believe one did, just a year or two ago, for sexual abuse, though I don't remember the specifics just now.

Btw... you should look up the concept of an ad hominem and how it's an argumentative fallacy.

After your initial post to me, you really don't have room to complain.

Can you please name two of these "many" scientists, and point us in the direction of their work so we can review it for ourselves? What were their findings?

I regret to say that in the 17 years or so since I observed these things, I have forgotten many of the people involved. However, it is really easy to find some examples by doing a quick Google search, were one inclined to find such examples.

Does the speed of light change in time?

NYT: Cosmic Laws Like Speed of Light Might Be Changing, a Study Finds

Space.com: Speed of Light, Other Constants May Change

I could easily pull up several more examples. It is interesting to me that the last 2 news stories are from 2001, a decade after I heard the matter was settled and buried. That shows how much I've kept up with it.

This is known as an "appeal to shame," and is not useful (nor generally allowed) in a scientific discussion.

Yeah, well, if I ever run into a scientific discussion, I'll keep your statement in mind. Not likely on the Internet, though.

I think you take this forum far more seriously than it deserves.

Regardless, let me give an example of why your suggestion that this is an invalid approach fails.

If I told you that a purple unicorn washed my spaceship every Thursday, and I EXPECTED you to take me seriously, wouldn't you ask me to prove it first?

Of course you would.

Or, I could just watch your spaceship on Thursday without you telling me anything.

Relative to which observers?

I already told you; relative to observers on Earth.

This different rate at which time passes to which you've referred above has already been described and formulated by relativity, so I'm curious how/why you think Humphrey's book is different.

Humphreys book is an application of Einstein's relativity. Einstein did not apply relativity to Humphreys' case. It appears that you don't understand what Humphreys proposed.

Please note, I am curious, and I have my eyes open, but I'm asking you to show me why it's important, not just tell me.

Sorry, my role here is limited to explanation, with limited argumentation.

What predictions would those be, and how can they be tested?

It would be best for you to read Humphreys own work and decide for yourself. Not that I expect you would.

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Your initial reply to me was sufficiently illustrative of what is wrong with people in science.

That reply was neither representative for the majority of the people in science, nor for the majority of the people in this forum. The last two sentences provided some funny irony, though.

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You don't seem to mind opinion when it is used to attack Creationists.

This line of discussion isn't appropriate for the physics section.

I regret to say that in the 17 years or so since I observed these things, I have forgotten many of the people involved. However, it is really easy to find some examples by doing a quick Google search, were one inclined to find such examples.

Does the speed of light change in time?

NYT: Cosmic Laws Like Speed of Light Might Be Changing, a Study Finds

Space.com: Speed of Light, Other Constants May Change

I could easily pull up several more examples. It is interesting to me that the last 2 news stories are from 2001, a decade after I heard the matter was settled and buried. That shows how much I've kept up with it.

Not too surprising to me. Scientists are always attempting to confirm results using other methods, or (better yet) find new physics in better investigations.

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You don't seem to mind opinion when it is used to attack Creationists.

In this, you are correct.

The rest of your post was just trolling flame bait, so ignored it will be. Tootles...

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Evolutionists like to jump with both feet on Creationists, and there is certainly a lot of hostility between the two camps. This is not entirely a good thing.
This really is not the place to start discussions whether evolutionists or creationists are right! You can post anything as long as it is inside the physics frames!
The reality is, smart people in general have extremely large egos and like to crush other people's. If someone on the street were to tell you that heavier objects fall faster than lighter objects, you shouldn't take this as a chance to make that person feel inferior to you.
It's not about feeling inferior, is about learning new things. I don't know who said it, but I've once heard this "everyone is smarter than me, because I learn something new from everyone"! I's not about feeling inferior!

...distant from Earth experiencing time at a different rate than Earth does.

Even you can experience time different from anyone on earth if you travel fast enough!

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Guys, I wouldn't bother arguing with Stan. The language of his posts seems to suggest that he's pretty much here to troll, and that no amount of evidence, or indeed logic, will sway his position.

You don't seem to mind opinion when it is used to attack Creationists.

Not really. A lot of what is described about them (Creationists) is generally true.

=======================================

Alright enough rant:

The links you provided are either speculation at best, or don't support your position at all. For example, if the speed of light does actually change it doesn't imply a young earth; this is known as the slippery slope fallacy.

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Guys, I wouldn't bother arguing with Stan. The language of his posts seems to suggest that he's pretty much here to troll, and that no amount of evidence, or indeed logic, will sway his position.

I'm not yet sure if this newb is a troll or just a noob.

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