The Speed of "Light"

Terrible Tom
Terrible Tom
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Topic 188140

Someone was telling me the other day that the speed of light has "decreased". I suspect that he was in error. The last I heard it was determined to be approximately 186,270 miles per second. Some net items I saw indicated that perhaps the speed of light isn't constant, and perhaps Einstein was way off base. I suspect this too is not the case. It would appear that this could perhaps have a bearing on the current einstein@home project if any of this is indeed the case. Can some of you folks shed any current light on this subject? I would appreciate it very much.

Andy The Astronomer
Andy The Astronomer
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The Speed of "Light"

> This story about the speed of light getting slower certainly seems to be doing the rounds at the moment. It seems to originate from certain Young Earth Creationist websites; the idea behind this is that the slowing speed of light indicates a young Universe. Specifically a 6,000-year-old Universe, which is what YECs believe in.

Needless to say, it's all nonsense. In an attempt to clarify matters I e-mailed the noted physicist and author John Barrow (one Creationist had claimed that Barrow's work vindicated the claim).

Here's what John Barrow had to say :

"The ideas about changing speed of light in the very early universe were
about changes in a very narrow interval of time very close to the initial
state (if there was one). They have no effect on determinations of the
age of the universe. The evidence for variations in the fine structure
constant in the last few billion years could be interpreted as indicating
a change in the speed of light. However, even if they were the magnitude
of the change in a few parts in a million over the entire history of the
universe -- utterly insignificant for dating etc."

I hope this helps.

Iron Sun 254
Iron Sun 254
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It would be very difficult

It would be very difficult for the constant C (the speed of light in a vacuum) to change without some major revisions on how we understand the universe to work.

Take E = MC^2 for example. This formula shows that matter can be converted in energy and back based on a set ratio (C^2). Now suppose C could change, what would happen...

For simplicities sake, lets set C=1. At some period in the past this mass of 1 is converted into energy...

E=MC^2
E=M(1^2)
E=M*1
E=1*1
E=1

Okay, time passes and now C= .5 and the energy of 1 is converted back to mass
E = MC^2
E/(C^2) = M
1/(.5*.5) = M
1/.25 = M
4 = M

We started out with a mass of 1 and ended up with a mass of 4... so where'd the extra mass come from? This just defies everything we understand.

------------------------------------
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alchymist
alchymist
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> Someone was telling me the

> Someone was telling me the other day that the speed of light has "decreased".
> I suspect that he was in error. The last I heard it was determined to be
> approximately 186,270 miles per second. Some net items I saw indicated that
> perhaps the speed of light isn't constant, and perhaps Einstein was way off
> base. I suspect this too is not the case. It would appear that this could
> perhaps have a bearing on the current einstein@home project if any of this is
> indeed the case. Can some of you folks shed any current light on this subject?
> I would appreciate it very much.
>
Wow -that means that all electronic devices that use delay lines will have to be recalibrated - they will now be too long! :)

Terrible Tom
Terrible Tom
Joined: 24 Feb 05
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Thank you, I agree, Tom > >

Message 6258 in response to message 6257

Thank you, I agree, Tom
> > Someone was telling me the other day that the speed of light has
> "decreased".
> > I suspect that he was in error. The last I heard it was determined to be
> > approximately 186,270 miles per second. Some net items I saw indicated
> that
> > perhaps the speed of light isn't constant, and perhaps Einstein was way
> off
> > base. I suspect this too is not the case. It would appear that this
> could
> > perhaps have a bearing on the current einstein@home project if any of
> this is
> > indeed the case. Can some of you folks shed any current light on this
> subject?
> > I would appreciate it very much.
> >
> Wow -that means that all electronic devices that use delay lines will have to
> be recalibrated - they will now be too long! :)
>

Terrible Tom
Terrible Tom
Joined: 24 Feb 05
Posts: 4
Credit: 33,879
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Nothing like some numbers in

Message 6259 in response to message 6256

Nothing like some numbers in a case like this! Thanks
> It would be very difficult for the constant C (the speed of light in a vacuum)
> to change without some major revisions on how we understand the universe to
> work.
>
> Take E = MC^2 for example. This formula shows that matter can be converted in
> energy and back based on a set ratio (C^2). Now suppose C could change, what
> would happen...
>
> For simplicities sake, lets set C=1. At some period in the past this mass of
> 1 is converted into energy...
>
> E=MC^2
> E=M(1^2)
> E=M*1
> E=1*1
> E=1
>
> Okay, time passes and now C= .5 and the energy of 1 is converted back to mass
> E = MC^2
> E/(C^2) = M
> 1/(.5*.5) = M
> 1/.25 = M
> 4 = M
>
> We started out with a mass of 1 and ended up with a mass of 4... so where'd
> the extra mass come from? This just defies everything we understand.
>
>
>

Terrible Tom
Terrible Tom
Joined: 24 Feb 05
Posts: 4
Credit: 33,879
RAC: 0

Now this response really gets

Message 6260 in response to message 6255

Now this response really gets to the heart of the matter, in a way that that the sunday school teacher will appreciate, I do agree, and the numbers on one of the other posts fit in very well too! Thanks again, Tom

> > This story about the speed of light getting slower certainly seems to be
> doing the rounds at the moment. It seems to originate from certain Young Earth
> Creationist websites; the idea behind this is that the slowing speed of light
> indicates a young Universe. Specifically a 6,000-year-old Universe, which is
> what YECs believe in.
>
> Needless to say, it's all nonsense. In an attempt to clarify matters I
> e-mailed the noted physicist and author John Barrow (one Creationist had
> claimed that Barrow's work vindicated the claim).
>
> Here's what John Barrow had to say :
>
> "The ideas about changing speed of light in the very early universe were
> about changes in a very narrow interval of time very close to the initial
> state (if there was one). They have no effect on determinations of the
> age of the universe. The evidence for variations in the fine structure
> constant in the last few billion years could be interpreted as indicating
> a change in the speed of light. However, even if they were the magnitude
> of the change in a few parts in a million over the entire history of the
> universe -- utterly insignificant for dating etc."
>
> I hope this helps.
>
>

kolch
kolch
Joined: 18 Jan 05
Posts: 28
Credit: 60,483
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It has been reported that the

It has been reported that the speed of light has slowed since the creation of the universe. To read some of these reports check these links:

From www.space.com
From www.newscientist.com

And one with a religion/creationist slant from www.answeringenisis.org

All make interesting reading.


team.

Catch your own wave...

Dennis
Dennis
Joined: 19 Feb 05
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> It has been reported that

Message 6262 in response to message 6261

> It has been reported that the speed of light has slowed since the creation of
> the universe. To read some of these reports check these links:
> .........
> All make interesting reading.
>

Yes, there is a running debate as to if G, C, h, e, alpha, are constant or not.
Every year or so there seems to be a study that says yes, then one that says no.....
see:
http://www.sciencedaily.com/releases/2004/04/040401080310.htm
which argues against the change.

The problem I have for studies like that is that they assume that when they see something with a large red shift it must be far away and in the distant past. If G was greater in the past, that too could have caused a red shift.
What that says to me is if those "constants" change they must be doing so "together" with some kind of relationship between them (large number hypothesis) or they just don't change.
If they change together the question is why -If they are constant, then the question is why.

Dennis

Czar Brent
Czar Brent
Joined: 20 Feb 05
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Credit: 860,674
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The changing in the speed of

Message 6263 in response to message 6262

The changing in the speed of light just doesnt make any sense to me. I worked in radar for years. The red shift is caused by movement going away, wether it be the source or the receiver moving. I understand that there could be other factors such as gravity that one would be able to perceive a redshift but I would think that this would only be aparent on the edges of some body (e.g. causing a prisiming effect where light is scattered). My work with radar was with the military and we did some really interesting things with it. "Red shifting" was a technique that was used for radar deception which is what I did. A red shift can be measured on near objects as well as distant objects. And its a measure as to the speed of which an object is moving away.

I hate to take on the mentality of yesteryear when the world was flat. But these people are wackjobs. Even more-so than the string-theorists. OOPS did I say that out loud?

WARNING! DiHydrogen MonOxide kills!

Jordan Wilberding
Jordan Wilberding
Joined: 19 Feb 05
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Credit: 715,454
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> I hate to take on the

Message 6264 in response to message 6263


> I hate to take on the mentality of yesteryear when the world was flat. But
> these people are wackjobs. Even more-so than the string-theorists. OOPS did
> I say that out loud?
>

Hello, just wondering what you have against string theory? Not trying to start a flame war, just interested in other peoples ideas.

such things just should not be writ so please destroy this if you wish to live 'tis better in ignorance to dwell than to go screaming into the abyss worse than hell

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