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Author Topic: The red shift  (Read 2558 times)

Offline Boris

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The red shift
« on: 16/10/2005 17:27:36 »
Even the Einstein has said that the matter can "redshift" the electromagnetic waves. So, the redshift we have in the scopes is due to the matter (dark, white, you name it) that lies between the observer and the object. I just can't buy the Doppler effect. The way i see it is that if there really is some expansion it has to be with a constant speed say a cub of space with side 1 light year expands with a certian amount. And then how come some galaxy superclusters are moving in certain directions, there shouldn't be such thing, right?





 

Offline Simmer

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Re: The red shift
« Reply #1 on: 16/10/2005 17:59:13 »
Interesting idea! As you say, gravitational redshift was predicted by Einstein's general relativity and has been observed in sunlight.  

I don't know what kind of gravitational environment you would need to cause the sort of redshift seen from distant galaxies though.  As I understand it the gravitational redshift from the sun is tiny. Any astrophysicist able to put some numbers to this?
 

Dr. Praetoria

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Re: The red shift
« Reply #2 on: 17/10/2005 22:59:31 »
I was interested in this post because in later life, Einstein tried to disprove his own theories and even, earlier he tried to disprove that light's velocity was not constant but gave up on that hypothesis.  So, goes the world of science.  Could such galactic discrepancies be do to a second big bang?
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Offline gsmollin

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Re: The red shift
« Reply #3 on: 18/10/2005 18:52:43 »
quote:
Originally posted by Boris

Even the Einstein has said that the matter can "redshift" the electromagnetic waves. So, the redshift we have in the scopes is due to the matter (dark, white, you name it) that lies between the observer and the object. I just can't buy the Doppler effect. The way i see it is that if there really is some expansion it has to be with a constant speed say a cub of space with side 1 light year expands with a certian amount. And then how come some galaxy superclusters are moving in certain directions, there shouldn't be such thing, right?







If I understand correctly, you are saying that you don't believe that recessional redshifts are Doppler shifts. This is true. If the redshifts were Doppler shifts, then distant galaxies would be receding at many times the speed of light, which is not possible. Yet, we measure just those redshifts. Its general relativity, and it makes special relativity seem homey and intuitive. The usual explanation is that space is expanding, and is carrying the galaxies away from us. In GR, length, velocity, acceleration, time, and matter and gravitation are all dependent. The simple tests of GR included the bending of light by  the sun. It's not light that was bent, but the space the light traveled through. This kind of bend, which is barely visible between us and the sun, becomes overwhelming at universal distances. Scientists on those distant galaxies, see us receding from them with superluminal velocity, and yet see themselves only drifting through space at a couple hundred miles(km) per second, compared to the CBR.

"F = ma, E = mc^2, and you can't push a string."
 

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Re: The red shift
« Reply #3 on: 18/10/2005 18:52:43 »

 

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