The red shift - what does it indicate?

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First of all - please don't give me warnings if I write something that is not correct here. I'm just trying to understand the Big Bang theory, and I have some problems with it.

OK, the red shift. What does it indicate? I don't believe it indicates velocity and distance, because there are numerous observations of quasars that seemingly have an arm connection to a galaxy, but where the galaxy and the quasar have very different red shifts. How can this be explained?
 

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  • #2
LURCH
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Justy to clarify, what do you mean by "an arm connection"?
 
  • #3
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Just that it's connected, don't mind the arm. It was probably a bad translation from Norwegian to English.
 
  • #4
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All quasars live in a host galaxy of some variety. You have a reference to the claim the galaxy and the quasar have very different redshifts?
 
  • #5
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Yes, I have on another computer. Will post it here soon. In my eyes, that red shift difference disproves the Big Bang theory.
 
  • #6
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The quasars were discovered in the 60s. They have very, very large redshifts, so they should be expected to be at the very boundary of the universe. Some scientists soon found that these objects populated the regions around large spiral galaxies. There were to properties of the quasers that were difficult for astronomers to understand using the expanding universe theory:

1. If you plot the appearent brightness against the redshift as one does for galaxies, one gets an unexpected scatter on the diagramme instead of the smooth curve. This seems to indicate that the quasars do not follow the hubble law. So they are not at their proposed redshift distances.

2. Quasars are very small compact objects, so if they are really at their extreme red**** distances, they've got to be the brightest and most energetic objects known to astronomers. It would take special mechanisms to explain them. However, we don't need that.

Paculiar galaxy NGC 7603 is one of the most striking examples of galaxy-quasar connections. One redshift is 8700km/s and one that is 17000km/s. How can they be connected? Some people said it's because it's actually not the same galaxy, it just appears to be that way. This proved to be wrong. The conclusion is therefore that redshift does not say anything about the distance.
 
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  • #7
russ_watters
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Paculiar galaxy NGC 7603 is one of the most striking examples of galaxy-quasar connections. One redshift is 8700km/s and one that is 17000km/s. How can they be connected? Some people said it's because it's actually not the same galaxy, it just appears to be that way. This proved to be wrong.
How was that proven to be wrong?

The thing about redshift is that today it is not the only measuring-stick for determining distance. For shorter distances, other measuring sticks (such as supernovas, pulsars, variable stars) agree quite well with the idea that redshift is related to speed/distance.

The idea that quasars are connected to the galaxies they are objects in nearby galaxies has a bunch of flaws:
-Some are not seen near galaxies, so they would either be alone in space or different types of objects (that look the same).
-The universe is literally filled with galaxies, so it should not be surprising that quasars are sometimes seen near nearer galaxies.
-There is no known mechanism to explain the redshift other than the distance/speed relationship.

So in your right hand, you have a pile of observations that fit together well with the standard model. In your left, you have one observation [type] that may not, but only if you reject the standard model to begin with, and there is no other evidence or theoretical backing for an alternative. Occam's razor alone should dictate that your right hand is probably holding the correct answer.
 
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  • #8
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NGC 7603 has been described as "the most impressive case of a system of anomalous redshifts discovered so far". Two galaxies of different redshifts, connected by a luminous bridge,and where the bridge connects to each galaxy -- precisely exactly at each of the two points -- there is a higher-redshift object. By virtue of the luminous bridge and the perfect positions of the two faint objects, it is highly likely that these four objects are physically linked and sharing the same space -- standard cosmological model or no.

The point is that any scientific claim must be falsifiable. To hold that redshift is an absolute indicator of distance must be to allow standards of evidence which will overturn that position. NGC 7603 is evidence which meets that standard, and if it is not sufficient to overturn the standard model all on its own, it is strong enough to require addressing by the proponents of the standard model.
 
  • #9
russ_watters
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NGC 7603 has been described as "the most impressive case of a system of anomalous redshifts discovered so far".
By who?
The point is that any scientific claim must be falsifiable.
Certainly.
To hold that redshift is an absolute indicator of distance must be to allow standards of evidence which will overturn that position.
It does.
NGC 7603 is evidence which meets that standard.
It isn't.
...and if it is not sufficient to overturn the standard model all on its own, it is strong enough to require addressing by the proponents of the standard model.
Not necessarily.
 
  • #10
russ_watters
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Here's an article that disagrees with your assertions about NGC7603:
The bright galaxy NGC 7603 has an extended spiral arm which appears to end exactly on a small, high surface brightness companion (referred to here as NGC 7603B). However, the companion has a much larger redshift than that of NGC 7603, placing it conventionally almost twice as far away. Deep plates presented here show that NGC 7603 actually extends for some considerable distance beyond the companion, and that there is evidence for past interactions which can explain the disturbed structure. Narrow-band H-alpha images show no sign of strong disturbances in the feature apparently leading to NGC 7603B, which would be expected if tidal interaction is currently taking place.

No strong anomalies have been found which would force the acceptance of the existence of a noncosmological redshift.
http://adsabs.harvard.edu/abs/1986ApJ...302..245S
 
  • #11
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Have you seen the picture. I don't think it looks like an accident. Do you?
 
  • #13
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Occam's razor alone should dictate that your right hand is probably holding the correct answer.
Well, if applying Occam's Razor, you oughtn't to believe in God either. I know lots of scientists who believe in God.
 
  • #14
Wallace
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Have you seen the picture. I don't think it looks like an accident. Do you?
Read the article that Russ linked to. We can do a lot better with modern telescopes than simply take a picture and try and decide if there is a line of sight alignment or if the galaxies are interacting. We see tell-tale emission from galaxies that are interacting that are not seen in this case.

If redshifts are not cosmological, how do you explain the Lyman alpha forest seen in Quasar spectra? How do you explain the Gunn-Petersen test results for high redshift qausars? If you are not familiar with these concepts, please ask for more info, but there is a lot more that we know about redshifts and the objects we see redshifted than you seem to be allowing.
 
  • #15
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Gunn-Petersen...sounds Norwegian.

Anyway, I'll check out the concepts you mentioned. I just find it hard to swallow that time and space was once created. How can you create something without time? How can anything happen at all?
 
  • #16
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To make it simple, the red shift indicates the following:-

1)Electromagnetic radiation( visible light most of the times) has been shifted towards the red end of the electromagnetic spectrum.The red end is the less energetic end.The visible light, of course, would have been reflected or emitted by an object.

2)Any increase in wavelength, including occurances in electromagnetic radiation of non-optical wavelengths.

3)When a light source moves away from the observer.( This is according to Doppler effect)
 
  • #17
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ok, I see.
 
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  • #18
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How can you create something without time? How can anything happen at all?
 
  • #19
Wallace
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Redshift due to relative velocity as well as redshift due to gravity are not assumed to occur but have been measured time and time again in laboratories on Earth. The GPS system would not work if these effects were not considered in the positioning calculations.

The natural explanation of cosmological redshifts is the combination of the recession of galaxies and the gravitational effect of the intervening material, both of which are proven physical processes, not merely assumptions.

To suggest otherwise requires an explanation of why the supposed 'intrinsic redshift' looks exactly the same as the normal explanation, for every single spectral line produced by every molecular species observed in quasar spectra. It's a big ask, and clearly a much more complicated explanation requiring an unknown mechanism as opposed to the well understood physical mechanisms invoked in the normal explanation.
 
  • #20
Wallace
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How can you create something without time? How can anything happen at all?
We don't pretend to know all the details about the Big Bang, however the basic observation that the Universe is expanding is extremely well supported by the evidence, and alternative explanations do not stack up well. It is unwise to reject the evidence of the basic parts of the theory just because the less well understood part (i.e. the very early universe) is philosophically uncomfortable for you. This is not the way scientific progress is made!
 
  • #21
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The universe is bent in a fourth dimension, while it's expanding. But it's not expanding into anything. I don't understand this...

Do you believe that the universe is closed, open or flat?
 
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  • #22
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"Have you seen the picture. I don't think it looks like an accident. Do you?"

There are plenty of instances of QSOs intersecting galaxies, or even other QSOs. Here's a link to a paper that looked at the properties of QSOs by the absorption lines they cause in the spectra of even higer redshift QSOs. The absorption and emission line redshifts match up well.

http://arxiv.org/abs/astro-ph/0605730
 
  • #23
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OK, I finally managed to look up the pair in question. They are in the SDSS by the way (www.sdss.org). First, they are both galaxies. Second, there are countless numbers of galaxy-galaxy pairs, mergers, etc. Look up the Arp catalog for one, lots of interating systems in there.
 
  • #24
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Astronomers believe that the age of the universe is 13.73 billion years plus/minus 120 million years. Does this mean that there was nothing before the BB?

Also, is redshift the only reason why astronomers believe this?
 
  • #25
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Astronomers believe that the age of the universe is 13.73 billion years plus/minus 120 million years. Does this mean that there was nothing before the BB?
This is a question that presently has no answer. Some cosmologists believe that the universe was created out of "nothing" via a quantum fluctuation. Others believe that there was a big "crunch" from a previous universe.

Both of these scenarios would seem to beg new questions. If created from a quantum fluctuation, a qf of what exactly? Does that imply that space existed before the universe, and does it also imply that other "universes" should exist, created in the same manner? If there was truly nothing, no space, no spacetime, then what fluctuated?

If there was a big crunch from a previous universe, then the most intuitive position (to me, anyway) would be that expansion and contraction have continued for infinity. If that were the case, then it is puzzling that there is no evidence to suggest our present universe will stop expanding and "crunch".

The one thing that is generally agreed is that our universe is getting larger, and at one time was smaller. Although even that is confusing, since many if not most cosmologists believe the universe is infinite, and therefore was still infinite when smaller. Not sure how to distinguish between a large infinity and a small one!

So to answer your question, it seems a matter of conjecture at this point.
 

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