An Astronomy question not related to gravity
28 Feb 2005 16:49:38 UTC
Topic 188136
(moderation:
The heading for this fourm says that it's for questions about science and physics. I'm probably wrong for posting this question here because it has nothing to do with gravity (at least, not directly) but I really would like to understand this.
A team of astronomers at UCSD have discovered a quasar whose red-shift (2.11) indicates that it is several billions of light years away and yet it appears "closely associated" with a galaxy that's only 300 million light years away. The article is HERE
What does this mean?
Does it mean that perhaps quasars aren't the distant objects with incredibly high energies that we thought they were?
Does it mean that their apparent red-shift may be due to something else and isn't attributable to Doppler effect?
Does it mean that they really aren't "closely associated" and that's only an illusion?
There are two secrets to life: 1) Don't tell everything you know...
An Astronomy question not related to gravity
)
It's interesting. Looking at the photos, there doesn't seem to be any reason why the object in question shouldn't be far beyond the galaxy, and we are seeing it through one of the spiral arms.
There have been instances before of quasars apparently "associated" with foreground galaxies, but which were just a chance optical alignment. I wonder if this is the same in this case.
> It's interesting. Looking
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> It's interesting. Looking at the photos, there doesn't seem to be any reason
> why the object in question shouldn't be far beyond the galaxy, and we are
> seeing it through one of the spiral arms.
>
> There have been instances before of quasars apparently "associated" with
> foreground galaxies, but which were just a chance optical alignment. I wonder
> if this is the same in this case.
I wondered the same thing. The article (well, press release really) didn't shed any light on what "closely associated" meant and why these guys think the object was "closely associated" with the galaxy.
I would think that the PhDs at UCSD wouldn't fall for associating an object with a galaxy just because it happens to fall in the line of sight. I'm still trying to find out more about the project. UCSD has a fairly decent astronomy section, don't they?
Thanks for your input.
There are two secrets to life: 1) Don't tell everything you know...
There are still some
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There are still some scientists who believe in the Steady State model of the universe but I can't see any way to explain a red shift other than cosmic expansion.
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THE SPACEPORT - The Other Side of Space
After doing a considerable
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After doing a considerable amount of research about this, I've decided that I *may* have stumbled into psuedo-science. This research was headed by Dr. Geoffrey Burbidge, who, along with his wife Margaret, are opponents of the The Big Bang and are seeking proof that the solid-state model is the only one that holds up. They gave their presentation at January meeting of the American Astronomical Society in San Diego (the SD in UCSD). No information on whether anyone laughed.
They have been examining a group called Stephan's Quintet for some time. They decided on this study because of a guy named Dr. Harlton Arp, a one-time assistant to Edwin Hubble and a professional astronomer.
Dr. Harlton Arp published a book in 1998 named "Seeing Red" in which he explained away red-shifts and argued that quasars aren't distant objects. A website about Dr. Arp and his beliefs appears HERE . After reading it (and a bunch of other stuff on red-shifts, quasars , and "closely associated" galaxies with low shifts), I am unconvinced. I'll admit that some of the postulations about quasars seem farfetched. The energy of a trillion suns? Eating a 100 stars a year to stay on? Sounds odd to me.
Harlton Arp's website is HERE .
I assume Dr. Geoffrey Burbidge and his wife have tenure at UCSD. Perhaps California has lots of folks who are ready to beleive that The Big Bang didn't happen.
There are two secrets to life: 1) Don't tell everything you know...
Wow that is
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Wow that is interesting...
I dunno I have been an amateur astronomer a long time and quasars and now blazars have always seemed a bit of an enigma. It wouldn't surprise me in the least if our current theories were over turned but I don't think that's going to happen even if the facts say otherwise.
I'll ask my Astro Prof at U.T. what he thinks
starcharter, If you want
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starcharter,
If you want to have fun, look up - Dirac's Large Numbers Hypothesis (one of my old FSU profs ) Basically it could be that the gravitational constant is not constant but can vary with age of the universe or mass density. It could be that some of the red shifts are not just all from Hubble changes from expansion but we are just looking back far enough in time to see very large gravitational red shifts.
see for example:
http://www.fdavidpeat.com/interviews/dirac.htm
(about 1/2 down the page, and notice in his own words he allows for expansion also- critics often miss that point)
That theory never "took off" but it has a lot of interesting features. My guess is a lot of new folks haven't even really looked at that old theory. Some of Dirac's old ideas like antimatter and things like that have a tendency to go out of fashion then supprise people latter.
Notice also that Robert Dicke thought the large number hypothesis had to be right for us to have carbon based life
Have fun,
Dennis
Dennis, I just wanted to
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Dennis,
I just wanted to thank you for turning me on to Paul Dirac. I'm still studying his work so I don't yet have an opinion other than a first take that he seems brilliant. You actually had classes with this man?
There are two secrets to life: 1) Don't tell everything you know...
> Dennis, > I just wanted to
)
> Dennis,
> I just wanted to thank you for turning me on to Paul Dirac. I'm still studying
> his work so I don't yet have an opinion other than a first take that he seems
> brilliant. You actually had classes with this man?
>
>
Yes, he was a FSU (His GR book was an outgrowth of one of the classes). I wanted like crazy to be his grad student, but he said he "didn't do that anymore". I am not a real physics person, - biophysics instead. He lived right up the hill from me and that "old guy" loved to walk/hike, so I made sure I "walked home" with him most days. (he loved/missed black current jelly - It took an order to England, but I got him some one Christmas- instant friendship). He never said much though- he was known for not saying much - after all if you ever compare his General Relativity book of 70 pages with Thorne/Wheeler's of 1300 pages, you would get the idea.
The classic example is when he asked the class after a lengthy proof if there were any questions. One students says I don't see how you got equation #4. And he said, Yes, but are there any questions?
I must admit I didn't understand much GR then, it was not until I spent a summer in the middle of the desert (Boron, Ca) with Eddington's Math.Theory of Rel, that it started get a little clearer. I can't follow all the string stuff and have to work to get the old traditional style.
I am now semi-retired, and wish that I went after GR. To understand it and get through the math, I have to totally focus for months and months and forget family, friends, TV, news, .... these old brain cells are a little slow now.
-Every wonder "WHAT IF I HAD...."-
Dennis
> I just wanted to thank you
)
> I just wanted to thank you for turning me on to Paul Dirac. >
Oh, yes, the only equation in Westminister Abbey is the Dirac equation on a plaque to him and is next to Newton's grave. And I guess you notice that Dirac had Newton's office at Cambridge that Hawkins has now.
He was a great man. I think that if he talked more to the public he would be known like Feynman. Not many left around like him. ..... perhaps Wheeler.
> I am now semi-retired, and
)
> I am now semi-retired, and wish that I went after GR. To understand it and
> get through the math, I have to totally focus for months and months and forget
> family, friends, TV, news, .... these old brain cells are a little slow
> now.
> -Every wonder "WHAT IF I HAD...."-
Sigh..More often than I want to admit. Probably more often than is healthy. What if I hadn't been drafted to go to Vietnam? What if I had gone back into Physics at UGA after service rather than getting a job and going for bucks?
It makes me so sad to see young folks who are in school and don't know how lucky they are. They skip lectures I'd kill to get to go to. They ignore studies, cut class, get drunk instead of ...well, sort of like we were. We didn't listen and there's an excellent chance they won't either.
For those who don't know about Paul Dirac (I didn't), his biography from the Nobel comittee (1933) is HERE . From reading Dirac, I got sidetracked into reading Robert Dicke. A couple of more days of this and I'll be forced to retackle Quantum Mechanics.
I'm at least as old as you are and very likely older. I've noticed that brain cells have a tendency to speed back up when they're used heavily. I restarted college a few months ago (IT) and am quite able to stay ahead of the 20 year olds. I'd suggest there isn't an age where you're too old to go after any educational pursuit that interests you.
John Wheeler?
There are two secrets to life: 1) Don't tell everything you know...