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Nobel Prize for Studying the Expanding Universe

I just read THIS article, and something about it just doesn't add up.

According to the article, the scientists in question have stated the the expansion of the universe is not slowing, but is constant.

However, there is this quote:
He said galaxies that are 3 million light years away from Earth move at a speed of around 44 miles per second (70 kilometers per second). Galaxies that are 6 million light years away move twice as fast.
The way I read it, that the universe was expanding twice as fast six million years ago as it was 3 million years ago.  So the expansion is slowing down.

Am I wrong in this?  How so?
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Clif
Asked:
Clif
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2 Solutions
 
TommySzalapskiCommented:
Light years are a unit of distance, like miles. So the ones that are farther away are moving faster but all are moving at a constant rate.
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Paul MacDonaldDirector, Information SystemsCommented:
It's been pretty well established that the farther an object is away, the faster it appears to be receding.

 It seems space itself is expanding. The more space between you and another object, the faster it appears to be moving away.
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TommySzalapskiCommented:
One light year equals the distance light travels in a year or about 5880000000000 miles (9460000000000 km)
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ClifAuthor Commented:
Distance equals time.

What we see six million light years away is what was occuring six million years ago.

What we see three million light years away is what was occuring three million years ago.

Is this not true?

If we a galaxy three million light years away moving at a rate of 70 km/sec, then that galaxy was moving at that rate three million years ago.  If we see a galaxy six million light years away moving at a rate of 140 km/sec, then that galaxy was moving at that rate six million years ago.
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TommySzalapskiCommented:
Yes. And that's why everyone always thought that the expansion was slowing down. This article (true or not) is claiming that this is not the case and that even though the farther objects are moving faster, it is not because of the time difference. It is claiming that all the movement is constant and there are other factors that caused the farther ones to be moving faster.
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TommySzalapskiCommented:
Of course, if the speed of light is actually decreasing, that would also explain the apparent expansion of space and the universe. So if you believe as some do (http://www.google.com/search?q=speed+of+light+not+constant) that the speed of light is actually slowing down, then maybe nothing is expanding.

It's all theory and it's very prestigious to successfully disprove the current thought so people will always be trying to come up with new explanations for things. Usually they are wrong, but occasionally they are revolutionary.
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ClifAuthor Commented:
So, they are saying that it is observed, but it's not the case.

I did not read that part anywhere in the text.  Can you point it out?
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deightonCommented:
if space itself is expanding, then points further apart will recede from each other more rapidly.  There is more space between them to expand, so the total rate at which they move apart is higher.

But they are also saying the rate of expansion is increasing
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TommySzalapskiCommented:
Yes. The rate is constantly increasing, not strictly constant.

Anyway, the article itself doesn't really address any of the hows and whys. It just states that they found that the expansion is increasing, not slowing and that it was verified by third parties. If you really want the nuts and bots behind it, you would have to track down the academic articles they published on their work.
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ClifAuthor Commented:
Odd that the article would say, "This is what people believed, and these scientists won an award by proving everyone wrong."  But not going into any suggestion, or even the hint of a suggestion, of what the scientists did that proved everyone wrong.
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TommySzalapskiCommented:
Well, it's a news article. Most readers will already feel like it's over their heads with what's there.
There's a little more technical detail here: http://newscenter.berkeley.edu/2011/10/04/saul-perlmutter-awarded-2011-nobel-prize-in-physics/
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ClifAuthor Commented:
Sorry, I still don't see what the data is that showed the Universe is speeding up.  Please cite the paragraph.
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TommySzalapskiCommented:
The whole section "Using supernovae as cosmic yardsticks" is basically all you get. They just took distance measurements. Speed is just change in distance over time. The measurements didn't line up with the expectations from the previous idea. Since things were farther away than they would have been at the previously assumed speeds, they must be moving faster than we thought.
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ClifAuthor Commented:
Since things were farther away than they would have been at the previously assumed speeds, they must be moving faster than we thought
Yes, at farther distances, which makes sense if you see farther away as also farther back in time.

Look, I'm no Sheldon Cooper or Leonard Hofstadter.  I'm sure these guys deserve whatever awards they got.  I'm just not seeing what they're seeing.  Or, more presicely, I'm seeing the exact opposite of what they're saying.

As I said in my second post, when I observe something six million light years away, I'm seeing it as it was six million years ago.  When I observe something three million light years away, I'm seeing it as it was three million years ago.

Therefore, if I see a galaxy three million light years away moving at 70 km/sec, I can say thet the galaxy was moving at 70 km/sec three million years ago.  If I then see a galaxy six million light years away travelling at 140 km/sec, I can say that that galaxy was moving at 140 km/sec six million years ago.

Ergo, if movement was at 140 km/sec six million years ago and 70 km/sec three million years ago, I can say that the movement is slowing, not speeding up.
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Paul MacDonaldDirector, Information SystemsCommented:
The six million year-old galaxy has a 3 million year head start.  If it accellerates at a constant rate, why wouldn't it recede twice as fast as a 3 million year old galaxy?
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aburrCommented:
"the expansion of the universe is not slowing, but is constant."
but the discovery said the expansion is speeding up, not constant





He said galaxies that are 3 million light years away from Earth move at a speed of around 44 miles per second (70 kilometers per second). Galaxies that are 6 million light years away move twice as fast."
A good point BUT the illustration in this and similar popular articles is NOT the basis for the discovery.
Basically they used intensity measurements to draw maps of the universe at different times.
The whole process was time consuming and required many intellectual steps.Many details are given in the following reference - (Riess et al. 2004, ApJ, 607, 655).
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ClifAuthor Commented:
The six million year-old galaxy has a 3 million year head start.  If it accellerates at a constant rate, why wouldn't it recede twice as fast as a 3 million year old galaxy?
It's not accelerating, though.  It's decelerating.

The farther back in time you go, the faster things are moving.  Or, contrarywise, the more recent (the observation of) the object is, the slower it's moving.

Which is my point.  The expansion isn't speeding up, it's slowing down.
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aburrCommented:
If you want more details of the expansion ork here are som more links.
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2011 Nobel Physics Prize Winners
Saul Perlmutter, Brian Schmidt, and Adam Reiss share the 2011 Nobel Prize in Physics "for the discovery of the accelerating expansion of the universe through observations of distant supernovae." Read more.
AIP is making available, free of charge, a selection of research papers these Nobel Laureates have published in their journals, Conference Proceedings, and Physics Today magazine. View these materials.
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ClifAuthor Commented:
First link gives me bios of the winners.  No details about why they believe the expansion is accelerating (despite observations to the contrary)

Second link gives me a bunch of other links to articles which may or might not answer my question.

Re The second link: How would you feel if you asked a question and I posted back, "The answer's here" and gave you the address to the Library of Congress?

Once (yet) again...  The observations stated in several places (including the links provided in this thread) say that galaxies farther away are moving faster than galaxies closer.  This is consistent with the belief that the acceleration of expansion is slowing.  That is, six billion years ago the speed of expansion was twice what it was three billion years ago.  (This, also, I have yet to hear an agreement on.)

Rather than baffle me with bullshit ((that is dumping a bunch of links on me hoping that I'll just be overwhelmed by the mass of information) how about a single link with a citation as to what caused these scientists to say, "While the observations show that the speed of galaxies six billion years ago was twice what it was three billion years ago, it's actually the opposite and here's why..."
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aburrCommented:
"how about a single link with a citation as to what caused these scientists to say, "While the observations show that the speed of galaxies six billion years ago was twice what it was three billion years ago, it's actually the opposite and here's why.."
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There is a very simple reason that a single linke saying what you want is does not exist.
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jmpg_70Commented:
My mind is blown by another scientist from my home town winning the Nobel prize.
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tliottaCommented:
The problem is that there is no fixed point of reference.

That is, six billion years ago the speed of expansion was twice what it was three billion years ago.  (This, also, I have yet to hear an agreement on.)

There is no good way to reach that conclusion from observed effects. The observation don't say how fast anything is moving. The observations are about how much the distances are increasing between the objects.

If you drive away from your house, you can notice that the distance between you and your house is increasing. Generally, you can also say that you are the one that's moving, not your house. That's because we use the surface of the Earth to provide fixed reference points.

But it can't work that way in cosmic distances. There's no way to know if the 6million-light-year object (6Mo) is moving at all. It is just as correct to think of it as remaining in one spot while we are the ones moving away. And if we are the moving object, what does it say about rates of acceleration/deceleration over cosmic timescales?

Now, imagine the 6Mo, the 3Mo and us.

Let's say that 3Mo is staying in one spot while 6Mo is moving away from it at the same rate we are moving away from it in the opposite direction. As we look at 3Mo, we see the distance increasing at a particular rate. We then look farther and see the distance to 6Mo is increasing twice as fast. Increases in distance only tell you relative information.

But that doesn't let you conclude that 6Mo is moving twice as fast as 3Mo -- 3Mo isn't moving at all, maybe.

And that's not even close to some of the really weird things about cosmic measurements.

Tom
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aburrCommented:
The illustration at the beginning of this thread of speed of galaxies vs distance is completely irrelevant to the Nobel prize. It written by somebody in a hurry. The difficulty with the illustration was pointed out by the asker of this question.
The Nobel work was done with astronomical objects with known intensity. There spectrum allowed the astronomers to know both their distance and their velocities. That enabled them to plot velocity vs age. The resultant graph is given here. (Note the graph is very schematic and is only roughly the same as the real data The variable expansion of the universe
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ClifAuthor Commented:
There is no good way to reach that conclusion from observed effects. The observation don't say how fast anything is moving. The observations are about how much the distances are increasing between the objects.
So when they said that galaxies six million light years away are moving twice as fast as galaxies three million light years away, they didn't really mean it?

I can not believe it!  They changed the article!  I was looking for the quote from the article that I had posted in the OP and it's gone!  No mention (now) that galaxies six million light years...  yada, yada.

I guess maybe someone heard my questioning and had to change the article to match with the outcome.  In other words, "If the facts don't fit the theory, change the facts."
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aburrCommented:
"In other words, "If the facts don't fit the theory, change the facts.""
NO
If you put up an incorrect illustration (not a fact), you remove it.
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ClifAuthor Commented:
Well, since they are changing the facts, I guess I'll be on my way.

I was going to spread out the grades and points, but it says I have to award a minimum of 20 points in a split (for a 50 point question, that's two askers), so I just picked the two with the most comments.  No offense to others with equally valid statements that did not get points.

Thanks for the discussion.
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TommySzalapskiCommented:
For future questions, you can increase the point value of the question if you want to split more or give more points.
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