Is the universe is decelerating or accelerating?

Are you are an open minded individual that thinks for yourself or is your knowledge the result of a google search and quoting established scientists? Please give me a chance to change our understanding of the nature of our Universe, or if you prefer, correct the errors in my logic.

This is an issue that has bothered me for quite some time; I have reviewed the current descriptions concerning the dimness of distant type 1a supernovas and have decided that the universe is decelerating, not accelerating, as taught by mainstream science.

First, I must state that I am not challenging the discovery that distant type 1a supernovas are dimmer than a linear rate of expansion would have predicted. This is an observational “fact”. What I find faulty is the common interpretation that this dimming of distant 1asn’s indicates “acceleration”.

The following the information represents the accepted “mainstream” description of the expansion of space-time.

1998 "Science" had the discovery that the universe was “accelerating” as the science discovery of the year. A couple of links below also espouse or explain this description.

http://www.lbl.gov/supernova/
http://www.urich.edu/~ebunn/phys131/jerk/11COSM.html
http://www.sciencenews.org/articles/20000212/bob1.asp

The graphical representation of the velocity distance relationship for 1asn’s is as follows.
http://www-supernova.lbl.gov/public/...ysicsToday.pdf

Note that the recessional velocity of the supernova is on the x axis, ( a measure indicated by z) , and the distance or look back time, as determined by brightness, is on the y axis. This is not the “standard” way to represent a graphical presentation of acceleration, which is usually a velocity versus time graph. This unconventional presentation of data is because the red shift z, is easy to measure accurately, and the distance measures derived from the light curve durations/intensity of 1asn’s are more subject to variation, manipulation, and interpretation.

Now it is important to establish definitions that all parties agree on.

Deceleration. An object that moves faster in the past than the present is defined as decelerating.
Acceleration. An object that moves slower in the past than the present is defined as accelerating.

If I walked into a room at 5 miles an hour and slowed to 0 by the time I reached the far wall, I would describe my motion as decelerating. Every observer in the room would also describe my motion as deceleration.

Graphically this looks like…

( Since I do not know how to present a graph on this posting I am putting the graphs up at my web site.
www.uniformexpansion.com. The link to the specific page with graphics is http://d77591.u25.existhost.com/gpage13.html)

An object moving faster in the past than the present indicates deceleration.

The further away a galaxy is, the further in the past it is observed.
The more in the past the galaxy is observed, the faster it’s observed recessional velocity.
A galaxy moving faster in the past than the present is decelerating; our universe is decelerating.

An observer on a nearby galaxy would observe our galaxy in “motion” as it “presently” occurs. An observer on a far off galaxy would be observing our galaxy’s cosmological expansion as it occurred in the past. Our own galaxy would be observed to have a cosmological expansion rate that was faster in the past than the present. All galaxies would be perceived as moving faster in the past than the present. Our universe is decelerating.

When astronomers are describing the universe as “accelerating” they really mean that the rate of deceleration appears to be slower in the past and faster in the present. This is opposite of what was expected. The rate of expansion of space-time was expected to be very fast when the universe began, and the rate should have slowed down at the greatest rate when the universe was young, due to gravitational interaction; When the Universe is young, everything is “close” increasing the results of gravitational interaction. When the universe is older and galaxies are spread far apart, the slowing effect of gravity should diminish the rate of deceleration. Since this is not what is “observed”, this has resulted in the description of the expansion of space-time as being “accelerated”. It is also the reason that additional “dark energy” and a “cosmological constant” has been assumed to occur at specific evolutionary times of our universe.

While the rate of deceleration appears to be slower in the past than the present, the overall description of the expansion of the universe is of a continuous deceleration.

This contradictory or unexpected rate of expansion in terms of it’s deviance from expected gravitational predictions has resulted in a number of complications and a resurrection of the Cosmological Constant. A series of “fudge factors” are being incorporated into the models of General Relativity to account for the effect, which, as far as I am concerned, indicates that mainstream cosmology does not have a grasp of the situation. This is also indicated by the incorrect description of the expansion of space-time as “acceleration”.

I do not wish to diverge too much from the original posting, but I should state that my proposed uniform expansion theory resolves the conflict. The rate of expansion is actually as expected, fastest at the beginning of time and continuously slowing down; The curve describing the rate of expansion is not flat as one approaches the beginning of time, but increases dramatically as one approaches the beginning of time, as expected based upon principles of gravitational interaction and what one would expect when envisioning a “big bang”. The assumption that distant type1a supernova’s are exactly the same as local supernovas is flawed. Since the effect of gravity is a function of time, (according to my theory, (which was a belief held by Dirac and Gamow)), the further in the past a supernova is observed, the smaller it is, since it takes less mass for a star to supernova. Since a supernova’s size is reduced, the amount of light produced is less. This results in the impression that the supernova is further away than expected; in actuality (according to predictions of uniform expansion theory) they are closer. Instead of a flattening of the curve describing the velocity of distant 1asn’s, the curve increases upwards at an ever increasing rate.)

Irregardless of the application of my Uniform Expansion Theory to negate the need for a Cosmological Constant and eliminate the arbitrary applications of Dark Energy at various stages of cosmic evolution to account for the unexpected dimness of “high” red shift supernovas, the first point still remains, at all times the expansion of space time is always slowing down. The universe is decelerating.

Snowflake

I don't know for sure, but I think the theory now is that the universe will expand forever, accelerating.

The universe is not an automobile accelerating down a highway. It's the expansion of the universe that is accelerating.

You seem to imply that no one can learn anything from established scientists or google searches. One would have to have a pretty closed mind to think that.

Your "decision" is wrong, based on flawed logic. You should listen more to established scientists and do more google searches before you make such misinformed "decisions."

The galaxy isn't moving. The space between here and there is expanding. The distant supernovas are 25% dimmer than they would be if the expansion of the universe was NOT accelerating.

Incorrect. They mean the expansion of the universe is not decelerating at all. It's accelerating.

So you think that the entire scientific community "does not have a grasp of the situation," and you are the only one who does have a grasp of the situation? And you expect to be taken seriously after espousing such a position?
I believe this assertion is disproven by observations of the dynamics of distant bodies.

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Everyone is entitled to his own opinion, but not his own facts.

Just a point: plotting a measured distance versus an expected one is a fine way to show acceleration. If there is no acceleration, the plot is a straight line. If there is an acceleration (whether positive or negative) you get a deviation from a straight line. A curve in the data therefore shows acceleration. Which way it curves lets you know if things are speeding up or slowing down.

Hi Cougar,

True to form you continue to try to represent the status quo. Keep up the google searches.

Anything specific you wish me to respond to?

Snowflake

Hi Bad Astronomer

You also stated “If there is no acceleration, the plot is a straight line.” (Referring to a velocity verses time graph describing “acceleration”).

This is wrong. I think you responded too quickly to my post to make this obvious mistake. A straight line with a negative slope represents deceleration at a constant rate. A straight line with a positive slope represents constant acceleration. A negative slope with a negative curvature (slope becoming steeper when moving from the abscissa) indicates a deceleration at an increasing rate of deceleration. This is what is indicated by the plot of Type 1asn’s.

Based upon the “Cosmological Team’s” plot, the universe is decelerating faster now than in the past.

Snowflake

I believe Bad Astronomer was referring to a distances vs. time graph, in which case a straight line does indicate zero acceleration (2nd derivative = 0).

Snowflake, what degree do you have in what field? I'm not saying that people with advanced degrees are always right, but I'm saying that if you don't have a PhD in astronomy and you want to tell someone who does that he's wrong, you better first check all possibilities that it might be YOU who is wrong.

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Everyone is entitled to his own opinion, but not his own facts.

Snowflake

It is good to see that someone else has different ideas.
I am no exception. I have questioned the BB concept a while back and find it full of holes (questions with no answers).

The 1a supernovas are, to me, not accurate distance indicators. They are supposed to be the explosions of white dwarfs that have accumulated mass from a host star to the tune if 1.44 solar masses that are the cause of the eruptions.
First of all, no hydrogen emissions are seen in these explosions and white dwarfs have a huge variation in mass and emission temperatures. Therefore, any accumulated masses would also have to be variable to causing larger or lesser explosins. The dwarfs temperatures should also be a factor in precipitaing the explosion.
Therefore, I cannot give these 1a supernovas much credibility.

cyrek1

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aka Michael Cyrek

Let's look at this from a different perspective.

Instead of considering the universe, let's consider a chunk of raw space - a cubic parsec, say. When I say "raw", I mean I am abstracting it from its contents (or its contents from it).

I have never seen why gravity should come into the rate of expansion of the universe, because I don't see why raw space should be affected by it.

Raw space seems to have a propensity to expand. In fact, that is one of its most curious properties. Question is: is this property a constant relative to time? It is one of the most fundamental properties in physics. It would please the Rev Occam if it were a constant.

We may judge (on the basis of observation) that our cubic parsec expands by 10% linear in a given number of years, and so (being three dimensional) becomes about one and a third cubic parsecs.

In a following period of the same duration, given that the propensity to expand is a constant, it expands by a further 10%. However, there is now more of the original chunk of raw space to expand. The overall linear expansion is 21% and the volume has grown by more than three-quarters.

Point is, we have the effect of compound interest. A constant rate of return on your investment results in an acceleration of your wealth. And a constant propensity of space to expand results in a continually increasing value for the Hubble variable.

The conclusion of cosmic acceleration deduced from the observation of supernova "standard candles" is entirely consistent with a constant propensity of raw space to expand - at least at first glance. The interesting question is whether this remains true at second glance - or indeed after much more careful scrutiny.

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Hi Hendy

Yes you are right, A distance vs. time graph (which is usually associated with expressing velocity), formed as a flat line, does indicate 0 acceleration, the velocity is constant. At no time in any of the plots by me or of the “cosmological team” is there any graph or discussion of such a simple plot. If BA thought this, he certainly was not paying attention, and to be honest, I think he quickly put in his two cents with out thinking. I have done that more than a few times myself.

The plot used by the cosmological team to express the “acceleration” of space-time is of intensity verses z which is not a distance only versus time only graph.( http://www-supernova.lbl.gov/public/...ysicsToday.pdf ) This graph corresponds to a distance verses velocity graph. Since distance can be translated to a (look back) time, the graph also corresponds to a time verses velocity graph. If one translates the relationship into the more standard graphical representation for acceleration, the graph has to be redrawn with velocity on the y-axis and time on the x-axis. High school physics textbooks illustrate the expression of acceleration by placing the velocity on the y-axis and time on the x-axis. This is a standard graphical technique. Velocity/ Time is plotted with Velocity on the y-axis and Time on the x-axis.

On a velocity vs. time graph, if the slope is positive, the object is accelerating. If the slope is negative, the object is decelerating. A negative slope with a negative curvature (slope becoming steeper when moving from the abscissa) indicates a deceleration at an increasing rate of deceleration. This is what is indicated by the plot of Type 1asn’s. Please check this out for yourself. Take the graph http://www-supernova.lbl.gov/public/...ysicsToday.pdf and redraw it in the standard V/t format. It’s slope will be negative, indicating deceleration. The slope will also be “flatter” the closer to the beginning of time the 1asn’s are measured.

Snowflake

Hi Cougar

You stated the following.
"Snowflake, what degree do you have in what field? I'm not saying that people with advanced degrees are always right, but I'm saying that if you don't have a PhD in astronomy and you want to tell someone who does that he's wrong, you better first check all possibilities that it might be YOU who is wrong."

Facts are facts, BA is wrong in this case, he was hasty and made a mistake.

(I also have received in the past superior grades in at least as many advanced dynamic college courses in mechanics at both the undergraduate and graduate level as BA (most likely). (Engineering major, multiple fields.) The dynamics courses at the graduate level fall more into stability issues, but they also include celestial mechanics. This level of education is not necessary to describe acceleration or deceleration. The concepts are found in high school physics texts. )

Snowflake

According to SNAP physicists, and the guy on the phone, light curves from type 1A supernovas indicate that the universe is accelerating. (He also says current measurements aren't powereful enough to indicate that anything other than the cosmological constant is responsible for this acceleration.) So I'm voting acceleration.
ANy attempt at refutation of this statement should be e-mailed to the guy on the phone, who declines to give me his e-mail address.

From my reading of recent books and journal articles, this is exactly correct; that is, this is our best description of what is happening based on observations.

Then you'll be pleased to know that Ryan Scranton et al. have reportedly found independent and more direct evidence of the existence of dark energy.

When CMB photons pass by a concentration of mass (such as a galaxy) and fall into its gravitational well, they gain energy. But then they lose the same amount as they climb out of the well.... or at least they would if all they encountered was normal matter. But if the well is also permeated with dark energy, as all of space is expected to be (according to theory), the well would appear shallower as a photon passes through it (or should I say, it would get more of a dark energy "boost" upon exit, since there would be more dark energy as the photon began to climb out of the well - 50,000 years after it entered the galaxy's gravitational influence.

So the CMB photon exits with a slight energy gain. This would make the cosmic microwave background slightly hotter where there are more galaxies. Scranton et al. identified just such a positive correlation between the CMB temperature map and the distribution of about 25 million galaxies. Assuming the universe is flat (as is generally thought), dark energy seems to be the only explanation for the correlation.

[I'm not sure if this finding continues to hold, as it was reported nearly a year ago in Nature on July 31, 2003. I also (vaguely) recall a similar finding that reached a different conclusion calling into question the entire CMB interpretation (?), but IIRC, fault was quickly found with that conclusion. ALSO, please note, Mr. Uniform Expansion that the temperature variation in the CMB is really, really small, and only within the last decade or so have we been able to design instruments capable of noticing any variation at all. Hence, (if this finding withstands scrutiny), the effect of expansion on the scale of galaxies is just barely detectable.]

__________________
Everyone is entitled to his own opinion, but not his own facts.

Ha! That means the space between M31 and our galaxy is “shrinking”. I thought so!

I’m constantly amazed that when I drive to New York, the space between me and New York shrinks. And when I drive home, the space expands. This is some mysterious part of “relativity” that I’m still trying to understand. Hopefully, a thorough Google search will explain it all to me.

Hopefully.

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þeodcyninga, þrym gefrunon,
hu ða æþelingas ellen fremedon.

Actually a really good explanation of this (among many other ideas) can be found in The Elegant Universe by Brian Greene.

That’s ok. I just found a simple explanation in the AAA Driver’s Guide. Seems that when I drive toward New York, that’s what makes it appear to come closer to me, and when I drive away from it, that’s what makes it seem as if the “space is expanding” between me and New York.

Yes, those are the “black holes”.

The black holes are the missing “dark matter”. That’s why we can’t see them. They aren’t really “missing”, we just can’t see them.

You could feed a farm with a straw man of this magnitude.

Snowflake,

The Perlmutter plot you link to *is* a distance versus time plot, shown exactly as you wish it to be, with distance on the y-axis, and time on the x-axis. Let's take a good, detailed look at the plot's axes.

The plot is of magnitude vs. redshift. More specifically, it is of magnitude vs. log(z). Magnitude goes as log(d)+constant, from the distance modulus. Redshift is (1/a)-1 {a is scale factor, the size of the universe}, and a goes like time to some power. (What the power is depends on, essentially, the temperature of the universe, and the precise value doesn't matter here.) So redshift goes as t^n-1, and log(z) goes as n*log(t)+constant. So the Perlmutter plot is basically of log(d) vs. log(t).

Since this is a log-log plot, a straight line is described by a slope of one, if it were exactly log(d) v. log(t). Since the plot is of a*log(d) vs. b*log(t), that slope is a/b. Any deviation from this slope, whether or not it is a straight line, is a curve on a d vs. t plot, and so corresponds to an acceleration. Further, since the slope seen is larger than a/b, there is an acceleration, not a deceleration, as distance increases more per unit time.

If you still think that the graph is time vs. velocity, please give me a detailed argument such as I have given you.

Dax

That's just what I was going to say!

Welcome to the Board hendy. Great to see another loony Kiwi here.

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It's always good to have back up on such matters, especially since snowflake can be hard to coonvince. Just consider it saving you some writing.

Welcome to the board!

Dax

Hi Tobin Dax

Thank you so much for your response. You have no idea how grateful I am for someone willing to “get down to the nitty gritty”.

You have made a mistake in understanding what z physically represents in the graph. The Cosmological Team’s graph of Intensity verses Z, has z representing velocity. While Z is dimensionally associated with a derivate of a distance measure, its dimensional units are “lost” (D/D) (wavelength/wavelength). This ratio in this graph physically corresponds to describing the velocity of a galaxy, be it “real motion” or cosmological, or some combination of the two. (Ignoring other complicating factors or other possible theoretical or gravitational considerations). The greater the value for z, the greater the velocity. Z physically is a measure of velocity in this graph, and velocity is dimensionally expressed as d/t. This graph has z on the x axis and this means that velocity is represented on the x axis, not time as you assert.

Z can also be used to describe other physical parameters of the universe, such as scale factor. When utilizing z in a graph, it is important to understand it’s physical representation. It would have been nice if the plot made by the cosmological team was “properly” drawn in conventional units. They should have included a graph in which the z is transposed to it’s units of velocity. It is responsible for much misunderstanding, as you have revealed by your arguments.

The same argument can be made for the leaving the y axis as relative brightness. Again, one has to know that relative brightness corresponds to distance. It is a shame the cosmological team does not have a strong enough theoretician on team advocating the expression of graphs in standard dimensional relationships.

Snowflake

A galaxy is an object
True or false

An object moving faster in the past than the present is decelerating
True or false

The further in the past a galaxy is observed, the greater its cosmological velocity
True or false

The closer to the present a galaxy is observed, the smaller the cosmological velocity.
True or false.

A galaxy moving faster in the past than the present is decelerating.

The universe is decelerating.

Snowflake

Your logic is impeccable, and so is your interpretation, however, since acceleration is necessary to explain the lack of a reverb peak in the CMB,
the official interpretation is that the universe is still accelerating, but at a slower rate.

The entire Supernova scenario is the most perverted misapplications of psuedo-science in the twentieth century, and yes I am including astrology, because Riess and Perlmutter should know better.

BB cosmologists assume a strictly relativistic distance modulus, and have cast the magnitude vs. distance curve in stone.
Even though Tully-Fisher, Cepheid and Tolman surface brightness tests refused to follow this curve, they do not even consider the possibility the curve might be wrong and consistently pump out luminosity – distance evolution studies that ALL demonstrate power function evolution that is proportional to redshift distance and totally at odds with ALL metallicity studies.

Even if relativist expansion is assumed, the total lack of agreement of these fundamental indicators makes the beginning of the Hubble flow the most widely scattered data plot in science – the curves only begins to fall into line at very great distances where all the various assumptions necessary to cohearce all of these measurements into a respectable alignment come into play. This is simply a case of twisting evolutionary parameters to meet preconceptions. This is bad science and it is wrong.

The distant Supernova Ia pose a variant of the same problem: the attenuation is too great, rather than too little; and since the supernova are excellent standard candles, again, instead of even considering that the distance modulus might be wrong, they replace the Hubble constant with a jerky model that defies any physical explanation: Tractor beams in space. These are unimaginative, lazy solutions to a cosmos that is begging for new, realistic answers.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Hey, Cougar, are you feeling all right old chap ... ?
I am back on the BABB for the first time in a few months. I write something seemingly plausible and innocuous - but actually fiendishly subversive - and you sign up to it!
Have you considered the implications ... ?
Do you want to reconsider ... ?

__________________
"True skepticism encompasses not dismissing evidence because it seems to defy rational explanation."

Snowflake,

Let me start by adding something which I forgot to mention in my previous post. z is dimensionless, as is a (which is what I failed to mention), and I never meant to imply otherwise. There are a number of ways to get a~t^n, and still have a be dimensionless. The units must cancel out, and that is entirely possible. (I'll have to look this up later, I guess, to show you.)

Now, I need to point out your misconception. Cosmological redshift is *not*, I repeat, *not* a Doppler shift. It does not represent the velocity of the galaxy. It represents how much space has expanded since the photons left the galaxy, which corresponds to a time as I have said earlier. Never have I seen cosmological redshift correspond to velocity; it is always taken as distance or time. That it the case here as well.

I have made no mistake, btw. z represents cosmological redshift, as it always does. You are mistakenly stating it represents a velocity, and you have not given a sufficiently detailed explanation for that arguement.

Finally, I think that the Perlmutter data is represented in the best way possible: the plot is a plot of what was measured by the team, with no added error or misconception by tweaking the axes to your "standard dimensional relationships." The chosen axes are appropriate for the intended audience of the article, who will understand that magnitude goes like distance and redshift goes like time.

Again, if you want to convince me that z goes like velocity (when it is not a doppler shift), you need to give me a thorough explanation.

Dax