Universe Expansion, Exotic vs. Dark Matter?

[pianoman1976]

Hello friends,

 

I just began reading a new book, 'The Creator and the Cosmos' by Hugh Ross. It was published in 1993.

 

I've barely made a dent in this book and I've already hit a wall. I'm confused about two things, and was hoping you could help clear up the confusion.

 

1. Ross states that the expansion of the universe is slowing. He implies this is popular opinion in the science community (circa 1993). I thought that the expansion was accelerating? What's the skinny on this?

 

2. Ross speaks of exotic matter. I'm familiar with dark matter. Has the terminology changed?

 

Thanks,

 

Ryan

[TheFaithfulStone]

1. Yes - the consensus position has changed. Look up the FLRW (I think) metric.

 

2. Nope, something different. Exotic matter is matter with negative mass energy. Dark matter is matter that doesn't interact with baryonic (regular) matter except gravitationally.

 

TFS

[pianoman1976]

 

2. Nope, something different. Exotic matter is matter with negative mass energy. Dark matter is matter that doesn't interact with baryonic (regular) matter except gravitationally.

 

TFS

 

Negative mass - like a tachyon? I thought that type of thing was dismissed some time ago?

[InfiniteNow]

Negative mass - like a tachyon? I thought that type of thing was dismissed some time ago?

 

You also thought that the current consensus was that expansion was accelerating. :eek_big:

 

 

Science is amendable. :eek_big:

 

 

Friedmann-Lemaître-Robertson-Walker metric - Wikipedia, the free encyclopedia

[pianoman1976]

I'm not understanding the FLRW metric completly. This equation states that both the energy density and the pressure causes the universe expansion rate to decrease.

 

Does this defeat the dark energy concept of quintessence?

[coldcreation]

Hello friends,

 

I just began reading a new book, 'The Creator and the Cosmos' by Hugh Ross. It was published in 1993.

 

I've barely made a dent in this book and I've already hit a wall. I'm confused about two things, and was hoping you could help clear up the confusion.

 

1. Ross states that the expansion of the universe is slowing. He implies this is popular opinion in the science community (circa 1993). I thought that the expansion was accelerating? What's the skinny on this?

 

2. Ross speaks of exotic matter. I'm familiar with dark matter. Has the terminology changed?

 

Thanks,

 

Ryan

 

 

 

Today, in the face of contradictory observational evidence (gathered during the 1990s, see SNe Ia data), cosmologists have resurrected a fragment from the debris of general relativity and have found for it a new identity and have affirmed thus its ‘material’ qualities. (One mans trash is another man treasure; so the saying goes). Recent interpretations of observational data have tilted the balance in favor of a nonzero cosmological constant or that we inhabit an open universe.

 

In the eyes of the beholder, a cosmological constant-dominated universe expands endlessly and is literally driven by a motor-like force (with the same name that Einstein attributed to the term in his equations designed to mediate equilibrium and stability of the universe).

 

The problem did not exist to the post-1998 extent back in 1993: The crux of the interpretation that the universal expansion is accelerating revolves round the following:

 

 

· Distant supernovae and their host galaxies appear to be receding slower than permitted by Hubble’s Law (the proportionality between redshift and apparent magnitude). Remarkably, the observations are consistent with an accelerating expansion of the cosmos. Commit to memory that if galaxies were receding with less velocity in the past (in the look-back time), it means that instead of decelerating as was predicted, the universe appears to be picking up speed, accelerating outward for the past few billion years.

 

· The large shells of radiation and material emitted by distant (ancient) supernovae appear to have a greater area than they would in a topologically flat space, making the source look very faint.

 

· The visible universe appears larger, deeper, younger, and emptier than previously suspected.

 

· Unexpected dimness of early supernovae gives the impression they are further away than their redshifts indicate, altering the predicted structure of the cosmos.

 

· These observations indicate that 96 percent of the matter and energy in the universe is missing (dark).

 

· Light from very remote objects takes longer to reach Earth—as if time and space (and the light propagating through it) were continually and increasingly ‘stretched’ with larger distances.

 

· The universe could be as young as 12.5 billion years old—a figure at odds with the age of some of the objects in it.

 

 

 

Couple the latter possibility with the emerging problem that metal-rich massive galaxies are discovered at increasingly greater distances and increasingly further back in time.

 

 

Something has only just begun

 

 

 

 

 

 

CC

.

[TheFaithfulStone]

Okay, the mass of a tachyon is imaginary, not negative, which is why it would always travel faster than c.

 

And quintessence is a theory of dark energy, not of dark matter.

 

TFS

[pianoman1976]

 

And quintessence is a theory of dark energy, not of dark matter.

 

TFS

 

oops. That was a typo. :)

[Pluto]

Coldcreation, you have logic. Good to see in this day and age.

 

Recent interpretations of observational data have tilted the balance in favor of a nonzero cosmological constant or that we inhabit an open universe.

 

 

I have read your other posts. Well done.

 

I have one problem, why is it that man's research shows that the universe is expanding proportionally away from earth. Is there an error in man's calculation or is it that man thinks himself as the centre of the universe.

[pianoman1976]

I have one problem, why is it that man's research shows that the universe is expanding proportionally away from earth. Is there an error in man's calculation or is it that man thinks himself as the centre of the universe.

 

There is no specific point being the center. It's all the center. Take a balloon for example. As it inflates, every point expands away proportionately. Take all the air out and you have just one point.

 

Galaxies are not moving through space in the conventional sense but are being carried along as the fabric of space itself stretches.

[coldcreation]

Coldcreation, you have logic. Good to see in this day and age.

 

 

 

 

I have read your other posts. Well done.

 

I have one problem, why is it that man's research shows that the universe is expanding proportionally away from earth. Is there an error in man's calculation or is it that man thinks himself as the centre of the universe.

 

We are in the center of the universe (both spatially and temporally)!

 

So too is everyone else (whomever, whatever and wherever they are), from their own perspective.

 

The calculations are not is error, it is the interpretation of cosmological redshift z (in my opinion) that is spurious.

[Pluto]

Hello Coldcreation.

 

Your right

[S.Ingvar]

(---)

I have one problem, why is it that man's research shows that the universe is expanding proportionally away from earth. Is there an error in man's calculation or is it that man thinks himself as the centre of the universe.

Yes, there are errors in the calculations behind the bigbang-interpretation.

 

When Edwin Hubble discovered the displacement (redshift) of the spectral-lines in the galaxies' radiation, the only known explanation at that time was the Doppler-velocity frequency-shift from sound-observations.

As a tentative hypothesis Hubble calculated the redshift as a velocity-effect caused by the galaxies receding.

 

The famous astronomer Halton Arp explains it as following:

If the wavelength of an absorption line in an object's observed spectrum appears at a wavelength that is, say, 1.56 times its 'normal wavelength' (the wavelength at which it is observed in a laboratory experiment here on Earth), then we say this object has a positive redshift of z = 0.56. The 'z value' is simply the observed fractional increase in the wavelength of the spectral lines. The simple interpretation of this is to say that this object must therefore be receding from us at 56% of the speed of light or 0.56 x 300,000 km/sec. Mainstream astrophysicists believe that recessional velocity, v = cz. This object, therefore, must be very far away from Earth.

 

But there is a general displacement law that I have found that shows how the radiation’s energy (of the galaxies) decline with increasing wavelength towards thermal equilibrium which is in the deep space at the heat death end as background radiation.

 

[math]\displaystyle \displaystyle \frac{\Delta\lambda}{s}=k[/math]

 

where [math]\Delta\lambda[/math] is the fractional displacement, s is the covered distance, and k is the constant for this relation.

 

This new law is consistent with Wien's displacement law.

 

This law is an entropy-law that is the same for electrodynamics (like light-waves), hydrodynamics (like water-waves), and air-dynamics (sound-waves).

The formula demonstrates that there is a constant proportional relation between wave-displacement and distance.

The same wave-displacement law but different constants.

Electrodynamic waves are fractionally displaced 6.6*10^-34 with the distance.

My experiment shows that water-waves are displaced 0.17 with the distance.

My experiment shows that sound-waves are displaced 10^-4 with the distance.

 

Consequently, the Universe is not expanding and there is no need for "dark energy".

 

Se my experiments via Google at "theuniphysics"

 

Dark matter is another misinterpretation of measurings of rotating galaxies' velocity curve.

Vera Rubin and her followers have only mixed up the orbital speed with the angular velocity.

So, "dark matter" is not needed to explain the galaxies' velocity curves that follow well known physical laws.

 

Ingvar

[coldcreation]

Yes, there are errors in the calculations behind the bigbang-interpretation.

 

When Edwin Hubble discovered the displacement (redshift) of the spectral-lines in the galaxies' radiation, the only known explanation at that time was the Doppler-velocity frequency-shift from sound-observations.

As a tentative hypothesis Hubble calculated the redshift as a velocity-effect caused by the galaxies receding.

...

Ingvar

 

Historically, (a) Hubble did not 'discover' the redshift of nebulae. (:shrug: there were several other interpretations (besides a Doppler effect) for the cause of redshift at the time (see the literature, Hubble's for example, or even Arp, since you quote him: Seeing Red). The de Sitter effect was known and so was 'tired light.' I beleive a fourth redshift effect was called the K term (William Wallace Campbell, Lick Observatory). I beleive the corrections are still made for this effect.

 

So at least three different mechanisms for redshift were known before 1929 (the famous year of Hubble's 'discovery').

 

On that score, most tired light models (but not all) have been excluded on observational grounds: There is not wavelength independence accross the spectrum, no bluring of the image, or two factors of (1 + z).

 

The K term is, if I recall, a more local effect on the surface of stars (e.g., white dwarfs).

 

The de Sitter effect remains, as it was in 1929, a viable alternative for the interpretation of cosmological redshift z. This effect is wavelength independent acrros the entire spectrum, there are by definition two factors of (1 + z) due to time dilation with increasing distance from the observer, etc.

 

If this interpretation had been chosen by Hubble, and it almost was, instead of the Doppler interpretation (this interpretation was more speculative at the time, and the math was unfortunately far more difficult, since it was founded on pure general relativity) the concept of instability associated with expansion, and thus the big bang, would likely never have raised its ugly head. The concept would have remained a curiosity, an artifact, as it was within the Friedmann equations, circa 1921.

 

 

It is a pitty today that the de Sitter effect is not scrutinized further. The 'discovery' that the universe is not expanding impinges upon it.

 

 

 

 

CC

[freeztar]

Today, in the face of contradictory observational evidence (gathered during the 1990s, see SNe Ia data), cosmologists have resurrected a fragment from the debris of general relativity and have found for it a new identity and have affirmed thus its ‘material’ qualities. (One mans trash is another man treasure; so the saying goes). Recent interpretations of observational data have tilted the balance in favor of a nonzero cosmological constant or that we inhabit an open universe.

 

In the eyes of the beholder, a cosmological constant-dominated universe expands endlessly and is literally driven by a motor-like force (with the same name that Einstein attributed to the term in his equations designed to mediate equilibrium and stability of the universe).

 

The problem did not exist to the post-1998 extent back in 1993: The crux of the interpretation that the universal expansion is accelerating revolves round the following:

 

 

· Distant supernovae and their host galaxies appear to be receding slower than permitted by Hubble’s Law (the proportionality between redshift and apparent magnitude). Remarkably, the observations are consistent with an accelerating expansion of the cosmos. Commit to memory that if galaxies were receding with less velocity in the past (in the look-back time), it means that instead of decelerating as was predicted, the universe appears to be picking up speed, accelerating outward for the past few billion years.

 

· The large shells of radiation and material emitted by distant (ancient) supernovae appear to have a greater area than they would in a topologically flat space, making the source look very faint.

 

· The visible universe appears larger, deeper, younger, and emptier than previously suspected.

 

· Unexpected dimness of early supernovae gives the impression they are further away than their redshifts indicate, altering the predicted structure of the cosmos.

 

· These observations indicate that 96 percent of the matter and energy in the universe is missing (dark).

 

· Light from very remote objects takes longer to reach Earth—as if time and space (and the light propagating through it) were continually and increasingly ‘stretched’ with larger distances.

 

· The universe could be as young as 12.5 billion years old—a figure at odds with the age of some of the objects in it.

 

 

 

Couple the latter possibility with the emerging problem that metal-rich massive galaxies are discovered at increasingly greater distances and increasingly further back in time.

 

You can add this one to the list ColdCreation:

Texas A&M University News & Information

The ESSENCE team can then use the value of the acceleration to figure out the density of dark energy, which they then use to calculate what is called the w-parameter. For Einstein’s cosmological constant to be correct, the w-parameter must equal -1, and so far, the results of the ESSENCE project seem to confirm that it is indeed very close to -1.

 

“The magic value is -1 exactly,” Krisciunas said. “If the number turns out to be precisely -1, then this dark energy is a relatively simple thing – it is Einstein’s cosmological constant.” The team won’t have the final results until later next year, but right now, the measurement is coming in at -1 plus or minus 10 percent error, Suntzeff said, so the initial data seems to point to Einstein being correct.