Unveiling the Dark Energy - The Expanding Universe
- 6 Jan 2001|
While light from a distant galaxy travels across space, space itself, like this ballon is expanding. As it expands, the wavelength of the light increases, and its spectrum shifts towards red. |
Light from the most distant galaxies has traveled billions of years, giving a snapshot of the universe at a fraction of its present age. If expansion were slowing under the influence of gravity, supernovae in distant galaxies should appear brighter and closer than their high redshifts suggest.
The distant supernovae found so far tell a different story. At high redshifts, the most distant are dimmer than they would be if expansion were slowing; they must be located farther away than would be expected for a given redshift - powerful evidence that the expansion rate of the universe is accelerating.
The cosmological constant
In the very dense early universe, when matter was close together, gravitational attraction was strong and expansion was slowing. Today, because of continued expansion, matter is farther apart and the density of the universe is low - so low that it has apparently dropped below the density of some unidentified dark energy now causing it to expand ever faster.
The dark energy may be what Albert Einstein called the "cosmological constant," an arbitrary term he added to the general theory of relativity to make sure it described a static universe. Although Einstein later abandoned the idea, evidence for an accelerating universe has forced cosmologists to consider the existence of a cosmological constant once again.
In a typical galaxy, type Ia supernovae occur only a few times in a millennium, and so far only several dozen have been measured with enough precision to answer key cosmological questions. Before the nature of the dark energy can be determined with confidence, observations of many more supernovae over a wider range of redshifts are needed - observations with much better control on systematic uncertainties.
Enter SNAP, the SuperNova/Acceleration Probe. Not only will SNAP be able to find thousands of type Ia supernovae every year, it will also shed new light on galaxy clusters, gamma-ray bursters, cold dark matter, weak lensing, asteroids, astronomical transients, and many other phenomena. But its primary mission is to discover the nature of the dark energy that accelerates the expansion of the universe.
In the ancient light from thousands of exploding stars, the mysterious energy that fills the universe will be unveiled.
In [1] the aether has the important property that it is not sense or seen when it is undisturbed. Thus, the aether is a possible form of âBlack Matterâ. Moreover, if this be the case the aether and any fluid motions superimposed on it follow the nonlinear Euler equations for the adiabatic monatomic ideal fluid. Therefore, all findings in [1] may possibly apply to the present laws of mathematical physics.
[1]"The Pervasive Hubble Expansion of the Universe". See, www.drleifrongved.com
Posted by: guest - 2008-06-13 - 16:46 GMT
Dr. Leif Rongved wishes to make an additional comment.
The predictable brightness of type 1a super Novae definitely shows that their brightness is greater than predicted by present theories of physics and the Hubble law. The brightness of quasars, believed to be distant galaxies, is not predictable. Their brightness may be different for many reasons. They may be galaxies of different size. They may be galaxies in the process of formation. However, all quasars with red shifts near or above unity have orders of magnitude greater than predicted by the straight line Hubble relation for standard galaxies. See for example Burbidge, G R and Burbidge E M, Quasi-Stellar Objects-A Progress Report, Nature, Volume 224, pages 21-24, October 1969. Thus the brightness of Novae adds support to the notion that quasars may well be distant galaxies. Moreover, both Novae and quasars with red shifts near or above unity suggests that the straight line Hubble relation for standard galaxies is incorrect.
Presently there is a widespread tendency in mathematical physics and astronomy to propose ad hoc laws to fix a specific inequity of present laws of physics. One is that the expansion of the universe is accelerating. An other is that curved space exerts a drag on the earths motions. There are other inequities waiting to be resolved. For example, the derivation of the cosmological red shift is a questionable application of Dopplerâs law.
There is a purely analytical paper in exact accord with Eulerâs nonlinear equations, The Pervasive Hubble Expansion of the Universe, which shows that the Hubble expansion is only a small part of a pervasive Hubble law. In one scoop the pervasive Hubble law resolves all the above mentioned inequities. Moreover, it resolves all paradoxes and peculiarities associated with Einsteinâs theories that have irritated and puzzled many scientists for years. The paper is presently under review for publication. However, a PDF format of it is available on the web site, www.drleifrongved.com.
Remarkably the paper is in complete accord with all present laws of physics at the present time. It suggests changes to all laws of physics by about one part in 10 billion parts per year as long as the distances fore or back in time are much less than the Hubble age of the universe. The changes increase without limits when the distance back in time approaches the Hubble age.
Posted by: guest - 2007-11-26 - 05:40 GMT
The Accelerating Expansion of the Universe is a Figment of Imagination.
The brightness of type Ia supernovae is very predictable. Their observed brightness is used to predict their distances away from us. This type Novae within galaxies with red shifts near and above unity are brighter than expected from their distances away. There are now several assumptions around to explain the larger than expected brightness of Novae.
One assumption is that galaxies near us recede with greater velocity than galaxies farther away. An other is that all galaxies accelerate away from us. By these assumptions and the observed large scale isotropy of the universe the acceleration must be the same in all directions relative to us. Or the acceleration must be a function of their distances away from us. Since all galaxies accelerate away from us the forces on their near sides must be greater than the forces on their far sides. Therefore, if âitâ is whatever accelerates the galaxies, âitâ must be greatest at our galaxy and must diminish as one proceeds on any radial line away from us.
This is OK if we assume that we are at the center of the universe, which is an entirely unacceptable assumption.
Or it is OK if we assume that âitâ is at the present time greater at any given galaxy of the universe and less at all others, which is also an unacceptable assumption.
Or it is OK if one can show that âitâ, uniformly distributed throughout the universe, causes the galaxies to accelerate away from us. This notion is completely at odds with our every day experience. We are exposed to an atmospheric pressure of about 15 lb. per square inch. This pressure does not push us apart, because it is equal on all sides of us. It does reduce our volumes a bit so that the pressure is sensibly constant throughout our body.
It is of interest to note that the Hubble expansion is in exact accord with Eulerâs nonlinear equations for all ideal fluids where the fluid pressure is a function of the fluid density. See for example, Rongved, L. "Fluid Dynamics of an Expanding Ideal Fluid", Quarterly of Applied Mathematics, Vol. XLVII, Num. 4, p 735-745. 1980. In this expansion the fluid pressure and density are gradually diminishing with time. However, they are uniform throughout space at any given time.
Another important property of the Hubble expansion is that on a large scale it is identical relative to all galaxies of the universe. Any galaxy will appear to be at the center of the expansion. It is in accord with the observed isotropy and uniformity of the universe on a large scale. Thus, the Hubble expansion makes sense for more than one reason. The accelerating expansion makes no sense at all!
For an explanation of the greater than expected brightness of Novae and quasars see the web site, www.drleifrongved.com. In one scoop one resolve the brightness problem and several outstanding questions and paradoxes of mathematical physics and astronomy.
Posted by: guest - 2007-11-15 - 11:55 GMT
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