Posted on 11/16/2006 9:07:52 PM PST by NormsRevenge
These snapshots, taken by NASA's Hubble Space Telescope, reveal five supernovae, or exploding stars, and their host galaxies in these images released November 16, 2006. The top row of images point to the supernovae. The bottom row shows the host galaxies before or after the stars exploded. The supernovae exploded between 3.5 and 10 billion years ago. FOR EDITORIAL USE ONLY (NASA, ESA, and A. Riess - STScI/Handout/Reuters)
The Orion Nebula is seen in an image taken from the Hubble and Spitzer space telescopes. FOR EDITORIAL USE ONLY (NASA/Handout/Reuters)
My BS meter is full on this one.
U.S. Senator Barbara Mikulski (D-MD), ranking Democrat on the commerce, justice and science subcommittee of the Senate Appropriations Committee, answers questions at a news conference at the Goddard Space Flight Center in Maryland, October 31, 2006. NASA announced earlier in the day that there will be a shuttle mission, planned for May 2008, to service the Hubble Telescope and keep it operational through 2013. (Jonathan Ernst/Reuters)
That picture explains why the repulsive force causing the universe to expand.
The cosmological constant was a fudge factor introduced by Einstein in an attempt to create a static Universe. Does this prove that the Universe is static?
No - as I understand it, it means accelleration, with more rapid acccelleration over time, as objects get further apart. Truely anti gravity.
It was an artificial mathematical quantity. Invented by Einstein to stabilize his world view. It made the equations work.
Yeah, right.
News Release Number: STScI-2006-52
Hubble Finds Evidence for Dark Energy in the Young Universe
http://hubblesite.org/newscenter/archive/releases/2006/52/
Whatever it is it is "dark" only to us, because we don't have the means to "see" it (to detect it) because we don't know exactly what it is. I think "dark" is an unfortunate label for it.
Background information useful for exploring this news release:
http://hubblesite.org/newscenter/archive/releases/2006/52/astrofile/
What Are HST's New Results on Dark Energy Telling Us?
1. Astronomers have greatly improved the accuracy in the measurements of the acceleration in the cosmic expansion. In 1998, astronomers discovered that the expansion of our universe is speeding up, propelled by the repulsive force of "dark energy." The nature of this dark energy remains a mystery.
2. Astronomers have strengthened the evidence that the early universe was decelerating, but that it gave way to acceleration by around 4 to 5 billion years ago.
3. Astronomers have obtained the first meaningful measurement of the strength of dark energy in the distant past. It appears to have roughly the same strength that it does today, with a value consistent with Einstein's cosmological constant but does not prove Einstein was right. Astronomers are trying in particular to determine how much pressure this dark energy exerts for a given energy density, and if the relation between pressure and density remains constant or changes with time.
4. The "pressure" exerted by dark energy far back in time was negative, as it remains today, resulting in a repulsive gravitational force.
5. The new results rule out any rapid changes of in the "strength" of the dark energy's pressure, and in so doing, they rule out certain models for the dark energy. By observing a larger sample of supernovae, the researches have been able to place tighter constraints both on this "strength" of the dark energy and on its constancy. One possibility is that the dark energy represents the energy of empty space (the physical vacuum). The physical vacuum has a peculiar property that its pressure is negative, resulting in a repulsive force of gravity. Other models for the nature of dark energy involve fields (a bit like the electromagnetic field) that decay with time.
6. There is strong evidence that the Supernovae Type Ia, the "standard candles" used to measure the rate of cosmic expansion, have not changed over the past 10 billions years, i.e., supernova evolution is not fooling astronomers into drawing false conclusions about dark energy. The new results yield the tightest constraints to date on both the "strength" of the dark energy pressure and on its constancy. The results are consistent with Einstein's cosmological constant. This means that at least some models that involve varying fields can be ruled out.
Hmmm.... the "Cosmological 'Constant'" is not so 'constant' after all. 'Fudging' with equations to satisfy the data on the false premise of a static universe yields an expanding universe in observational fact, as we now understand. If the universe were to be slightly less homogenous than presently perceived, could the "Big Bang" itself be a more local universe phenomenon in a greater whole?
Further, because Einstein was trying to account for a static universe, his "dark energy" equation could not possibly be the explanation for this phenomenon.
This article is really saying that this data no longer supports the Big Bang theory.
Oh, I see. The article wasn't very clear. Here's how it works.
Einstein's equations without the cosmological constant provide for essentially three solutions: a universe that collapses back upon itself, or a universe that expands forever, slowing down somewhat as it goes, or a universe that expands forever, but whose expansion eventually slows to a crawl. You can think of these as being akin to ballistic trajectories: the parabolic arc of an artillery shell, the escape trajectory of a deep space probe, or the orbital launch of a space shuttle.
Einstein assumed that the universe would neither expand nor contract, so he added in the cosmological constant. This parameter, depending on its value, can fine-tune the fate of the universe: the universe can collapse like the spiking of a volleyball, or it can accelerate outwards ever faster, like a rocket, or it can just hover in place, which is what Einstein wanted it to do.
Some time later, Edwin Hubble discovered that the universe was indeed expanding. It wasn't what Einstein expected, but it did seem to fit with the expanding cosmologies predicted if the constant were zero. So everyone assumed the constant was simply zero.
In recent years, however, it was discovered that the universal expansion isn't slowing down as required. In fact, it's speeding up! This most recent measurement confirms it by using Type 1a supernovae, which all have the same brightness. This allows us to measure how far away they are by how dim they appear. Also, we can measure how fast they are moving away from us by their redshift, and by how slowly they appear to cool off. That gives us all we need to see how the expansion has changed over time, if we can find enough Type 1a supernovae at a wide variety of distances.
If the expansion of the universe is speeding up, that means it can't be following one of the "ballistic" trajectories described by a zero cosmological constant. The constant must have a nonzero value very different from what Einstein originally wanted--opposite sign, in fact--but it must be nonzero nevertheless.
YEC INTREP
Wrong! It all depends on the value of the parameter. Read reply #17.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.