Dark Matters

[PPI Karl]

There are paranormal theorists who believe dark energy has a connection to certain kinds of paranormal activity.  I'm intrigued by the possibility, by I fear I'm out of my ken to understand the connections.  Regardless, it does look more and more as though whatever dark energy is, it does now have a higher probability of existing and affecting us.


Bizarre Dark Energy Theory Gets Boost From New Measurements
by Clara Moskowitz, SPACE.com Senior Writer
Date: 15 March 2011 Time: 11:15 AM ET

Gazing deep into the universe, NASA's Hubble Space Telescope has spied a menagerie of galaxies.
This image represents a typical view of our distant universe. In taking this picture, Hubble is looking
down a long corridor of galaxies stretching billions of light-years distant in space, corresponding to
looking billions of years back in time.  CREDIT: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

New measurements of the expansion rate of the universe lend new support for the theory of dark energy that suggests a mysterious force is pulling the cosmos apart at ever-increasing speeds.

Scientists have few ideas why such a force would exist, but the evidence for dark energy ? which like dark matter has remained elusive to detection attempts ? is growing, and a competing hypothesis can apparently be ruled out.

In a new study, a team of researchers led by Adam Riess of the Space Telescope Science Institute in Baltimore, report that they've calculated how fast the universe is expanding to a greater degree of accuracy than ever before, shrinking the error bars on their measurements by about 30 percent.

The improved accuracy comes thanks to the Wide Field Camera 3 on the Hubble Space Telescope. It's a new instrument that was only installed on the orbiting observatory in 2009, during NASA's last space shuttle mission to upgrade the space telescope.

"Without the improvement in efficiency capability from the new camera, it just wouldn?t have been feasible," Riess told SPACE.com Monday (March 14). "It's just a different generation of technology than the previous camera."

The researchers used the new camera to observe a special class of exploding stars called type 1a supernovas, which are useful because they always release the same amount of light. Astronomers compare this intrinsic brightness to their measured brightness ? which varies depending on how far away from Earth they are ? to judge cosmic distances.

The new measurements confirm astronomers' growing consensus that the universe is not only expanding like a balloon, but picking up speed in doing so.

Based on our current laws of gravity ?namely, Einstein's theory of general relativity ? that's unexpected. To explain this surprising reality, scientists came up with dark energy, which would counteract the force of gravity that tries to pull the universe inward. But to date, dark energy has remained undetectable to astronomers.

Dark energy opponents
Not all experts are comfortable with the idea that a strange force is mysteriously tugging the universe apart.

"Theorists have come up with very creative ways to get out of dark energy, which would be great because we don't understand dark energy very well and it would be nice to find a way that the universe was simpler," Riess said.

One such alternative is the idea that our cosmic neighborhood ?the solar system and the whole Milky Way galaxy ? happens to sit at the center of a relatively empty bubble of space eight billion light-years across.

If this were the case, we would measure the same accelerated expansion rate we do, except it would be an illusion created by our special position in the void.

But the new precision measurements of the universe's expansion seem to rule out that idea, which predicts a somewhat different value for the expansion rate.

"This new paper by Riess et al. reduces the errors on the measurement of [the expansion rate], and so improves even further the already high confidence that one should have in saying that these models are ruled out," said Timothy Clifton, an astrophysicist at the University of Oxford who was not involved in the new research. "In this sense, they improve the evidence for the existence of dark energy."

However, Clifton cautioned that the new measurements do not disqualify all versions of the void model. In some more complicated scenarios in which the big bang did not happen at the same time at all points in space, this hypothesis could still be valid.

Ultimately, Riess said many scientists are dubious of all the void models anyway.

"I know that a lot of people have not taken that theory very seriously because of a major problem with it," he said. "We tend to believe theories where we don?t live in any special place in the universe. That would be very strange ? why should we be in a special place?"

Now that scenario is even less likely to be true, Riess said.

"But on the other hand, dark energy's pretty weird too," he said.

However, it looks like we may be stuck with it.

Riess and colleagues report their findings in the April 1 issue of The Astrophysical Journal.

[PPI Tracy]

The subject is absolutely fascinating. I'll bet there is a connection.  I will be the first to admit, it's hard to understand the complexities of it all, but it is still so interesting to at least try and learn about it.

[PPI Brian]

It's a very complex topic, and I know that I'm not the only one who doesn't fully understand the concept, but in it's simplest form it makes sense. There's more to this world (and this universe) than meets the eye. Very elegant. 

[PPI Tracy]

Yes sir, you are correct...on all fronts.