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Have Scientists Determined the Exact Dimensions of the Universe?

A team of scientists from Washington believe that they have managed to establish the exact size of the universe to within 1 per cent accuracy.

In a remarkable development, the researchers, who were working with the Baryon Oscillation Spectroscopic Survey (BOSS), have been able to measure the distances to galaxies that are over 6 billion light years away.

"There are not many things in our daily lives that we know to 1-percent accuracy," said David Schlegel, a physicist at Lawrence Berkeley National Laboratory and the principal investigator of BOSS. "I now know the size of the universe better than I know the size of my house."

This level of precision is unprecedented, and may provide the most enlightened source of data regarding the curvature of space. The measurements indicate that the universe expands on a level plane, allowing its shape to be evaluated using Euclidean geometry, where straight lines are parallel and the angles in a triangle add up to 180 degrees.

"One of the reasons we care is that a flat universe has implications for whether the universe is infinite," Schlegel said. "That means — while we can't say with certainty that it will never come to an end — it's likely the universe extends forever in space and will go on forever in time. Our results are consistent with an infinite universe."

The new technology has been able to highlight the properties of "dark energy", the unknown force that appears to be driving the expansion of the universe. Dark energy is believed to make up around three quarters of the total mass and energy of the universe, far outweighing other forms of matter. Although scientists have been able to ascertain that it exists and how much of it there is, they still don't really know what it is.

"We don’t yet understand what dark energy is, but we can measure its properties," Daniel Eisenstein, a Harvard University astronomer working with the survey, said in a statement. "Then, we compare those values to what we expect them to be, given our current understanding of the universe. The better our measurements, the more we can learn."

The scientists studied the locations of 1.2 million galaxies, and found that the new measurements substantiated the concept of the "cosmological constant," a theory originally put forward by Albert Einstein; based on this, it appears that dark energy has remained constant since the birth of the universe. The new results have been compared with previous surveys, enabling scientists to ascertain how the universe has developed.

"Making these measurements at two different distances allows us to see how the expansion of the universe has changed over time, which will help us understand why it is accelerating," explained University of Portsmouth astronomer Rita Tojeiro, who co-chairs the BOSS galaxy clustering working group along with Jeremy Tinker of New York University.

The astronomers used a spectrograph on the Sloan Foundation's 2.5-meter telescope at Apache Point Observatory in New Mexico to make their observations.

"On a clear night when everything goes perfectly, we can add more than 8,000 galaxies and quasars to the map," Kaike Pan, who leads the team of observers working with the spectrograph, said in a statement.

The new results, which were presented by Schlegel and his colleagues on January 8th at the 223rd meeting of the American Astronomical Society, will pave the way for even more accurate assessments of universal dimensions in the future.

Schegel added: "Future surveys will be doing more of this, both filling in this map of the universe, [and] the enormous volume of the universe we have yet to map out and doing this with even higher precision."

So, mysterious dark matter is the driving force behind the universe; what do you think this is?

Your comments are always welcomed here at Unknown Country, where we attempt to expand your mind faster than dark matter - subscribe today to join our own unique corner of the universe!

(from NASA's website)
What is Dark Matter?
Maybe it was a result of a long-discarded version of Einstein's theory of gravity, one that contained what was called a "cosmological constant." Maybe there was some strange kind of energy-fluid that filled space. Maybe there is something wrong with Einstein's theory of gravity and a new theory could include some kind of field that creates this cosmic acceleration. Theorists still don't know what the correct explanation is, but they have given the solution a name. It is called dark energy.

So they don't know what it is, but it is not on earth.
On earth we know that energy is never created or destroyed, but according to the NASA website, dark matter is being created .... really?
I think we still need to come up with a new hypothesis - this one seems to have too many holes!

So in other words "we know with 99% certainty that we are maybe probably right". Scientists gotta love 'em.

We will just throw "Dark Energy" (oooooohhhh scary name lol) in with "Gravity" and "Consciousness" as one more of the things that scientists know everything about except what it really is.

Anyone who believes they can measure infinity is, of course, a fool.

I have not read the details of their research, but they have to be talking about the OBSERVABLE Universe, not the entire Universe. Why? Because the only parts of the Universe we can see are where light was able to reach us in the time since the Big Bang. And there's the problem, the Universe is so large that not all the light has gotten here yet. And since the Universe appears to be expanding, it never will get here. We will never see the entire universe, ever. Plus in about 10,000 years, if we are still around the sky will have far fewer stars to see.

So we can only see a small part of the Universe.

From Wikipedia (while not trustworthy for most things is pretty safe with mainstream science articles):

"Some parts of the universe may simply be too far away for the light emitted from there at any moment since the Big Bang to have had enough time to reach Earth at present, so these portions of the universe would currently lie outside the observable universe. In the future, light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable. However, due to Hubble's law, regions sufficiently distant from us are expanding away from us much faster than the speed of light (special relativity prevents nearby objects in the same local region from moving faster than the speed of light with respect to each other, but there is no such constraint for distant objects when the space between them is expanding; see uses of the proper distance for a discussion), and the expansion rate appears to be accelerating due to dark energy.

Assuming dark energy remains constant (an unchanging cosmological constant), so that the expansion rate of the universe continues to accelerate, there is a "future visibility limit" beyond which objects will never enter our observable universe at any time in the infinite future, because light emitted by objects outside that limit would never reach us.

(A subtlety is that, because the Hubble parameter is decreasing with time, there can be cases where a galaxy that is receding from us just a bit faster than light does emit a signal that reaches us eventually). This future visibility limit is calculated at a comoving distance of 19 billion parsecs (62 billion light years) assuming the universe will keep expanding forever, which implies the number of galaxies that we can ever theoretically observe in the infinite future (leaving aside the issue that some may be impossible to observe in practice due to redshift, as discussed in the following paragraph) is only larger than the number currently observable by a factor of 2.36.

Both popular and professional research articles in cosmology often use the term "universe" to mean "observable universe". This can be justified on the grounds that we can never know anything by direct experimentation about any part of the universe that is causally disconnected from us, although many credible theories require a total universe much larger than the observable universe. No evidence exists to suggest that the boundary of the observable universe constitutes a boundary on the universe as a whole, nor do any of the mainstream cosmological models propose that the universe has any physical boundary in the first place, though some models propose it could be finite but unbounded, like a higher-dimensional analogue of the 2D surface of a sphere that is finite in area but has no edge."

So, the size of the Universe is unknown; it may be infinite.
The region visible from Earth (the observable universe) is a sphere with a radius of about 46 billion light years, based on where the expansion of space has taken the most distant objects observed. A "light year" is the distance light travels in a year, or roughly 6 trillion miles. So the part we can see is 46 billion times 6 trillion miles in any direction.

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