Dark Energy confirmed? ..by the Wiggles!!

Holographic Universe or Computer Simulation? Big Bang or God?

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Dark Energy confirmed? ..by the Wiggles!!

Postby chrLz » Sat May 21, 2011 1:49 pm

I confess when I saw this, I thought for a moment it might be that thingamajig they just took up to the ISS (would have been fast work!), but it isn't. As you will see if you follow the link - this 'confirmation' has actually been done by... the Wigglez. :)

http://www.bbc.co.uk/news/science-environment-13462926

Before you get all excited..
However, despite scientists being able to infer the existence of dark energy and dark matter, these phenomena still elude a full explanation.


Sigh. So it seems we still don't know the answer to the Ultimate Question.. you know, life, the universe and everything..
"To wear the mantle of Galileo, it is not enough that you be persecuted by an unkind establishment. You must also be right." - Robert L. Park (..almost)
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Re: Dark Energy confirmed? ..by the Wiggles!!

Postby Access Denied » Sun May 22, 2011 5:54 pm

[seconds that sigh]

Typical pop science reporting… hyping up the “mysterious” nature of the unfortunately named “dark” energy and “dark” matter beyond all reason and opening the door for all manner of woo to be inserted in it’s place.

[cue the pseudoscientific crank rants]

As the article notes somewhat to it’s credit…

The results tell us that dark energy is a cosmological constant, as Einstein proposed.

Like a hundred years ago…

Of course Einstein called this his “greatest blunder” because until relatively recently, we didn’t have the technology to confirm it so he had to settle for adding an “unknown” constant (somewhat of an oxymoron) to his equations to fit the data and his belief that the Universe is static…turns out he was right to do that but for the wrong reason. However, it’s such a vanishingly small quantity (in terms of energy density) that it can only be measured (observed) on the galactic scale. It has no effect here on Earth because it’s so incredibly weak…yet the Universe is so incredibly large it adds up to be the dominant “force” in the Universe.

The reality is space sucks…

Literally.

This should really come as no surprise to anyone who has held their hand over the end of a vacuum cleaner hose… fwuump! In the case of a vacuum in air, the cause of this “negative” pressure (force) is easily explainable due to the difference in the number of air molecules in the high pressure region (the atmosphere around you) and the low pressure region (inside the vacuum cleaner where the motor is turning a fan that is moving air molecules out the exhaust faster than they can come in)… matter in the gas phase naturally wants to expand and “fill” (diffuse into) the available space due to the second law of thermodynamics.

[in other words, move (or decay if you will) from a higher energy state (e.g. as measured by temperature or in this case pressure) to a lower one… or, as I like to put it, everything dies and things tend to go from bad to worse]

Anyone see the analogy here yet?

In the case of the observable Universe, the vast majority of it is filled with “empty” space… I put empty in scare quotes because the vacuum of space is in theory a false vacuum because it’s not truly empty, it has a very tiny (non-zero) energy potential associated with it as predicted in quantum field theory. Turns out when you add up all the energy contained in the amount of “empty” space in the Universe (as measured by inference) it has the same value as Einstein’s cosmological constant. This tells us our physics (within the limits of GR and QM) and models (e.g. FLWR and ΛCDM) are most likely correct and, if nothing else, has some considerable bearing on the ultimate fate of the Universe as first noted by Coleman and de Luccia…

Gravitational effects on and of vacuum decay
S. Coleman and F. De Luccia. Phys. Rev. D 21, 3305–3315 (1980)
http://link.aps.org/doi/10.1103/PhysRevD.21.3305
http://www.slac.stanford.edu/cgi-wrap/g ... b-2463.pdf (PDF)

The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it. However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. This possibility has now been eliminated.

So, given it’s possible we’re living in a false vacuum and the Universe appears headed towards inevitable heat death, what is the true nature of “dark” energy and why is it causing the Universe to expand into oblivion?

To me it seems quite simple really, “dark” energy is the difference in pressure between the false vacuum that fills the Universe we live in (the spacetime that emerged out of the so-called singularity during the Big Bang) and the true vacuum of that which lies beyond it… nothing.

Literally.

The constant yet ever so slight “tension” if you will between something and nothing that’s trying (but so far has failed) to suck us in…

[fwuump!]

The good news is gravity is much stronger and will continue to hold the various clumps of matter together (galaxies, stars, planets) that make up the structure of our Universe for far into the foreseeable future… at least the next 10^100 years.

Of course, as always, I could be wrong though… :)


P.S. I moved this thread to the “Reality” section due it’s ontological implications.

ETA: For anyone interested, I see Marcus at PF has posted a more “informative” comment... 8)

puzzled by "new" confirmation of dark energy
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