Friday, March 31, 2017

Remember Dark Matter? Well, Forget About That - Science

Enigmatic dark energy, thought to make up 68% of the universe, may not exist at all, according to a Hungarian-American team. The researchers believe that standard models of the universe fail to take account of its changing structure, but that once this is done the need for dark energy disappears.  (Science Daily:  Explaining the accelerating expansion of the universe without dark energy)

This announcement comes from the Royal Astronomical Society and those royal societies have some big smokes.

Ed:  it's a real weeper losing something no-one could see and no-one could detect

It surely is.  This is an astronomical loss.  The Yin of the Universe lots its Yang.  Tragedy.



This is a frame from an animation that shows the expansion of the universe in the standard 'Lambda Cold Dark Matter' cosmology, which includes dark energy (top left panel red), the new Avera model, that considers the structure of the universe and eliminates the need for dark energy (top middle panel, blue), and the Einstein-de Sitter cosmology, the original model without dark energy (top right, green). 

The panel at the bottom shows the increase of the 'scale factor' (an indication of the size) as a function of time, where 1Gya is 1 billion years. The growth of structure can also be seen in the top panels. One dot roughly represents an entire galaxy cluster. Units of scale are in Megaparsecs (Mpc), where 1 Mpc is around 3 million million million km.

Credit: István Csabai et al.


You got all that, right?

Ed:  did you?

Not a sausage.


We will skip straight to the punchline but the interested student is invited ... the article has a discussion on why any of this matters.  We just want to know what they found and see below.


We will just take their word for it since they have a cool graph.

Dr Dobos adds: "The theory of general relativity is fundamental in understanding the way the universe evolves.  We do not question its validity; we question the validity of the approximate solutions.  Our findings rely on a mathematical conjecture which permits the differential expansion of space, consistent with general relativity, and they show how the formation of complex structures of matter affects the expansion.  These issues were previously swept under the rug but taking them into account can explain the acceleration without the need for dark energy."

- SD

Watson:  dark energy just poofed

That it did, Watson; it's never to be seen again.

Watson:  we can't see it now

Fair enough

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