Cosmologic philosophy: 5 articles on fine tuning (Introduction)

by David Turell , Wednesday, November 23, 2016, 21:03 (2922 days ago) @ David Turell

How the universe exists on a knife edge of forces is explored:

https://www.newscientist.com/round-up/cosmic-coincidences

"The more we look at the universe, the stranger it appears. From the geometry of space-time to the masses of the elementary particles, its properties are finely tuned to allow life to exist. More bizarrely, though, it seems to be teetering on the brink of not existing at all. Here we look at five of its seemingly most implausible traits – and ask what might lie behind them

https://www.newscientist.com/article/mg23230970-600-cosmic-coincidences-matter-and-ener...

"Our cosmos’s five most startling coincidences – and what lies behind them
But the values are still close enough to be perplexing – and according to our standard cosmological model, the similarity is relatively new. The very early universe was dominated by dark matter. “At that time, dark matter density was 95 orders of magnitude larger than the density of dark energy,” says Nicolao Fornengo at the University of Turin, Italy.

"But dark matter’s density has been dropping as the universe expands, while the density of dark energy is widely assumed to remain constant over time, making it steadily more dominant. A few billion years ago, dark energy became denser than dark matter – causing the universe’s expansion to begin racing away (see “The universe is flat as a pancake. Coincidence?“).

"Still, it seems we live in a special time where neither entity is able to dominate the other.

https://www.newscientist.com/article/mg23230970-700-cosmic-coincidences-everything-poin...

"COSMOLOGISTS called it the axis of evil. Spotted in 2005 in the cosmic microwave background, the all-pervading afterglow of the big bang, the axis was a peculiar alignment of features where we would have expected nothing but randomness.
The name was justifiably melodramatic, given that it threatened our established view of the universe. At the heart of that picture is the cosmological principle, which says that the universe appears the same on the largest scales no matter where you happen to be looking. This is what you’d expect in the aftermath of an explosion like our big bang, with all the constituents winding up mixed together in a randomised, homogeneous soup. The reality, it seemed, wasn’t like that – and despite steadily improving measurements, the axis has stubbornly refused to vanish.

https://www.newscientist.com/article/mg23230970-800-cosmic-coincidences-the-universe-is...

"According to Einstein’s general theory of relativity, matter and energy bend space and time, and the amount of stuff the universe contains will determine its ultimate fate. If the universe is dense enough to curve space-time in on itself, all that gravity will eventually collapse it back down to nothing. If the universe’s density is low, it curves outwards – and the weakness of the gravitational pull will mean it expands forever.

But our universe seems to fit in neither camp. The most powerful test of its geometry is the variation in the cosmic microwave background, the radiation emitted shortly after the big bang. According to measurements of this radiation, the density of matter and energy is such that the universe does not curve either way: it is perfectly flat. After an eternity, its expansion should grind to a halt.

"..in the late 1990s, when very distant exploding stars were inexplicably seen to be dimmer than expected. This suggested that the universe’s expansion was accelerating rather than slowing down. The proposed fix was to say that a large proportion of the universe exists as dark energy, a new ingredient allowing it to remain flat yet expand ever ...

https://www.newscientist.com/article/mg23230970-900-cosmic-coincidences-everythings-at-...

"Space is all the same temperature. Coincidence?

"Distant patches of the universe should never have come into contact. So how come they’re all just as hot as each others?

https://www.newscientist.com/article/mg23230971-000-cosmic-coincidences-the-universe-is...

"The Higgs boson makes the universe stable – just. Coincidence?

"If the mass-giving particle were much lighter, the cosmos would quickly collapse in on itself. It’s hard to explain how we’re all still here.

Comment: the universe sure looks designed to me. And to you?