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Predictable Universe

This story from Quanta Magazine, link below, is another clear example of why cosmology needs a Cosmology Uncertainty Principle. I posted about that principle on June 12.
Excepts from the story clearly reveal this problem:

In classical physics, the universe is predictable: If you know the laws that govern a physical system and you know its initial state, you should be able to track its evolution indefinitely far into the future. The dictum holds true whether you're using Newton's laws to predict the future position of a billiard ball, Maxwell's equations to describe an electromagnetic field, or Einstein's theory of general relativity to predict the evolution of the shape of space-time. "This is the basic principle of all classical physics going back to Newtonian mechanics," said Demetrios Christodoulou, a mathematician at ETH Zurich and a leading figure in the study of Einstein's equations. "You can determine evolution from initial data."

But in the 1960s mathematicians found a physical scenario in which Einstein's field equations — which form the core of his theory of general relativity — cease to describe a predictable universe.

"The loss of predictability that we seem to find in general relativity was very disturbing," said Eric Poisson, a physicist at the University of Guelph in Canada.

As I tried to convey in my June 12 post, the entire universe is certainly NOT predictable. It can be on smaller scales, like the elliptical orbits in our solar system, where accurate predictions are demonstrated with occultations or space probe trajectories.

Once the scale broadens to a galactic scale precise predictions are literally impossible.
At that galactic scale the model must be based on probabilities.The motions of a trillion stars in a galaxy cannot be defined with classical physics even if a valid initial state could be determined somehow (it can't). A model using probabilities can only be approximate, never deterministic or predictable.

When cosmology expects the universe to be predictable its predictions are doomed.
When the inherent limitation of a model based on probabilities is recognized, cosmology will become less prone to these unproductive diversions.

I did not waste time on the mentions of black holes which EUT knows don't exist.


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