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Sunday, 1 October 2017

Mission creep?

Cosmologist Sean Carroll asks, Is anything constant?
November 28, 2015 Posted by News under Cosmology, Physics


From PBS:

The ability for seemingly constant things to evolve and change is an important aspect of Einstein’s legacy. If space and time can change, little else is sacred. Modern cosmologists like to contemplate an extreme version of this idea: a multiverse in which the very laws of physics themselves can change from place to place and time to time. Such changes, if they do in fact exist, wouldn’t be arbitrary; like spacetime in general relativity, they would obey very specific equations.

So are we now enlisting Einstein on behalf of the multiverse? Out of interest, what would he have thought?

We currently have no direct evidence that there is a multiverse, of course. But the possibility is very much in the spirit of Einstein’s reformulation of spacetime, or, for that matter, Copernicus’s new theory of the Solar System. Our universe isn’t built on unmovable foundations; it changes with time, and discovering how those changes occur is an exciting challenge for modern physics and cosmology. More.

Physicist Rob Sheldon responds,

We’ve dissected Sean “the cosmologist” Carroll before, who is willing to sacrifice cosmology to the altar of Darwin, promoting “evolution” of “multiverses”. In this article he is equivocating on the word “change” to suggest that if Einstein showed that spacetime was changeable, then evolution must be true. I would argue that it merely demonstrates Cosmology to be in smaller denominations than the other bills of truth in circulation.

Seriously, though, attempting make Evolution the “one thing that is constant” in a changing world, reverses the usual hierarchy of “biology being made out of the laws of physics”, replacing it with “physics being made out of the laws of biology”. Now I’ve read Rosen’s “Essays on Life Itself”, so I won’t say that life is “nothing but” complicated physics, yet surely it would be equally incorrect to adopt Sean’s view that cosmology is “nothing but” evolution of physical constants.

Yet this is a perfect illustration of the dualist tension that swings between extremes. Newton’s deterministic, clock-like universe had fixed laws, fixed mechanisms, fixed purpose, fixed boundary conditions, while Carroll’s evolutionary, biological universe has changing laws, changing mechanisms, changing (if even existing) purpose, changing boundary conditions. The miracle of science, however, stands between the extremes.

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