Cosmologic philosophy: can the constants change (Introduction)

by David Turell , Saturday, November 28, 2015, 18:20 (3283 days ago) @ David Turell

In our universe can the constants change. Sean Carroll thinks it is possible:-http://www.pbs.org/newshour/updates/if-space-and-time-can-change-is-anything-constant/- If Einstein's lesson is that purportedly foundational aspects of reality like space and time are actually dynamical and evolving, it's natural to wonder whether the numerical parameters that specify the laws of physics are similarly flexible. Could Newton's constant, which sets the strength of gravity, or quantities like the mass of the electron, actually change with time?-The answer seems to be: maybe. According to our best current measurements, the numerical values for physical parameters in our world seem to be pretty constant. But the possibility that they could change is very real. In a sense, that's the secret to the Higgs boson, which was discovered at the Large Hadron Collider in 2012. Famously, the Higgs “gives mass” to elementary particles like electrons and the different quarks. It does that because there is a Higgs field filling space, interacting with all of those particles. But that background Higgs field wasn't always there. We believe that in the earliest moments after the Big Bang, the Higgs field was stuck at zero, and quarks and electrons had zero mass. These quantities may look constant to us now, but almost every physicist thinks that they have changed since the universe first started.-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.-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.-Comment: I don't know why Carroll makes that positive declarative statement in bold above. He makes no case for it. It has changed in the past as he shows, but we don't know that the future holds that probability. At least for the moment he is honest about multiverses.