I remember hearing that there have been some hints that physical constants have changed over time. If they have then the laws of physics wouldn’t be time invariant.
I have not heard of any such theory becoming a credible candidate for acceptance, although I see no logical contradiction in such—my impression is that discovering a time-varying term would be as surprising as discovering energy is not conserved. For fairly fundamental reasons, actually.
Note that in GR defining energy consistently is tough. Doing it so it is globally conserved is even harder. We only really have local conservation, and the changing background of GR in cosmology is in some sense effectively the same thing as changing physical law.
I remember hearing that there have been some hints that physical constants have changed over time. If they have then the laws of physics wouldn’t be time invariant.
Anyone else recall anything along those lines? Wikipedia isn’t terrible helpful.
I have not heard of any such theory becoming a credible candidate for acceptance, although I see no logical contradiction in such—my impression is that discovering a time-varying term would be as surprising as discovering energy is not conserved. For fairly fundamental reasons, actually.
Note that in GR defining energy consistently is tough. Doing it so it is globally conserved is even harder. We only really have local conservation, and the changing background of GR in cosmology is in some sense effectively the same thing as changing physical law.