New cosmology needs new science demarcation

Cosmologist Sean M. Carroll writes in Discover magazine:

Things get still more interesting when we add string theory to the mix. String theory is currently the most promising way to explain the fundamental properties of all the particles and forces in our universe. ... In short, string theory predicts that the laws of physics can take on an enormous variety of forms, and inflation can create an infinite number of pocket universes. ...

A lot of people, both inside and outside the scientific community, are viscerally opposed to the idea of other universes, for the simple reason that we can’t observe them—at least as far as we know. ...

These concerns stem from an overly simple demarcation between science and nonscience. ...
Right now we don’t know, and that’s fine. That’s how science works; the fun questions are the ones we can’t yet answer. The proper scientific approach is to take every reasonable possibility seriously, no matter how heretical it may seem, and to work as hard as we can to match our theoretical speculations to the cold data of our experiments.

The main point of the article seems to be that Sean has a lot of untestable speculations, but it is all okay if we accept some redefinition of science.