Nick:

We can be certain. That is the point. Sure, 'altered states' are always
possible. Within that state, however, nothing we know would be
discernable in any meaningful way as no term would hold its
definition... including those that we require to live and think.

So, if you posit a location where Oxygen is not Oxygen but could be
something else, then you also posit a place where we could not exist.

"Maths" is a tool we use to describe relationships that exist
independent of the description, amongst other things. We can consider
behaviors that do not behave as we expect. That this is fiction or
wishful does not prevent the consideration inasmuch as we cannot have
it both ways. Getting a bit deeper into your contention that I would
describe loosely as "anything is possible" (please correct me if that
is not apt), I would accept that absolutely. In an infinite universe,
there are infinite possibilities. But science is brutal in the making
of choices and their consequences. We as carbon-based water-dependent
oxygen-burning life-forms are the product of a whole bunch of 'choices'
(accidents, consequences, happy coincidences) made along the way of
getting us to us. And at the same time, we have become defined into a
very narrow niche as a result.

Change a _very few_ of the constants that got us here, and we go
*POOF*. Put us as we are in an environment where such consants are
actually different, we go *POOF*.

Again, we can't have it both ways.

Peter Wieck
Wyncote, PA