Nick:

Oxygen will be the same wherever and whatever (like pi). What may be
different would be allotropes and isotopes. One has to be fairly
careful when nibbling around the edges of very basic science (and
math). Those things have immutable aspects despite fondest wishes to
the contrary. My contention is that it will be those aspects that will
allow the initiation of communications between species that otherwise
share _NOTHING_ else in common.

I wrote a shorter version of this that seems to have disappeared.
Please forgive if it suddenly appears.

Peter Wieck
Wyncote, PA