The universe is a big place. Estimates vary, but there are something like 1010 galaxies, 1022 stars, and 1080 atoms. Such numbers are hard to get your mind around, even in an era when trillions (1012) is commonly used when measuring government debt.
But this is just the observable universe. Cosmologists are now pretty convinced that the true reality is a multiverse, or many parallel universes existing at the same time. Naturally, one wonders how many such universes there might be.
Imponderable as this question may seem, a duo of physicists at Stanford University has taken a stab at answering it. The analysis can be found at the open access preprint site for physics and related disciplines. (Aside—how come chemists don’t do this?)
The mathematics of quantum fluctuations required to understand the work will tax most readers, as will the final answer: 10^10^10 . This is a number that is virtually impossible to comprehend or even to write down. It has over 1010,000,000 digits!
With all those uniquely different universes, there surely is lots of potential for chemistry beyond even our wildest imaginations. Perhaps a different periodic table, unusual reactions, compounds we can’t imagine in our own universe. Maybe even altogether inconceivable life forms.
Apparently such gigantic numbers as 10^10^10 lead one to unchecked speculation. But perhaps a quantity we can better understand is Douglas Adams’s answer to the “ultimate question of life, the universe and everything,” as recounted in the estimable Hitchhikers Guide to the Galaxy—42. I can relate to that one.