Hello everyone, welcome to the Mindscape Podcast. I'm your host, Sean Carroll.

Sometimes when talking about cosmology, I will remind people that our universe,

which is about 14 billion years old, or roughly, order of magnitude 10 to the 10 years old,

which sounds pretty old, is nevertheless pretty young, in some sense.

Our universe is just a baby compared to how old it will be.

Of course, we don't know exactly how old the universe will get,

but according to the leading cosmological models that we have right now,

the universe will get infinitely old. There's no reason for it to ever end.

And anyway, it will use up its fuel in some finite amount of time.

The sun's shining, the stars are shining, galaxies are shining,

but this shining won't go on forever. Stars are going to burn up their fuel in about 10 to

the 15 years. So that's 100,000 times the current age of the universe.

And then the last black hole will evaporate away, we think, roughly speaking,

about 10 to the 100 years from now. In other words, about a Google years from now,

in the original notion of the word Google before the search engine took it over.

The idea of a number 10 to the 100 was actually invented,

sort of almost as a joke, just as to stand in for a really big number you would never

actually think to use. Today's guest, Antonio Padilla, Tony Padilla, as he's known,

thinks otherwise. And he's written a wonderful new book called Fantastic Numbers

and Where to Find Them, a cosmic quest from zero to infinity, where he talks about these big numbers,

Google, and of course it's cousin the Googleplex, which is 10 to the power of a Google,

but then even way bigger numbers than that. Number theorist mathematicians, theoretical

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