Googols and Googols

In 1938, mathematician Edward Kasner asked his nine-year-old nephew for a name for a large number—and his nephew promptly replied: “Googol.” A googol is a number equal to 10^100, or if you wanted to write it out, it would be a 1 with 100 zeroes following it. Already, this number is larger than the number of elementary particles in the known universe, which only amount to approximately 10^80. As if this wasn’t enough, the term was then extended to an even bigger number: a googolplex, which is 10 to the power of a googol—i.e., 10^(10^100). To write this out, it would be a 1 followed by a googol number of zeroes. Here’s where it gets intensely cool: you cannot physically write this number out in its entirety, because there is not enough space in the universe. Even if you wrote in unreadable one-point font, it would take up about 3.5×10^96 metres, while observable universe is only estimated to be 8.80×10^26 meters. So, you’d still need more paper than you could stuff into the entire universe—and furthermore, if you wrote at an average rate of two digits per second, it would take you more time to write it out than the age of the universe so far. And yet, even a googolplex comes nowhere near infinity. Numbers are awesome.

Watch Carl Sagan explain