A googolplex is the number 10, or equivalently, 10. Written out in ordinary decimal notation, it is 1 followed by 10100 zeroes, that is, a 1 followed by a googol zeroes.
History
In 1920, Edward Kasner's nine-year-old nephew, Milton Sirotta, coined the term googol, which is 10, then proposed the further term googolplex to be "one, followed by writing zeroes until you get tired". Kasner decided to adopt a more formal definition because "different people get tired at different times and it would never do to have Carnera a better mathematician than Dr. Einstein, simply because he had more endurance and could write for longer". It thus became standardized to 10.
Size
A typical book can be printed with 10 zeros. Therefore, it requires 10 such books to print all the zeros of a googolplex. If each book had a mass of 100 grams, all of them would have a total mass of 10 kilograms. In comparison, Earth's mass is 5.972 x 10 kilograms, the mass of the Milky Way Galaxy is estimated at 2.5 x 10 kilograms, and the mass of matter in the observable universe is estimated at 1.5 x 1053 kg. To put this in perspective, the mass of all such books required to write out a googolplex would be vastly greater than the masses of the Milky Way and the Andromeda galaxies combined, and greater than the mass of the observable universe by a factor of roughly 7 x 1039.
In the PBS science program ,, astronomer and television personalityCarl Sagan estimated that writing a googolplex in full decimal form would be physically impossible, since doing so would require more space than is available in the known universe. One googol is presumed to be greater than the number of atoms in the observable universe, which has been estimated to be approximately 1078. Thus, in the physical world, it is difficult to give examples of numbers that compare to the vastly greater googolplex. However, in analyzing quantum states and black holes, physicist Don Page writes that "determining experimentally whether or not information is lost down black holes of solar mass... would require more than 10 measurements to give a rough determination of the final density matrix after a black hole evaporates". The end of the universe via Big Freeze without proton decay is expected to be around 10 years into the future. In a separate article, Page shows that the number of states in a black hole with a mass roughly equivalent to the Andromeda Galaxy is in the range of a googolplex. Writing the number would take an immense amount of time: if a person can write two digits per second, then writing a googolplex would take about 1.51 years, which is about 1.1 times the accepted age of the universe. is a high estimate of the elementary particles existing in the visible universe, mostly photons and other massless force carriers.
Mod ''n''
The residues of a googolplex, starting with mod 1, are: This sequence is the same as the sequence of residues of a googol up until the 17th position.