Question
Suppose you are designing a proton decay experiment and you can detect 50 percent of the proton decays in a tank of water. (a) How many kilograms of water would you need to see one decay per month, assuming a lifetime of $10^{31}\textrm{ y}$ ? (b) How many cubic meters of water is this? (c) If the actual lifetime is $10^{33}\textrm{ y}$, how long would you have to wait on an average to see a single proton decay?
1. $7.2 \times 10^{5}\textrm{ kg}$
2. $720 \textrm{ m}^3$
3. 100 months
Solution Video