Imagine a stack of exactly 10^(42.8 million) pennies, one after the other.
How tall is this stack?
At a rate of one penny per millisecond, how many generations of family members will be needed to stack all of the pennies, assuming each generation has twice as many kids as the previous, that new generations are born every 23.8 years, that each person lives exactly 82.3 years, that people will develop arthritis if they stack pennies for over 3.82 hours continuously (and need a 2 hour long break to not develop it), and that every person needs at least 3 hours of sleep a day (using polyphasic sleep of course) and 1 hour to eat and use the restroom?
Is there enough mass on Earth to make all of these pennies? How about in the solar system? The galaxy? The observable universe?
Now imagine that these penny-stacking people have lives, and need at least 22 years of standard education and 4 years of education at a special penny-stacking university before they can stack pennies. How much more time is needed to stack the pennies now?
Please show your work.