At present the longest-running scripted U.S. prime time television series is The Simpsons. But how long can this show keep going?
Last year Fox had a series titled Minority Report, based on the story by Philip K. Dick. The series takes place the later part of this century. During one of the first few episodes a faux ad for The Simpsons' 75th anniversary spectacular was shown on a video screen.
Could it really last that long? There is one way to estimate the possibility.
In 1969, John Richard Gott III looked at the Berlin Wall and asked himself how long it would exist. Gott was witnessing something that would probably stand many years to come or something that would fall down tomorrow. All Gott could infer is that he was observing a thing at a random point in its lifetime. This became Gott's "Copernicus method" of lifetime estimation.
The Berlin Wall was 8 years old in 1969. If Gott was witnessing the Berlin Wall at a point in time 50% of the way through its lifetime, then West Berlin would be separated from East Germany another 8 years; Because it had been up for 8 years and might be halfway through its life. However, if Gott had been witnessing it 5% of the way through its lifetime, then the Berlin Wall would stand another 152 years. Calculating that 8 years is 5% of its life, then 160 years is 100% of its life minus the 8 years it had already existed at the time. But maybe the Berlin Wall might have fallen sooner rather than later. If 1969 was 95% of the way through the Berlin Wall's lifetime, then it would stand another 5 months. If 8 years is 95% of the Berlin Wall's life then 8.42 years is 100% of its life. Since it had already been up 8 years, it would have .42 years, or five months, left.
In this way a confidence interval for the lifetimes of certain classes of things can be estimated. In the previous example a 95% confidence interval for the lifetime of the Berlin Wall would be 8.42 to 160 years, which contains the age of the wall (about 28 years) when it came down beginning in 1989.
At the time of this writing it is September 15, 2016. Let's assume that there is nothing special about this day and this is being written on a random date during the lifetime of The Simpsons TV run. The Simpsons started airing about a month after citizens began demolishing sections of the Berlin Wall, roughly 26.74 years ago. If The Simpsons are only 5% of the way through its lifetime then new episodes will continue to air for another 508.06 years. (100% of its lifetime being 534.8 years - 26.74 years for the 5% that it's already been airing. If 26.74 years is 95% of The Simpsons' life then 28.147 years is 100% of its life; or 1.407 years left).
In other words with 95% accuracy The Simpsons' TV run should end sometime between saturday, February 10, 2018 and friday, October 06, 2524. Even with my lazy liberal use of rounding errors a 75th anniversary spectacular is statistically possible.