Looking Back At Apollo 17, and Why We Stopped Going To the Moon (examiner.com)

MarkWhittington writes: The 43rd anniversary of the mission of Apollo 17, the last time men walked on the moon, has elicited a strange kind of nostalgia, and no little melancholia in some parts of the media. These qualities are captured in a story in IO9 that purports to tell us why no one has been back to the moon in over four decades and why we might soon return at last. Deadline Hollywood informs us that "The Last Man on the Moon," a documentary on Apollo moonwalker Gene Cernan, is set for a release to both theaters and video on demand in February, having been shown at film festivals for the past year or so,

Comments

Re:TL;DR

[Koen Lefever]

You fell for the Gambler's fallacy.

You misunderstand gambler's fallacy.

Let's say the chance to come back alive is indeed 50%.
We had 8 missions. The chance for the 9th is still 50%.
We have no missions. What is the chance that we get 9 missions coming back alive? (1/2)^9 = 0.001953125 = 0.2%.

Gamblers fallacy would be saying after 8 successful missions that the change for the 9th is 0.2% - which is not what the GP said.

GP is talking about statistical significance.

If the chance top come back alive is 50%, we expect 4.5 out of 9 missions to come back alive.
Null hypothesis: The difference between 4.5 expected and 9 observed missions coming back alive is due to chance.
Alternative hypothesis: The chance to come back is higher than 50%
SD = sqrt((1/2)^2*(1/2)^2) = 0.25
z = (observed result - expected result)/SD = (9 - 4.5)/0.25 = 18
NormalCDF(18,infinity) = 1.04E-70% = the chance that the probability to come back alive is indeed 50%


Conclusion: GP is correct, it is very unlikely that the chance to come back alive was 50%.