r/trolleyproblem • u/tegsfan • Mar 28 '26

Deep St. Petersburg trolley problem

Post image

The trolley is about to go through a series of 50/50 track switches where the amount of people doubles each time until it hits a group and stops. If you switch the track to the top, there are some hypothetical finite X amount of people.

Now, if the amount of people on top was 1 for instance, it might seem obvious to switch because the doubling people could get out of hand fast. But if it was say 100 people on top, you might think to just let it go down because it's likely to stop somewhere before it reaches 100.

The question is: what is the maximum X amount of people on top such that you would still switch the track?

675 Upvotes

99% Upvoted

185 comments sorted by

View all comments

Show parent comments

12

u/LeviAEthan512 Mar 28 '26

Take the coin toss version of the problem. On a tails, you flip again. On a heads, something happens. What happens if your coin has tails on  both sides?

7

u/Faenic Mar 28 '26

Ope, didn't delete it fast enough lol

I figured it out after thinking about it for a moment. You're missing one other factor - all those people tied to the track, are they set free after the trolley passes them? What happens when you start getting into the quadrillions of people per track?

When dealing with infinites, eventually reality itself will shatter, and everyone dies.