4 ms·
> In the real world, your past uniquely determines your future. If a physicist knows how the universe starts out, she can calculate its future for all time and
by Archelaos 5y ago
> In the real world, your past uniquely determines your future. If a physicist knows how the universe starts out, she can calculate its future for all time and all space.
No (or only in very special configurations). See for example the n-body problem.[1]
[1] https://en.wikipedia.org/wiki/N-body_problem https://en.wikipedia.org/wiki/N-body_problem
- 7373737373 5y agoIndividual particle decay is also truly random/unpredictable
- infiniteL0Op 5y ago
- ben_w 5y agoThe reason we can’t predict the outcome of an N-body problem is that arbitrarily small mistakes radically change the result, the maths itself is fine. Quantum mechanics, as several other commenters have observed, is where to look for the fundamental unpredictability. I wonder how long it takes for the quantum uncertainty of a planet to become macroscopic due to the chaotic behaviour in N-body problems…
- progval 5y ago> In the physical literature about the n-body problem (n ≥ 3), sometimes reference is made to the impossibility of solving the n-body problem (via employing the above approach).[citation needed] However, care must be taken when discussing the 'impossibility' of a solution, as this refers only to the method of first integrals