Solar system and $n$ body problem
102572
Is the orbit of the planets around the Sun chaotic?
95940
Conservation of angular momentum in a planetary system
118407
Birthday Problem applied to collisions
20775
Distribution of orbital velocities in a disk galaxy for N-body simulation?
114934
Bootstrap Paradox in Interstellar
64168
Problem 4.6, I. Martin Isaacs' Character Theory
14409
A problem about function N
157750
A reverse birthday problem: no pair out of 1 million aliens shares a birthday; what is their year length?
142519
Uniqueness and Existence problem
112980
Planetary model of atom still valid?
110958
How to solve for any given natural number n?
81530
A simple explanation of Kepler's Third Law
106033
Solve the system in $\mathbb{R}$
11627
Find the center of the symmetry group $S_n$.
118634
The system of equations
57954
How many transitive relations on a set of $n$ elements?
63571
The Mississipi counting problem, this time in circle