Atom: the key to the cosmos

Last night I watched another Jim Al-khalili documentary on Youtube, "Atom: the key to the cosmos" which is the second part of his 2008 Atom series.  Its another well explained programme on the components of the atom and nuclear physics.  He describes how Ernest Rutherford's students accidentally created hydrogen by using radium to split the nitrogen atoms in the air, thereby becoming history's first ever alchemist. Al-Khalili then mentioned the strong nuclear force which holds the positively charged protons in the nucleus of an atom together, preventing them from repelling each other.  This was another thing that was mentioned in my GCSE physics class but I then forgot in the midst of time.  So thanks for reminding me, Jim.