Sadly it's no longer on iPlayer in the UK but if you use a bit of search wizardry I'm sure you could find it. The 15 Billon Pound Railway https://www.bbc.co.uk/programmes/b04b7h1w
There is a great Numerphile video that links sphere packing to mathematics. https://youtu.be/CROeIGfr3gs
Sadly it's no longer on iPlayer in the UK but if you use a bit of search wizardry I'm sure you could find it. The 15 Billon Pound Railway https://www.bbc.co.uk/programmes/b04b7h1w
There is a great Numerphile video that links sphere packing to mathematics. https://youtu.be/CROeIGfr3gs