Is a very important thing.
Rope is thicker,
But string is quicker.
Spike Milligan probably wasn’t considering the structure of the universe and unifying the four forces of nature when he wrote that lovely poem.
He was, however, possibly correct as “String Theory” is one method being explored to bring Gravity, Electro-magnetic and the Strong & Weak Nuclear forces together into one unified theory of everything.
"The Elegant Universe" series from PBS draws directly upon the book by it’s host, physicist Brian Greene, and covers the history of this quest from Newton to todays latest theories. It can be viewed on-line and has an excellent website with supporting material including “making of”, biographies and teaching resources.