This is well worth an hour of your time.
It has some interesting comparisons with our civilisations today, however at the end when he stated that 'if these guys hadn't collapsed, we wouldn't be here doing this today', I wish he had explained his logic to arrive at that conclusion - true we may not be using the same alphabet or language today, but any number of technological innovations could have been discovered and disseminated by another civilisation in the intervening millenia to put us at or near where we are today - perhaps even centuries earlier! So it seems at the face of it to be a pretty bold statement.
