Why 'no cigar' for the definition of 'post-modernism'?
It starts from the treatment of 'pre-modernism'.
The speaker used a partly apt astronomical analogy to help the audience grasp the spectrum (if there is one) from 'pre-modern' through 'modern' to 'post-modern'
He characterised the pre-modern world as one where the sky was considered to be a dome and the stars holes poked in that dome and letting light in.
I detect here the influence of the tendentious hermeneutic which tells us that Genesis 1 betrays some sort of primitive 'world view' where the sky was conceived as a type of dome. So, we can laugh that aside. It also fails to acknowledge the influence of acceptance of Genesis 1 at face value as one of the driving forces of the formation (and thus, the success) of modern science. Genesis 1 overturns animism, polytheism and the various other 'spookims' that prevented intellectual exploration of the physical world. It also challenges the crippling idealism and essentialism of ancient philosophy. Modernism unfortunately did not dismantle these flaws.
If there is a pre-modern view, then it would be one un-influenced by the biblical teaching of Creation and uncritically melds fantasy supernaturalism, superstition, and hierarchical social structures; based themselves on the aforementioned fantasy supernaturalism and superstition. Nothing to do with a false history of serious astronomy.
This is reminiscent of the Rip Van Winkle fallacy of flat-earth belief whereas it has been known by serious thinkers from ancient times that the earth was probably a globe. Indeed, there are robust allusions to such in the Bible itself. Isaiah has one.
When the analogy got to Modernism it referred to external certainties, which I agree is a major component of modernism; in short, there are objective independent truths that can be discovered, understood and instrumentalised in everyday life.
As it moved to post-modernism, it returned to shaky ground. The central plank of the post-modernist platform is the absence of a critical basis for distinguishing between positions. Everything from moral epistemology to instructions for using a toaster are (it seems) up to the subject. There is no object worth talking about (except when a post-modernist relies on the certainties of aeronautical engineering for air travel, I suppose), but only 'discourse' to be analysed, typically to demonstrate its failure to meet the standards, ironically, of post-modernism. If it doesn't then, just before the critique collapses in an echo of logical-postivist self-refutation, it is subject to the sneering disdain of post-modernist ontological removal.
However, we were told that the central plank was (confusingly and inaccurately) Stephen Hawking's 'discovery' of the Big Bang. Once again, a theologian signifying (perhaps unwittingly) his commitment to a naturalist world in idealist rejection of the world described in the Bible.
So, plenty to discuss, in our 'guided discussion', but I don't know that such discussion would have been welcomed.
Ironically, the Bible Project video he showed relied on the world described in the Bible, on the implication that there is only one ontologically unified world ('universe'), rather than the split world of 'contemporary discourse/modern science' over here, and (is it pre-modern?) detached biblical spiritual-ethical world over there...confusing us as to which world is really real, and is the one we are in.