The difference between; scientific approach, hypothesis and science. "Quite probably" - the only difference between you and the people presenting theories of infinity are that; they have spent more time "thinking about it". You have no answers - neither do they. Are their conclusions, as to why they have no answers, more relevant than your thoughts? Beautifully; yes and no.
They have followed an academic trail of thought and reached, with regard to answering the question, absolutely nowhere. If part of, any one of, those trails lead to an answer - you could argue that they are ahead of you. Thing is though... none of those trails, so far, have lead anywhere. So, therefore; you, by thinking along your own trail of thought, could be ahead of those heading in the wrong direction.
It has all happened before. Generations of "great thinkers" were wrong before Einstein turned up. We are watching, what in all likelihood, is interviews with, what can be compared to; pre-einsteinians discussing what some of the laws of physics may look like.
The work being done by these researchers is commendable and their approach is scientific. Their thoughts have merit as hypotheses, but they remain just that. There is a monumental difference between;
scientific approach, hypothesis and science. If the boundaries between them begin to blur, so does the quality of presentation.
A Trip to Infinity arguably ventures into that, slightly messy, borderline - potentially confusing the audience to believe it is science, rather than a hypothesis, that is being presented. Giving a scientific approach the seal of science is a somewhat confusing and deceptive approach.
The choice of wording is sometimes, when it comes to theoretical physics, is a bit unfortunate - it may sound confusingly close to "Physics". There is a "general belief" that a scientist is someone who "knows the truth" in a given field - and not one that has theory. With regard to Theoretical Physics it's in the name - it's theoretical, a theory. The discipline has spearheaded many of the greatest discoveries. The problem arises when it is presented as something it is not.
We are shown a film asking questions for us, providing no answers (as there are none to be had), concluding that "love is greater than infinity, and maybe it would help if we viewed ourselves as cats...
At best "A Trip to Infinity" will inspire some viewer to "go out there" and contribute to our collective awareness. At worst it will cause viewers to question the whole validity of scientific results and draw the conclusion; "Science" doesn't know Jack - so why bother. If everything is guesswork I may as well go for the most popular opinion" - and that maybe worrying.