The 2018 "How to Build a Time Machine" documentary looks at how close we have come to building a time machine.
For decades this has been the dream of many, inspired by the possibilities of moving backwards and forward in time that Einstein's theory of general relativity allows. The idea of travelling back in time to see the human race as it was 200 years ago, or going forward 300 years to see what has been learned seems exciting but is any of this actually possible?
Fact is, very little is known about the basics of time. Is it really a state that just exists and we are living through an illusionary slice of it? Or does time only exist at this very moment and looking to the past is simply looking at an imprint of foregone events that do not exist anymore? These are just some of the ideas discussed in "How to Build a Time Machine".
The BBC is back on form with this science documentary. Some of the concepts of time travel that are explored in the documentary are relatively basic and have been explored in other Horizon programs, however, many new ways to think about time were also presented.
My one quarrel with the film is the dig at Donald Trump, which sullied some of the really good scientific theories. One interviewee said, "you couldn't go back in time a kill a young Donald Trump". Yes, this was actually said in a science documentary. Frankly, this comment should have never made into the final cut. Would the BBC have allowed the same thing to be said about Hillary Clinton? I doubt it.