Christopher Nolan’s new sci-fi movie, Tenet, has both grossed $323.5 million in the box office and baffled its viewers due to its complex and ‘out of this world’ storyline.
The movie follows the protagonist, as he is called, through a mission in which he is racing against the clock to prevent cosmological doom.
Nolan re-envisioned time travel. Instead of simply going backward, the world was progressing inversely. In other words, time was reversed by reversing entropy.
In the real world entropy increases as time progresses in what’s known as the thermodynamic arrow of time, as theorized by British astrophysicist Arthur Eddington. When a glass is broken, or a bed is unmade, that is entropy. Reverse entropy would be the glass coming back together or the bed making itself; in other words, the retrogression of time.
In Tenet, the characters are threatened by this “inversion” of the universe’s timeline, working to understand and manipulate the dangerous idea of reverse entropy. The protagonist and his acquaintances follow successful and crude weapon salesman Andrei Sator, played by Kenneth Branagh, through the time inverter machine.
Once the characters pass through, their entropy is inverted. They talk and walk backwards. They perspire and pick objects up inversely. Fire becomes extremely cold. Ice becomes extremely hot. Everything is the opposite of its normal state.
This is, in theory, how the universe would function when it starts collapsing onto itself billions of years from now. The concept stems from the idea that the total entropy of a system, or in this case the universe, increases with time. In the cosmological context, the direction past-to-future is usually related to the development of chaos, or entropy. Therefore, the inversion of entropy would technically mean a reversed timeline; in other words, time travel.
Entropy and its inverse state are difficult concepts to grasp. However, understanding them makes Tenet’s convoluted plot slightly more comprehensible. For those up for the challenge, Tenet is available in all theaters.