Interstellar is a rollercoaster of emotions for all-first time (and revisiting) watchers. From perplexing gravitational physics to the ethicality of extinction, it has it all and then some. But what stuck with me the longest (outside of the desire to dive headfirst into a black hole) was fear. Pure, unadulterated fear, not of the possibility of extinction or the chasms of the unknown, but of the literal concept of time.

How is it possible for twenty-three years, four months, and eight days to fly by in some three hours? How is it possible to miss an entire lifetime, whilst existing in that very same lifetime? On Miller's planet, time went by differently than it did on Earth, a phenomenon proposed not by Interstellar, but by Albert Einstein in 1915.

Time dilation, as it was coined, became a fundamental concept in Einstein’s theory of general relativity. Einstein observed a clock tower from his tram as he sped away from it, taking note of the apparent change in its appearance with his progress. Making use of this time, he attempted a thought experiment where he imagined going at higher speeds, indeed, the cosmic speed limit, and hypothesized that the faster an observer travelled, their perception of time would change - their perceived passage of time would decrease, and time would appear to slow down. In general relativity, this dilation of time comes about as a result of gravity.

According to Newton’s laws, the velocities of different bodies are not fixed. Rather, these velocities are measured relatively, indicating that two bodies travelling parallel to each other in the same direction will appear to travel slower than their velocities relative to a stationary observer. This law is universal, hence applies to all bodies, everywhere in the universe. However, James Maxwell had theorized that the speed of all electromagnetic radiation was a constant. In applying and conjugating these laws together, Einstein questioned what would happen if he could theoretically speed up enough to travel at the speed of light...

To further explain his theory of relativity, Einstein introduced the concept of “spacetime”, proposing that the two are intrinsically linked. To accomplish this, he established time as a fourth “dimension”, outside of the three we are accustomed to - length, breadth, and height...

Experimental proof in recent years has built upon the theory of time dilation, with the first evidence collected fifty years ago using muons and their half-lives...

This, in a nutshell, is time dilation, and this is why time seemed to have “snuck by” in the Interstellar universe. On Miller’s planet, a single hour was equal to seven years on Earth...

Works Cited

• Ash, Arvin. “Time Dilation - Einstein's Theory Of Relativity Explained!” YouTube, 13 April 2018, https://www.youtube.com/watch?v=yuD34tEpRFw. Accessed 5 January 2025.
• Fowler, Michael. “Special Relativity: What Time is it?” Virginia Edu, https://galileo.phys.virginia.edu/classes/252/srelwhat.html.