The Time Dilation Effect in the Movie Interstellar

In Tuesday, October 3rd 2017, the Humanity House organized a film watch of the Interstellar at night. “The Interstellar is a 2014 epic science fiction film directed, co-written and co-produced by Christopher Nolan and talks about “[a]A team of explorers travel through a wormhole in space in an attempt to ensure humanity's survival”(IMDB). While possessing magnificent scenes and fascinating plots, Interstellar also emphasizes on its scientific accuracy. Director Nolan invited Caltech theoretical physicist Kip Thorne as an scientific consultant to ensure the movie’s rationality. To more specific, one detail in the film is that there is no sound heard when the Endurance(the spacecraft) collapses due to Doctor Mann’s failure in docking operation. This is because sounds can not spread in the outer space which is vacuum. Next, in this blog I will illustrate another interesting physical concept behind the movie: “the time dilation effect”.

The time dilation effect “is the phenomenon where two objects moving relative to each other (or even just a different intensity of gravitational field from each other) experience different rates of time flow”(thoughtCo). It states that time does not always elapse in a well-known constant speed as 1sec/sec but might change on an object which has relative velocity to the observers or situates near the black hole. For example, a clock which is moving runs slower than a static clock. In 1970, two scientists, Joseph C. Hafele and Richard E. Keating flew planes around the world with atomic clocks on board. When the trips are completed, the clocks were compared to the reference clocks at the U.S. It was found that 273±7 nanoseconds had been gained on the planes' clocks.("Hafele and Keating Experiment") .The time dilated effect is incorporated in an impressive part of the plot in the movie: in order to retrieve Miller's data, Cooper and Doctor Brand stay in the Miller’s planet which is near the black hole (the Gargantua) for hours. However, after returning to Endurance, they discovered that 23 years have elapsed on Earth while Cooper’s daughter, Murphy has been the same age as her father. This phenomenon is caused by the fact that the elapsed time in the Miller’s planet is extremely slower than that of earth because of its proximity to the Gargantua: approximately one hour spent on the planet equals seven years on the earth!

Why does the elapsed time on an object near the black hole is different from that for us on the earth? Next, In order to better explain this phenomenon, some knowledge about the black hole needed to be provided first: “the black hole is a super compact piece of matter which is so compact that it bends space time so much that even light cannot escape it”(Shreyash Phakade-Pawar. Quora). Also, It generates a strong gravitational field which is the region of space surrounding it in which another body experiences a force of gravitational attraction.(dictionary.com) Thus, as LeQuel la in the stack exchange explained that:

“The basic principle[about the time dilation] is that because of the curvature of spacetime around a black hole, the amount of "distance" a beam of light has to cover is greater near a black hole. However, to an observer in that gravitational field, light must appear to always be 300,000 km/sec, time has to slow down for that individual as compared to someone outside that gravitational field as related by the time/distance relationship of speed.”

To add up, the key point is that the speed of light always is around 300,000 km/sec in all circumstances. However, near the black hole where the spacetime are bended, a beam of light needed to move a larger distance than it is in normal case. It is known that distance equals time multiple velocity . In order to keep the speed of light constant, the time itself has to be slowed near the black hole.

Lots of fascinating physical concepts are incorporated elaborately in the science fiction films. While there is sensorial enjoyments for these arts forms, there are also intellectual enjoyments to learn about these scientific theories behind them. As a physic major student, I appreciate that the Humanity House provides us the opportunities to watch great movies included both humanistic and scientific elements.

Work Cited

IMDB. Interstellar. http://www.imdb.com/title/tt0816692/

"Hafele and Keating Experiment"

ThoughtCo. Time Dilation. https://www.thoughtco.com/time-dilation-2699324

Quora. “What is an explanation for time dilation on Miller's planet in “Interstellar”?”

https://www.quora.com/What-is-an-explanation-for-time-dilation-on-Millers-planet-in-%E2%80%9CInterstellar%E2%80%9D

Stack exchange. “How exactly does time slow down near a black hole?”

https://physics.stackexchange.com/questions/25759/how-exactly-does-time-slow-down-near-a-black-hole