In Case You Didn’t Know These Details in ‘Interstellar’

I Why do spacecraft keep rotating in space in the film?

The rotation generates centripetal force to simulate Earth's gravity. As the spacecraft rotates, it creates an inertial centrifugal force, which can substitute for gravity according to the equivalence principle of general relativity. As described in the film, the rotation allows the spacecraft to generate gravity akin to that on Earth's surface, providing astronauts with a sense of normalcy in space.

For interstellar travel, gravity is not just about comfort but also essential for maintaining life and health. Prolonged weightlessness inevitably leads to muscle atrophy, osteoporosis, and other health issues for astronauts, hence the necessity of creating artificial gravity.

II Why does Professor Brand believe obtaining Black Hole data is impossible, and why didn't Cooper die when entering the Black Hole?

According to Stephen Hawking's theory, even approaching a Black Hole would result in being torn apart by its supergravity. However, Kip S. Thorne suggests that while we confirm aspects of Black Holes through vast amounts of data, their actual nature remains unknown. Thus, based on Thorne's theory, Cooper and the robot TARS survived inside the Black Hole.

III What's the deal with Professor Brand's equation, and why did he confess to lying before his death?

Due to Earth's severe blight crisis, humanity needed to leave the planet to survive, prompting Professor Brand to devise two plans. Plan A aimed to evacuate humanity to habitable planets, while Plan B involved sending astronauts to find new habitable worlds, with no return intended. While Plan A was the preferred option, it required resolving a significant problem: how to move all of humanity into space.

Years ago, anomalies in gravity caught Professor Brand's attention, leading him to believe that gravity could be controlled. However, the inability to reconcile quantum mechanics and relativity meant his gravity equation couldn't be used without Black Hole data. Brand knew this but kept it secret, deceiving others into believing Plan A was viable to maintain hope and unity among humanity.

IV Why did the space exploration team go to Miller first?

The order of proximity to the Black Hole for the three planets was Miller, Mann, and Edmunds. Data transmission suggested Miller was likely habitable. Upon exiting the Wormhole, they would utilize the Black Hole's gravitational pull to reach Miller first, conserving fuel. Miller's gravity is 130% that of Earth's, which explains the massive waves due to tidal forces.

V Why prioritize Mann over Edmunds?

Signal loss from Edmunds and Mann's continued signal made Mann appear more reliable. Additionally, Mann's credentials made him theoretically the most trustworthy. Furthermore, after the ordeal at Miller, their remaining fuel couldn't support a return trip after exploring Edmunds' planet, and Cooper's desire to reunite his family played a significant role.

VI Why did Mann attempt to kill Cooper?

Mann desired survival, and transmitting false information about his habitable planet was his ploy to attract rescue and return to Earth. Wanting to maintain his heroic image, Mann intended to go back alone and preserve his fabricated story.

VII Why was Romilly killed in an explosion?

To conceal his lie, Mann deactivated the exploration robot holding the actual data and set it to self-destruct. If Romilly had repaired it and accessed the data, he would have been killed in the explosion.

VIII Why did Cooper detach the lander using the Slingshot effect to send Brand out of the Black Hole? Couldn't they leave together?

Limited fuel, the need for reverse propulsion through the lander's detachment per Newton's third law, and the potential to gather singularity data to save humanity factored into the decision. Cooper's decision to enter the Black Hole with TARS held the possibility of retrieving singularity data.

IX How did Cooper decipher the sand coordinates?

Murph believed an unseen entity (the "ghost") was communicating with her, leading her to interpret Morse code from the anomalies in her room. Cooper, however, dismissed this interpretation. When they witnessed the dust patterns during the storm, Cooper realized the anomalies were due to gravitational anomalies, leading to the binary interpretation and discovery of NASA's geographic coordinates.

X Analyzing Cooper's message of "stay," the NASA coordinates and singularity data left for his daughter

Initially, Cooper thought Plan A was doomed, regretting leaving his daughter to take a chance. Later, when he learned of the possibility of Plan A's success, he sent vital data to his daughter, hoping to save humanity.

XI How did Cooper decode the sand coordinates?

Cooper struggled to correspond with Earth's timeline while in the tesseract, leading to reasonable temporal deviations. Since the timeline was flat, his actions could spill over to other points in time, leading to frequent gravity anomalies in the recent timeline.

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