Extreme Time Dilation

So, what's so special about this scene? Just in the span of this five second clip from this planet, a lot has happened on Earth. I mean, a lot. You might be wondering why. Well, just after they touched down on the planet, Joseph Cooper said something very important.

So, seven years per hour. What he means by that is that if they spend one hour on that planet, time will pass seven years back on Earth. So how is that possible? The short answer is that it's because they land here, deep in the gravitational well of an immense black hole. So, what's the difference between being in a super-strong gravity zone and being in a weaker one, like on Earth? To address this concept, we need to visualize it with a simple thought experiment.

We have person A floating near a massive object with a lot of gravity and person B just casually floating in an empty void of space. person A shines a green laser beam towards person B. Because light is a form of vibration, the laser beam has a color that corresponds to 600 trillion vibrations each second. Now, light is also a form of energy and as that beam of light comes out of the gravity of the massive object, it loses a lot of energy.

This loss means there's a decrease in frequency. So by the time that beam of light reaches person B, its frequency will have decreased by some factor. That means instead of the green light at 600 trillion vibrations a second, person B gets only, let's say, 10 billion vibrations per second, which is a microwave radio beam. This phenomenon is called Gravitational Red Shift.

But not so fast, individual wiggles don't just go anywhere and disappear. Since person A creates 600 trillion wiggles every second while person B, only gets 10 billion every second, the only way this can happen is if 1 second on one astronaut's clock is not the same as 1 second on the other astronaut's.

In other words, it only takes 1 second for person A to create those 600 trillion wiggles, but it will take 60,000 seconds or nearly a day for person B to receive them. Time isn't merely a construct designed by humanity. It arises as a consequence of the physical world of our universe, and the passage is experienced differently by different entities within it. Even Einstein pointed out that the concept of time dilation defies everyday logic.

According to Einstein's special theory of relativity, the greater the acceleration of an object, the slower it will move through time. On Earth, gravity's pull is modest. On the surface of a neutron star, where time is slowed by a few hours per day, gravity's pull is enormous. And at the surface of a black hole, time is slowed to a halt, where the gravity is so humongous that nothing can escape, not even light.

The concept of this slowing of time plays a major role in Interstellar. Miller's planet is depicted as being present in Warped SpaceTime near the black hole, Gargantua. Because of this, the planet exists deep within the black hole's gravitational well. So, although it's in a stable orbit and in free fall, which means the astronauts don't feel the black hole's gravity, they're still under its influence. So if we apply Einstein's relativity here, we would know that Miller's Planet would experience time at a very slow rate.

But here on Earth, gravity is at a modest rate and the gravitational force of the sun is also a billion times weaker than Gargantua. So while the three astronauts spend a few hours on the planet, decades pass in the outside universe.

All of this information is brought to you from the book 'The Science of Interstellar,' written by the scientific consultant for the film. In real life, this process is happening everywhere in space. One interesting example is our International Space Station. When the ISS moves fast in orbit, time dilates or slows down compared to a stationary observer here on Earth. Technically speaking, it is in a different time frame than we are.

So by calculating the difference through Einstein's equations, we could correct the time at the ISS. Because we use a lot of references to the movie Interstellar here, we might as well just take a case study of how filmmakers technically do this time dilation feel in the movie In the opening scene, when Cooper and his team step on Miller's Planet, an intense music with clock ticking element starts. For every 60 seconds of the track, there are 48 ticks of the secondhand sound. So each tick is an interval of 1.25 seconds.

According to the movie, every hour on Miller's Planet equals about seven years on Earth, let's do the math on this. There are 3600 seconds in an hour, and there are 24 hours in a day. So to get seven years, we need to multiply. Seconds in a day, days in a year, all multiplied by seven years. Roughly, we'll get about 220 million seconds in seven years. This gives us a conversion factor of about 61,400 seconds, which pass on Earth for every second spent on Miller's planet. Multiply this by the interval between each tick, and you get 77,000 Earth seconds or about 21 hours.

- After grasping all of this information, of course we want to ask the following questions. Is this extreme time dilation plausible in real life? Could we even land on the surface of such a planet?

Interested in learning more? We’ve dedicated an entire video to exploring this topic, going deeper into the science surrounding it. You can watch the full discussion through the link below.