When the crew in Interstellar went down to Miller's planet then came back up we find that 23 years have passed for Romilly. Can someone please explain why and how did that happen?

IIRC it was something related to the black hole, but Romilly was orbiting the planet itself. Why did time pass longer for him? Why did the landing on the planet make such difference?

2 Answers 2


The reason for this is what's called gravitational time dilation, which generally states that the stronger the gravitational potential, the more slowly time passes. Black holes like Gargantua have massive gravitational pull, so strong that even light can't escape. Miller's planet is so close to Gargantua that time actually moves more slowly on the planet than for objects further away.

As such, one hour of time spent on the planet's surface was equivalent to 7 years passing in earth time, or "normal" time I guess you could say. That's why when they finally made it back to their ship, Romilly was significantly older, as was everyone they'd ever known. Romilly wasn't orbiting the planet, he was actually pretty far out from it, far enough that he wouldn't be affected by the time dilation caused by Gargantua.

  • Though, as to your last paragraph, I don't think the wormhole had any significantly big time-dilating effect, it doesn't seem to have that much huge gravitation at all. The huge time difference between Cooper and Murph was primarily due to Gargantua alone, as detailed in this related answer.
    – Napoleon Wilson
    Nov 22, 2014 at 14:23
  • You're right. Checked with a physics buddy of mine and he confirmed that the wormhole is just a shortcut to a distant point, but that light still travels through that shortcut at the same speed, thus time would pass exactly the same as it would.
    – MattD
    Nov 24, 2014 at 19:35
  • I've eliminated that paragraph to make the answer more accurate. If you still feel additional corrections are needed, please let me know.
    – MattD
    Nov 24, 2014 at 19:36
  • 1
    Seems fine now.
    – Napoleon Wilson
    Nov 24, 2014 at 20:04

What I thought, is explained in the image. Not sure to what extent it "can be" even considered to be correct. Lets hope, I have understood at least a part of it.

Example shown in Image -

On Miller's planet, when an obj A travels for some units of time and it reaches the destination point Q. (P to Q) So meanwhile on Earth, (if we consider that Earth is in different space/planes, hence considered as tilted line with reference to Miller's planet), to reach to point Q from point P, it would take greater time with respect to Miller's planet. (As general understanding/maths is that, two co-ordinates on the straight line, when dropped on a tilted line [perpendicular to the straight line], will generate relatively higher distance on tilted line.)

So, assuming this concept, time spent on Earth is greater than that of the Miller's planet.

enter image description here

  • 1
    This restates the question rather than attempting to answer it.
    – Chenmunka
    Sep 19, 2016 at 17:22
  • Mmm - it does attempt to answer the question. I've removed the restatement of the question which confuses the matter.
    – iandotkelly
    Sep 19, 2016 at 23:37
  • 2
    However I don't think its a very good answer ... Nitin, unfortunately this does really require an answer based on physics, which you said you don't really understand.
    – iandotkelly
    Sep 19, 2016 at 23:38

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