In Interstellar the crew lands on a planet near a black hole, where the gravity field was so powerful because of the black hole that they had spend many years on the planet (relative to their station).

They freely walked on this planet. The planet's and Gargantua's gravity together did not give such a powerful field, so they could walk on the planet, so they couldn't spend so much time on the planet, right?

I thought that time distortion couldn't be big if they didn't feel big gravity on those planet.

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    The planet they landed on was in orbit around Gargantua, so they experienced as much 'force' from Gargantua as someone in the ISS feels of Earth's gravity. The time dilation effects of Gargantua (or Earth) still apply. – Andrew Thompson Sep 30 '15 at 14:15
  • Good question. You would think that a gravitational force massive enough to produce a 7 year to 1 hour time dilation, would be strong enough to be felt physically. The black hole is strong enough that Miller's planet is Tidally Locked, so it doesn't even rotate on it's own axis any more. – cde Sep 30 '15 at 14:51
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    @cde Why would it be felt physically? They're orbiting around the black hole. We don't get sucked towards the sun either. (Besides that you might also want to upvote the question if you think it is a good one.) – Napoleon Wilson Sep 30 '15 at 14:52
  • @NapoleonWilson because we only feel 0.0006g's from the sun, compared to the 1g from the earth at sea level. The distance from the sun is great enough, and the mass of the sun low enough compared to the mass of the Earth, and humans so small that it's negligible on human scale. Yet the Sun and moons produce tidal waves, causing ocean water to stretch 1 meter. Gargantua is so freaking massive that it bends space time on a scale of 61360 to 1 at the edge of its event horizon. It boggles the mind that it would have no noticeable effect. – cde Oct 3 '15 at 23:41
  • @cde Being tidal locked doesn't mean you'd have to feel the gravity of the black hole while on the planet. The Moon is tidal locked to the Earth. Yet when walking on the Moon you don't feel a lot of the Earth's gravity. But I am not even sure that planet was tidal locked to the black hole. I don't think the tidal waves seen on that planet would be possible if it was indeed tidal locked. – kasperd Oct 5 '15 at 7:57

They freely walked on this planet because you are correct in that the planet's own gravity wasn't very high, not so much higher than earth's gravity. Iin fact they explicitly say in the movie that the gravity is 130% of earth's gravity.

However, the extreme relativistic time dilation they experience (1 hour on the planet equals 7 years on earth) comes not from the planet but from the black hole Gargantua's gravitational influence, which has an extremely high mass (approximately 100 million times the mass of our sun, according to scientific advisor Kip Thorne) and to which the planet is very very near. This is what causes the huge time distortion relative to the station (which is in a farther orbit around Gargantua and thus isn't subject to its heavy time dilating effects).

The reason they in turn don't physically feel Gargantua's very high gravity -- in the sense of getting abnormally dragged towards the planet or the black hole -- is because the planet itself is on a stable planetary orbit around Gargantua and thus in a state of continuous freefall (in the same way we on earth don't actually feel the sun's high gravity but only earth's due to orbiting around the sun). But the planet and its inhabitants are still subject to Gargantua's extreme gravitational influence and the resulting time dilation, of course.

  • I couldn't be bothered trying to turn my comment into an answer, but.. yeah that. :) – Andrew Thompson Sep 30 '15 at 18:01
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    Also, isn't it the huge gravity from the black-hole-plus-star-combo that results in the absolutely massive waves? – user568458 Oct 4 '15 at 2:37

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