The physicist himself said it was due to gravity and it's been proven time and time again, it is because of that. It wasn't the planet's gravitational field causing the time anomaly, but instead, the gravitational field of the black hole.
It does not allow you to communicate at the speed of light, however allows you to send Morse-code (Low-Frequency Waves) in a second to something being affected by approximately 15G.
Please correct your research.
Talking upon facts, the higher the gravity, the slower time moves for you compared to the rest of the universe. Increase your gravity and you can get a radio wave which would've usually taken a year to deliver in a matter of hours. A more detailed visualization of this is provided in the movie 'Interstellar' and this scientific research was later on verified as correct by a famous physicist.
To be honest, you can experience this at the ISS space station. The difference isn't large because earth's gravity is 0.8 while in space it is approximately 0G (not 0G exact - proven in a previous post of mine : http://www.sciencefo...ro-gravity-0-g/). The difference in time would be that a minute here would be 0.2 minutes there, meaning that 5 minutes here is 1 minute there.
On the grand-scale; if you're near a planet which is near a black hole, where the gravity of the black hole would be 600G and the planet having a 0.8G gravity similar to earth, a minute there would be 590.2 minutes here. 600G is the gravity of a small black hole just so you know, a giant one like in the middle of the Milky Way would have a gravity force of over 10,000G. Be near that and every minute there would be a week here.
Not true at all. Were you watching Interstellar lately?
Relativistic velocity is responsible for the time dilation effect in which you're referring to, so that water planet in the movie Interstellar experienced some extreme time dilation because it was orbiting a black hole sun, at its distance it was circling that body close to the speed of light. That's why one minute there was equal to years off-world, not because it had super high gravity itself. You actually have time dilation in reverse, if you generate spatial-temporal distortions (which, again, is exactly what I'm talking about when I refer to superluminal communication) you're going to slow down signals relative to the rest of the universe, not speed them up, unless you're going faster than light and experience negative time, like when Cooper entered the Event Horizon of the black hole in Interstellar. When you go past the event horizon spatial distortions are superluminal (which is why light gets trapped and time loses it's causal meaning within the singularity of a black hole). Superluminal communication is not possible without distorting space time, and interstellar communication is delayed for millions of years if you're just on the other side of the Milky Way. Relativistic time dilation doesn't change a thing.
Edited by Super Polymath, 21 April 2017 - 09:21 PM.