Questions after watching the movie Interstellar Awesome movie, but as a physics student, some questions do crop up


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*When they travel to the watery planet, they say that 1 hour on this planet is 7 yrs om earth.  How is this possible? Is the planet moving at a speed close to $c$? Or does strong gravitational field influence time? 

*When he enters the black hole, how does he do to the time dimension? Assuming that he somehow does, how did he get to the bedroom of all the places? I mean, he could have gotten anywhere in the space, why even earth? 

*How could he touch the books if only gravity crosses dimensions? Does electromagnetic force cross dimensions too?

*How was he rescued from a black hole? I thought even light can't escape it....

*What is cooper station? Is it a planet? Are we to assume that plan A worked and thats how they got everyone there?

*When they went to the watery planet, how was it that signals were received but not sent? Is this possible? 
I understand there are inaccuracies in movies, but I heard Nolas hired physicists to figure out how to make the most accurate movie....so I thought there may be a problem with my understanding.  
 A: 
1.When they travel to the watery planet, they say that 1 hour on this planet is 7 yrs om earth. How is this possible? Is the planet moving at a speed close to c? Or does strong gravitational field influence time? 

Sure. This is gravitational time dilation. It's due to the gravitational field of the black hole. You can calculate it using
$$\frac{d \tau}{dt}=\sqrt{1-\frac{3r_s}{2r}}$$
You can use this to figure out how far they are from the black hole.

2.When he enters the black hole, how does he do to the time dimension? Assuming that he somehow does, how did he get to the bedroom of all the places? I mean, he could have gotten anywhere in the space, why even earth?

This is speculative.

3.How could he touch the books if only gravity crosses dimensions? Does electromagnetic force cross dimensions too?

This is also speculative. Note, though, that brane cosmology postulates that electromagnetism and the nuclear forces are trapped on our "brane", while gravity can travel through the "bulk".

4.How was he rescued from a black hole? I thought even light can't escape it....

The speculation continues. . .

5.What is cooper station? Is it a planet? Are we to assume that plan A worked and thats how they got everyone there?

It's an artificial habitat (or interstellar ark) that humanity is in. Specifically, it's an O'Neill cylinder.

6.When they went to the watery planet, how was it that signals were received but not sent? Is this possible?

I'm not sure this is ever cleared up.
