The ending of Interstellar Explanation

The ending of Interstellar

• Question 1: After Mann's betrayal, and failure to attach to the Endurance, they are left with limited fuel, so try to slingshot themselves through the gravity of Gargantua. Doing this, they calculate that they will lose 53 years of Earth-time. Unfortunately, Cooper has to sacrifice himself for Brand to have the fuel to make it to Wolf's planet.

Here's the question: Why has Cooper and Brand not aged differently? Even if Cooper's time in the tesseract doesn't count towards earth time, he would have still lost a substantial amount of time moving towards the center. Is it just that it was for such a short time that it didn't matter? that seems hard to believe considering the massive change in gravity.

• Question 2: Okay, so Cooper ends up inside the tesseract, and is able to communicate with Murph because gravity is able to travel through time yadda yadda. It is clearly stated, that "they"(future humans) have placed the tesseract there("They are closing it"), because Cooper is the only one able to communicate with Murph because of love. But how did they place the tesseract there? I need someone to explain the concept of what is happening. Was it because the gravity inside the black hole was so intense that they were able to manipulate it further than what Cooper is able to do with Murph? Even then, if the only reason Cooper is able to manipulate Murph's timeline is because of the bond of love, then who is able to communicate with Cooper? Is there a link through love to him from the future? Is that not a bit speculatory for the person watching to assume that?

Answer

Question 1 bothered me as well. My current rationalization is that after he leaves the tesseract, he is moved through both space and time, traveling to Saturn's orbit at around the same time he left Brand.

Question 2, I think you place too much emphasis on love's role. My view on that idea was that he was the only member of the "away team" who still had a connection to someone on Earth capable of ensuring humanity's survival, not some mystical power love has to create tesseracts. The tesseract was just a way created for him to perceive the relationship between time and gravity that existed in the black hole