Basically, time passes slow for people travelling super-fast, like in space, and this is showing McConaughey seeing his daughter grow old faster than him cuz he's a spaceman
People who are traveling super fast; or people who are in a huge gravitational field experience the time dilation. For example: if you were near a black hole for 5 mins, there is potential for years to go by on Earth depending on how close you were and how strong the gravity is. In this case he was near a black hole for a few hours and I'm that time about 30 years went by.
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