The life-action short film (probably less than 30 minutes) starts with a scene where a kid falls (near a tree, I think), and his mother finds him (I think the kid passed out due to the fall). The kid grows up to become a space explorer with the task of finding life somewhere in the universe. I believe a robot (or the ship with robot voice) is supposed to wake him up when life is found (the man is in hibernation).
The man wakes up (due to some error?) and feels a "presence" calling him. The robot/ship tells him it was his imagination (and that he has to go back to hibernation, I think). When the man asks how long he has been asleep, the robot/ship says something like "that number will be difficult for you to comprehend" and then a screen is shown with several 9's on it (like 10,000 9's, I think). No life was found anywhere in the universe (and probably the "universe collapsed").
After some discussion, somehow the robot/ship reveals that it can recreate a big bang. The man asks the robot to do it and try to search for life again. Maybe this time they will find it. The robot says something like "That won't work". The man asks "How do you know?". The robot replies "Because I've already done it". Then the man asks how many times and the robot replies "That number will be difficult for you to comprehend".
During all this time the man feels the presence calling him and feels that he has to open the ship's door. The robot insists that it is his imagination. Eventually the man opens the door to meet the presence (and the man passes out, I think) and the scene goes back to the kid passing out and his mother taking care of him.
I thought the name was "Infinity", "Infinite", "Aleph 0", or something like that (a mathy name), but I can't find it anywhere. If I remember correctly there was a trailer of it (3-4 minutes) in Youtube, and it was very hard to find the full short film. It was probably created somewhere between 2005 and 2017.