>What is the purpose of life?
purpose
the reason for why something is done
On Earth, life began when a series of chemical reactions created a molecule that could replicate itself. In the process of evolution by natural selection, those replicating molecules competed against each other and their environment and became increasingly better at replicating themselves.
Everything organism does serves one and only one purpose: to replicate itself.
>Is time infinite?
Entropy is the only physical quantity that requires time to have a particular direction. Time proceeds to the direction of increasing entropy. Entropy always increases by time in the universe. The relative rate of time can be seen as relative increase of entropy in the system.
Time proceeds only when entropy can change. So time is not infinite; it is bounded by entropy, which cannot be infinite as we can easily define a perfectly ordered system and a perfectly disordered system.
>Do humans have free will?
Human's will is a series of inevitable chemical and physical reactions. In that sense humans are like any other object in the universe; their future is fully determined. So the answer at micro-scale is no.
However, at macro-scale, humans make choices depending on what they feel and what they know. If there were a machine that calculated "the will" of a human, it wouldn't affect the humans decisions unless it told human about those calculations, in which case the humans mind would change, requiring further calculations.
In an example: In state X, John dies today in car accident. Computer calculates that. If it informs John about it, the state of John will change to Y. In state Y, John doesn't die in car accident, so his future is not inevitable, in a macro-scale.
>Why is there something rather than nothing?
This is a easy one, because it requires absolutely no knowledge on science, only logic. If we weren't, we wouldn't know. If we are, we know.
Any other "unsolved mysteries"?