Answer:
The big rip theory
Explanation:
I believe what you are referring to is the big rip theory, in which the universe expands faster than the speed of light Kurzgesagt refers to it as a "horizon" but in reality it's a little more complicated than that. Eventually the expansion of the universe will accelerate far beyond the speed of light creating space between molecules until eventually all matter is fleeting and the entire universe is an endlessly vast cosmic void with not but the occasion molecule left from a time when things weren't so lonely.
I think Y is the answer to number 4
The economy will never be fully employed in the future the economy will be completely unemployed because pretty soon we will invent robots that'll take our jobs
The answer is negative reinforcement. It is because negative reinforcement is where a particular behavior of a person is being stopped or being prevented in a way to prevent of producing an outcome that would likely be considered as negative. It could be seen above as Kendra avoids doing her used to behavior just to prevent herself from having no television which would be a negative outcome if it happens.
