Which of the following statements comparing the two possible futures of our universe is NOT correct?
a) A high-density universe will last for about another billion years, whereas a low-density universe will last for about another trillion years.
b) A high-density universe will collapse, whereas a low-density universe will expand forever.
c) A high-density universe is older than a low-density universe.
d) A high-density universe will experience a "heat death," whereas a low-density universe will experience a "cold death."
