253 Essays on Infinite Lifespans   Marc Geddes that no fire, no heroism, no intensity of thought and feeling, can preserve individual life beyond the grave; that all the labors of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and that the whole temple of Man’s achieve- ment must inevitably be buried beneath the debris of a universe in ruins- all these things, if not quite beyond dispute,  are  yet  so  nearly  certain  that  no  philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul’s habitation hence- forth be safely built.” [9] However, to a scientist, it is not known how the universe will  end,  if  at  all.  It  seems  that  the  universe  might  go  on expanding forever, but the nature of dark energy is not well enough understand to be very sure. It is important to under- stand that even if the average entropy density of the universe has  to  inevitably  increase,  this  does  not  mean  that  it  ever has to reach a maximum and stop dead. Even if the universe comes to an end, it may still be possible for life to survive forever. In 1979, English physicist Freeman Dyson published a paper [10] in which he argued that even in a universe with finite energy an intelligent being could still think an infinite number of thoughts. He considered the case where the uni- verse kept expanding, but started to ‘die’ as useable energy ran out. He found that as the universe grew colder and colder advanced beings could still live forever by thinking thoughts at a slower and slower rate. Physicist Frank Tipler considered the opposite scenario - the universe one day stops expanding and starts to collapse under the force of gravity, coming to an end at a ‘big crunch’. His idea was that as the universe grew hotter and hotter, intelligent beings could still live forever by