252 An Introduction to Immortalist Morality It is interesting to point out that the suggested foundation for morality can be empirically falsified. Perhaps we cannot prove that the quest for immortality should be the ultimate value, but we could disprove it. If science ever determined that it is impossible for life in the universe to last forever, the quest for immortality is impossible and cannot be justi- fied.  So, does the scientific evidence rule out the idea that life could, in principle, survive forever? Some have thought so. One argument that life cannot survive forever comes from a law of physics known as the second law of thermodynam- ics. This says that the entropy of an isolated system (a system which exchanges no matter or energy with its environment) must always increase. Entropy is a measure of how disordered the system is. For instance science writer Adrian Berry once wrote:  “Preserving  a  living  body  forever  would  violate  the second law of thermodynamics.” [8] In fact the second law of thermodynamics does not imply that a living thing has to decay. Living things are not isolated systems. They constantly exchange matter and energy with the environment. For instance the human body excretes waste and takes in air, food and water. So long as a living thing con- tinues to take in new energy, there is no reason why it has to decay. The biosphere of planet Earth as a whole is exchanging energy with the wider solar system. What about the universe as a whole, however? The universe appears to be an isolated system  in  which  entropy  has  to  increase.  Will  all  sources of useable energy one day run out? Will everything decay? The great philosopher Bertrand Russell certainly thought so. He wrote these depressing words: “That man is the product of causes that had no previ- sion of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and his beliefs, are but the outcome of accidental collocations of atoms;