I just finished reading Max Tegmark's book "Our Mathematical Universe."  What I found to be particularly interesting is Tegmark's calculations that humans are most likely the only sentient species in the universe.  This goes contrary to a common opinion that the odds are in favour of other sentient life existing in the universe.  So what if we are the only sentient life in the universe?  Tegmark believes that since this is in his opinion an exceedingly likely reality, then we have a lot of responsibility on our shoulders including especially the immediate preservation of our own species, which our own negative natures such as the stockpiling of nuclear weapons continually threatens, yet this is hardly a public issue.  In this regards according to the figures Americans spend 10 billion dollars on cosmetic surgery each year, one half the budget of NASA.  This doesn't even go into the military budget, which dwarfs NASA's budget entirely, but where is our priorities and awareness?  If Earth life has the only sentient beings in the universe, this is a particularly disturbing thought.  Even more frightening a statistic in his book is that almost 50% of Americans think the earth to be less than 10,000 years old.  Mostly this is due to poor education, but even more frightening are the educated people who actually believe this although in a very low minority.  Yesterday I had an unpleasant conversation with a client who is a neurosurgeon consultant who told me that he thought the earth was less than 10,000 years old and that the deluge happened.  When I noted that there was no evidence for a global deluge that wiped out almost all life on earth in the fossil record, he reverted to faith.  The insanity of faith beyond reason is a true danger that as Tegmark suggests should be replaced by rationality and I agree.