i teach at the university massachusetts amherst and i and director of the professional writing and technical communication program there ready for a lay audience is not presented so interesting challenges and one of them is to as it were translate scientific jargon into language that everyone can understand i think many books many good books begin with simple question this and sometimes the question of certain questions of children and what began we were life for me or what began me thinking about when life was a very simple question the child's question which is how strange can life get and our favorite book of mine as a child was dr seuss's if iran is here it begins with a with a young boy is changes that's just what i'd do the lions and tigers and that kind of stuff they have up here now are not quite good enough you see things like these in just any old zoo they're awfully old living entity are old perhaps as old as history but attempts to define a life have taken two approaches one one might say a functional approach that is you define an organism according to what it does so we might say an organism grows it breathes or it eats it produces is stars do all those things kindle flames do things and few of us would call stars and candle flames alive we could add something else to the list and we could say well  to be alive reproduces itself problem is crystals reproduce themselves and we wouldn't call crystals or worker ants and mules do not reproduce themselves most of us would agree that wor living so the functional definition of life seems to hit some roadblocks the other way to define life has been a more materialist approach that is to say define it not by what it has a long binding molecule it all it all of it has twenty or so amino acids presence at its base all of it uses water as a bio solvent that is to say the liquid medium which enables complex chemistry the but it's not clear and it wasn't clear to the off authors of the national research council report whether like necessarily  would help us perhaps is not to come up with a definition not a laundry list of components but rather a theory of life and to have a theory you need another example do we have only one example  that is to say that life on earth life we know is one example of life all life we know and this is important to understand all life we know is related all life we know descends from a single universal ancestor one single celled creature that existed billions of years ago we know this because all life we know share certain characteristics it shares d n a or r n a it shares those twenty three amino acids it shares the thousands of chemical pathways and if we had another example of life another kind of life that didn't have all those characteristics we would have life that descended from a nother and that would be weird life in the early  life living in salt lakes life in the dead sea life in the great salt lake life living strange to say even chernobyl in the true don't believe nuclear reactor in living off the radiation somehow repairing its d n a they found life they said all the assumptions were shown to be false they assumed among other things life  and something to move around on and then they'd just covered bacteria living in cloud no one had expected all but it may do scientists especially nasa scientists founder and director of nasa ames astrophysics and master of chemistry lab he's very interested in comets and many astronomers have said i think it's almost become that what it comet is is a dirty snowball meaning it's it's it's ice and a little bit of rock and maybe some organic material in dulles as though that we really don't know what comets are of it's there a long ways off and the they rather defy examination from a distance and what he and his colleagues at nasa ames have done is say well let's let's not worry about them out of their lives just try to make our own homemade comet and that's what they've done and they've got  they've got a chamber that simulates deep space it's about the size of a coffee can and they removed the air from it they lowered the temperature to a few degrees above absolute zero and what they've done there by is create a very good simulation deep space then they introduced a few very simple molecules into it and and they bathed those molecules in ultraviolet radiation weren't expecting much to happen but what they did and what did happen surprised them a great deal the molecules combined and then they recombined and recombined again and they they became was no way for them to get together certainly no way for them to form complex molecules and now most many astronomers believe that the water on earth than water on thousand and two the national research council commissioned a report called the limits of organic life in planetary systems and that was the first time that that anyone had thought seriously about these questions or anyone any group had thought seriously about these questions in some detail and they concluded with a report that appeared in two thousand and seven that was very ambitious it tried to define life and as provisional definition of life was a chemical system that involves darwinian evolution and they also they tried as best they could to define the outer limits of life and concluded that it is possible that life does not need to be based on carbon it is possible that life does not need water as a solvent it is possible that life might use a binding molecule that is other than d n a or r n a that whereas these were ideas that appeared of course in science fiction for decades but this is the first time that this  happened in this is the first time we've seen scientists produce a serious piece about this nasa's strategy for looking for life on other worlds informally has been called follow the water or find of the water that is to say the assumption there has been that all life means water as a bio  liquid methane even other things these would be these these would be compounds that would probably not be liquid on and that prospect excites a certain subset of acts of biologist astrobiologist nasa astrobiology civilian very excited in the last few years by the discovery of water it does has a volume larger than all the oceans on earth combined this likewise is very exciting there seems to be prospects for liquid water beneath the saturn's moon and celeb as there seem to be prospects for liquid water on many of the moons the outer solar system and and all of this is very very exciting however that sort of life would be life much like ours and some scientists think that if life somehow travelled around a billion years ago travelled around the solar system via media your then that life might be related to  the actual biologists who think about weird life are not so much excited about mars or europa as they are about saturn's moon titan what's exciting about titan is that there are two sphere and it has would what on earth we would call hydrological cycle the that is to say the liquids are moving around if but but seitan is a very very cold place if life were there any kind of life with there it would certainly be very very different and it would probably most probably the scientists in recent years like planets many outnumber earth like planets by as many as ten to one the this is because the this is because simply because stars out number some like stars by about that ratio if you have a red dwarf star and a titan like planet orbiting at a certain distance you're going to you're going more examples of that kind of life than you would life like life that we know brandon carter is a scientist who introduced determine a concept anthropic principle the anthropic principle comes in many of its simplest form says that the universe in which we live seems to be designed to allow life that in itself is a fairly provocative statement among other reasons because it uses the word design carter is and a number of other people who thought about this don't all agree on what it means but when when we say the universe seems to design to support life we are obliged to look at some of the fundamental constants the natural constants in the universe and it comes as a surprise to many non scientists that these constants some of them seem quite arbitrary what do we mean by these constants well there are four fundamental forces in the universe we know gravity the gravity is a force you elect electromagnetism as a force there is also the strong force and weak for forces that work on the atomic and subatomic scales strange to say these forces have specific values gravity for instance has a specific value and scientists do not understand why it isn't stronger or weaker for years and years and years scientists took it as a given and no one questioned no one asked why until card and when he did other scientists began looking at the other constants not just the forces but strange of provocative to two carter and many other people it is that if you changed these values that is if you made gravity a little stronger or a little weaker or the weight of a proton a little lighter or a little heavier you couldn't have the universe we have gravity were a little weaker when the universe began when the universe began its inflation it would have just continue moved and it would have continued its inflation on checked and we'd have a universe of hydrogen atoms nothing like chemistry let alone life let alone us if the if they did force of gravity w stronger then it would have imploded it would have collapsed on itself very soon after its inflation and again we'd have no universe so one to one conclusion  where only one there are there are many perhaps an infinite number of people who hold with that that idea believe that their most of these other universes  they are empty of life they are just fields of loose hydrogen empty space variety of universes and which life would be impossible we just got lucky as it were were does this what's this have to do with weird life a few years ago a group of scientists suggested that if you would just did not just one parameter but a couple parameters of these these values particularly adjusted the weak force you still could have a universe with life and it would be very different  would be undoubtedly weird live by the definition we've been using here but it would work