Cosmology and our View of the World
What is Life?
Lead: Tyler Dupuis
Summary by Thomas Garvey
What is Life?
P. Shaver "Cosmic Heritage" Ch. 8-10
R. Holmes III. "Three Big Bangs", Ch. 3
The class discussion began with first setting out the parameters of what can be considered life. A general overview was presented about some very basic building blocks for creating a definition of exactly what a living thing is. To move forward, the discussion built its understanding that a life form must have a metabolism, be capable of replication, and undergo evolution over time. During this initial stage of the discussion a key concept was brought in that would reappear throughout the class period: Life is most easily discerned as an ongoing process and not some tangible object or collection of objects. These first few important characteristics helped each participant to move on through the presentation by establishing a core knowledge base on the topic. Life elsewhere in the universe may be vastly different from what we are familiar with on Earth. Extraterrestrial life could be problematic to detect with scientific instruments and may only be easily discernible by human interaction or observance. Something chemically very different from all current concepts of life may still behave and have processes very similar to what we classify as life.
The second slide presented listed seven requirements for life as we can currently define it. Homeostasis, organization, metabolism, growth, adaptation, stimuli response, and reproduction were given as qualities that all life as we know it possesses. A point was made that these qualities are undoubtedly biological in nature, and that these are qualities of life from a strong biological viewpoint. Arguments could be, and were, made on spiritual and philosophical ideologies. Interesting and challenging questions soon began to surface. “Could a life form have only some of these qualities?” “Does it need all of these qualities to be ‘alive’?” “Would we consider it life at all?” Participants began to argue these qualities, such as sensitivity to stimuli from surroundings. Professor deVries commented that iron displayed sensitivity to stimuli from its surrounds in the act of rusting, but questioned whether it displayed a true integral quality of life.
A strong point was made in reference to the widely known Ansari X-Prize, a multi-million dollar prize for achieving manned spaceflight by a private company that has spawned many similar competitions, in regards to creating life in a laboratory. If a prize were to be at stake for the first lab to create synthetic life, what would be the minimum requirements to satisfy the event organizers? Would it need to possess all the seven previously mentioned qualities, or only some? And if only some were needed, how many would be needed for that group to believe the lab satisfactorily created synthetic life?
Discussion of mechanical devices, such as robots and computers, were a reoccurring topic throughout the class. In previous classes, the concept of consciousness was discussed and a large portion of time was spent on whether or not machines could become conscious entities. For something to possess a level of intelligence and understanding that we could label as being conscious, would it have to be an organic, living thing following the seven qualities or not. If consciousness could arise in these machines, would we think of them as life forms, because if not we then agree that nonliving beings could be conscious. This conversation evolved into whether life is simply a binary comparison between objects – it is either alive or it is not – or whether there is a spectrum of life in many different forms possessing some qualities while lacking others.
A number of students were in support of the idea that machines are indeed a type of living thing, and if not, they are extremely close (and one day may reach that status). This idea was aided with the construction of another definition of life: A self-sustaining closed system of low entropy. The understanding is that natural processes always move in the direction of creating a higher level of entropy, where life is a system that actively works against this process by utilizing energy from the environment to maintain a lower level of entropy within its system boundaries. This also holds true for mechanical devices such as computers and their volatile memory banks. This idea went further with a prediction that as nanotechnology becomes more advanced and prevalent, that robots on a nanoscopic scale may be able to form together as tiny modules of a large, complex system. This system would be similar to how trillions of cells work together to create larger, complex life forms. Machines may very well one day be able to construct themselves (“reproduction”) from raw materials and energy sources.
A quality of life is the ability to reproduce, and thus through reproduction it possesses the ability to evolve over the course of several generations. Does life necessarily have to be capable of reproduction? Viruses present a challenge to some peoples’ beliefs about what life is. Would viruses exist without life? And if there were a world full of viruses, but nothing else that we would currently define as a life form, what would viruses be considered as? These questions and others brought up the idea that there may have been an environment on early Earth where there were tens of thousands of complex organic molecules, all of which were essential to creating life. They just weren’t put together in the right manner to be considered a full-fledged life form. From this a concept of an “immortal cell” was brought into the discussion, or the idea that there may have been several species of life that did not reproduce and therefore did not undergo any form of evolution. Once they came into existence, they stayed that way, but were perhaps destroyed at the onset of reproducing life forms that multiplied rapidly and were able to adapt to ever changing environments. Again, this idea ties into the spectrum of life, where these things may very well be considered living but “not as alive” in the same manner we are familiar with in our current understanding.
A closing statement was a revisit to the “X-Prize” for synthetic life: What if a lab were able to bring back to life something that had once died? What else could be closer to a living thing than something that has recently died? This sparked a debate about the definition of death. Due to popular media coverage of past near death experiences, it was argued that if something were brought back from the dead, did it actually experience death, or a phenomenon very similar? A definition for death was introduced – death is a state from which there is no return to a previous state. Therefore, if something were to die and come back alive, it could not have actually experienced death.
As with nearly all previous discussions, this presentation lasted well after the allotted time period and tracking of the conversations had to cease even as some students and professors continued debating. Answers to some of the questions presented led to even more challenging and intriguing questions and perhaps we will discover more in future discussions of this topic.