Life. How can we define it?
What is life?
Life is an interesting subject. Particularly the origins of life. Being an atheist I often hear the idea that life cannot come from non-life. But of course at some point life came from non-living material. The problem with discovering origins is then explaining how a non-living system could evolve into a living one.
There is another problem, of course. That is the definition of life. What is it? How do we define it?
There are many definitions of life as it turns out. Some give us two or three main criteria and others give us at least 6 to 10 and more. The fact is that there is no definitive criteria for life. No standard one at any rate.
This is the problem for two new fields of study. The first is computers and AI. The second is the search for life on other planets. As far as AI is concerned, if it becomes sentient then it will not fit in to any definition of life we have thus far. Will we be able to recognize when an AI becomes sentient? Surely if they are alive they will want to be recognized as such. If we do that, of course, it brings up a whole range of issues as to whether it is moral to use them and treat them as property.
As for space exploration, will we recognize a different kind of life form if we see it? Are we only looking for life like we have here on earth? If we do will we be missing other life because we have such a narrow definition of what it is? After all, to say biological life is redundant to most of us. Saying biological life is like saying life life. The only life we recognize right now is biological.
Some have proposed that fire is alive as it meets a lot of the criteria we have set down. It fits some definitions perfectly. Some have even suggested that the earth is a living organism in its own right. Taking away some of the new age connotations of that argument, and the mystical idea that it is somehow conscious, it makes sense in the same way a group of people create new entity called a culture, society, an economy, etc. All things that join together seem to produce another level of existence.
For instance, two different types of atom merging together create a new substance on our level of existence.
It is my contention that the religious who say life cannot come from non-life may be right, but not for the reasons they think. Something about what we are made of must have the potential to produce life even if it is not itself biological.
As it turns out at the root of all things biological and not biological are made of energy/mass. The quantum is a hotbed of creativity and movement regulated by the nature of energy/mass itself. All things, be they on earth or elsewhere in the universe, are all made of the same substance in different configurations and forms.
All things biological and not biological are related intimately due to this fact.
Some geneticists have suggested that all life has DNA. So is that the criteria we want to use to describe life? That probably leaves AIs out of the picture completely, and yet those in the AI field as well as others predict we will eventually see sentient AI and not that far in to the future. I think that is a good definition for most biology, but perhaps not for life.
If life is an emergent property of energy/mass then energy/mass has at least the potential for producing life. But I think life is more fundamental then even that.
Years ago we used to talk about the animate and the inanimate. Things that were alive were animated and things that were not were inanimate. But because we discovered the quantum world we know now that even a rock is filled with movement internally. We know empty space is not empty at all, but teaming with quantum movement. The entire universe is animated through what it is, energy/mass.
If animation had remained the criteria for life, then there would be nothing but life in everything. Nothing but this quantum dance. It is not biological, but it is alive. Energy is life. What more basic criteria can there be for life than energy? It is not sentient life, it is not biological. But without energy there is no life at all. What animates us all is energy. Nothing else does.
And of course it is amazingly creative due to its nature.
So my answer to those that say that life cannot come from non-life is to say there is no such thing as non-life. There are a lot of things that are not biological, but there is nothing but life. We should be defining types of life rather than narrowly defining life itself to the point that it will cause us problems both legal and ethical in the future.
The question should perhaps be: how do biological entities come about from non-biological processes?