The definition of life is trivial: it is what biologists are interested in. If you want to know if something is alive, just count the biologists following it. Rabbits? Yes. Bugs? Yes. Viruses? Yes. Protons? No. Memes? Not really. Computer viruses? No.
Might the definition change, as biologists encounter new stuff and develop an interest? Sure. Does that make the old definition wrong? No.
That's not a very useful definition. What is it, then, that biologists are interested in? If you answer "life", your definition is circular and without informative value.
It is a perfect definition for exactly that reason.
The boundary between life and not-life is exactly where biologists' interest fades. If you wonder why something is not alive, just ask any biologist why it is not interesting. Different biologists may give you different answers, but all their answers are useful.
Remember when science was the pursuit of knowledge of the observable world? What you're talking about is a rigid classification of facts - almost as if "organizing the world's information" from a single dominant perspective was a worthwhile ends in itself...
That is inherent in trying to define "life": inventing a word for a distinction the universe doesn't care about, but people do. The people who care most are, exactly, biologists.
If you don't care much, then you aren't a biologist, and don't need an answer.
That is empirically not true. Sugar is not alive, but it is of interest to biologists. Viruses are not generally considered to be alive, but are of interest to biologists. Priors are not alive, but are of interest to biologists.
Additionally, scientists do not actually divide themselves into neat little boxes. A Biochemist does chemistry. A Quantum biologist does quantum physics. A Computation biologists does compute science.
This is a very Twain-esque definition. It's very good, thank you for posting it (and for providing entertainment by patiently replying to those arguing vainly against its irrefutable logic).
> life is self‐reproduction with variations [not the main gist of the article just one of the definitions they threw out]
So i guess fractals are alive on that view.
For the article in general. I kind of agree and disagree. I agree stressing too much about it is kind of futile, and the real world is full of shades of grey. But i disagree that throwing our hands up and hiving up is the right approach. Its still important to have some rough definition so we have shared understanding what we are talking about. Asking if something borderline is alive or not is not the interesting question, but it doesn't follow that we should have no definitions at all.
I like the concept you are proposing here like "Are fractals alive".
I dont think fractals are alive as they need you to execute them.
When I think about this I see there is a difference between the equation of a fractal which is like a description of it and the actual fractal which exists after somewhere the equation is executed.
Here the equation is like DNA and fractal itself like a cell.
Self replication in this case would be a property of the fractal itself.
Self reproducing means they can execute the reproduction part themselves or at least this is how I see it.
Life is a self-generated process of self-sustaining action. "If an organism fails in that action, it dies; its chemical elements remain, but its life goes out of existence."
An outer loop of evolution with an inner loop of learning, all powered by the self affirming principle of reproduction which is the source of all meaning.
Oftentimes philosophers wonder about the origin of meaning, how semantics come from syntax. Meaning comes from the need for life, even seemingly unrelated values derive from life affirming values.
We may as well go back to the classical theory of life: it's that which breathes. That is, if it's got active respiration, it's alive. So, a virus infected cell is alive but a virus alone is not. Once cellular respiration stops, the cell is dead.
Probably I'm missing something here, but anyway, I think a definition of life should not be based on self-reproduction.
Indeed, most of what we perceive as 'alive' does self-reproduce. But that might be just a consequence of the fact that a bulk of autonomous material is complex and can rarely occur on its own.
There have probably been some forms of life that could self-reproduce, as well as species that you would really call alive but could not self-reproduce. However, only the self-reproducing ones did grow in numbers and that is almost all we see today.
I think we can state definitively there 'have been some forms of life that can self-reproduce' to slightly paraphrase you (since we are an example). Unfortunately the opposite claim, that there have been forms of life that couldn't reproduce will be very hard to falsify, unless we happen to meet a very long-lived one.
Self reproduction might be necessary but not sufficient to define life. Crystals reproduce, for example, but we wouldn't likely call that life?
I have seen other summaries of this description as replacing step 2 with "mutation" or using simulation of a Turing machine as being synonymous with mutation
I am not a fan of this analysis, I think two rules is too many. Really there should be only one rule: no rules.
Plus, I think the second rule necessarily implies the first, since the theory of the universal Turing machine sufficiently allows for self-reproduction which later outlined the sketches for cellular automata and subsequent models such as Conway's Game of Life.
I've gotten it down to more or less one rule. Keep being. Everything else flows from that one rule, often with surprising consequences. Coelacanths are better at keeping being than mountains and continents.
30 comments
[ 2.3 ms ] story [ 76.1 ms ] threadMight the definition change, as biologists encounter new stuff and develop an interest? Sure. Does that make the old definition wrong? No.
The boundary between life and not-life is exactly where biologists' interest fades. If you wonder why something is not alive, just ask any biologist why it is not interesting. Different biologists may give you different answers, but all their answers are useful.
If you don't care much, then you aren't a biologist, and don't need an answer.
Additionally, scientists do not actually divide themselves into neat little boxes. A Biochemist does chemistry. A Quantum biologist does quantum physics. A Computation biologists does compute science.
Did you mean prions?
A biochemist decides whether a chemical is interesting according to whether it is made by or affects something alive. And so on.
Computers, bikes, music and pizza
I almost forgot money from grants... silly me
So i guess fractals are alive on that view.
For the article in general. I kind of agree and disagree. I agree stressing too much about it is kind of futile, and the real world is full of shades of grey. But i disagree that throwing our hands up and hiving up is the right approach. Its still important to have some rough definition so we have shared understanding what we are talking about. Asking if something borderline is alive or not is not the interesting question, but it doesn't follow that we should have no definitions at all.
I dont think fractals are alive as they need you to execute them.
When I think about this I see there is a difference between the equation of a fractal which is like a description of it and the actual fractal which exists after somewhere the equation is executed.
Here the equation is like DNA and fractal itself like a cell.
Self replication in this case would be a property of the fractal itself.
Self reproducing means they can execute the reproduction part themselves or at least this is how I see it.
There is a theory that our world is a simulation. Would that make us all not alive?
Using such code to implement a fractal-creating program is an interesting concept...
https://en.m.wikipedia.org/wiki/Metamorphic_code
Oftentimes philosophers wonder about the origin of meaning, how semantics come from syntax. Meaning comes from the need for life, even seemingly unrelated values derive from life affirming values.
Indeed, most of what we perceive as 'alive' does self-reproduce. But that might be just a consequence of the fact that a bulk of autonomous material is complex and can rarely occur on its own.
There have probably been some forms of life that could self-reproduce, as well as species that you would really call alive but could not self-reproduce. However, only the self-reproducing ones did grow in numbers and that is almost all we see today.
Self reproduction might be necessary but not sufficient to define life. Crystals reproduce, for example, but we wouldn't likely call that life?
1) Self-reproduction
2) Simulation of a Turing machine
I have seen other summaries of this description as replacing step 2 with "mutation" or using simulation of a Turing machine as being synonymous with mutation
I am not a fan of this analysis, I think two rules is too many. Really there should be only one rule: no rules.
Plus, I think the second rule necessarily implies the first, since the theory of the universal Turing machine sufficiently allows for self-reproduction which later outlined the sketches for cellular automata and subsequent models such as Conway's Game of Life.