For a multicellular metazoan, it is that the collective cellular processes still work. This automatically means that such an organism dies in some parts before others (cf. "brain death"), but once the major processes fail, the others will eventually fail too.Originally posted by Mattius_
What physical property separates the two?
This is a good start.Originally posted by zoobyshoe
Doing my best to evade trying to
define "life" I would say that
what distinguishes that which is
alive from that which is dead for
me is that that which is alive
must be engaged to some
extent in the attempt to improve
or elaborate upon it's status quo.
That which is dead no longer exerts any effort of any kind on
its own behalf and is at the
mercy of any force that acts upon
It is by virtue of this that I
would never consider rocks, or
minerals, or individual elements
to be possessed of life.
Originally posted by heusdens
Life als is able of reproducing itself, in more or less the same form.
And life distinguishes itself from the environment.
And life needs to take in sources of energy to sustain itself, it needs a form of metabolism.
So does a computer virus. Which is why they are called 'virus'. Are computer viruses alive?Originally posted by heusdens
Life also is able of reproducing itself, in more or less the same form.
Yes, living beings are different from the environment by virtue of being alive. Like any fundamental principle, such as 'matter', 'space', 'time', life can only be defined tautologically.And life distinguishes itself from the environment.
So does my car.And life needs to take in sources of energy to sustain itself, it needs a form of metabolism.
Life, seemingly like all things in our universe, is a phenomenon named by humans, which isn't bounded by a nice neat couple of lines of demarcation. Life, is a part of everything else which does something neat, but nothing which is unique nor removed from everything else which happens."I was thinking about this earlier today when Larry Yaeger was talking about ‘what is life?’ and mentioned at the end something I didn’t know, about a special field of handwriting recognition. The following strange thought went through my mind: that trying to figure out what is life and what isn’t and where the boundary is has an interesting relationship with how you recognise handwriting. We all know, when presented with any particular entity, whether it’s a bit of mould from the fridge or whatever; we instinctively know when something is an example of life and when it isn’t. But it turns out to be tremendously hard exactly to define it. I remember once, a long time ago, needing a definition of life for a speech I was giving. Assuming there was a simple one and looking around the Internet, I was astonished at how diverse the definitions were and how very, very detailed each one had to be in order to include ‘this’ but not include ‘that’. If you think about it, a collection that includes a fruit fly and Richard Dawkins and the Great Barrier Reef is an awkward set of objects to try and compare. When we try and figure out what the rules are that we are looking for, trying to find a rule that’s self-evidently true, that turns out to be very, very hard.
Compare this with the business of recognising whether something is an A or a B or a C. It’s a similar kind of process, but it’s also a very, very different process, because you may say of something that you’re ‘not quite certain whether it counts as life or not life, it’s kind of there on the edge isn’t it, it’s probably a very low example of what you might call life, it’s maybe just about alive or maybe it isn’t’. Or maybe you might say about something that’s an example of Digital life, ‘does that count as being alive?’ Is it something, to coin someone’s earlier phrase, that’ll go squish if you step on it? Think about the controversial Gaia hypothesis; people say ‘is the planet alive?’, ‘is the ecosphere alive or not?’ In the end it depends on how you define such things.
Compare that with handwriting recognition. In the end you are trying to say “is this an A or is it a B?” People write As and Bs in many different ways; floridly, sloppily or whatever. It’s no good saying ‘well, it’s sort of A-ish but there’s a bit of B in there’, because you can’t write the word ‘apple’ with such a thing. It is either an A or a B. How do you judge? If you’re doing handwriting recognition, what you are trying to do is not to assess the relative degrees of A-ness or B-ness of the letter, but trying to define the intention of the person who wrote it. It’s very clear in the end—is it an A or a B?—ah! it’s an A, because the person writing it was writing the word apple and that’s clearly what it means. So, in the end, in the absence of an intentional creator, you cannot say what life is, because it simply depends on what set of definitions you include in your overall definition. Without a god, life is only a matter of opinion."
Originally posted by Arawn
So living beings have a tendency to decrease entropy locally.
Hmm, don't forces of nature more like increase entropy, since they are destructive forces? Wind, rain and UV rays don't make buildings or maintain bodies; they erode them. They are tools of entropy a living being must fight against. From this point of view the natural forces seem like the exact opposite of the living.Originally posted by zoobyshoe
This is true but it can't be used
to distinguish that which is alive
from that which is dead because
of all the non-living natural
forces a person could think of
that do the same thing: the wind
the tides and waves, rain, snow,
UV rays etc.
Well, if you use the same terms as you did with life, they do locally and temporarily decrease entropy. Eg. in the formation of charged clouds for storms. Or they work to drive life along by providing energy, even though the ultimate product is, as you say, an increase in entropy.Hmm, don't forces of nature more like increase entropy, since they are destructive forces?