Definition of Living Thing ?

[adamstewart]

What is your definition of a 'living' thing. That is, what criteria must something meet in order to be considered "alive."








Then,

-&gt; <font color="white"> How is "fire" different? </font> &lt;-



Adam

To me...

Life is based on carbon compound (on earth at least) but to avoid the big debate saying that oil contain carbon and isn't alive. A few requirement other than that :

Should contain molecular components (lipids, proteins, etc.)
They require energy to sustain themselves.
They contain at least one cell (plant/animal based)
It can maintain a certain degree of homeostasis (it's compound doesn't go crazy)
They evolve at certain speed

Now this is for life as we know it...on earth. ET life form wouldn't need to be carbon based.

[send_the_msg]

1. can accept outside information and react, in multiple ways, based on that information.

i think all plants and animals fit into this catagory, but no elements do.

It’s not easy to come with a complete answer, but all living things must:
Be composed of cells, grow, generate energy, respond to environment, maintain stability (homeostasis) and reproduce.

“What criteria must something meet in order to be considered "alive."”

I suppose the battle that gives to survive.

[Hamish McBagpipe]

This has been done a couple of times recently. Anywho, ____ is a chemical reaction that fills the usual criteria. It is clearly not alive. Neither is a computer virus. Most of us from high school biology know that a real virus (and some other lower forms) with its incomplete strands of DNA (RNA?) is the cutoff point with some saying a virus strand is not alive, some saying it is, but few claiming life can exist without ANY genetic components at all.

[Piers]

I guess it depends on context.

Is it possible to have a conscious self-aware entity that is not alive?

If such a thing exist I would like to see it...some religion fanatics could probably find some /images/graemlins/smile.gif

[J. Stew]

Anything that eventually dies.

[mythrilfox]

Only if you have defined a living thing as self-aware, which most people do not.

[ThinkQuick]

[ QUOTE ]
To me...

Life is based on carbon compound (on earth at least) but to avoid the big debate saying that oil contain carbon and isn't alive. A few requirement other than that :

Should contain molecular components (lipids, proteins, etc.)
They require energy to sustain themselves.
They contain at least one cell (plant/animal based)
It can maintain a certain degree of homeostasis (it's compound doesn't go crazy)
They evolve at certain speed

Now this is for life as we know it...on earth. ET life form wouldn't need to be carbon based.

[/ QUOTE ]

yes these are characteristics that fit, though you should also include reproduction, response to stimuli, and growth (waste/mass production, etc.). We use these to distinguish living from nonliving things,
but regardless, something cannot be living if it does not fit into one of the 4 kingdoms. <font color="white">fire </font> does not

[Alex/Mugaaz]

I thought I read before that silicon based life was theoretically possible.

Yeah silicon based life is theoritically possible, since it ressemble carbon in many ways...however it has some problem maintaining double and triple bonds hence it could be hard to have an advanced form of life...but who knows what is out there. One problem though, oxidation of C is a gaz, CO2...oxidation of Si is a solid...which further limit the possibilities of advanced life form developing from it.

If you like StarTrek, I think they have some sort of thing that is silicon based and alife...don'T know it's name I'm not a big fan myself.

[RainDog]

I will venture to say that every "thing" is "living" under my definition of the term. But then to define the term is to answer the question no?

Everything is connected and is at all times interacting or at least capable of interacting with all other "things". So I rather prefer to view it as one living entity (perhaps even God) of which we are all part.

Don't agree? You obviously haven't done enough drugs.

"And what if all of animated nature
Be but organic Harps diversely fram'd,
That tremble into thought, as o'er them sweeps
Plastic and vast, one intellectual breeze,
At once the Soul of each, and God of all?"

[laurentia]

Here is an introduction to chemoton theory with comparison to other definitions of life:

http://home.wxs.nl/~gkorthof/korthof66.htm