What is Life?

So I was thinking, what does it mean for something to be "alive?" The classic definition I remember from biology is that something which is alive must reproduce, respirate, respond to its environment, consume food etc. All life on this planet fits into this criteria, but Ive never been really satisfied with it. For instance, fire would technically be alive by this definition, whereas someone who is sterile (and so cant reproduce) wouldnt be alive.

I wonder about this, because we are already looking for life elsewhere in the universe, but we dont actually know what we are really looking for. I think we would know whether something is alive or not when we discover it, but we cant seem to get a watertight definition beforehand.

It gets more complicated when you start to consider consciousness. Imagine if we had a supercomputer powerful enough that it actually became conscious, just like we are. Speaking to it would be exactly like speaking to a person, it would have emotions, feelings, could think abstractly etc. In fact this computer would be a "he/she" rather than an it. I dont think anyone would argue that he isnt conscious, but is he alive? he cant reproduce, he cant physically respond to his environment, and he doesnt consume food and excrete waste in the traditional sense. What if the computer transplanted into a robot, capable of manipulating its environment? Is he alive then? What if he could repair itself and build replicas?

I personally think that our current definition of life is very narrow and known-earth centred.

I think the word 'life' may not have any real meaning when you look at it too deeply.

Consider, we don't say that the chemical reaction of burning is alive yet the succession of chemical reactions which make up us is considered to be alive.

In the 'medium scale' world we live in I think MRS NERG is just about adequate but I dount there is a clear definition between life and nonlife when you look too closely at it.

http://theflatearthsociety.org/forum/index.php?topic=23609.0   

I think the word 'life' may not have any real meaning when you look at it too deeply.

Consider, we don't say that the chemical reaction of burning is alive yet the succession of chemical reactions which make up us is considered to be alive.

In the 'medium scale' world we live in I think MRS NERG is just about adequate but I dount there is a clear definition between life and nonlife when you look too closely at it.

Some form of passing information on. A la genetics.

Fire isn't alive, because though it reproduces, it's offspring do not carry any of it's traits, they carry the traits of the fuel they are burning.

One could argue that combustion is a common aspect passed on in each instance. [/troll]

There is no decrease in entropy in the system. Something I'd consider necessary for something to be considered living.

I understand your delema. I've talked about this exact thing before and my pantheistic interpretation was ridiculed.  But in all honesty, there is no distinct line between living and not living.  Just as Chris said: what makes one series of chemical reactions living and some other not? 

I understand your delema. I've talked about this exact thing before and my pantheistic interpretation was ridiculed.  But in all honesty, there is no distinct line between living and not living.  Just as Chris said: what makes one series of chemical reactions living and some other not? 

Genetics.

but isn't it a little short-sighted to say only one set of chemicals creates something similar to genetics?

but isn't it a little short-sighted to say only one set of chemicals creates something similar to genetics?

Who claimed only one set of chemicals did that?

Life, in the biological sense, is carbon based.  This is because carbon forms strong bonds that are ideal for building.  This allows for digital replication.  This is a dead give away for life.  However, it has been proposed that silicon could be used to build life as it also readily forms such bonds. 

but isn't it a little short-sighted to say only one set of chemicals creates something similar to genetics?

I never said only one set. I just meant it had to some how pass on the information from the thing that made it.

Quote from: EvilToothpaste on July 16, 2009, 11:13:20 PM

but isn't it a little short-sighted to say only one set of chemicals creates something similar to genetics?

I never said only one set. I just meant it had to some how pass on the information from the thing that made it.

What about those self replicating chemicals which don't use DNA? Is that life?

http://www.wired.com/wiredscience/2009/01/replicatingrna/

Quote from: Raist on July 16, 2009, 11:32:59 PM

Quote from: EvilToothpaste on July 16, 2009, 11:13:20 PM

but isn't it a little short-sighted to say only one set of chemicals creates something similar to genetics?

I never said only one set. I just meant it had to some how pass on the information from the thing that made it.

Like a VIN plate?

You have self replicating vin plates?

Enough with the low quality/trolling posts.



@Tom, their lack of a metabolism would be the main separation. Sure they replicate, but they in no way interact with their environment outside of the actual replication. I believe things like this really blur the line between living and unliving because that is just an artificial distinction we have made to describe ourselves.

Quote from: Raist on July 17, 2009, 01:34:07 PM

Quote from: KillaBee on July 17, 2009, 11:47:14 AM

Quote from: Raist on July 16, 2009, 11:32:59 PM

I never said only one set. I just meant it had to some how pass on the information from the thing that made it.

Like a VIN plate?

You have self replicating vin plates?

No. I pointed out a VIN plate is a piece of information passed on from the thing that made it (automotive manufacture machine). So is a car alive because it contains information from the thing that made it.

It's not trolling. I'm working through your argument. It's called debate. This is what TFES is all about. Smile and enjoy it.

No, unless the press that made the vin plate made another press to make vin plates it is not at all what I described, though it does put the vin plate at the level of messenger RNA.

Congrats on sucking at analogous arguments.

Did I say that was the only requirement?

Again, if you keep assuming things you make outrageous statements barely related to the argument. Your reasoning skills are very low, I'd say you are at the level of borderline mental illness.

Quote from: Raist on July 18, 2009, 04:10:49 PM

Did I say that was the only requirement?

Did you state any other requirements?

Remember to keep the ad hominems to CN. Thanks.

There is a difference between an ad hominem and a deductive statement based on someone's views and actions.

Did I say that was the only requirement? Did my statement imply that everything that passes on information was alive? No. My statement implied "Things that are living must pass on information" hence me using the word requirement. You then used false logic to turn my statement into "Everything that passes on information is alive"

Please go away.

I said it has to, not that everything that does so is life.


If I said a qualification for being a ball cap is that it has to be a cap, does that mean that every cap is a ballcap?

No. Your logic is bullshit.

The classic example of your flawed logic is, all ducks have feathers, but not everything with feathers is a duck.

I said "It has to pass on hereditary traits" And life does. I didn't say "Things that pass on hereditary traits have to be alive." You can not always assume the converse of a statement.

Quote from: Raist on July 18, 2009, 05:33:47 PM

I said "It has to pass on hereditary traits" And life does. I didn't say "Things that pass on hereditary traits have to be alive." You can not always assume the converse of a statement.

But if I was given something, and asked to determine if it had life, what questions would I ask? This is the question asked in the OP. Your answer is "it had to some how pass on the information from the thing that made it."

VIN plates do that.

...?

Now you are assuming again that I gave you blatant instructions on how to determine if an animal is living or not.

It must utilize energy with some chemical reaction.
It must use some form of heredity to pass on its traits.
It must be able to do these things on its own, or with the help of other members of its species.

I'm going to stop there, but I may be missing some necessary descriptions for a non biased description of life, I left out the contained within a cell and a few others due to them being Earth biases, but I will add to it

"Responds to stimuli"

KillaBee, you're a fucking douchebag.  Jesus christ man, relax; this isn't a thesis defense.  But I guess that's your M.O.: just jump on someone else's back when you really have nothing to add.  If you had something to contribute you would have done so in your first post, otherwise you're just trolling. 

KillaBee, you're a fucking douchebag.  Jesus christ man, relax; this isn't a thesis defense.  But I guess that's your M.O.: just jump on someone else's back when you really have nothing to add.  If you had something to contribute you would have done so in your first post, otherwise you're just trolling. 

As much as I agree with your sentiments about KillaBee (and I do, believe me), please keep profanity out of the serious discussion boards.

Life is simply the ability to breath, nothing more.

Life is simply the ability to breath, nothing more.

The oceans are lifeless.

Quote from: Friend 001 on July 20, 2009, 08:06:26 AM

Life is simply the ability to breath, nothing more.

The oceans are lifeless.

aside from marine mammals

Quote from: Raist on July 20, 2009, 10:35:18 PM

Quote from: Friend 001 on July 20, 2009, 08:06:26 AM

Life is simply the ability to breath, nothing more.

The oceans are lifeless.

aside from marine mammals

Cool story?

Quote from: semperround on July 21, 2009, 12:21:46 AM

Quote from: Raist on July 20, 2009, 10:35:18 PM

Quote from: Friend 001 on July 20, 2009, 08:06:26 AM

Life is simply the ability to breath, nothing more.

The oceans are lifeless.

aside from marine mammals

Cool story?

how so?