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Author Topic: What is life and where did it come from?  (Read 21274 times)

Offline thedoc

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What is life and where did it come from?
« on: 19/12/2014 14:37:55 »
A big part of finding ET is understanding what life actually is.
We speak
to Nick Lane to find out how life and non-life are distinguished
Read a transcript of the interview by clicking here

or Listen to it now or [download as MP3]
« Last Edit: 19/12/2014 14:37:55 by _system »


 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #1 on: 30/09/2014 23:58:42 »
The essence of life seems to be a local reversal of mesoscopic entropy.

Where did it come from? Why would anyone think it came from anywhere else? The conditions for the continuation of life seem to be fairly narrow, yet widely available on the surface of this planet, so evolution is most likely to have begun here. The question is whether it started first on the hard surface or (more likely in my uninformed opinion) on the sea bed.
 

Offline chiralSPO

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Re: What is life and where did it come from?
« Reply #2 on: 01/10/2014 00:40:09 »
Alan, I have to respectfully disagree.

There are many spontaneous local reversals of entropy, including crystallization, condensation, accretion (even on planet scale). There are also many patterns that self propagate. There's more to it than that.

Also, a tortoise in the galapagos could be forgiven for thinking that all life was particularly well evolved for life on his rock, and therefore must have begun there. I'm not saying that I know of any evidence that we originated elsewhere, but the possibility cannot be dismissed just because it looks like life is too well adapted, and requires conditions found only on Earth (as far as we know for certain so far).
 

Offline PmbPhy

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Re: What is life and where did it come from?
« Reply #3 on: 01/10/2014 05:35:51 »
Quote from: alancalverd
The essence of life seems to be a local reversal of mesoscopic entropy.
Someday we'll all have to sit down and decide when a definition of the terms that we use here is required. Lol!

Tell me something, Alan. What in the world is mesoscopic entropy and why should it have anything to do with life? I myself tend to believe there is a relation to energy and life but I've never had the time to sit down and seriously think about it.

Quote from: alancalverd
Where did it come from? Why would anyone think it came from anywhere else? The conditions for the continuation of life seem to be fairly narrow, yet widely available on the surface of this planet, so evolution is most likely to have begun here. The question is whether it started first on the hard surface or (more likely in my uninformed opinion) on the sea bed.
I myself think that life started off as something quite different than what we think of when we think of life and then the method of propagating  change worked itself and then evolution.
 

Offline PmbPhy

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Re: What is life and where did it come from?
« Reply #4 on: 01/10/2014 05:42:51 »
Quote from: chiralSPO
Alan, I have to respectfully disagree.

There are many spontaneous local reversals of entropy, including crystallization, condensation, accretion (even on planet scale). There are also many patterns that self propagate. There's more to it than that.
In this context this is known as negative entropy. Schrodinger wrote a book called What is Life? in 1944 which has something to do with entropy. Not sure what though. See http://en.wikipedia.org/wiki/Entropy_and_life
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #5 on: 01/10/2014 09:59:11 »

There are many spontaneous local reversals of entropy, including crystallization, condensation, accretion (even on planet scale). There are also many patterns that self propagate. There's more to it than that.


It's misleading to think of entropy simply as disorder. It's really about probability. So a crystal, whilst being highly ordered, is in a lower energy state than a liquid of the same material and thus, at any temperature below its melting point, more probable.

However we look at living things, they are extremely improbable and locally out of equilibrium with their environment. But they do die, exhale, and generally cause chaos. Ergo mesoscopically and locally (both in space and time) negatively entropic even though their components are microscopically obeying all the usual Gibbs equations.
 

Offline flr

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Re: What is life and where did it come from?
« Reply #6 on: 01/10/2014 13:51:13 »
Life is a vague term.

From the point of view of how it works, the biological species could be considered automatic robots of some sorts executing a code in-scripted in their DNA, i.e., a biological individual might be a mecanical-hydrodynaqmical-biochemical-electroddynamical robot composed of trillions of cellular sized micro-robots.

However, what is striking about biological species is that their brain create an internal representation of the world accesible only from 1st person perspective of the raw sensation of something. It seems to me that this internal representation of things put together by our brain [which from 1st person perspective 'it-feels-like-something' while for 3rd person perspective there is no feelings at all]  has to be related to the capacity of biological species to be/have conscious (or self-conscious).

The most important aspect regarding biological species sufficiently evolved to have nervous system is their consciousness (and self-consciousness for most evolved species).
« Last Edit: 01/10/2014 13:54:00 by flr »
 

Offline PmbPhy

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Re: What is life and where did it come from?
« Reply #7 on: 01/10/2014 14:36:25 »
Quote from: flr
Life is a vague term.
I disagree.

Quote from: flr
From the point of view of how it works, the biological species could be considered automatic robots of some sorts executing a code in-scripted in their DNA, i.e., a biological individual might be a mecanical-hydrodynaqmical-biochemical-electroddynamical robot composed of trillions of cellular sized micro-robots.
Its actually for this reason that think that life is a well defined term in that its automata, i.e. little organic robots.
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #8 on: 01/10/2014 17:06:27 »
OK, if life is not a vague term, please define it!
 

Offline PmbPhy

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Re: What is life and where did it come from?
« Reply #9 on: 01/10/2014 17:37:44 »
Quote from: alancalverd
OK, if life is not a vague term, please define it!
This type of query is a common error in both math and science. It assumes that just because something is not vague then there must be a clear definition to it.

A perfect example from math is the term set. People try to define a set as a collection of objects but all that does is require us to define the term "collection" thus putting us back in the same place that we started from.
« Last Edit: 01/10/2014 18:19:34 by PmbPhy »
 

Offline flr

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Re: What is life and where did it come from?
« Reply #10 on: 02/10/2014 16:31:40 »
Wouldn't life have a special [extra]meaning because it can lead to conscious creatures?

Without self-aware creature how will be universe in 10^1000 (which might consists mainly in a soup of photons) be more interesting that today's universe that is highly structured, since the same law of nature apply anyway.?
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #11 on: 05/10/2014 21:37:08 »
OK, if life is not a vague term, please define it!

So I'll answer my own question. Life is the common property of living things. Now that remains undefined but at least it refers to something that can be defined since we can define the characteristic actions of a living thing, or we can list all things that we call living.

You might argue that there are still unresolved borders: is a virus alive? Not really a problem because the initial categorisation was only for convenience, as with species. We can look at another abstract noun: beauty. Yes, it's the common property of beautiful things, and we can list a whole lot of people, animals, sunsets and artefacts that everyone agrees as beautiful, but there will be unresolved borders.

So if you want to get mathematical, life is the characteristic of a fuzzy set. And I won't define fuzzy or set! 
 

Offline Bill S

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Re: What is life and where did it come from?
« Reply #12 on: 07/10/2014 22:42:29 »
This might add some thoughts to the mix.

http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf

“Self-replication is a capacity common to every species of living thing, and simple physical intuition dictates that such a process must invariably be fueled by the production of entropy.”
 

Offline Ethos_

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Re: What is life and where did it come from?
« Reply #13 on: 07/10/2014 23:54:15 »


So if you want to get mathematical, life is the characteristic of a fuzzy set. And I won't define fuzzy or set!
I detect a genuine brilliance in that statement alan, but if I may, I would like to add one small addition.

"Life is the characteristic of a fuzzy set that makes the futile attempt at resisting entropy."

« Last Edit: 07/10/2014 23:56:55 by Ethos_ »
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #14 on: 08/10/2014 19:05:26 »
This might add some thoughts to the mix.

http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf

“Self-replication is a capacity common to every species of living thing, .”


....except for the mule, hybrid roses, GM rice, several humans.... The problem is that "species" is undefined but generally (but not exclusively) used to retrospectively label a group that has reasonably successfully reproduced. Sexual reproduction pretty well guarantees nonreplication, and if exact replication were the order of living things, there would have been no evolution. The best we can say in this line is that some living things beget more living things, which isn't much of a definition.   
 

Online yor_on

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Re: What is life and where did it come from?
« Reply #15 on: 08/10/2014 19:36:52 »
How about consciousness. If we would find a crystal able to have a conversation with us, would it be 'alive'?
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #16 on: 08/10/2014 23:00:02 »
If I was allowed to make one rule for this and every discussion forum, for all time, it would be to remove any post that uses the word "consciousness" without defining it.

I have yet to enjoy a conversation with a slug or the lettuce it is eating, yet to the best of my knowledge they are both alive. On the other hand, mediums and churchgoers claim to have conversations with people who are dead, or entities that never existed.
 

Online yor_on

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Re: What is life and where did it come from?
« Reply #17 on: 09/10/2014 17:47:46 »
heh, slightly arid (as in dry that is :) response there my dear Alan.
You do have a point, and i think I agree, although that also depends on what we mean by consciousness? If we now would include the slug? what is 'self aware'? Is that a acceptable definition of consciousness? Is that just me having a problem with defining it as carbon based? then again, a crystal might not be the best definition if so :)
=
Nomenclature sux at times.
« Last Edit: 09/10/2014 17:50:02 by yor_on »
 

Offline alancalverd

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Re: What is life and where did it come from?
« Reply #18 on: 09/10/2014 19:08:15 »
There are very simple machines that are self-aware but far from alive. My present car engine checks its state of health and won't let me drive too fast if it isn't feeling completely happy. I have disconnected the bit that stops me driving into things (reversing sonar that can activate the brake) but the gadget that stops the wheels spinning or locking seems to be quite handy, as are the automatic windscreen wipers. In short, the car knows how to protect itself and its occupants from major trauma, and is aware of its relationship with its rapidly changing environment. Slugs are even more clever, though a bit short of defence mechanisms. 
 

Offline jeffreyH

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Re: What is life and where did it come from?
« Reply #19 on: 09/10/2014 21:09:26 »
OK define unconsciousness.
 

Offline Bill S

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Re: What is life and where did it come from?
« Reply #20 on: 09/10/2014 22:21:26 »
Quote
....it would be to remove any post that uses the word "consciousness" without defining it.



It's those annoying intervals between sleeps.
 

Offline flr

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Re: What is life and where did it come from?
« Reply #21 on: 10/10/2014 18:18:44 »
How about consciousness.

I believe this is the key question.
Is consciousness a result of the physical processes taking place in the brain? Can consciousness be fully explained by what happens in brain?
Neuroscience identified neuronal connections for certain basic conscious processes, however it cannot explain why passing of ions/e- through a certain neuronal pathway result in subjective experience of one particular person. 

Many critical biological processes are controlled by brain at subconscious level (such as heart rate, breathing, sugar level in blood, etc).
Why then haven't nature produced only philosophical zombies?

Quote
If we would find a crystal able to have a conversation with us, would it be 'alive'?

It could also be a smart computer program, in which case does not need to be 'alive'.
How could we know if it has conscious or it is just a smart computer code/bot?

-----



 

Online yor_on

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Re: What is life and where did it come from?
« Reply #22 on: 10/10/2014 18:22:19 »
That's one interpretations of what self aware could be. Another might be when you're aware about yourself, think I saw some writing that monkeys seems to know that they were looking at themselves, when looking in a mirror. Some other animals just don't make that connection, So let's go get back to that crystal again (ahem, not carbon based though) showing it a mirror :)

the darn thin should be deciding if it notice though? I've seen it said somewhere that crystals are notoriously bad in showing their emotions. Still, even so it might be self aware.
 

Online yor_on

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Re: What is life and where did it come from?
« Reply #23 on: 10/10/2014 18:27:26 »
And yeah, a Turing machine of sorts. But if it evolved naturally, wouldn't that be intelligence?
 

Offline flr

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Re: What is life and where did it come from?
« Reply #24 on: 10/10/2014 18:37:24 »
OK define unconsciousness.

there is something it is like to be in that state from a subjective or first-person point of view.
 

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Re: What is life and where did it come from?
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