What is life?

[franklu]

From the view of physics and chemistry, a life is no more than a kind of system with some interesting physical and chemical properties. In the lecture of the winner of Nobel prize of physics in 2004,David Gross,he presented 25 problems in future phyiscs. One of those questions asks, if there is some theorctical biology, if it have underlying conceptal structures,like physics, and if new mathematics is needed for the description of such theory.

This is an very interesting question, isn't it? I'd like to regard a biological object as a physical system. But how can we understand the behavior of such a system? How can it evolve? How can we give a compact expression for the rules that govern the behavior of such biological systems in theory?

Any guy got any idea?

[Nevermore]

If you ever find a answer to that question, give God a call. Here's his number: 847-744-7879 Tell him Alex sent you.

[Deathby]

Even if we find some unifying theory of physics, there will still be stuff like harmonic motion or meteorology that is so complicated to calculate from those basic few laws that it might as well be a different equation altogether.

 

Meteorology is based upon simple stuff, hot to cold, high to low. Yet it is one of the most complicated parts of physics because it is so complex.

 

Perhaps biology is a very advanced extension of chemistry. In that case, even if we find a unifying theory of biology, evolution into higher forms would be the equivalent of meteorology which would take even longer to find equations for, derived from this basic theorem. Evolution is affected by so many factors, that chaos theory dictates that only general trends can be found and no specific equation or hard-and-fast rule. In fact in biology rules are meant to be broken, since that would give you an advantage in survival.

[The Rebel]

Isn't life simply something that is born, grows and dies.

 

A table does not grow, it doesn't die, it remains a table, therefore is inanimate . .. lifeless.

 

A tree grows and can die, as do plants, animals etc.

 

That's my perception of life

[franklu]

Even if we find some unifying theory of physics' date=' there will still be stuff like harmonic motion or meteorology that is so complicated to calculate from those basic few laws that it might as well be a different equation altogether.

 

Meteorology is based upon simple stuff, hot to cold, high to low. Yet it is one of the most complicated parts of physics because it is so complex.

 

Perhaps biology is a very advanced extension of chemistry. In that case, even if we find a unifying theory of biology, evolution into higher forms would be the equivalent of meteorology which would take even longer to find equations for, derived from this basic theorem. Evolution is affected by so many factors, that chaos theory dictates that only general trends can be found and no specific equation or hard-and-fast rule. In fact in biology rules are meant to be broken, since that would give you an advantage in survival.[/quote']

 

 

Yes. It is just the complexity of such a question that attract our attention and consideration. Maybe the answer is too complicated for us to give a simple, definite description for its behavior. But I still believe we can find a compact description for its underlying rules. Take quantum dynamics for example, we can never predict the motion of a quantum object, but we have founded a very simple description for its underlying rule. Even if chaos is too compex to give it a definite equation for its motion, we still can find the rules for its motion and evoluation.

[Ophiolite]

Isn't life simply something that is born' date=' grows and dies.

 

[/quote']So, stars are alive then?

[The Rebel]

So, stars are alive then?

 

There's always one ain't there.

 

ok then, is born, grows, reproduces and dies

[Sorcerer]

I would disagree that a star grows, it certainly may change in size, but inorder for "growth" in a biological sense nutrients and energy from the external environment are taken up and changed into more of the organism.

 

A star does reproduce, but the order is specific, first it dies, then it reproduces. i.e. a supernova explodes, and its debris are taken up by nebulae, these then produce more stars.

[Mokele]

What about fire? It starts, grows, can split off into new fires, and eventually is extinguished. It can even be said to "eat" and break down the chemicals it "eats" for their chemical energy.

 

Mokele

[reverse]

life is what happens to you when you are making other plans.

 

well, you baited me with the question.

 

I heard it was anything that had MRSGREN

Movement resperation...etc etc.

[Sorcerer]

Fires very analogous to life, like life it is a controlled chemical reaction that relies on its environment. The key thing that Life has that fire doesn't, is encoded information which can be passed onto its offspring.

 

Anyway the 7th form Biology definition of life is MRSGREN

 

Movement (This includes movent as growth occurs, i.e. sedantry organisms like plants)

Respiration

Sensitivity (to external stimuli)

Growth

Reproduction

Excretion

Nutrient requirements

[Goalfinder]

What about fire? It starts' date=' grows, can split off into new fires, and eventually is extinguished. It can even be said to "eat" and break down the chemicals it "eats" for their chemical energy.

 

Mokele[/quote']

In its simplest form life is composed of two energies potential and kinetic, again in its simplest form as chemicals such as hydrogen, oxygen, carbon etc, both of these i.e the energy and chemicals are present in living as well as non-living. Maybe its the third differentiating factor something electrical (as in neural networks or signals that pass through our body) that makes them different; makes the the chemicals react, resulting into their forming bonds releasing energy in form of heat which further produces more reactions. The same electrical signals control them through muscle movement in humans later to make these chemicals (blood,food etc) move in certain directions.

Now according to me all these three are measurable and to some extent controllable by external means. Even at the risk of sounding far-fetched : could there be some kind of software invisible to the eye (or senses) that controls the electrical signals in living ? It could be a main differentiating factor since its presence its visible only in the actions it initiates, we are all the time measuring the actions and the results but unable to recognize its presence . anybody knows more about this ? I will be putting up a section of kinetic and potential energy in animation format soon on my site http://www.goalfinder.com, I seek to research and present this aspect life through animation. Would it be worthwhile ?