So everyone knows the difference between life and death is, right? You're alive. That rock on the sidewalk is not. But looking at the molecular structures of humans, we're the same as that rock on the sidewalk, except our molecular stucture is far more complex. What exactly is "different" about our own molecular structure that makes us alive, than say a piece of carbon mixed with oxygen, nitrogen, calcium, phosphate, hydrogen, sodium, and whatever other elements are present in our body? What exactly makes a molecular structure "living?"

And what exactly is life defined as? Is there a "fine line" between a person that's alive, and a person that's dead? How do you truly determine whether a person is dead or not? People have been saved from complete heart failure, brain failure (strokes), etc. People have been saved after their nervous systems are fried by electricity. There's so many people out there that "should" be dead. How are they still alive? Is there truly a fine line between life and death? And do you think people can cross this line and go back?

Lastly, what's the difference between the molecular stucture of a dying person, and a person who just died? They're still the same elements in the same arrangment, are they not? In that case, why is one person dead, and the other alive?



If there's truly scientific proof that can answer these questions, well I didn't do my research properly then. In that case, I apologize. But I've finished high school Biology, and I've talked to my biology teacher about this, and have yet to come across any answers.

So everyone knows the difference between life and death is, right? You're alive. That rock on the sidewalk is not. But looking at the molecular structures of humans, we're the same as that rock on the sidewalk, except our molecular stucture is far more complex. What exactly is "different" about our own molecular structure that makes us alive, than say a piece of carbon mixed with oxygen, nitrogen, calcium, phosphate, hydrogen, sodium, and whatever other elements are present in our body? What exactly makes a molecular structure "living?"
thats a question for organic chemistry. Whats really interesting is a gentleman who, a few years ago, converted inorganic matter to organic matter. He won a Nobel Prize for it(can't remember his name off hand, he won the prize for chem. and peace). Otherwise, I would say that the line that seperates us is drawn between being 'sentient' ie capable of experiencing pain and 'not sentient' ie the rock in the sidewalk.

And what exactly is life defined as? Is there a "fine line" between a person that's alive, and a person that's dead? How do you truly determine whether a person is dead or not? People have been saved from complete heart failure, brain failure (strokes), etc. People have been saved after their nervous systems are fried by electricity. There's so many people out there that "should" be dead. How are they still alive? Is there truly a fine line between life and death? And do you think people can cross this line and go back? After a couple of hours, they're not coming back. But the cases of people miraculously coming back is a mystery of modern science. Sometimes people who are greatly attached to their friends and family have a hard time dying, both in combating a disease and finally letting go. I have relatives who have been at death's doorstep for years and can't let go.

Lastly, what's the difference between the molecular stucture of a dying person, and a person who just died? They're still the same elements in the same arrangment, are they not? In that case, why is one person dead, and the other alive?
At first glance this looks simple-minded, but you're onto something fweddie. Things like an absence of new oxygen being introduced to cells and electrical activity in the brain shutting down are signs that a person is dying; they are not necessarily the reason that a person is dying. In fact, each one could occur individually and a person could still technically be considered 'alive.' I would say when a person's consciousness can no longer interact with the body in any way, all of the physical signs of death have aligned and they're moving on to something else.



If there's truly scientific proof that can answer these questions, well I didn't do my research properly then. In that case, I apologize. But I've finished high school Biology, and I've talked to my biology teacher about this, and have yet to come across any answers.[/QUOTE]

thats a question for organic chemistry. Whats really interesting is a gentleman who, a few years ago, converted inorganic matter to organic matter. He won a Nobel Prize for it(can't remember his name off hand, he won the prize for chem. and peace). Otherwise, I would say that the line that seperates us is drawn between being 'sentient' ie capable of experiencing pain and 'not sentient' ie the rock in the sidewalk.

However, there's still the question on why organic matter is "alive" and inorganic is "dead." Organic or not, they're still made up from atoms in different arrangements. I'm pretty clueless about physics, especially on the subatomic level, but I just can't grasp the idea on why different arrangements of subatomic particles can produce something living - no matter how complex the arrangement is. Because all elements are basically made up of protons, neutrons, and electrons, no? I don't understand anything beyond this, like neutrinos or quarks or whatever, so I suppose Lywelyn or someone else is gonna come along and make my brain explode sometime soon :p

Do you have an article, a name, or anything? I'd love to read more into this.

After a couple of hours, they're not coming back. But the cases of people miraculously coming back is a mystery of modern science. Sometimes people who are greatly attached to their friends and family have a hard time dying, both in combating a disease and finally letting go. I have relatives who have been at death's doorstep for years and can't let go.
I don't think it's proper to bring religion into this debate, but this reinforces my beliefs in creation. I think this may be a subject, or phenomenon is you will, that cannot be adaquetly explained by science, at least not with our present knowledge on quantum physics. (That's the word, right? If not, then I mean the study of subatomic particles.)

At first glance this looks simple-minded, but you're onto something fweddie. Things like an absence of new oxygen being introduced to cells and electrical activity in the brain shutting down are signs that a person is dying; they are not necessarily the reason that a person is dying. In fact, each one could occur individually and a person could still technically be considered 'alive.' I would say when a person's consciousness can no longer interact with the body in any way, all of the physical signs of death have aligned and they're moving on to something else.
Ok, forget humans. How do you define life and death for a unicellular organism? There's no "brain" or nervous system. There may not even be oxygen (ex. anaerobic bacteria). Is there an actual change in the molecular, or even subatomic structure, that occurs when an organism truly "dies?" If not, the question still stands. How exactly do you determine the difference between an organism 1 second away from dying, and an organism that died 1 second ago? Can you even determine, to the second, when an organism is "dead?"

rocks dont have DNA - living things do. ummm.......im sure there is heaps of other differences too, they dont have cells like we do, chromosomes etc. the way a dead persons body is made isant different to how a living persons body is , the dead persons body just isant working anymore... i dont understand it much either...im not a scientist, but the brain activity doesnt happen anymore and elecrical impulses from the brain dont happen any more....yep that probably doesnt answer your question

What exactly makes a molecular structure "living?"
Cellular metabolism perhaps?

Cellular metabolism perhaps?

Your cells still continue to metabolize for a time after you die. This question is much like the question over when a fetus becomes more than a collection of cells and becomes a person.


Really, this has been a major philisophical question for quite some time. This is where we start getting to arguments over dualism and materialism and souls because, really, science has no definitive answer for what the spark of life is.

Your cells still continue to metabolize for a time after you die. This question is much like the question over when a fetus becomes more than a collection of cells and becomes a person.


Really, this has been a major philisophical question for quite some time. This is where we start getting to arguments over dualism and materialism and souls because, really, science has no definitive answer for what the spark of life is.

The organs die after the organism dies, then the tissues die, then the cells die. Most people view the death of a person as equivalent to the death of the brain. Cells, on the other hand, die when they cease metabolic activity. Since they would build up the waste products of metabolism at death, cells would have a different chemical composition after death. Same goes for humans.

The organs die after the organism dies, then the tissues die, then the cells die. Most people view the death of a person as equivalent to the death of the brain. Cells, on the other hand, die when they cease metabolic activity. Since they would build up the waste products of metabolism at death, cells would have a different chemical composition after death. Same goes for humans.
But what about a cell 1 second away from dying and a cell that died 1 second ago? I think this is beyond chemical composition, and more of atom structure and subatomics. Yes, a dead cell would be chemically different than a living cell, but if that's completely true, then the chemical composition changes in an instant when the cell dies? I'm not a scientist, but I highly doubt that. So then the other option is that there is no fine line between life and death, and more like a "transition zone." Whether or not that's true is cannot be proven by pure science, but involves philosophy as well.

But anyways, speaking from a strictly scientific point of view, what exactly is different about the molecular structure between dead and living things? Yes, living things have DNA, but isn't DNA also composed of elements that dead things are composed of? Namely phosphate, carbon, oxygen, hydrogen, and nitrogen. Are any of those elements "alive?" Then why do they, when arranged into sugar, phosphate, and nitrogen groups, create something that makes a living thing "alive?" If you further break down atoms, you get protons and neutrons, which all matter is composed of. (Ok, maybe not exotic matter with negative mass and stuff, but I'm only talking about "normal" matter on earth) So basically, if you break down a rock and a person to the simplest forms, (forget chemistry, and pull out the quantum physics books), then we're all protons and neutrons, which are futher broken down into quarks if I'm not mistaken - the only difference between me and a rock is the arrangements of those subatomic particles. What I'm interested in is, what properties do certain arrangements have that create "life?" How do those arrangements differ from something that is not alive, whether it's a rock, or a cell that died 1 second ago.

Cruithne, I understand how and why the chemical properties of a dead organism changes, but I'm interested in how those arrangements (of molecules) started life for the organism, and how they set the living thing apart from a non-living thing, not how those arrangements change after death.

Thanks for the info on cellular metabolism, however, I'm more interested in the physical properties (if possible, down to a subatomic level) between a living organism and a non-living thing, rather than the chemical properties.

ps. When I posted this thread, what I really wanted was scientific answers to some questions that have intrigued me for so long, and not ideas or personal views on the subject. Yes, science has room for debate also, but I don't feel this will actual turn into one. If you (mods) feel this should be in the Completely Off-Topic section, by all means move the thread. :)

pps. Lywelyn, wanna share some of your wisdom? I'm truly lost here in this subject.

But what about a cell 1 second away from dying and a cell that died 1 second ago? I think this is beyond chemical composition, and more of atom structure and subatomics. Yes, a dead cell would be chemically different than a living cell, but if that's completely true, then the chemical composition changes in an instant when the cell dies? I'm not a scientist, but I highly doubt that. So then the other option is that there is no fine line between life and death, and more like a "transition zone." Whether or not that's true is cannot be proven by pure science, but involves philosophy as well.

While death is a transitional process and not an instantaneous one, the "fine line between life and death" is understood as the point at which no return is possible. If I get sick, I get closer to death than when I am well. However, since I recover, I do not die when I get sick. This point of no return is vague, however.

But death may not even exist! Technology could progress to the point at which people could bring people back from the dead, even those long dead. But if we will be brought back, will we really have been dead?

But anyways, speaking from a strictly scientific point of view, what exactly is different about the molecular structure between dead and living things? Yes, living things have DNA, but isn't DNA also composed of elements that dead things are composed of? Namely phosphate, carbon, oxygen, hydrogen, and nitrogen. Are any of those elements "alive?" Then why do they, when arranged into sugar, phosphate, and nitrogen groups, create something that makes a living thing "alive?" If you further break down atoms, you get protons and neutrons, which all matter is composed of. (Ok, maybe not exotic matter with negative mass and stuff, but I'm only talking about "normal" matter on earth) So basically, if you break down a rock and a person to the simplest forms, (forget chemistry, and pull out the quantum physics books), then we're all protons and neutrons, which are futher broken down into quarks if I'm not mistaken - the only difference between me and a rock is the arrangements of those subatomic particles. What I'm interested in is, what properties do certain arrangements have that create "life?" How do those arrangements differ from something that is not alive, whether it's a rock, or a cell that died 1 second ago.

Cruithne, I understand how and why the chemical properties of a dead organism changes, but I'm interested in how those arrangements (of molecules) started life for the organism, and how they set the living thing apart from a non-living thing, not how those arrangements change after death.

Thanks for the info on cellular metabolism, however, I'm more interested in the physical properties (if possible, down to a subatomic level) between a living organism and a non-living thing, rather than the chemical properties.

The living and non-living do not differ at the subatomic level (since they don't differ at the atomic level). Look at your computer. It contains among other things a mother board, processor, monitor, video card, operating system, and internet browser. None of these by itself is displaying this web page. You are viewing this page as the result of these parts working together. Life has the same characteristic. I think it's called emergent properties. Neither the nucleic acids, lipids, or proteins in cells are in themselves life.

I'm getting the general idea of what you're asking, but you're asking many questions and sort of blurring them together. I have a degree in (bio)chemical engineering, so I'm familiar with the scientific side of the issue.

Okay, when talking about the chemistry of life and when are we dead and the differences therein... I begin to wonder about another definition of life. It is easy to say that something is alive if it is made of living cells, or in the case of mammals and other more complex life forms, when it's brain is still active.

But here's a query. What about artificial life? If a machine was given complex enough computer technology and programming to work as fast as a human brain and was given sentience, would they be alive? Say they can feel pain, they have inner monologue, they fear death, and they wonder. Yet, they are not made of living cells nor do they have a heart beat or anything of that matter.

Do we deny this creature the mysteries of the afterlife or the possiblity of a soul? I'm sure this idea is probably the main topic of another debate somewhere, but it definetly overlapse.

Okay, when talking about the chemistry of life and when are we dead and the differences therein... I begin to wonder about another definition of life. It is easy to say that something is alive if it is made of living cells, or in the case of mammals and other more complex life forms, when it's brain is still active.

But here's a query. What about artificial life? If a machine was given complex enough computer technology and programming to work as fast as a human brain and was given sentience, would they be alive? Say they can feel pain, they have inner monologue, they fear death, and they wonder. Yet, they are not made of living cells nor do they have a heart beat or anything of that matter.

Do we deny this creature the mysteries of the afterlife or the possiblity of a soul? I'm sure this idea is probably the main topic of another debate somewhere, but it definetly overlapse.

You're describing sentience, not life.

While death is a transitional process and not an instantaneous one, the "fine line between life and death" is understood as the point at which no return is possible. If I get sick, I get closer to death than when I am well. However, since I recover, I do not die when I get sick. This point of no return is vague, however.

But death may not even exist! Technology could progress to the point at which people could bring people back from the dead, even those long dead. But if we will be brought back, will we really have been dead?
Wow, I never thought of death as both a transitional process and a fine line before. It makes a lot of sense to me, even if scientifically it is not proven. Thanks!

I'm a little skeptical about the technology that may prevent death or even bring people back from the dead. It sounds pretty impossible, but who knows what the future may bring. A few decades ago going to the moon was impossible. Before that flying was impossible. A part of me actually wishes science would stop advancing so fast =o/



The living and non-living do not differ at the subatomic level (since they don't differ at the atomic level). Look at your computer. It contains among other things a mother board, processor, monitor, video card, operating system, and internet browser. None of these by itself is displaying this web page. You are viewing this page as the result of these parts working together. Life has the same characteristic. I think it's called emergent properties. Neither the nucleic acids, lipids, or proteins in cells are in themselves life.

I'm getting the general idea of what you're asking, but you're asking many questions and sort of blurring them together. I have a degree in (bio)chemical engineering, so I'm familiar with the scientific side of the issue.
Sorry I didn't make things too clear in my last post. I was just trying to post everything, and I guess I didn't bother to organize them into coherent paragraphs.

Anyways, my main question is: if everything is composed of protons and neutrons and electrons, with the only difference as the arrangement of these particles, what properties do certain arrangements have that make something "alive?" Even if you put every element present in the human body together, you won't have a living organism. What properties do the particular molecular structures in our body have that make us living?

It sort of makes sense to me that life is a result of all those particles forming parts that work together. Your computer example is a basically a simplification of this - that different parts work together to make, or show something, and that the parts alone are useless in themselves. But it doesn't make sense to me that as these parts and processes get complicated, they can have "living" properties, such as reproduction, metabolism, and even higher mental processes such as learning and speech.


And good point Keystone. If life is the result of immensely complex molecule arrangements, then would we in the future be able to create life, and "put life into non-living things?" Our body is broken down into proteins and amino acids, which are obviously non-living. So it makes sense that if we posess the technology, we can create "artificial life" from non-living things.

I think I phrased the topic wrongly. Instead of life and death, the more approriate title would be "Fine line between living and non-living things?" What exactly is the line between a living organism, and a non-living thing?

Life can be looked at as the interval between birth and death. Life is the time between your birth and death.

And i think scientifically, life is any animate organism. And notice i said organism- not an android or lego robot.

if everything is composed of protons and neutrons and electrons, with the only difference as the arrangement of these particles, what properties do certain arrangements have that make something "alive?"

Well, with a scientific answer: Cells form to work together and make muscle/organ tissue. They all work together to form the actual organ that works on its own (an animate organism, working). Those organs all work together to form an organ system (digestive, respiratory, etc.), including your skin (which is an organ).