This is a factual question about how medical science, being clinical and objective, explains the difference between life and death? Not to be morbid, but what does the dead body lack that the live body has? Yes, in the majority of cases, medical science can point to some distinct demarcation point between being life and death: a failed heart, a bullet, an infection, a disease.
Yet, consider a SIDS event. A perfectly healthy baby passes away leaving no evidence of a point of failure! No clear demarcation point between life and death. Would medical science have to admit there is something more at work here they cannot measure in a lab? How does medical science explain what separates us from a $5 bag of chemicals?
If there is no factual answer, please don’t be shy to say so.
Seriously though: In short, you are saying that the model we have works 99% of the time. But, 1% remains unknown. In the least, that 1% speaks to the fact there must be something more out there to know which, objectvely - giving science its due - may or may not be a soul. I see…
Even in a SIDS case, you can still say, “This person is dead.” The organs stop working, biochemical processes stop, electrical activity in the brain stops, etc.
The living body is two things - the bag of chemicals, and the ongoing self-sustaining well-organized chemical reactions we call “life”. A dead body is just the former. (plus some disorganized chemical reactions commonly called “rotting.”)
How is a running auto engine different from one which is shut off? All the same parts are there, and in the same physical arrangement. All the potential is there. But the self-sustaining process of rotation, compression, combustion, and expansion is not happening.
A living human has trillions more moving parts than a car engine and billions more processes that all have to be working within their design envelopes for the human to “run”. Which is why restarting one from dead has proven so difficult, while starting car engines is easy.
And this is also why, for very simple cases like heart has ceased pumping but the rest of the interlocking chemistry factory has not yet collapsed, we can restart the heart and get the whole system going again. Because almost the whole system really was still going.
As to SIDS, even reading the wiki points out that there is a lot of evidence about what happened. It isn’t a black-box mystery, except maybe to the newspapers.
Right now SIDS is a catchall diagnosis, used when we don’t have the tools to determine the exact cause of a particular death. IOW, SIDS isn’t a thing, but rather the medical termininology equivalent to your kitchen junk drawer full of odds and ends. If the case doesn’t fit in one of the other well-categorized drawers, it goes into the junk drawer called SIDS. Given that, iIt would be silly to expect a single clear cause to appear, where we have an *Ah ha! *moment and SIDS is cured like measles was.
As we get better at sorting out what happened to any given case, the number of SIDS cases will decline as the number of XYZ Syndrome cases climbs from a baseline of zero today, even if the total death count remains unchanged.
So don’t ascribe deep philosophical significance to what’s really just a category in a database.
No, the model we have works 100% of the time. Death is always defined as a neutralisation of neuronal membrane potential within the central nervous system.
You aren’t correct in saying that SIDS has “no evidence of a point of failure! No clear demarcation point between life and death.” There is a very clear point of failure: there is no membrane potential within the brain. There might be lots of reasons why that occurred, but we know that this is the failure.
Life is a process. We know when the process has stopped, even if we don;t know why. To steal and example from Jack Cohen, beating an egg is also a process. We can look at an egg while it is being beaten and note that it is being beaten. And we can look at an egg after it has been beaten and note that it is no longer being beaten. But we can’t usually say why it stopped being beaten. Maybe the beater broke, maybe the person doing the beating got bored.
Would you suggest that science has to admit that there is something more at work because they can’t measure why the egg stopped being beaten?
Just because we can’t answer why the egg stopped being beaten, that doesn’t mean that there is some mysterious spirit of egg beatingness that is essential for the process. The process is complex, when it stops we cant say precisely why its stopped, only that it has. And that is as true for the process of life as for the process of egg beating.
An self-sustaining chemical reaction that maintains a neuronal membrane potential within the central nervous system. That is all that separates us from a $5 bag of chemicals. If you could get the same reactions running in your $5 bag of chemicals then it would be human.
I’m not sure what you think isn’t adequately explained that you feel this thread necessary. A person is dead when all the bits stop, just the same as a computer or a car. The only difference is that the human body can’t be restarted since it dies when all the parts have worn out or a major part has been damaged so that it can’t run anymore, and once it dies, the resources to keep all the tiny cells and whatnot alive stop flowing, so those all die. A dead body quickly becomes irreparable even if all the bits are fine.
But like I said, there’s no difference between a dead person and a car that’s been turned off in terms of explaining “on” and “off”. When on, they both take in some sort of input energy, use chemical reactions to create work, and expel waste products. They continue to do this until the machinery to accomplish this fails and can be repaired no more. Unless you believe that a car has a soul that somehow flutters out the moment its pistons rust in place, then you understand what happens when a human body dies.
Only because no one has bothered to instrument a baby and watch him die. There are theories - central sleep apnea (not obstructive sleep apnea) has been suggested as a possible cause - but until we have the technology to determine such a thing by close inspection of the baby’s brain after a SIDS death, it will remain a mystery. Maybe someday we’ll be able to put a dead baby’s entire DNA profile into a super powerful computer, and use software to simulate his growth/development from a fertilized egg into a baby, and then identify exactly what happened.
I’m not sure what kind of demarcation you’re looking for. Even in people who are declared clinically dead, they can be (and have been) brought back to life.
Science would only have to admit that there are phenomenon not yet discovered/understood. See my earlier paragraph regarding instrumenting a baby and watching him die. This is theoretically possible, but ethically prohibited. That’s not a failing/shortcoming of science, it’s a (wise) self-imposed limit on what we are willing to do to gain knowledge.
Carl Sagan: “The beauty of a living thing is not the atoms it is made of; it’s the way those atoms are put together.” Maybe not a truly factual answer, but it’s the essence of it. a bottle of nitrogen and oxygen, a pile of carbon, a bucket of water, and test tubes of assorted trace elements. You can present those things as described in that sentence, or use the blueprint contained in 46 chromosomes to assemble them, over the space of a couple of decades, into a fully-formed adult human being.
SIDS would be a pretty good example of something that could be measured in a lab; unfortunately the babies aren’t being measured in a lab so many times the exact mechanism is unclear.
The factual answer to your first question is that clinical death is commonly defined as the irreversible absence of brain activity in a euthermic individual, or some variant thereof.
Because we have a lot of neurons, we most commonly die in pieces–a neuron at a time, if you had a theoretical clock with enough ticks (even more precisely, a dendritic connection at a time…). There isn’t an absolute marker until everything is gone including the brainstem.
Medical science (hey; just regular ol’ “science”)says we are our chemicals and chemical processes. So are monkeys, amoebas, plants and viruses, so don’t get too carried away wondering whether the fact that some things are alive and some things are dead means there is some sort of Greater Truth that there is Something Beyond Just Chemicals. Nor does the fact that “alive” and “dead” exist along a spectrum of chemical processes without a sharp demarcation have any particular significance or mystery attached to it.
What is a soul? When does it come into being, in the sperm and egg or after they join? How much does it weigh? Is there one for every person, or are they shared. Do primates have souls? If not, why not. How far down the food chain do souls exist? Dog, bird, worm, bacteria, virus?
As opposed to defining the point of death by deciding which of many specific, objective, and measurable physical criteria is the correct one.
As usual, religious concepts just make things less clear, not more clear.
If you split someone’s head open and transplant half of their brain into a goat, and the other half into a cow, fixing it so the two halves can properly control the host, and then transplant the brain of another man back into the original body…
There seem to be two questions in the opening post: one being does science have theories regarding the difference between a live person and a dead person and does science have theories regarding the “soul”, or consciousness. I think you are more interested in the soul question, but it is hard to tell.
As other posters have pointed out the difference between life and death is the difference in chemical processes that are taking place and are largely understood.
As for what causes me to be conscious and you to be conscious (I guess that you are conscious too, but really there isn’t any way for me to be sure), I do not believe scientists have any idea whatsoever. I don’t think they even have serious guesses as to what it could be, let alone guesses that can be falsified by experiment using today’s technology.
I believe your characterization of scientists as thinking they know everything is completely off base. Uncertainty is central to science. Science is not defined by theories that are proved true, but by theories that survive by not yet being proved false. Scientists can have a high level of confidence in theories that not only have not been proved false but make interesting additional predictions that turn out to be true based on actual experiment, but they can never know for certain that a theory is true.
If you have time I encourage you to listen to Richard P Feynman’s lectures about physical laws located at http://research.microsoft.com/apps/tools/tuva/. It isn’t specifically about what you are asking, but I found the insights into how scientists evaluate theories illuminating, and I believe this directly addresses incorrect statements like “scientists believe they know everything”.
No, we do not know, but there are lots of “serious guesses” being actively researched. Here is a sampling of resources concerned with scientific research on consciousness:
Including a certain poster on this board who was declared dead for 45 minutes at 16 months following a seizure. I was supposed to be a human vegetable.
The answer as far as I know is that no such neat demarcation exists, beyond the technological one of “can we bring them back to function?” The body gradually loses function and breaks down, over time going from fully functioning life, down into ever less functional states of life, until it eventually isn’t functioning at all. There’s no neat black line. Life isn’t some binary quality that is either there, or absent.
The question in the OP has been pretty thoroughly answered. The point I would like to add is that our definition of what constitutes “dead” has varied over history according to what we can measure, and what we can “restart” a reasonably full function life from.
When we could only measure pulse, and couldn’t restart from a stopped pulse, lack of pulse was considered dead. We now know that even lack of measurable brain activity (depending on what’s used to measure it) doesn’t mean that the chemical processes that are life have irreversably stopped.
Current scientific understanding (although as yet untested by experiment) is that an exact copy of a living body, including electrical and heat energy state, would be equally alive.
There was a experiment done, though I can’t remember it’s name, were a scientist weighed people on the brink of death, and then after they had died.They then repeated this with dogs. the weight of the dogs stayed the same whereas the humans were all 4 grams lighter. Makes you think.
