Q: If energy is neither created nor destroyed, what happens to the energy within our bodies and brains when we die?

Quick note: If you’re presently grieving, don’t read this.

The original question was: If energy is neither created nor destroyed, what happens to the energy within our bodies and brains when we die?  I think I understand that the metabolic energy tied up in our cells will be used in the decomposition process, but what about the electrical energy in our brains/bodies?  This would seem to be a measurable amount of energy that at the moment of death is no longer required by the body/brain and would have to go somewhere.  I’m not asking from a theological or spiritual perspective, but strictly as a question of physics.

… [is there] a measurable radiation of heat at the moment of death.  Do you know if there have been experiments that have measured the heat loss and correlated it to the known amount of electrical energy in the human body?


Physicist: Electrical energy is nothing special.  Just like the chemical energy in our bodies, it breaks down into heat.  For example, the heat given off by light bulbs (or electric heaters for that matter!) is a result of electrical energy.  When electricity is flowing to a light bulb, that’s where the electrical energy is going; it’s turning into light.  When you pull the plug (so to speak) what tiny, tiny amount of electrical energy there is in the wires runs out almost immediately.

The term “electrical energy” is actually a little vague.  So, to be specific, in our nervous system there are tiny ion pumps that maintain an imbalance of charges between the inside and outside of the nerve cells.  When a nerve cell fires, charges are allowed to suddenly flow through the cell membrane in a process called an “action potential“.  The way electricity flows along nerve cells is different from the way it flows down a telegraph wire (“inside-to-outside” instead of “along”), but whatever.  The point is, there are mechanisms that maintain an imbalance of charge (which is electricity waiting to happen), and that imbalance is drained a little bit every time the nerve fires.

Death (excluding spectacular deaths) isn’t instantaneous.  In fact, what with medical science, it’s become more and more difficult to even define when people are dead.  Time was you could define death as being a lack of heart beat, but people have come back from worse (by that metric, Dick Cheney has been dead for a while).  Death is more of a break-down of the whole system, as opposed to a sudden event.  The heart stops doing whatever hearts do when they’re not loving, oxygen and nutrients stop going where they’re needed, and in short order the nerve cells in the body lose the wherewithal to pump ions.  Like batteries that are no longer being recharged, they run down.  Nothing special.  Like every kind of energy, whether electrical, kinetic, sonic, or sports fever, the electrical potential in the body eventually becomes heat energy (it’s an entropy thing).

The energy we “carry around” takes the form of chemical energy like fats and sugars.  When our nervous system creates electrical energy we lose an equal amount of chemical energy.  So, rather than being energy itself, life is all about moving energy around from one form to another.

What this question is clearly really about is the fact that it seems as though there’s a fundamental difference between animate and inanimate people.  Admittedly, dead folk are a hair less energetic than living people (with some exceptions).  There are a few kinds of energy (surprisingly few), but spiritual energy doesn’t seem to be one of them.  In terms of physical energy, the difference between a living body and a very recently dead body is just a question of how that energy is being organized.  Living critters in general are very good at using chemical energy for things like moving, growing, etc.  Newly dead critters have about the same amount of chemical energy, it’s just that they don’t use it.  Instead, whatever comes along to consume the body uses it (whether that’s fire or decomposition or whatever).

There have been many, surprisingly callous, attempts to measure a drop in energy and/or mass leaving the body at the so-called “moment of death”.  However, these experiments have been vague and, much worse, unrepeatable.  The most famous is the experiment by Dr. Duncan MacDougall in which, by putting patients dying of tuberculosis on giant scales, he found that those patients lost 21 grams on average between life and death.  To be fair, homeboy had 6 data points (that is: people) and a lot of statistical noise, so his conclusions have about the same amount of statistical weight as “vaccines cause Autism“.  To date, there are no confirmable experiments that show that anything special happens during death, other than a general “shutting down”.  In particular, nothing that’s both “inspiring” and verifiable seems to suddenly leave the body when we die, materially or energetically.

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58 Responses to Q: If energy is neither created nor destroyed, what happens to the energy within our bodies and brains when we die?

  1. roberta says:

    @ James dunkerton, thank you for saying that, with everything I have been reading on here, I was beginning to think I was the only one who knew the concept ‘you don’t know that’. As I said the first time, “it’s the uncertainty that’s hard for me.”, but in time we learn to move away from it, some better than others. What scares me now is that one day my son will feel this way.

  2. James Robertson says:

    Is the purpose of human evolution, to one day replace our mortal body with a “Bionic Body,” that uses electromagnetic energy to function with unlimited mental and physical superiority?
    A body that doesn’t require the nutrients a mortal body requires, is mortal disease resistant and allows a mortal being before they die to program their bionic computer brain with all the pertinent information needed to carry-on their “purpose for being” for hundreds of years to come; or until someone or something breaks their life cycle!

  3. Firstly may I say that there is no purpose or meaning to life,do animals have a purpose or meaning except to be eaten by us.
    Secondly,I don’t think that they will ever create cyborgs.The brain is much too complicated to replicate,with it’s trillions of neurons and synapses.They might be able to create new organs such as liver,kidneys and heart but there is no cure for an ageing brain.I can visualize life extension but not infinity.

  4. Rachhel √ says:

    Interesting article but where can I find more on the cycle of energy from the human body after death? I’m fascinated with the chain of events that happens when the body decays… its a full circle I think with the energy maybe esome loss during transfer

  5. First of all,who says that energy can’t be created nor destroyed?These theories by physicists should not be taken as gospel.They theorise that the big bang came from nothing,how can ‘nothing’ explode?.There must have been some form of energy there in the first place to cause an explosion.So we are back to the ageless question,who or what created that energy?As for your constituent atoms when you die Entropy will make proper provision for those.

  6. jimthebutcher says:

    I think the real question here is what happens to the consciousness when we die. The physical body and its constituent molecules can easily be seen to be a system definable in terms of matter and energy and thusly predictable by our knowledge of physics,no brainer. However, science has yet to explain what thots are in terms of matter and energy. Science can not touch or measure or contain a thought, and therefore it is niether matter nor energy but something verry unique occupying our spacetime with perhaps an entirely different set of laws governing its behavior. Are thoughts just a measure of entropy,order, a natural progression of matter to form more and more complexity and out of this complexity -consciousness. They are at very least able to observe this continuium of spacetime but could easily be on the outside looking in,or conversly on the inside looking out. Our spacetime has quantum fluctuations,”random” spikes popping in and out of existance,the quantum soup, and also has that persnickity law of thermodynamics that favours maximum randomness. It is because of this that some say life cannot possibly evolve out of the cosmos because it is clearly much more ordered than the dust from which it came. Yet if we trace the timeline of our BIG BANG theory is not the entire universe becoming more complex from the original sigularity 13 or so billion years ago to the stars and galaxies and life we see today?
    Perhaps life is some sort of negative quantum fluctuation of entropy,yet clearly the dating process shows there is definitely a conscious control of procreation and it is not random. Life very well may be the conscious efforts of an unseen entity that has the ability to manipulate quantum fluctuations and is not the result of the natural laws of physics. In witch case what happens upon our death depends on the rules that govern the quantum effect,so far to our scientists it appears random,I beg to differ.
    “life, don’t talk to me about life.Here i am with the brain the size of a planet and even I don’t know”- marvin.

  7. Theories,beliefs and faith are all very well Roberta,but the simple truth is that we don’t know the answer to your question.If we knew there was a better place awaiting us after death we would all be queuing up outside the door of Dignitas.If indeed there is an omnipotent entity then it doesn’t interfere with life in any way,it is purely random.I say this from experiential knowledge.We can see Entropy at work in our everyday lives,we don’t need scientific proof.So if he/they leaves it to randomness,which seems to be the case,he/they just include a few constants that are irreversible in this great game of life.

  8. SpiritM says:

    @James Dunkerton
    “Firstly may I say that there is no purpose or meaning to life,do animals have a purpose or meaning except to be eaten by us”

    The purpose of our lives is to maintain the continuity of our species, add to the already known knowledge and provide that as a solid base to our next generation. Every species does this only. While doing all this nature keep on takes our test, if we pass well and fine else the species or the individual(s) is/are eliminated. This is why many of the species are extinct now.

    @jimthebutcher
    I believe consciousness is a process not a thing. It is the process that links our memories, our thoughts, emotions and feelings to give us a subjective experience of objective reality. This process exists as a result of our brain (neurons) and the entire nervous system. In short consciousness has physical basis for it’s existence but is not physical in itself and it cease to exists when we die.

    I do not believe in religious and spiritual propaganda of “Universal Consciousness”

    Thoughts and emotions originates in our unconscious mind. As of now scientist can capture our thoughts up to 8 sec before they become conscious in our conscious mind. I think they capture our thoughts in terms of brain regions activity.

    Thanks :)

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