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Mass of the human soul

  1. Jan 22, 2005 #1
    mass of the human soul....

    quirky sounding title so sorry.

    I have heard somewhere that human mass reduces by a few grammes or so when they die and some people say that this is the soul leaving.

    Ok - so I'm pretty sure that is not the case.

    If you consider the flow of blood around the body - then do you think it is possible that a small but measurable gyroscopic effect would manifest itself (due to the motion of the blood crossed with the earths rotation). Obviously this gyroscopic type cross force would stop when the blood stopped flowing (death) leading to a reduction in 'mass' (well, weight).

    Wierd thought - any comments?
  2. jcsd
  3. Jan 22, 2005 #2
    According to Plato, "the soul is a spiritual principle of thought that should govern human choice and action". According to Aristotle, "each living thing is composed of "matter and form," the soul is the human "form," the organizing principle that shapes the chaos of matter into a human creature rather than some other kind".

    In terms of Christianty, the soul is the seat of intelligence and free will and refers to the "spiritual" activity of humans. The immortality of the soul is based on the notion that it has a "spirit" which is able to survive the loss of the body.

    There is clearly a difference between the terms "soul" and "spirit" which are often used interchangeably. The Hebrew word for soul is "nephesh" which means literally "life". Hebrew denotes the spirit as "ruach" and refers to it as the immaterial part of man.

    The greek of the New Testament denotes a difference between the soul (psyche) and the spirit (pneuma). The spirit is also referred to as the immaterial part of man. I believe the soul (psyche)is just what the greek word implies - the makeup of man. Our soul is how we relate to others and understand ourselves. Ones spirit is how they relate to God.

    So, the fundamental question to me is not what is a soul; But, what scientific method has been devised to answer such questions? IMHO, the answers to such questions lie beyond the scope of the scientific method and cannot be answered by science.
  4. Jan 22, 2005 #3


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    Blood flows in a closed circuit, so if there was any influence of Earth's rotation it would cancel out. Even if there was any net influence, it would be different according to our position.
    Finally, there is no way to find a few grams difference in a body that weights 70 odd kg.
  5. Jan 22, 2005 #4
    it's 21 grams. (according to a movie)
  6. Jan 22, 2005 #5


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    Mass measurementat the parts per hundred thousand level of resolution is a non-trivial procedure. Meaurement of the mass of a live organism while it is losing water, metabolising, and moving (center of mass is rising and falling with breathing and circulatory processes) does not allow the steps necessary for high resolution mass measurement to be accomplished (thermal equilibration of the mass with the instrument, exclusion of convection currents, mechanical equilibration of balance arms with loads, and on, and on, and on ----).

    Yeah, people have placed terminal patients on large balances, read numbers, and following expiration, have read other numbers --- probably as many gain mass as lose mass --- but, "cherry picking" data is a hallmark of this type of "research," so we aren't informed of the "gain" cases.
  7. Jan 22, 2005 #6
    Hmmm... my first reply.....
    Let's take a look at this.

    1.) What's a gramme?

    2.) Does Sean Penn really have any acting ability?

    3.) Parts per 1e5 aren't too bad... However parts per 1e7 on up are not unreasonable for analytical balances and controlled conditions. But what do we need?

    The average human weighs 70 kilos maybe? So if we're considering 2.1e-2 kilos out of 7.0e1 kilos... we have a spread of what? Not too much, but even from the 7 in 70 to the 1 in 21, we're not asking much more than our parts per 1e5. So instrumentation is no problemo...

    4.) Keeping a lock down on the corpse... Not too difficult. Respirometers, like the ones used by nasa for training purposes, calculate moles of water, oxygen, carbon dioxide, puke etc. with excellent precision while people are in the midst of stress testing. They also collect things like sweat, for comp. analysis. A limp body presents no extra significant challenge.

    5.) Cherry Picking? Very real phenomena! However in this case, I think we have the entertainment media machine getting you to fork another 20 bucks to take your date to see Sean Penn.

    6.) Conclusion... There's nothing new under the sun. Or Dan Rather would have been all over it by now. Then again, he might have been all over it anyways, "this just in.... documents proving that HMO's are putting a lid on the apparent loss of 21 grams (grammes?) from dead hospital patients. How will you protect you and your family from these unscrupulous monsters who would seek to swindle you out of your hard earned 21 grams?"

    7.) Other thoughts... All silliness aside, the process of death should in theory change over all "mass". See, when a person dies, their little bodies will fill up with acid, lactic acid I believe, as metabolic processes are starved of oxygen. Chemical bonds are broken and created all over the body here. There should be a net gain or reduction of total mass. But um... Good luck measuring that. (you could estimate it though and would find that the number will no business being measured in grams.) :smile:

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