In the movie 21 Grams it is claimed people loss 21 grams at the moment of death. Is there any truth to this? What is is the origin of this belief.?
Snopes covers it quite well.
Basically some physician started weighing his dying patients, the expectation being that when they died and the soul departed, then the corresponding drop in weight of their cadavaer would allow him to state how much a soul weighed.
I haven’t seen the move and don’t intend to but …
The statement implies that the victim was on a delicate balance at the time of death; that the exact instant of death was determined with considerable precision; and that 21 grams is the amount for everyone.
Let’s take the case of a 200 pounder who dies. There are 4333 of those 21 gram packets in 200 lb so the weight loss was determined to one part in 4333 or 0.023%.
And, of course the exact instant of death isn’t really that certain and even if it were, that time as determined by a doctor might not be the same time that God has decided that the soul should depart. That’s what’s being implied isn’t it? That the sould weighs 21 grams?
Sounds mighty suspect to me.
There was an experiment a few years ago (1988), in which a “scientist” attempted to measure the weight of worms when they died, and found that a mass of worms lost 90 micrograms. Before you accept this as settled, you should read James Randi’s commentary on the matter. It’s about halfway down the page, near a photo of what looks like it could be a mass of worms, with a skull and crossbones superimposed.
I remember reading that a while back. I actually mentally attributed it to Cecil… 
Anyway, I like the way they tactfully worded the title, so as not to crush the hearts of believers. Rather than saying, “At death, the human body loses 21 grams due to the soul leaving”, they say, “A physician once placed dying patients upon a scale in order to measure the weight of the human soul” and lable it as true lol.
Definitely could have done it differently =)