transubstantiation.

transubstantiation.
© 2005 Jamie Zawinski <jwz@jwz.org>

I've been thinking about transubstantiation, the belief of many branches of Christianity that when you take communion, the bread and wine transform physically into the flesh and blood of Christ. According to the Catholic Church as late as 1965, this is literally true, not just symbolism: the flesh is present, the bread is gone.

So let's run some numbers.

The Roman Catholic Church says that there are around 1.1 billion baptized Catholics in the world today.
The current world population is 6.3 billion (17% Catholic.)
The world population in A.D. 1930 was around 1 billion.
The world population in A.D. 1 was around 300 million.
If we assume an average lifespan of 50 years (which is probably low, since the curve is so steep at the modern end) that gives us 40 non-overlapping "generations". So if we put 1, 2, and 6 in the last three buckets, and .4 in every previous bucket, that gives 23 billion as a guess at how many people have been alive during the last two thousand years. (I'm not sure this is a valid generalization to make; do you have a better guess?)
I'm not sure how quickly Christianity grew, but let's guess that 12% of all those people were Christian, of a variety that believed in transubstantiation. (I think this is probably a reasonable guess because Christianity was very widespread by the 10th century or so, and by the numbers above, 83% of the population came after that.)
How often do these folks take the Eucharist, on average? For the devout, it will be once a week, or maybe even more frequently. But we don't know how many of the total number of baptized Catholics above are practicing, so let's guess that the average is 4×/year. At a 50 year lifespan, that's 200×.
By my measure, one "sip" is 1/4 fl. oz.
One serving of Ritz crackers is 5 crackers at 100 grams, or 20 grams per cracker. However, modern communion wafers are significantly thinner than crackers. So let's be conservative and call this 2 grams per cracker.
An adult male contains about six quarts of blood.
The current average weight for an American male is 180 pounds, but Americans are fatties and people used to be smaller, so let's call the two-millennium average 120 pounds.

Which gives us:

	23,000,000,000	people
×	12	%
×	200	communions
=	552,000,000,000	servings

×	0.25	fl. oz.
=	138,000,000,000	gallons of blood

×	2	grams
=	2,433,903,400	pounds of flesh
=	1,216,952	tons of flesh

So how big is Jesus?

(If you assume that only the priest drinks the wine instead of every supplicant having a sip, then the blood ratio is smaller by around two orders of magnitude, depending on the priest/non-priest ratio.)

By comparison, the largest living animal on Earth is the Blue Whale, at a paltry 150 tons (a mere 2,500× bigger than you). It is believed that the largest dinosaur, the Argentinosaurus, weighed only 90 tons.

However, perhaps Jesus, like Wolverine, has amazing regenerative powers (in which case, it's surprising it took him three days to return from the dead. But maybe he was just taking a little time-out.)

I'm told that the average person sheds 40 pounds of skin in a lifetime, and that 70% of household dust is dessicated human. I will leave further research along this line of thinking to others.

Update:

I have been informed of prior related research along these lines at everything2: "How many atoms of Jesus do you eat every day?"