Re: Total feasible human population over all time?
- From: Rolf Nelson <rolf.h.d.nelson@xxxxxxxxx>
- Date: Sat, 15 Sep 2007 22:07:00 -0000
One of the reasons people are probably hesitant about this sort of thing
is that you haven't stated your underlying assumptions, but have put
have stipulated that there are no "trans-humans" (yet these
non-trans-humans live 10^10 years). This leaves the level of
technology, ability, and ambition that you're looking for rather vague.
My intention was to make it *less* vague in that area, since we know
what the ambitions of (genetically 20th century) humans are like are
like better than we know an arbitrary post-human's ambitions. But,
point taken, it is an odd scenario.
Here is my WAG:
1. The limiting factor will be energy, rather than how much carbon
etc. you have lying around to build things with. After all, you can
fuse the useless hydrogen you come across into more useful elements,
or delay peoples' births until room opens up for them.
2. I put the energy efficiency at only .001 of total matter (dark and
baryonic), partly because there will be inefficiencies with collecting/
storing/transporting/transforming the energy, and partly because I'm
not sure how well we can shove the dark matter into black holes. I
used (3*10^-27 kg / (meter^3)) for the matter density.
3. Having no source how much matter we can grab or colonize before the
accelerating expansion of the universe puts it out of reach, I
arbitrarily guess that we can colonize all matter currently within 10
billion light-years of us.
4. My miserly energy ration will be 300,000 nutritional Calories per
day, for use for synthesizing/recycling food, and for all other pro-
rated energy uses.
Google tells me:
(.01 * ((4 * pi) / 3) * ((10 billion light years)^3) * ((3 *
((10^(-27)) kg)) / (meter^3)) * (c^2) * .001) / ((300 000
(kilocalories / day)) * (10 billion years)) = 2.08594846 * 10^42
That's about 10^52 person-years.
Notes about Google Calculator:
1. The 10 digits of precision offered are a testament to the
incredible pinpoint accuracy of my calculation.
2. It gives the equal-sign, not approximately-equal sign. It's a good
thing pi is a rational number, otherwise it would not have been
possible to give the exact number above in exponential notation.
3. I just now tried typing 10^100 on Google in hopes it would emit a
joke about calculating googol on Google, but alas in doesn't.
4. When you type "googol" in the Google Groups editor, the online
editor gets angry at you and gives you a dotted red line.
--
Rolf Nelson <http://rolfnelson.blogspot.com>
.
- References:
- Total feasible human population over all time?
- From: rolf . h . d . nelson
- Re: Total feasible human population over all time?
- From: M. Trimble
- Re: Total feasible human population over all time?
- From: Mike Combs
- Re: Total feasible human population over all time?
- From: Rolf Nelson
- Re: Total feasible human population over all time?
- From: Erik Max Francis
- Total feasible human population over all time?
- Prev by Date: Re: Total feasible human population over all time?
- Next by Date: Re: Dangerous places for nuke use...
- Previous by thread: Re: Total feasible human population over all time?
- Next by thread: Re: Total feasible human population over all time?
- Index(es):
Relevant Pages
|