4 ms·

Interestingly, 2% annual growth in amount of utilized matter becomes physically impossible to sustain for even ~1000 years. Short ballpark math: https://gist.

Interestingly, 2% annual growth in amount of utilized matter becomes physically impossible to sustain for even ~1000 years. Short ballpark math: https://gist.github.com/pveierland/4aeaa5e9ab90de69787b732a9dd7d48e https://gist.github.com/pveierland/4aeaa5e9ab90de69787b732a9...

Matticus_Rex 3y ago
Have we ever hit anywhere near that?
- pveierland 3y ago
  I'm not sure which metric would be the best to use - we did reach it in population growth during the 1900s. However I mostly think the calculation is an interesting exercise to calibrate our expectations for what sensible growth rates can be. https://ourworldindata.org/grapher/natural-population-growth https://ourworldindata.org/grapher/natural-population-growth
tzs 3y ago
My examples for how fast exponential growth gets out of hand: • At 1% annual population growth starting now without access to faster than light travel in ~12000 humans the total volume of all human bodies would exceed the volume of the 12000 light year radius sphere that humanity would be limited to. • At 1% annual energy growth in energy needs starting from now in ~12000 years our annual energy use would equal the energy of the entire universe. All the mass including dark matter converted to energy (E=mc^2) and all the gravitational potential energy and all the dark energy...one year of human use. • At 1% annual population growth starting now in ~12300 years the total mass of all human bodies would exceed the mass of the observable universe. Let's break that last one down into waypoints along the path to needing the entire universe. Starting from now with 1% annual population growth and assuming humans don't evolve so much in the next 12000+ years to be massively (no pun intended!) smaller: • 3400 years until we need the entire mass of the Earth plus to Moon for human bodies. • 600 years after that and we need to add Jupiter's mass. • 700 years more and we need all the mass in the solar system. • It is then 2000 years until we need to mass of the entire Milky Way galaxy. • A mere 100 years later we need to add the mass of the Andromeda Galaxy. • That's 6800 years from now. From there it is another 5500 years to need to add the rest of the observable universe.

Matticus_Rex 3y ago

Have we ever hit anywhere near that?

pveierland 3y ago
I'm not sure which metric would be the best to use - we did reach it in population growth during the 1900s. However I mostly think the calculation is an interesting exercise to calibrate our expectations for what sensible growth rates can be. https://ourworldindata.org/grapher/natural-population-growth https://ourworldindata.org/grapher/natural-population-growth

tzs 3y ago

My examples for how fast exponential growth gets out of hand: • At 1% annual population growth starting now without access to faster than light travel in ~12000 humans the total volume of all human bodies would exceed the volume of the 12000 light year radius sphere that humanity would be limited to. • At 1% annual energy growth in energy needs starting from now in ~12000 years our annual energy use would equal the energy of the entire universe. All the mass including dark matter converted to energy (E=mc^2) and all the gravitational potential energy and all the dark energy...one year of human use. • At 1% annual population growth starting now in ~12300 years the total mass of all human bodies would exceed the mass of the observable universe. Let's break that last one down into waypoints along the path to needing the entire universe. Starting from now with 1% annual population growth and assuming humans don't evolve so much in the next 12000+ years to be massively (no pun intended!) smaller: • 3400 years until we need the entire mass of the Earth plus to Moon for human bodies. • 600 years after that and we need to add Jupiter's mass. • 700 years more and we need all the mass in the solar system. • It is then 2000 years until we need to mass of the entire Milky Way galaxy. • A mere 100 years later we need to add the mass of the Andromeda Galaxy. • That's 6800 years from now. From there it is another 5500 years to need to add the rest of the observable universe.