| > The entirety of human history since prehistoric times Extrapolating from the past doesn't always work. There are real limits. Take the rate of energy consumption of human civilization for example, which is currently about 17 terawatt[1]. Thermodynamics tells us that after doing useful work, practically all of that energy ends up as waste heat. (A small fraction is stored, e.g. aluminium stores some energy. I assume this is negligible.) The power received by the Earth from the sun is about 170,000 terawatt[2], a factor 10,000 more. So plenty of room for growth, right? But now take a modest 2% yearly growth. This is a factor 1.02 each year. So 500 years of 2% growth would be a factor 1.02^500 = about 20,000. Maybe we could actually do that with fusion power. But then we'd have two suns(!) worth of extra waste heat to deal with. This cannot work. Current concerns about global warming pale in comparison. Even if we found a way to radiate all that heat into space as infrared, e.g. by concentrating the heat into country sized radiator panels, 35 years of 2% growth would double the waste heat again. A similar calculation can be done for the growth of anything physical. And even if you continue growth off Earth, you'll soon hit the limits of the solar system. Even the volume of an expanding sphere at light speed cannot keep up with an exponential function. [1] https://www.theworldcounts.com/stories/current_world_energy_... [2] https://news.mit.edu/2011/energy-scale-part3-1026 |