The physicist in the dialogue says:
We need to ignore inflation as a nuisance in this case: if my 10 units of energy this year costs $10,000 out of my $100,000 income; then next year that same amount of energy costs $11,000 and I make $110,000—I want to ignore such an effect as “meaningless” inflation: the GDP “growth” in this sense is not real growth, but just a re-scaling of the value of money.
This strikes me as just wrong. If energy prices rise proportionally to GDP but other prices don't, there's still real GDP growth.
This strikes me as just wrong. If energy prices rise proportionally to GDP but other prices don't, there's still real GDP growth.
His example didn't need to be there; he could have just said "let's use real values instead of nominal values" and the economist would have agreed with him. I understood that as an aside to the reader that he was going to deal with real changes (in which the percentage of your income you spend on X changes), rather than nominal changes (in which the percentage stays the same).
A dialogue discussing how thermodynamics limits future growth in energy usage, and that in turn limits GDP growth, from the blog Do the Math.
I think this is quite relevant to many of the ideas of futurism (and economics) that we often discuss here on Less Wrong. They address the concepts related to levels of civilization and mind uploading. Colonization of space is dismissed by both parties, at least for the sake of the discussion. The blog author has another post discussing his views on its implausibility; I find it to be somewhat limited in its consideration of the issue, though.
He has also detailed the calculations whose results he describes in this dialogue in a few previous posts. The dialogue format will probably be a kinder introduction to the ideas for those less mathematically inclined.