Hacker News new | ask | show | jobs
by codethief 1020 days ago
> This boiling temperature conclusion makes the assumption that we continue using thermal power (steam engines, etc...), where waste heat is around 60%.

No, it doesn't. The waste heat, at the very end of the day, is always rather close to 100%. I.e. we use all that electric energy we generate to power computer, fridges, and many other machines, all of which – sooner or later – convert that electric energy to heat. (And, well, maybe a bit of chemical binding energy, depending on the application. But then, a few decades later, those products of our work will usually fall apart and/or are being burnt or torn down.)

> you could have non thermal fusion like Helion's

No, you can't. As the author says:

> this statement is independent of technology. Even if we don’t have a name for the energy source yet, as long as it obeys thermodynamics, we cook ourselves with perpetual energy increase.

Free free to have a look at his other article (the one he links in the paragraph above) for some more details -> https://dothemath.ucsd.edu/2011/07/galactic-scale-energy/

1 comments

100% of the heat we get from the sun is currently lost as waste heat, by one means or another. So you're not boiling the oceans by any reasonable projection of energy usage increase of solar energy.

(yes yes some of it is reflected back into space as non-IR light, but you can also lose IR-emissions back into space without heating the Earth as well).

Most of that incoming heat is reflected / radiated off actually. It doesn't "stay" on Earth.

https://en.m.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

That is literally what I said.
My apologies then, I understood your comment differently!