We were absolutely not sure how fire really works when we used it in caves eons ago.
Comment on France runs fusion reactor for record 22 minutes
tburkhol@lemmy.world 4 days agoIf you’re not sure how the fire works, it seems kind of stupid to build a turbine for it.
Llewellyn@lemm.ee 3 days ago
scarabic@lemmy.world 3 days ago
We also did not build turbines then.
Also, a campfire is not plasma, so you probably shouldn’t be building any turbines either.
Llewellyn@lemm.ee 3 days ago
Fire is low temperature plasma. A campfire has fire.
scarabic@lemmy.world 2 days ago
Very hot flames can contain enough ions / free electrons to be considered a plasma but a wood campfire the likes of which cavemen built, which is what we are discussing here, do not achieve such temperatures. If cavemen wielded acetylene torches then they might have more experience with plasma.
If you were thinking something simple like “fire is plasma” that is reductive, and the cases where flame is plasma are not the everyday kind. Hence, when I said “a campfire is not plasma” I was being pretty specific. Your reply that ”fire is a low temperature plasma,” as an unqualified blanket statement, is wrong. Go read on it. It’s interesting.
grue@lemmy.world 3 days ago
Leaving the arguments up to this point aside, your comment on its own doesn’t make much sense. The beauty of of a steam turbine electrical generator is that you don’t have to care how the heat gets generated. You can swap it out with any heat source, from burning fossil fuels, to geothermal, to nuclear, to whatever else and it works just fine as long as the rate of heat output is correctly calibrated for the size of the boiler.
tburkhol@lemmy.world 3 days ago
That’s my point: fusion is just another heat source for making steam, and with these experimental reactors, they can’t be sure how much or for how long they will generate heat. Probably not even sure what a good geometry for transferring energy from the reaction mass to the water. You can’t build a turbine for a system that’s only going to run 20 minutes every three years, and you can’t replace that turbine just because the next test will have ten times the output.
I mean, you could, but it would be stupid.
grue@lemmy.world 3 days ago
Good point. Uncertainty over the magnitude and longevity of the heat source, and therefore how big to make the turbine and whether it would remain in operation long enough to exceed the payback period of its cost, is definitely a valid reason not to bother attaching a steam generator to a thing.