There are always parrots, or frogs or wallabies or something that wont let a project go ahead

Bobby. wrote on Oct 19^th, 2014 at 8:53am:



Peccerhead the woody-pecking parrot

MumboJumbo wrote on Oct 18^th, 2014 at 10:34pm:


Please, sir, please, sir?

What physical material do we have that can withstand temperatures as hot as the sun?  For extended periods?

I must check my shares in the unobtainium mine.  They'll go well with the shares that Bobby is selling in the wishful thinking mine.   

Brian Ross wrote on Oct 19^th, 2014 at 11:40pm:


Ah, see this is your error in reasoning. You're confusing heat energy with temperature. If the reaction was simply bottled up and let go to equilibrium, then the outer box would definitely get heated up to the millions of degrees we're talking about and then melt/vapourise and be ruined.

But, it would not be. Take a car radiator or a CPU fan by way of analogy. Without the radiator or the fan, the car/CPU would overheat. But, with the radiator/fan, the car/CPU will not overheat. Now, let's extend the analogy to that of the fusion reactor.

Consider that heat transfer is *not* instantaneous. It, like all physical reactions, takes time. (If you don't believe me, fire up your BBQ. It takes time to heat up). Heat is just another form of energy. With a little high-school physics, you should be aware that:
dq = mc*dT, where dq is the change in heat energy, m is the body's mass, c it specific heat, and dT is its change in temperature.

Using conservation of energy, it is possible to heat something up and not change its temperature so long as you cool it at the same rate. Ie, energy out = energy in.

Let's return to the situation of the wall of the reaction chamber now. In simple terms, there will be a large but finite amount of heat energy being absorbed by way of infrared radiation from the fusion reaction. In other words, a lot of energy is coming into the chamber wall. If you want it to stay cool, you can counteract this by making sure that the same amount of energy goes out of the chamber. In practical terms, this means using something analogous to a souped-up radiator.

This is also how the reactor would generate electricity. The radiator transports the heat energy away from the chamber, heating water to steam. This is then fed into a turbine to produce electricity.

Any questions, class?

DaS Energy wrote on Oct 19^th, 2014 at 10:22pm:



The coal & oil industries will not like this if it's true.

They have $trillions invested in stinking hydrocarbons.

Bobby. wrote on Oct 20^th, 2014 at 9:13pm:


Thanks, Bobby. And if Brian wants more detail, I'm quite happy to give it to him - if he can handle the math.

Bobby. wrote on Oct 20^th, 2014 at 9:15pm:

Yeah, but I think that's why there's a good chance it won't take off (at least not until hydrocarbons become prohibitively expensive). Think of all the other excellent renewable energy sources - tidal generators, bio-fuels, umpteen different solar sources (not just photoelectric cells), and on and on the list goes. Why don't these projects take off? Well, imho, it's because they're expensive. Private companies can't fund it because of government monopolies on the electrical grid. Governments won't fund it because nobody will replace all those lost "donations" from Big Oil.

So, in short, we're f-ed (at least in the short term).

MumboJumbo wrote on Oct 20^th, 2014 at 11:01pm:



Not only that -
a mere 32 km below our feet is an inexhaustible supply of energy.
Beneath the crust the earth is red hot.
I think the deepest hole ever drilled was 12 km by the Russians
so 32 km does not seem out of the question for geo thermal power from anywhere on earth.