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MIT-designed project achieves major advance toward fusion energy

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Re: MIT-designed project achieves major advance toward fusion energy

#351

Post by ncmncm »

Kelteseth wrote: post #332
ncmncm wrote: post #146

Earlier quoted context omitted.

The amount of this we can realistically put to use is, always and forever, exactly zero . The only useful outcome of any of this work is a generation of plasma-fluid physicists with practical experience. Pray we can find them something useful to do when the whole enterprise finally collapses.

Huh, I heard the same (tinfoil) argument about climate change, that all scientist make up the crisis to keep their jobs/funding.

Scientists are not the ones making the big bucks on fusion demonstrator construction. But, obviously, somebody is. Are. Every cent of overrun goes into a pocket. None of it evaporates.

Re: MIT-designed project achieves major advance toward fusion energy

#352

Post by gpm »

jeremyjh wrote: post #349
amelius wrote: post #336

Earlier quoted context omitted.

The thermodynamics argument would hold only for a closed system. If we send big blobs of lava into space, and import big chunks of solid rock back to Earth, then theoretically we should have no problem.

> If we send big blobs of lava into space I honestly can't tell if you are joking. The energy expenditure to get anything into orbit would produce more heat than you are offsetting.

Depending on the design of the system, the energy could well be expended in orbit and not contribute to the heating of earth (think about designs like a space elevator).

He's basically describing a giant air conditioner... it's definitely theoretically possible.

Re: MIT-designed project achieves major advance toward fusion energy

#353

Post by nobody9999 »

qPM9l3XJrF wrote: post #309
mchusma wrote: post #112

Earlier quoted context omitted.

You are right, people who flippantly dismiss fusion just don't understand it. -Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not). - Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon…

"Fusion is in theory something that could give us true energy abundance." What does fusion give us that existing nuclear power plant tech doesn't?

>What does fusion give us that existing nuclear power plant tech doesn't?

The energy generated per unit mass in a fusion reaction is ~9 times that generated in a fission reaction[0]:

   Considering the mass of the four protons/hydrogen
   nuclei (4.029106u) and the mass of the Helium 
   produced (4.002603u) we get a mass difference of 
   0.026503u or 24.69MeV. So it is easy to see that 
   fusion reactions give out more energy per 
   reaction. However, the energy per unit mass is 
   more relevant. This is 0.7MeV for fission and 
   6.2MeV for fusion so it is obvious that fusion is 
   the more effective nuclear reaction.
Which leads to a great deal of confusion on my part as to why we're not spending enormous amounts of money on Fusion R&D. Given the potential of the technology, you'd think we'd have long ago decided to spend whatever was necessary to commercialize hydrogen fusion as a power generation mechanism.

The phrase "electricity too cheap to meter" is likely somewhat hyperbolic, but in comparison to pretty much any other mechanism fusion is enormously more productive and efficient.

[0] https://www.physlink.com/education/askexperts/ae534.cfm

Re: MIT-designed project achieves major advance toward fusion energy

#354

Post by nobody9999 »

kongin wrote: post #233
mchusma wrote: post #112

Earlier quoted context omitted.

You are right, people who flippantly dismiss fusion just don't understand it. -Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not). - Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon…

>You are right, people who flippantly dismiss fusion just don't understand it. I have a couple of physics degrees, hot fusion is the energy of the future and it always will be. This is not a physics problem, this is an engineering problem and we are just not willing to invest enough money to solve the engineering.

>I have a couple of physics degrees, hot fusion is the energy of the future and it always will be. This is not a physics problem, this is an engineering problem and we are just not willing to invest enough money to solve the engineering.

You're spot on. Which makes no sense at all. Given the potential of commercial fusion, we should be (globally) spending at least several tens of billions per year on R&D.

Assuming the engineering issues are solved, those hundreds of billions would be chump change compared to the economic benefits of volume of cheap, clean power.

Re: MIT-designed project achieves major advance toward fusion energy

#355

Post by zo1 »

codethief wrote: post #303
roenxi wrote: post #299

Earlier quoted context omitted.

We're talking a world where humanity has enough energy on tap that not only could it have feasibly evaporated the Pacific Ocean, but that it basically has evaporated the Pacific Ocean, as a side effect of doing something else. We can barely speculate about such a world, but interstellar travel would not be much of a challenge with that sort of energy abundance. We'll find a way.

> but interstellar travel would not be much of a challenge with that sort of energy abundance. I don't think I agree. 1) The extremely high (but still finite) amount of energy required to evaporate the Pacific Ocean is still much less than the infinite energy you need to accelerate even one single space traveler to the speed of light. Infinity is weird. Of course we won't be trying to reach the speed of light but the…

Not quite sure I follow. On earth we're mostly limited to radiation to get rid of excess heat, I understand that part. But on a space-ship, can we not just expel the heat via mass? I.e. We super-heat some dense materials and just shoot them out.

Re: MIT-designed project achieves major advance toward fusion energy

#356

Post by f00zz »

lyaa wrote: post #325
codethief wrote: post #281

Earlier quoted context omitted.

> Fusion is in theory something that could give us true energy abundance. Well, at least for a few hundred years but then: > if you plot the U.S. energy consumption in all forms from 1650 until now, you see a phenomenally faithful exponential at about 3% per year over that whole span. The situation for the whole world is similar. […] the Earth has only one mechanism for releasing heat to space, and that’s via (infrar…

The quoted argument is too simplistic and ignores feedback processes that would prevent reaching the catastrophic prediction. We can't predict 400 years so flippantly. The population will most definitely not continue to grow (in fact it will start to decrease slightly the more countries reach "developed" status), and the energy consumption per-capita will also stagnate. After all, there is a huge difference between g…

Reminds me of those late 19th century predictions according to which in 50 years London would be neck-deep in horse poop

Re: MIT-designed project achieves major advance toward fusion energy

#357

Post by Chris2048 »

ncmncm wrote: post #316
choeger wrote: post #304

Earlier quoted context omitted.

"Just handed the money", my ass. Did you ever work in science? How to you even think that money should be distributed in scientific institutions? Everyone gets a share based on ... what? Their degree? Number of publications? Consensus by committee? And for comparison, look what the ISS has brought us commercially: We have a fully commercial manned spaceflight planned for next week. That is a massive achievement witho…

Handing 99% of the money to contractors for what will in short order be thousands of tons of radioactive slag contributes minimally to actual research. The developers of the overwhelmingly more practical FRC reactor are left to get by on scraps. Elsewhere in science, money is, in fact, being "granted" directly to scientists. This has gone on since long before you were born. All of the "scientific work on" ISS is done…

> All of the "scientific work on" ISS is done with crew literally pushing an "on" button

Why is this relevant?

Re: MIT-designed project achieves major advance toward fusion energy

#358

Post by pfdietz »

DrNuke wrote: post #263
mchusma wrote: post #112

Earlier quoted context omitted.

You are right, people who flippantly dismiss fusion just don't understand it. -Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not). - Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon…

The fusion equivalent of Ballmer’s infamous “developers developers developers” line is “materials materials materials”… and we’re getting there quickly!

And materials may not be the biggest problem! That should be "RAMI RAMI RAMI" (Reliability Availability Maintainability Inspectability).

Paper studies of fusion reactor designs given an availability figure, but this is mere aspiration, chosen because that number is necessary, not because it known to be achievable. The few actual studies of how available a fusion power plant would be (using MTBF and MTTR figures from related technologies) have come to very troubling conclusions: the plant may be operating just a few percent of the time. Getting fusion technology to the point where working reactors aren't perpetually down for repair is even more important than developing materials tolerating higher neutron displacements-per-atom (because it's hard to do the latter without the former). This requires building an experience base with all the kinds of things that will go into a fusion reactor. It also argues for making fusion reactors as small as possible (so there are fewer things to break); this is probably the best argument for these small high field devices (but an even better argument for high-beta plasma configurations).

Re: MIT-designed project achieves major advance toward fusion energy

#359

Post by pfdietz »

xbmcuser wrote: post #184
mchusma wrote: post #112

Earlier quoted context omitted.

You are right, people who flippantly dismiss fusion just don't understand it. -Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not). - Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon…

Yeah we need Fusion if we want to put back the carbon into the ground as the rest can mostly help us bring down new carbon use but Fusion can bring down the cost of carbon capture to actually reverse global warming as well. So far the world is just looking at mitigating or slowing it down only which is simply put not enough.

> we need Fusion if we want to put back the carbon into the ground

There is nothing about fusion that makes it essential for putting carbon back into the ground.

Re: MIT-designed project achieves major advance toward fusion energy

#360

Post by Symmetry »

aaronblohowiak wrote: post #246
tcmart14 wrote: post #216

Earlier quoted context omitted.

I'd say yes and no. You most definitely have a point here as I agree that their model, or view, is different than NASA. However, if NASA had not happened, would even conceiving of a different model or target had happened? Not to mention just initial research into rocketry. It maybe could have happened without NASA, but probably with a severely higher initial investment.

The soviets had a very strong space program and arguably their rocket designs have had a significant impact on spacex…

Super Heavy does look a lot more like an N1 than a Saturn V, after all.
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