[HN Gopher] University of Texas-led team solves a big problem fo...
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       University of Texas-led team solves a big problem for fusion energy
        
       Author : signa11
       Score  : 196 points
       Date   : 2025-05-12 12:21 UTC (10 hours ago)
        
 (HTM) web link (news.utexas.edu)
 (TXT) w3m dump (news.utexas.edu)
        
       | perihelions wrote:
       | https://arxiv.org/abs/2410.02175v2
        
         | RhysU wrote:
         | > We report on a data-driven method for learning a
         | nonperturbative guiding center model from full-orbit particle
         | simulation data.
         | 
         | > Then we describe a data-driven method for learning from a
         | dataset of full-orbit a-particle trajectories. We apply this
         | method to the a-particle dynamics shown in Fig. 1 and find the
         | learned non-perturbative guiding center model significantly
         | outperforms the standard guiding center expansion. Our proposed
         | method for learning applies on a per-magnetic field basis;
         | changing requires re-training.
         | 
         | Is this interpolation at its heart? A variable transformation
         | then a data fit?
         | 
         | Anyone know which functionals of these orbits are important? I
         | don't know the space. I am wondering why the orbits with such
         | nuance should be materially important when accessed via lower-
         | order models.
        
           | wizardforhire wrote:
           | Haven't read the article yet, yet alone the paper but based
           | on what you've quoted these are ongoing challenges with
           | regards to confinement. Think tokamak vs stellarator.
           | Magnetoplasmahydrodynamics is hard because you have all the
           | complexities of the navier-stokes combined with Maxwell and
           | thats just scratching the surface. Sensitive dependence on
           | initial conditions has never been so sinister as in plasma
           | confinement. Orbital perturbations quickly lead to turbulent
           | instabilities which lead to containment breach which can lead
           | to multi-million degree hyper velocity jets tearing a hole
           | through your multi-billion dollar toy in seconds.
        
       | xyst wrote:
       | Is there a collective repository on breakthroughs in energy
       | generation by fusion? Sure, this team solves one "big" problem.
       | But hints there are a plethora of other problems (or technology
       | limitations) in this field.
        
         | DennisP wrote:
         | Part of the excitement these days is that the general march of
         | technology has removed a lot of those technology limitations,
         | due to advances in superconductors, lasers, supercomputers,
         | fast high-power electronics, etc. (Superconductors and
         | computers would be the ones relevant to stellarators, of
         | course.)
        
           | tiahura wrote:
           | How is that different than the excitement 30 years ago?
        
           | lupusreal wrote:
           | Even with all of these advancements I don't see how you get
           | around fusion reactors still being more complicated and
           | expensive to build as fission reactors, and just as
           | radioactive due to the huge amounts of neutron radiation the
           | "easiest" kinds of fusion produce.
        
             | gnfargbl wrote:
             | The difference is that waste from neutron activation is
             | "just" an engineering problem which might have an
             | engineering solution (we hope).
             | 
             | Waste in the form of long-lived nuclear fission products is
             | fundamentally an unsolvable issue. Transmutation has been
             | proposed but isn't really practicable, shooting it into the
             | sun isn't really an option either, so the only choice is to
             | confine it for geological timescales somehow.
             | 
             | Both options are really much better, in my opinion, than
             | pumping more carbon dioxide into our biosphere.
        
               | pfdietz wrote:
               | > "just" an engineering problem
               | 
               | This is a major fallacy that makes people think DT fusion
               | is more promising than it actually is.
               | 
               | Engineering problems are perfectly capable of killing a
               | technology. After all, fission after 1942 was "just an
               | engineering problem". And DT fusion faces very serious
               | engineering problems.
               | 
               | I include cost issues as engineering problems, as
               | engineering cannot be divorced from economic
               | considerations. Engineering involves cost optimization.
        
               | lupusreal wrote:
               | True. Launch loops are "just" an engineering problem
               | which could be built with known materials but in reality
               | the engineering problems are so huge it's hardly any
               | better than space elevators which call for undiscovered
               | materials.
               | 
               | You also have the associated economic problems; the up-
               | front cost of a launch loop would be so huge that you
               | could never convince anybody to build it instead of using
               | rockets. Fusion has the same problem; even if you can
               | design a fusion power plant that produces net power, it
               | needs to produce net power by a massive margin to have
               | any chance of being economically competitive with fission
               | let alone solar.
        
               | Sevii wrote:
               | Storing fission waste products is a solved problem. You
               | can either reprocess them as is done in France. Or you
               | can store them forever. Neither approach is difficult or
               | poorly understood. We can store an infinite amount of
               | fission waste products in the ocean, underground or in
               | the mantle.
        
               | lupusreal wrote:
               | Nuclear waste isn't an engineering problem at all, it's a
               | social problem. Objectively, dropping it all into a deep
               | ocean crevice is utterly safe and effective but you'll
               | never get the ignorant public who go off feelings to buy
               | into it.
               | 
               | Fusion is only better insofar as the public don't yet
               | understand how radioactive the reactor will become, but
               | counting on that ignorance is a bad long term strategy.
        
             | roflmaostc wrote:
             | And fusion reactors cannot end up like a Chernobyl
             | disaster. That's a huge safety plus and one of the major
             | concerns many countries are phasing out fission reactors.
        
             | RetroTechie wrote:
             | Safe (!) fission reactors are simple? Ok.
             | 
             | Never mind what's required to deal with the fuel & waste
             | products.
        
               | lupusreal wrote:
               | They're a hell of a lot simpler than fusion reactors.
        
       | tiahura wrote:
       | Is this a variation of the Fleischmann-Pons method?
        
         | gnfargbl wrote:
         | No, this has absolutely nothing to do with so-called "cold"
         | fusion. Cold fusion was a hypothetical type of room-temperature
         | nuclear fusion. It was reported in 1989 but not successfully
         | replicated. It can't possibly work because of the Coulomb
         | repulsion between nuclei is far too strong for them to come
         | into contact at our everyday energy levels.
         | 
         | This work is related to actual genuine nuclear fusion, the kind
         | that occurs at energy scales sufficient to overcome that
         | Coulomb barrier. At those energy scales it becomes very hard to
         | manage the plasma in which fusion occurs. This is a claimed
         | advance in plasma management.
        
           | pfdietz wrote:
           | Ordinary fusion doesn't overcome the Coulomb barrier either.
           | In a purely classical sense, fusion wouldn't happen, since
           | the thermal energies are well below the height of the Coulomb
           | barrier.
           | 
           | What happens is that thermal energies get high enough that
           | the nuclei get close enough to have a significant rate of
           | tunneling through the barrier. It's a quantum mechanical
           | effect.
           | 
           | There is a nonzero rate of tunneling through the barrier even
           | at room temperature -- just extremely low, far lower than
           | putative cold fusion claims.
        
           | Sniffnoy wrote:
           | > It can't possibly work because of the Coulomb repulsion
           | between nuclei is far too strong for them to come into
           | contact at our everyday energy levels.
           | 
           | Worth noting that (while obviously not what is normally meant
           | by "cold fusion") muon-catalyzed fusion is possible and is
           | cold, so the above statement can't be quite right.
        
             | gnfargbl wrote:
             | Technically correct, yes, but muonic atoms have a lifetime
             | on the order of microseconds. They aren't really relevant
             | to the everyday-scale physics I was discussing.
             | 
             | There is however Lattice Confinement Fusion [1] which
             | claims to overcome the Coulomb barrier through some kind of
             | "screening" from the electron cloud in the lattice. That
             | seems more like it would work on at everyday scales, though
             | I don't understand it nearly enough to offer any opinion on
             | viability.
             | 
             | [1] https://www1.grc.nasa.gov/space/science/lattice-
             | confinement-...
        
             | bell-cot wrote:
             | True...but without an _extremely_ cheap source of muons
             | (half-life: 2 microseconds), muon-catalyzed fusion will
             | forever be condemned to  " _in theory_ , you could..."
             | purgatory.
        
       | scythe wrote:
       | It is a little jarring to hear "data-driven" and
       | "nonperturbative" in the same sentence. It sounds a little bit
       | like saying you designed a boat with a better lift-to-drag ratio.
       | "Wait, is it a boat or a plane?". So, I opened the paper fully
       | expecting to not understand anything, and I was pleasantly
       | surprised.
       | 
       | > First we deduce formally-exact non-perturbative guiding center
       | equations of motion assuming a hidden symmetry with associated
       | conserved quantity J. We refer to J as the non-perturbative
       | adiabatic invariant.
       | 
       | Simply: this is not just some kind of unsupervised ML black-box
       | magic. There is a formal mathematical solution to _something_ ,
       | but it has a certain gap, namely precisely what quantity is
       | conserved and how to calculate it.
       | 
       | > Then we describe a data-driven method for learning J from a
       | dataset of full-orbit a-particle trajectories. [...] Our proposed
       | method for learning J applies on a per-magnetic field basis;
       | changing B requires re-training. This makes it well-suited to
       | stellarator design assessment tasks, such as a-loss fraction
       | uncertainty quantification.
       | 
       | With the formal simplification of the dynamics in hand, the
       | researchers believe that a trained model can then give a useful
       | approximation of the invariant, which allows the formal model,
       | with its unknown parameters now filled in, to be used to model
       | the dynamics.
       | 
       | In a crude way, I think I have a napkin-level sketch of what
       | they're doing here. Suppose we are modeling a projectile, and we
       | know nothing of kinematics. They have determined that the
       | projectile has a parabolic trajectory (the formal part) and then
       | they are using data analysis to find the _g_ coefficient that
       | represents gravitational acceleration (the data-driven part).
       | Obviously, you would never need machine learning in such a very
       | simple case as I have described, but I think it approximates the
       | main idea.
        
         | ChrisMarshallNY wrote:
         | One of the nice things about LLMs/ML, is that they can pound
         | away at something for a billion cycles, and do exactly the same
         | things that you or I would do.
         | 
         | for _ in 0..<1000000000000 { do_something_complicated() }
        
           | kjkjadksj wrote:
           | Isn't that one of the nice things of computers in general not
           | a feature of llm?
        
             | ChrisMarshallNY wrote:
             | The difference is the complexity of the repeated task
        
               | BandButcher wrote:
               | But don't those complexities still boil down to machine
               | level instructions??
               | 
               | Or can/do llms operate outside of a CPU? Thanks
        
               | ChrisMarshallNY wrote:
               | I'm not getting into angels and pinheads, but modern ML
               | has the ability to perform "fuzzy analysis," and
               | interpret results in a far more flexible manner, than
               | ever before.
               | 
               | They may not be able to match an MIT Ph.D, at analyzing
               | experimental feedback, but they can probably match a lot
               | of research assistants.
               | 
               | It's like having a billion RAs, all running experiments,
               | and triaging the results. I understand that is how they
               | have made such good progress on medicines, with AI.
               | 
               |  _> "I have not failed. I 've just found 10,000 ways that
               | won't work."
               | 
               | -Attributed to Thomas Edison_
        
         | elcritch wrote:
         | Often in physics the equations are already known or can be
         | derived. However, taking a formula, generally a PDE, and
         | solving it efficiently is the real trick. Also as you point
         | out, formulating the equation in terms of core invariants you
         | wish to hold, plays an important part.
         | 
         | Finding simplified easy to solve solutions and using them to
         | estimate solutions and using adjustments to get closer to the
         | real solution is a baselime technique. That's the core of the
         | pertubative approach in physics which uses :
         | https://en.wikipedia.org/wiki/Perturbation_theory#:~:text=Pe...
         | 
         | However, now it's possible to train AI models to learn much
         | more complex approximations that allow them to run much quicker
         | and more accurately. A prime example is DeepMinds AlphaFold,
         | IMHO.
         | 
         | I haven't read up on the research to much, but I'd place firm
         | bets that AI models will be critical in controlling any viable
         | fusion technology.
        
       | red75prime wrote:
       | > high-energy electrons that can punch a hole in the surrounding
       | walls.
       | 
       | What does it mean? Beta radiation can cause structural damage? Is
       | it really a problem?
        
         | regularfry wrote:
         | The electrons are high enough energy that they can damage the
         | wall, yes. But also they're simply a route for energy loss from
         | the plasma that you don't want. E.g.
         | https://www.nature.com/articles/s41598-023-48672-7
        
         | jmyeet wrote:
         | Yes. It's a significant problem for two reasons:
         | 
         | 1. High energy particles destroy the container. Alpha
         | particles, which are just Helium nuclei, are quite small and
         | can in between metal atoms. Neutrons too. High energy electrons
         | too; and
         | 
         | 2. It's an energy loss for the system to lose particles this
         | way.
         | 
         | Magnetic confinement works for alpha and beta particles because
         | they're electrically charged. Neutrons are a far bigger
         | problem, such that you have fun phrases like "neutron
         | embrittlement".
        
       | chiffre01 wrote:
       | TLDR for the paper and article:
       | 
       | The paper introduces a new, data-driven method for simulating
       | particle motion in fusion devices that is much more accurate than
       | traditional models, especially for fast particles, and could
       | significantly improve fusion reactor design.
        
         | nk8620 wrote:
         | Is that what the paper is about? I thought there was some heavy
         | physics breakthrough. I wanted to read the paper, but given
         | this TLDR, I'm having second thoughts. I'll probably just use
         | an LLM instead now.
        
       | jmyeet wrote:
       | I remain skeptical that fusion will ever be a commercially viable
       | energy source. I'd love to be wrong.
       | 
       | The engineering challenges are so massive that even if they can
       | be solved, which is far from certain, at what cost? With a dense
       | high-energy plasma, you're dealing with a turbulent fluid where
       | any imperfection in your magnetic confinement will likely dmaage
       | the container.
       | 
       | People get caught up on cheap or free fuel and the fact that
       | stars do this. The fuel cost is irrelevant if the capital cost of
       | a plant is billions and billions of dollars. That has to be
       | amortized over the life of the plant. Producing 1GW of power for
       | $100 billion (made up numbers) is not commercially viable.
       | 
       | And stars solve the confinement problem with gravity and by being
       | really, really large.
       | 
       | Neutron loss remains one of the biggest problems. Not only does
       | this damage the container (ie "neutron embrittlement") but it's a
       | significant energy loss for the system and so-called aneutronic
       | fusion tends to rely on rare fuels like Helium-3.
       | 
       | And all of this to heat water to create steam and turn a turbine.
       | 
       | I see solar as the future. No moving parts. The only form of
       | direct power generation. Cheap and getting cheaper and there are
       | solutions to no power generation at night (eg batteries, long-
       | distance power transmission).
        
         | lordfrito wrote:
         | No one wants to acknowledge that the economics will likely
         | never work out for the reasons you mentioned. Too much
         | maintenance -- and very expensive maintenance at that. It's far
         | cheaper cost per watt to build a traditional fission reactor
         | and run/maintain that.
         | 
         | Another reason is that transmission distribution costs are half
         | of your energy bill... so even if you could theoretically get
         | fusion energy generation for "free" (which is impossible)
         | you've still only cut your power bill in half.
         | 
         | Edit: I meant to say distribution costs not transmission.
         | Looking at last months bill I paid $66.60 to deliver $51.76 of
         | energy (about 56% of my total bill was delivery). The raw
         | distribution charge was $49.32 or 42% of the bill. I'm not
         | alone in these numbers, but your mileage may vary.
        
           | cmrdporcupine wrote:
           | And the transmission costs argument is precisely why we'd
           | likely be better off solving the problem of distributing
           | power production across a more decentralized grid with a lot
           | of wind and solar and battery _all over the place_
        
             | bell-cot wrote:
             | Problem: the capital & maintenance costs of the grid vary
             | very little with its utilization %.
             | 
             | So if you build loads of wind & solar & battery all over -
             | either (1) you've got to build _so_ much battery capacity,
             | all over, that you 'll never need the grid, or (2) you've
             | still got to build the grid to get you through occasional
             | "calm & dark" periods.
             | 
             | Either way, you're looking at vastly higher capital
             | expenses.
        
               | markvdb wrote:
               | Not necessarily. A slightly different approach might
               | become lower TCO in the medium term:
               | 
               | - moderately overbuild solar
               | 
               | - batteries for short term storage
               | 
               | - natural gas for seasonal storage
        
           | WillAdams wrote:
           | Excellent points.
           | 
           | One wonders if this is why Lockheed-Martin dropped their
           | effort:
           | 
           | https://www.lockheedmartin.com/en-us/products/compact-
           | fusion...
           | 
           | (that page is still up, but news reporting indicates it has
           | been dropped)
        
           | jmyeet wrote:
           | Transmission is a really interesting problem that creates all
           | kinds of distortions.
           | 
           | Say a house uses 10,000kWh per year at $0.10/kWH so
           | $1000/year electrcitiy bill. Now say you get a solar system
           | that produces 5,000kWh per year, focused in the summer months
           | (where your power bill tends to be higher anyway). You may
           | even export some of that power back to the grid. Have you cut
           | your power bill in half? No. It's probably down ~20-25%.
           | 
           | Why? Because regardless of how much power you use (within
           | limits) you still need a connection to the power grid and
           | that needs to be maintained. You'll often even see this on
           | the electricity bill: fixed charges like "access charge" per
           | month.
           | 
           | We benefit from being on a connected grid. Your own power
           | generation might be insufficient or need maintenance. It's
           | inefficient if everyone is storing their own power. So it's
           | unclaer what the future of the power grid is. Should there be
           | large grids, small grids or no grid?
        
             | VagabundoP wrote:
             | There also resilience. Having small to medium local storage
             | increases the stability of the grid.
             | 
             | Renewables and something like Iron-Salt battery containers,
             | would be pretty efficient over all. Easy to roll-out, very
             | safe.
             | 
             | We'll still need some sort of base load somewhere and
             | backup to restart everything obviously. But the big giant
             | power plants (with the huge capital costs, delays and NIMBY
             | headaches) might become less necessary.
        
             | robertlagrant wrote:
             | > the summer months (where your power bill tends to be
             | higher anyway)
             | 
             | This depends on where you live!
        
           | rixed wrote:
           | > transmission costs are half of your energy bill
           | 
           | Wait, what?
           | 
           | Wikipedia[0] seems to disagree:
           | 
           | > Long-distance transmission (hundreds of kilometers) is
           | cheap and efficient, with costs of US$0.005-0.02 per kWh,
           | compared to annual averaged large producer costs of
           | US$0.01-0.025 per kWh
           | 
           | Do you maybe mean that half electrical energy dissipate
           | between production plant and consummer? But that figure seems
           | quite large compared to what I can find online, and this
           | would not be a problem with "free fusion".
           | 
           | Care to explain?
           | 
           | [0]:
           | https://en.wikipedia.org/wiki/Electric_power_transmission
        
             | entropicdrifter wrote:
             | Where I live I pay about $0.09 per kWh for generation and
             | about that much for transmission as well. I think that's
             | what they're referring to, the literal bill they get from
             | their current provider.
        
             | lordfrito wrote:
             | I meant to say distribution costs not transmission. Looking
             | at last months bill I paid $66.60 to deliver $51.76 of
             | energy (about 56% of my total bill was delivery). The raw
             | distribution charge alone was $49.32 or 42% of the bill.
             | I'm not alone in these numbers, but your mileage may vary.
             | 
             | My point is that the infrastructure related to the delivery
             | of energy to a physical location is a non trivial part of
             | an energy bill, and that this part doesn't go away
             | magically because "fusion".
        
             | bell-cot wrote:
             | Long-distance transmission, of huge quantities of
             | electrical energy, _IS_ very efficient.
             | 
             | Distributing tiny fractions of all that energy to each of
             | millions of individual residences, then maintaining all the
             | short/complex/low-capacity wiring needed to do that - that
             | part ain't the least bit efficient.
        
         | bryanlarsen wrote:
         | We're at a point where even "free hot water" is not competitive
         | with solar for power generation. It costs more to build a 1GW
         | coal power plant than it does to build a 3GW solar power plant
         | (the 3X is capacity factor compensation). And most of the cost
         | of that coal power plant is the steam turbine and its
         | infrastructure.
         | 
         | We're not at that point yet with natural gas because a combined
         | cycle turbine is more efficient than a steam turbine.
        
           | nothercastle wrote:
           | People really don't understand how huge that is. There is no
           | way to make the math on nuclear or fusion work when the power
           | extraction portion of the plant costs more than solar even if
           | you zero out the generation costs
        
             | doctorwho42 wrote:
             | I see this is fallacy, there are a ton of industrial
             | processes that use a ton of power just to produce heat. A
             | great early use case for fusion will directly use the heat
             | for these industrial processes. For example, aluminum
             | requires ~14-17MWh to produce 1 ton... If you use the heat
             | directly you reduce your processes inefficiency by removing
             | the conversions: heat to steam to electric to heat.
             | 
             | Yeah, next 50 years you might not see coal/nat gas being
             | replaced by fusion. But you will see fusion displacing
             | chunks of what those powerplants will be powering
        
               | nothercastle wrote:
               | To take advantage of this you would need to build an
               | integrated power/manufacturing hub. The project would be
               | extremely expensive and difficult to finance in places
               | that don't have strong central planning.
        
               | hwillis wrote:
               | > A great early use case for fusion will directly use the
               | heat for these industrial processes.
               | 
               | There is no chance that _early_ fusion plants will be
               | small enough to justify building them in the same
               | building as a factory. They will start large.
               | 
               | > For example, aluminum requires ~14-17MWh to produce 1
               | ton
               | 
               | The Hall-Heroult process runs at 950 C, just below the
               | melting point of copper. It is close to twice the
               | temperature of steam entering the turbines. It is not
               | something that can be piped around casually- as a gas it
               | will always be at very high pressure because lowering the
               | pressure cools it down. Molten salt or similar is
               | required to transport that much heat as a liquid. Every
               | pipe glows orange. Any industrial process will
               | effectively be a part of the power plant because of how
               | difficult it is to transport that heat away.
               | 
               | Also NB that the Hall-Heroult process is for creating
               | aluminum from ore, and recycling aluminum is the primary
               | way we make aluminum.
        
               | o1inventor wrote:
               | > Every pipe glows orange. Any industrial process will
               | effectively be a part of the power plant because of how
               | difficult it is to transport that heat away.
               | 
               | Industrial parks centered around power plants might
               | become a thing in the future, being looked at as
               | essential infrastructure investment.
               | 
               | Heat transport could be seen as an entire sub-industry
               | unto itself, adding efficiency and cost-savings for
               | conglamorates that choose to partner with companies that
               | invest in and build power plants.
        
               | ryao wrote:
               | > I see this is fallacy, there are a ton of industrial
               | processes that use a ton of power just to produce heat. A
               | great early use case for fusion will directly use the
               | heat for these industrial processes. For example,
               | aluminum requires ~14-17MWh to produce 1 ton... If you
               | use the heat directly you reduce your processes
               | inefficiency by removing the conversions: heat to steam
               | to electric to heat.
               | 
               | The other guy was correct while you are the one who
               | posted the fallacy. If using heat from nuclear sources to
               | drive aluminum production were feasible, people would
               | already be doing it using heat from HTGR reactors rather
               | than waiting for nuclear fusion reactors to be made. The
               | reason it is not feasible is because the heat is an
               | output, not an input. The actual input is electricity,
               | which is what drives the reaction. The 940-980degC
               | temperatures reached during the reaction are from the
               | electricity being converted into heat from resistive
               | losses.
               | 
               | It should be noted that production nuclear fusion
               | reactors would be even more radioactive than nuclear
               | fission reactors in terms of total nuclear waste
               | production by weight. The only reason people think
               | otherwise is that the hypothetical use of helium-3 fuel
               | would avoid it, but getting enough helium-3 fuel to power
               | even a test reactor is effectively an impossibility.
               | There are many things that are hypothetically attainable
               | if all people in the world decide to do it. The permanent
               | elimination of war, crime and poverty are such things.
               | Obtaining helium-3 in the quantity needed for a single
               | reactor is not.
               | 
               | However, the goal of powering the Hall-Heroult process
               | from a nuclear fusion reactor is doable. Just use solar
               | panels. Then it will be powered by the giant fusion
               | reactor we have in the sky. You would want to add
               | batteries to handle energy needs when the sun is not
               | shining or do a grid tie connection and let the grid
               | operator handle the battery needs.
               | 
               | Finally, industrial processes that actually need heat at
               | high temperatures (up to around 950degC if my searches
               | are accurate) as input could be served by HTGR reactors.
               | If they are not already using them, then future fusion
               | reactors will be useless for them, since there is no
               | future in sight where a man made fusion reactor is a
               | cheaper energy source than a man made fission reactor.
               | Honestly, I suspect using solar panels to harness energy
               | from the giant fusion reactor in the sky is a more cost
               | effective solution than the use of any man-made reactor.
        
             | megaman821 wrote:
             | Agreed, fusion is a cool physics problem for now. In the
             | far futrue, if it can scale down, it my have applications
             | in shipping or space.
        
           | chasil wrote:
           | However, solar caused problems in Spain recently due to its
           | lack of mechanical inertia, which brought their grid down due
           | to frequency instability.
           | 
           | Fusion would use a conventional turbine with boiling water.
           | Is this a better source of mechanical inertia than hydropower
           | or fission?
           | 
           | Is there a better way to solve the problem of frequency
           | instability?
           | 
           | Why is this fact downvoted? This article mentions "synthetic
           | inertia;" what are its drawbacks?
           | 
           | https://www.bloomberg.com/news/articles/2025-05-09/spain-
           | bla...
           | 
           | https://archive.ph/VI32e
        
             | bryanlarsen wrote:
             | Solar caused problems in Spain because it was
             | misconfigured. AC inverters are a fabulous source of power
             | stabilization; many grids choose to install batteries and
             | inverters for grid stabilization.
        
               | chasil wrote:
               | The article mentions that largish batteries are needed
               | for synthetic inertia, which I am guessing use A/C
               | inverters. Spain appeared to lack sufficient batteries.
               | 
               | Obviously, this configuration of solar and battery banks
               | will work more optimally when they are closer to the
               | equator.
               | 
               | Will different types of power grids be required for areas
               | further away, or is it practical to ship power long
               | distances to far Northern/Southern areas?
        
               | bryanlarsen wrote:
               | Synthetic inertia needs a large DC source. At the time of
               | the outage, solar power was a large DC source.
        
             | belter wrote:
             | Nobody knows the cause of the energy outage in Spain,
             | Portugal and France... except the U.S. Energy Secretary
             | Chris Wright, a chill for the oil and fracking industry.
             | 
             | Could you point to the outage conclusion report?
        
           | lossolo wrote:
           | > It costs more to build a 1GW coal power plant than it does
           | to build a 3GW solar power plant (the 3X is capacity factor
           | compensation)
           | 
           | That "3X" figure assumes a high-insolation region (CF ~25 %).
           | In Central Europe, where solar CF is only ~12 %, you'd need
           | about 5x the PV capacity to equal a 1 GW coal plant's annual
           | generation. How does scaling up to 5 GW of PV change the cost
           | comparison vs a coal plant?
        
           | fakedang wrote:
           | > We're at a point where even "free hot water" is not
           | competitive with solar for power generation.
           | 
           | You're making the obvious mistake here of equating 1 GW solar
           | with 1 GW of any other source with a 95-99% baseload
           | capacity. To achieve the equivalent result, you'll need to
           | have at least >2 GW actual solar power to equally compare the
           | two.
           | 
           | Granted, in most developed places, solar still beats coal,
           | but this is why in many developing economies with ample coal
           | resources, it makes more sense economically to go with the
           | coal plants.
           | 
           | Take any other resource, say hydel or geothermal - solar and
           | wind quickly go down in economic efficiency terms compared to
           | these, in most cases almost doubling or tripling in costs.
        
             | bryanlarsen wrote:
             | > To achieve the equivalent result, you'll need to have at
             | least >2 GW actual solar power to equally compare the two.
             | 
             | Which is why I compared 1GW of coal power to 3GW of solar
             | power.
        
               | bee_rider wrote:
               | I can't really imagine how the person who responded to
               | you managed to miss that, it was like the middle 1/5'th
               | of your post. Oh well, I guess it is impossible to write
               | a post well enough that somebody won't jump in with a
               | correction... right or wrong!
        
           | ryao wrote:
           | Comparing solar power generation to solar hot water seems
           | wrong to me because there is solar hot water:
           | 
           | https://www.energy.gov/energysaver/solar-water-heaters
           | 
           | I recall hearing that they are 80% efficient while
           | photovoltaics tend to be around 20% efficient.
        
             | bryanlarsen wrote:
             | We're talking about electricity generation here, not heat
             | generation. People have tried generating electricity using
             | solar heat, but we've stopped doing that because it's too
             | expensive.
             | 
             | https://en.wikipedia.org/wiki/Solar_power_tower
        
               | aziaziazi wrote:
               | > We're talking about electricity generation here, not
               | heat generation
               | 
               | As a peer post noted (without back it up but seems
               | reasonable):
               | 
               | > Only 20% of our energy needs are supplied by
               | electricity.
               | 
               | It is a fair viewpoint to talk about energy instead of
               | only electricity. For exemple the current EV are build
               | using charcoal (steel and cement for the infrastructure)
               | and parts/final product are moved around continent with
               | oil (ships). Same for solar panels and their underlying
               | steel structure. Same for the road were using those EV,
               | etc... there's technical solutions for those, but they
               | didn't prove to be economically competitive _yet_. So
               | I'll happily take that 80% efficiency when we need
               | relatively low heat : domestic and commercial AC and
               | water heating. Those are by far the most energy intensive
               | usage in the residential sector when there isn't an
               | electric vehicle and are most needs in pick time
               | (mornings, evening at winter). We better take that +60%.
        
               | bryanlarsen wrote:
               | Any low heat solution is going to have a very difficult
               | time competing economically with heat pumps, which often
               | have an efficiency > 300%.
               | 
               | The most economical solution for reducing our carbon
               | emissions by 95% is doing these two steps in parallel:
               | 
               | 1. Use electricity instead of fossil fuel 2. Generate
               | electricity in carbon free manner
               | 
               | Yes, there are some use cases this doesn't work well at
               | yet: steel & ocean transport are two you listed. But it
               | does cover the 4 biggest sources of carbon emissions:
               | ground transport, heating, electricity generation and
               | agriculture. The big 4 are 95% of our carbon emissions.
        
               | ryao wrote:
               | The Rheem heat pump for domestic hot water that I have in
               | my home claims a maximum energy savings of 75%. That
               | implies that at 20% efficiency out of my solar panels,
               | the efficiency of photovoltaic panels + the heat pump is
               | equal to the 80% efficiency of solar hot water. However,
               | this ignores losses from DC to AC and the lines.
               | 
               | The photovoltaic panels have the added bonus that the
               | energy can be used for other purposes (e.g. transport,
               | HVAC, computers, cooking, laundry, A/V equipment) should
               | my hot water needs be low compared to what the system is
               | designed to produce. However, from a pure efficiency
               | standpoint, it is unclear to me which approach is better.
               | They seem to be a rough tie, with losses for both
               | approaches making the real world worse than ideal
               | conditions. I am not sure if one is better than the other
               | in the actual real world and if anyone who knows the
               | answer is kind enough to share it, I would find the
               | answer enlightening.
        
             | SigmundA wrote:
             | Doesn't matter that much if you have excess solar
             | available, beyond that many who do solar also tend to go to
             | a heat pump water heater which is 400% efficient bringing
             | photovoltaics in line with solar hot water without running
             | plumbing up to the roof and now that roof space can be used
             | to power many things rather than just hot water.
             | 
             | https://www.energy.gov/energysaver/heat-pump-water-heaters
        
               | ryao wrote:
               | The two being equal in efficiency is true in a best case
               | scenario, but that ignores real world effects such as
               | inverter losses. I wonder which would be superior in a
               | real world test.
               | 
               | That said, in my home, I use net metered photovoltaic
               | panels with a Rheem heat pump for domestic hot water.
               | This was not done because I considered it to be a better
               | solution, but because it was the only solution available
               | to me from local installers.
        
               | SigmundA wrote:
               | Solar hot water has to account for pumping losses as
               | well, its going to be in the same ballpark but the
               | electric heat pump hot water system is much more flexible
               | in how the power is used and decouples production from
               | use along with electrical vs plumbing on the roof which
               | is simpler and dare say less prone to issues.
               | 
               | Solar thermal heating used to make more sense but cost of
               | photovoltaics has come down so much along with relatively
               | cheap heat pump systems nobody is doing the former
               | anymore it seems.
               | 
               | I just got a large solar system installed and next up is
               | a heat pump water heater as thats the second largest user
               | of power next to the HVAC, plus it will cool and
               | dehumidify my garage some where the solar inverter and
               | batteries are located, converting some of the waste heat
               | from the inverter into hot water at the same time.
        
           | BurningFrog wrote:
           | A 3GW solar power plant takes up a _lot_ of land. Around
           | 360km2 of land according to my AI, FWIW.
           | 
           | We _can_ live with huge land areas converted to power
           | generation, but more space efficient alternatives will be a
           | big improvement.
        
             | thinkcontext wrote:
             | 40% of US corn acreage is used for something like 10% of
             | gasoline. This is an unfathomable amount of land. Solar
             | yields 20x the amount of energy per acre. On top of that
             | many are finding efficiencies of colocating solar with
             | agricultural activities (agrivoltaics). And there's also
             | replacing agricultural activities on marginal or water
             | stressed land.
             | 
             | Conclusion, land isn't really a constraint in the US.
        
               | BurningFrog wrote:
               | Yeah, I'm not saying solar power is impossible.
               | 
               | Just pointing out that there are real downsides to this
               | energy source, like all the others.
               | 
               | Now is not the time to stop developing energy sources.
        
             | bee_rider wrote:
             | I don't have any reason to doubt it, but it seems like a
             | basically easy computation to verify or for the AI to show
             | its work.
             | 
             | Anyway, the area issue seems not too bad. In the US as
             | least, we have places like the Dakotas which we could turn
             | like 70% of into a solar farm and nobody would really
             | notice.
        
             | triceratops wrote:
             | What if you include all the parking lots and warehouses and
             | large commercial facilities in the world too?
        
             | bryanlarsen wrote:
             | Your AI is messing with you. 1MW requires ~6 acres, so a GW
             | requires 6000. A square mile is 640 acres. Being generous,
             | let's round up to 10 square miles. Times 3 and convert to
             | square kilometers gives 78.
        
         | hovering_nox wrote:
         | Nobody is building commercial plants any time soon; it's still
         | in the experimental phase, with new discoveries happening
         | almost every month.
         | 
         | I see it similarly to the difference between a car with a
         | combustion engine and an electric one. Combustion engines are
         | fully developed. We're reaching the maximum possible
         | performance and utilisation. It's a dead end. However, with
         | electric cars, for example, new battery development is far from
         | over. E.g sodium batteries.
         | 
         | And just off the top of my head, in fusion, the discovery of
         | better electromagnets, as happened a while back, can quadruple
         | energy output.It's not a dead end, and writing it off would be
         | short-sighted.
        
           | CGMthrowaway wrote:
           | They are building a commercial plant right now, and it will
           | come online in the next 10 years.
           | https://news.mit.edu/2024/commonwealth-fusion-systems-
           | unveil...
        
             | Lutzb wrote:
             | Unless I missed something they haven't even completed their
             | technology demonstrator (planned for 2026). No construction
             | has taken place in 2025.
        
         | bell-cot wrote:
         | Yep.
         | 
         | But so long as there is a boatload of prestige and funding to
         | be harnessed via fusion research, it'll be a Really Big Thing.
         | 
         | Centuries ago, an ambitious and clever alchemist could harness
         | a fair quantity of those things via transmutation research. Vs.
         | these days, we have repeatedly demonstrated the ability to
         | transmute lead into gold. But somehow, there's no big talk
         | about, or prestige in, or funding for scaling that process up
         | to commercial viability.
        
           | jmyeet wrote:
           | There are a couple of factors in play with any research,
           | including fusion. If there's money to be had for funding then
           | somebody will research it.
           | 
           | But another more nefarious factor is the nexus of fusion
           | energy research and nuclear weapons research [1]. To build
           | and maintain a stockpile of nuclear weapons (specificially
           | thermonuclear weapons) you need appropriate trained nuclear
           | energy physicists.
           | 
           | [1]: https://thebulletin.org/premium/2024-11/the-
           | entanglement-of-...
        
         | AntiEgo wrote:
         | The steam reactor I guess you might be describing is tokamak,
         | which i agree will be a dead end technology.
         | 
         | There are interesting small fusion reactors that skip the steam
         | step. They compress plasma magnetically, and when the fusion
         | happens, the expanding plasma in turn expands the magnetic
         | field, and the energy is harvested directly from the field. No
         | steam and turbines.
         | 
         | Here is the video where I learned about it:
         | https://www.youtube.com/watch?v=_bDXXWQxK38
         | 
         | Maybe any physicists in this thread could share insight on how
         | feasible this is?
         | 
         | Your main point stands of course: this is a moonshot project,
         | and solar works TODAY!
        
         | HarHarVeryFunny wrote:
         | > With a dense high-energy plasma, you're dealing with a
         | turbulent fluid where any imperfection in your magnetic
         | confinement will likely dmaage the container.
         | 
         | This is true of Tokamak type designs based around continuous
         | confinement, but perhaps less so with something like Helion's
         | design which is based on magnetically firing plasma blobs at
         | each other and achieving fusion through inertial confinement
         | (cf NIF laser-based fusion), with repeated/pulsed operation
         | rather rather than continuous confinement.
         | 
         | No doubt the containment vessel will still suffer damage, but I
         | guess it's a matter of degree - is it still economically viable
         | to operate or not, which I guess needs to be verified
         | experimentally by scaling up and operating for a sufficiently
         | long period of time. Presumably they at least believe the
         | approach is viable or they'd not be pursuing it (and have an
         | agreement in place with Microsoft to power one of their data
         | centers with one of the early units).
        
           | fpoling wrote:
           | There are serious theoretical objections to Helion approach
           | so I am very sceptical to their approach. Stellarators on
           | other hand do not have any known theoretical obstacles and
           | avoid the problem of plasma instabilities.
        
             | HarHarVeryFunny wrote:
             | What are the theoretical problems? Aren't they already
             | achieving fusion with their test reactors, so what's the
             | problem with scaling up and producing net energy?
        
               | hwillis wrote:
               | A 12 year old achieved fusion with a test reactor he
               | built himself:
               | https://www.npr.org/2020/10/09/922065766/tennessee-teen-
               | beco...
        
               | HarHarVeryFunny wrote:
               | OK, and hobby rocketists have nailed a SpaceX style
               | landing too, but so what?
               | 
               | Have you seen the videos of Helion's reactor - hardly a
               | basement project. Sam Altman (OpenAI) also has personally
               | invested hundreds of millions of dollars into Helion,
               | presumably after some due diligence!
        
               | roarcher wrote:
               | High-profile investors are not a signal that something
               | will be successful, no matter how smart they may be in
               | some other domain. Lots of people who should have known
               | better invested in Theranos, too.
        
               | hwillis wrote:
               | Helion's device is a toy. They have nothing that would
               | let them scale past designs of the 70s and say a lot of
               | very suspect things, like that they want to use worse
               | fuel mixes and calling one of the oldest and simplest
               | designs "new" and "unique".
        
               | epistasis wrote:
               | While googling for the exact amount that Altman invested,
               | I found this press release from 2021:
               | 
               | "Helion Raises $500 Million, Targets 2024 for
               | Demonstrating Net Electricity from Fusion"
               | https://www.helionenergy.com/articles/helion-raises-500m/
               | 
               | And also an r/fusion post documenting prior claims:
               | 
               | > "The Helion Fusion Engine will enable profitable fusion
               | energy in 2019," - NBF 7/18/2014.
               | 
               | > "If our physics holds, we hope to reach that goal (net
               | energy gain) in the next three years," - D. Kirtley, CEO
               | of Helion in the Wall Street Journal 2014.
               | 
               | > "Helion will demonstrate net energy gain within 24
               | months, and 50-MWe pilot plant by 2019," - NBF 8/18/2015.
               | 
               | > "Helion will attain net energy output within a couple
               | of years and commercial power in 6 years," - Science News
               | 1/27/2016.
               | 
               | > "Helion plans to reach breakeven energy generation in
               | less than three years, nearly ten times faster than
               | ITER," - NBF 10/1/2018.
               | 
               | > Their newest claim on their website is: "We expect that
               | Polaris will be able to demonstrate the production of a
               | small amount of net electricity by 2024."
               | 
               | https://www.reddit.com/r/fusion/comments/133ttne/can_we_t
               | alk...
               | 
               | I'm sure all this came up in any due diligence as well.
               | They are on Series E after all.
               | 
               | More than a decade of missed milestones is not the type
               | of company that gets this many rounds of investment.
               | 
               | A lot of people _really_ want fusion to happen, and
               | happen sooner. I think that leads to people taking far
               | higher risks with the capital. This sort of investment is
               | always risky, but donating to a grander cause of
               | technology advancement can be a reason for the
               | investment, in addition to expected future value of the
               | investment.
        
           | hwillis wrote:
           | IMO Helion should not be taken seriously:
           | https://www.youtube.com/watch?v=3vUPhsFoniw
        
         | aeve890 wrote:
         | >And stars solve the confinement problem with gravity and by
         | being really, really large.
         | 
         | Kinda. The main catalyst of stellar fusion is quantum
         | tunneling. Temperature and gravity together are not enough to
         | overcome the Coulomb barrier.
        
           | snowwrestler wrote:
           | Quantum tunneling does not work differently in the core of
           | the Sun than it does on the surface of the Earth.
           | 
           | So what _is_ the difference between those two places?
           | Temperature and pressure. In the Sun those arise from
           | gravity. On the Earth, we need to create them mechanically.
        
         | perrygeo wrote:
         | There are three main hurdles here
         | 
         | First, actually getting fusion to positive energy ROI. That's
         | step zero and we're not even close.
         | 
         | Second, scaling the production of fusion in an safe and
         | economical way. Given the utter economic failure of fission
         | nuclear power (there has never been a profitable one), my
         | priors are that the fusion advocates are vastly
         | underestimating, if not willfully ignoring, this part.
         | 
         | Finally, even if we do get to "too cheap to meter" energy, what
         | then? Limitless electricity is not the same thing as limitless
         | stored energy. Only 20% of our energy needs are supplied by
         | electricity. To wit, the crucial industrial processes required
         | to build the nuclear power plant in the first place can only be
         | accomplished with combustible carbon. A power plant cannot
         | generate the energy to build another power plant. Please let
         | that sink in.
         | 
         | We're already seeing countries with photovoltaic and wind
         | hitting $0/kW on sunny windy days - the grid is nearly
         | saturated for daytime load. There isn't enough demand! This
         | makes the economic feasibility of fusion even less attractive.
         | No one is going to make money from it.
        
           | Vanclief wrote:
           | Where did you get the data that there has never been a
           | profitable one? Not calling you out, but curious of where you
           | are getting this data.
           | 
           | I would expect that there have been multiple nuclear power
           | plants that provide a net positive return, specially on
           | countries like France where 70% of their energy is nuclear.
        
             | Retric wrote:
             | France lost an incredible amount of money on nuclear
             | through capacity factor issues. The numbers are so bad they
             | don't want to admit what they are.
             | 
             | However a reasonable argument can be made the public
             | benefited from externalities like lower pollution and
             | subsidized electricity prices even if it was a money pit
             | and much of the benefit was exported to other countries via
             | cheap off peak prices while France was forced to import at
             | peak rates.
        
               | amenhotep wrote:
               | Regulatory burdens on fission account for negative
               | externalities to an arguably overzealous degree, whereas
               | fossil fuel energy has been until recently allowed to
               | completely ignore them. Doesn't seem like a fair
               | comparison.
        
               | Retric wrote:
               | Regulatory burdens on fission result from the inherent
               | risks and negative externalities. You're never going to
               | see huge long term exclusion zones with coal, but nuclear
               | has two of them right now (Ed: Overkill though the
               | current size may be) which also have massive government
               | funded cleanup efforts.
               | 
               | So while regulations may be overkill it's not arbitrary
               | only hydro is really comparable but hydro also stores
               | water and reduces flood risks most years. Fusion sill had
               | real risks, but there's no concern around $500+ Billion
               | cleanup efforts.
        
             | bpfrh wrote:
             | Not really in the sense that the owning company has managed
             | to survive without the state stepping in and give them
             | money.
             | 
             | Most reactors are old and in need of repair, most of these
             | earlier than planned afaik.
             | 
             | There is also the bigger issue that some reactors are shut
             | down in the summer because cooling water would leave the
             | reactor so hot that it would be a danger to the animals
             | living in the river.
        
             | jmyeet wrote:
             | Not a single one of the ~700 nuclear power plants has been
             | built without significant government subsidies [1][2].
             | 
             | Additionally, the industry as a whole is shielded from the
             | liability that would otherwise have bankrupted it multiple
             | times. Notably, the clean up from Fukushima will likely
             | take over 100 years, requires tech not yet invented and
             | will likely cost as much as a trillion dollars [3]. In the
             | US, there is a self-insurance fund paid into by the
             | industry, which would've been exhausted 10-20 times over
             | from a Fukushima level disaster. Plus, Congress severely
             | limits liability from nuclear accidents, both on a per-
             | plant and total basis ie the Price-Anderson Act [4].
             | 
             | Next, it seems like it's the taxpayer who is paying to
             | process and store spent nuclear waste, a problem that will
             | persist for centuries.
             | 
             | Even with all this the levellized-cost-of-energy ("LCOE")
             | of fission power is incredibly expensive and seemingly
             | going up [5].
             | 
             | Some want to reduce costs by using more off-the-shelf tech
             | and replicating it for scale, most notably with small
             | modular reactors ("SMRs") but this actually makes no sense
             | because larger fission reactors are simply more efficient.
             | 
             | [1]: https://theecologist.org/2016/jan/04/after-60-years-
             | nuclear-...
             | 
             | [2]: https://www.ucs.org/resources/nuclear-power-still-not-
             | viable...
             | 
             | [3]: https://cleantechnica.com/2019/04/16/fukushimas-final-
             | costs-...
             | 
             | [4]: https://www.yuccamountain.org/price_anderson.htm
             | 
             | [5]:
             | https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
        
           | psunavy03 wrote:
           | I won't dispute that fission power has enormous capital
           | costs. But how much of its alleged "failure" has been the
           | utter FUD that's been pushed for the past 50+ years about how
           | we'd all be glowing if nuclear power was widespread?
           | 
           | I mean sure, waste disposal is a serious issue that deserves
           | serious consideration. But fission waste contaminates a
           | discrete area. Fossil fuels at scale cause climate change
           | that contaminates the entire freaking planet. It's a travesty
           | we haven't had a nuclearized grid for 20-30 years at this
           | point.
        
         | jMyles wrote:
         | Agreed.
         | 
         | The problem(s) of scale are not only those of scaling up, but
         | also scaling down.
         | 
         | One of the best and most unsung benefits of solar is that it is
         | profoundly easy and intuitive to build a very small (ie,
         | vehicle- or house-sized) grid.
         | 
         | In an increasingly decentralized and stateless world, it makes
         | sense to look for these qualities in an energy source.
        
         | onlyrealcuzzo wrote:
         | You realize this is what people said about solar energy and
         | nuclear energy at one point, right
         | 
         | And before someone chimes in and says Nuclear doesn't make
         | sense - it made sense at plenty of times and in different
         | places.
         | 
         | It doesn't make sense in Western countries that are hell bent
         | on making it as expensive as possible, strictly to ensure it
         | doesn't get built, so we stick on fossil fuels as long as
         | possible.
        
           | jmyeet wrote:
           | This is a meaningless argument people trot out all the time
           | for things they just don't understand. Sometimes it applies
           | but often it doesn't.
           | 
           | For example, people will dismiss arguments saying FTL is
           | likely impossible because people once said that about going
           | to the Moon. To be fair, there was some logic to the anti-
           | Moon argument based on physics. The big change came with
           | multi-stage rockets that solved the weight and thrust
           | problems. And even then it's close [1].
           | 
           | There are good, physical reasons why FTL is highly likely
           | impossible. You know, based on phnysics.
           | 
           | Likewise, the challenges to commercial fusion are also based
           | on physics. Fusion reactions produce neutrons. Neutrons can't
           | be magnetically contained. Neutrons destroy the container
           | and, more importantly, lose energy from the system.
           | 
           | But saying "people once said the Earth was flat" or "people
           | once said we couldn't get to the Moon" and so on are just
           | meaningless platitudes. [1]: https://www.realclearscience.com
           | /blog/2017/07/06/if_earth_wa...
        
         | Projectiboga wrote:
         | There are multiple potential fusion reactions, duterium and
         | tritium like in our home star The Sun is the most researched.
         | There is also research into ones with Lithium and other left
         | side elements. Finally the one I think has the best future is
         | aneutronic fusion with Boron11 plus hydrogen, it gives off
         | three alpha particles which can be converted directly to
         | electricity. the leading model is Field Reversed Fusion.
         | https://spectrum.ieee.org/aneutronic-fusion
        
         | snowwrestler wrote:
         | > I remain skeptical that fusion will ever be a commercially
         | viable energy source. I'd love to be wrong.
         | 
         | I'm also skeptical, but I think the emphasis of my skepticism
         | is on "commercially viable" as opposed to an available energy
         | source. That is, I think fusion development will (and should)
         | proceed anyway.
         | 
         | There's a good argument that nuclear fission is not really
         | commercially viable in its current form. Yet it provides quite
         | a lot of commercially available electricity. And it also powers
         | aircraft carriers and submarines. And similar technology
         | produces plutonium for weapons. In other words, I don't think
         | fission's continued availability as a power source is a
         | strictly commercial decision.
         | 
         | I think there's a quite a lot of technology that is not
         | directly commercially viable, like high energy physics, or the
         | space program. But they remain popular and funded. And they
         | throw off a lot of commercial side benefits.
         | 
         | The growth of solar for domestic consumer power will certainly
         | continue and that is a good thing. But I bet we'll have fusion
         | too in the long run. There's no lack of ideas for interesting
         | things to do with extreme amounts of heat and power. For
         | example I'm hopeful that humanity eventually figures out space
         | propulsion powered by fusion.
        
         | o1inventor wrote:
         | I wonder how much research has gone into neutron-deficient
         | materials for shielding?
         | 
         | Depleted uranium is one example but that has terrible
         | implications due to radioactive pollution that would result,
         | disposal costs and risks, etc.
         | 
         | Surprised theres not more research into meta-materials and
         | alloys that are neutron-resistant, neutron-slowing, or neutron-
         | absorbing.
        
         | emtel wrote:
         | I have no idea why you are being downvoted. The chances of a
         | power source that _doesn't even work yet_ will out-compete one
         | that is currently on both an exponential price decline curve
         | and exponential capacity growth curve are pretty close to 0.
        
         | ryao wrote:
         | Nuclear fusion as an energy source has major unsolved problems.
         | Off the top of my head:                 * The super conducting
         | metals required for confinement randomly stop superconducting.
         | * The fuels produce absurd amounts of radiation and the
         | Helium-3 solution for that might as well be fairy dust, since
         | even if we convert the energy global economy to helium-3
         | production, we will not have enough by orders of magnitude to
         | power hypothetical fusion reactors that would handle our needs.
         | Strip mining the moon for it is supposedly a way to get it, but
         | defacing the surface of the moon for minuscule amounts of
         | Helium-3 per acre is unlikely to ever be profitable.
         | * The amount of radioactive materials produced from the
         | experiments are many times those produced in fission reactors.
         | 
         | This is just off the top of my head. Until recently, I would
         | have included the inability to produce more energy than we put
         | into it on this list, but LLNL's breakthrough a few years ago
         | seems to have solved that. I suspect that someone with time to
         | look into the practical issues involved in building a fusion
         | reactor would find other issues (such as the design not being
         | practical to use in a production power plant and thus further
         | research being needed to make one that is).
         | 
         | I wonder if the only reason countries fund nuclear fusion
         | research is to keep nuclear scientists from finding employment
         | in the production of nuclear weapons.
        
           | paul-schleger wrote:
           | I'd love to see some references on those three claims. None
           | of them make sense to me.
        
         | reubenswartz wrote:
         | I'm thinking perhaps the best place for a fusion reactor is 93
         | million miles away. It's already up and running, and we're
         | making huge strides in energy collection and storage...
        
       | blindriver wrote:
       | Can someone tell me what the likelihood of a humongous explosion
       | from nuclear fusion could be? All these nuclear physicists
       | dealing with enormous amounts of energy, like the LHC or China
       | with their attempts at nuclear fusion really terrify me that it
       | might provoke a huge reaction that will devastate the planet. Is
       | this possible or do they have a true fail-safe in place that
       | prevents it?
        
         | ahazred8ta wrote:
         | There's nothing to 'prevent'. There's not enough energy in the
         | hydrogen in the chamber to cause an explosion. Your high school
         | science teacher could have explained this to you.
        
         | hwillis wrote:
         | > All these nuclear physicists dealing with enormous amounts of
         | energy, like the LHC
         | 
         | The LHC uses ~86 megawatts, about the same power as a 747's
         | engine at full throttle. It's about the same as a small natural
         | gas powered turbine. GE builds gas turbines that produce 800+
         | MW.
         | 
         | The LHC is just a controlled environment to study the kind of
         | particle collisions that are happening all over the earth every
         | day. We live next to a giant fusion reaction, and freak
         | particles come in from outer space all the time. We have
         | detected many particles with millions of times more energy than
         | the particles in the LHC- the Oh-My-God particle had 20 million
         | times more energy.
         | 
         | > Can someone tell me what the likelihood of a humongous
         | explosion from nuclear fusion could be?
         | 
         | Fission self-sustains. Each reaction produces 3 neutrons that
         | can start another reaction. It explodes because the neutrons
         | grow like 3, 9, 27 etc.
         | 
         | Fusion does not. You have a number of atoms, and 2 of those
         | atoms have to find each other to fuse. One reaction does not
         | make any other reactions more likely. Unlike fossil fuels or
         | fission reactions, the fuel cannot be lit. It can only burn
         | when carefully confined. You can only build up enough flame to
         | break the containment vessel, at which point it goes out. Since
         | the inside of the vessel is basically a vacuum, it will
         | _implode_ instead of exploding.
        
           | blindriver wrote:
           | Thank you for the great answer, unlike the other responser.
        
       | munchler wrote:
       | > This work was supported by the U.S. Department of Energy.
       | 
       | Unfortunately, sentences like this are going to be way less
       | common soon.
        
         | libraryatnight wrote:
         | It's been sad reading the posts of the various people in the
         | sciences and academics that I follow.
        
         | agumonkey wrote:
         | Hopefully this will be short lived, like financial crisis.
         | Hopefully.
        
           | KennyBlanken wrote:
           | You can't just hit "pause" on this stuff.
           | 
           | I have at least one friend who runs a biomedical research
           | lab.
           | 
           | From conversations, here is what it going on:
           | 
           | - incoming students and researchers have been retracting
           | their applications because of fear of ending up in detention
           | for having something the regime doesn't like on their phone
           | or on social media, or having their photo snapped at a
           | protest about something the regime doesn't like, or their
           | research being on a subject the regime doesn't like...or even
           | something as stupid as the letters "trans" appearing as
           | _part_ of a word like  "transgenic." (That's actually
           | happened.)
           | 
           | - the schools have had to retract offers for others because
           | there's no money to pay their stipends or for their
           | lab/office space
           | 
           | - meeting with their administrations to discuss how long
           | their schools can float salaries for lab staff. Admin
           | assistants, scientific support staff like lab and animal
           | technicians, and so on.
           | 
           | - planning phases of the euthanization of their organism /
           | animal models
           | 
           | - planning phasing of the liquidation of lab equipment (in a
           | market being flooded with such equipment)
           | 
           | My friends are talking about not being able to bear making
           | their techs or researchers mass-euthanize research animal
           | populations (typically rodents) and doing it themselves, in
           | tears. Many of them justify the normal 'sacrifice' of
           | research animals because their deaths help us advance science
           | - but in this case, it's just because some transactional
           | dickhead can't directly draw a crayon line between their
           | research and GDP. But it's also because it's a visceral
           | representation of scientific progress being destroyed. All to
           | "own the libs" (but really to give billionaires tax cuts.)
           | 
           | One said they are trying to figure out what to do now that
           | their career, which they have spent two decades of 60+ hour
           | weeks on, is basically over - what little positions are left
           | will see hundreds if not thousands of applicants. Salaries
           | will plunge both out of necessity and a saturated labor
           | supply.
           | 
           | The damage that has been done in less than 6 months to
           | scientific research is immesurable and the consequences will
           | be generational.
           | 
           | If you don't believe me, go through your list of friends,
           | coworkers, family, etc and see who works in research and see
           | what they're posting on social media or talk with them.
           | 
           | Got any friends who work in companies that make scientific
           | equipment, reagents, etc? They might not have a job already,
           | or soon.
           | 
           | Kids get into science in part because their parents or a
           | family member is in science. Or they see a cool show on PBS
           | about science. All that's going away. We're going to see a
           | precipitous drop in the number of people pursuing scientific
           | educations and careers.
           | 
           | Billionaires are about to find out that it doesn't matter how
           | much money you have if your kid has cancer and there's nobody
           | to treat them, no drugs being researched or manufactured, no
           | diagnostic equipment (that was in part funded by research
           | project grants), and o on.
        
             | mschuster91 wrote:
             | > Got any friends who work in companies that make
             | scientific equipment, reagents, etc? They might not have a
             | job already, or soon.
             | 
             | Nothing to lose any more? Then go and protest, hard. It's
             | too late to undo the damage already caused, but a huge part
             | of why Trump was able to rise to power was because there
             | was by far not enough protest against him.
        
               | ngangaga wrote:
               | > but a huge part of why Trump was able to rise to power
               | was because there was by far not enough protest against
               | him.
               | 
               | There are a lot of reasons to be skeptical of this claim.
               | For one thing, it's not clear that trump voters respect
               | protestors in the first place. For another thing, we're
               | an extremely geographically distributed population, and
               | most of our cities already swing strongly blue. This
               | means protesting is generally a high-effort, low-return
               | activity.
               | 
               | Whatever _will_ provide friction I do not know, but I don
               | 't think protests are going to play a major role outside
               | of maybe providing a narrative about how angry people
               | are. But it's important to note that a significant number
               | of people vote for Trump _because_ he makes certain
               | people angry.... If the right people  "protest" in a
               | ridiculous enough manner, you're going to likely
               | strengthen the resolve of his base. Granted, I suspect
               | this isn't much of an issue with science funding, but
               | it's something to keep in mind.
               | 
               | My attitude is: if this country doesn't want science
               | research, let it, follow the research overseas, and let
               | your absence speak for itself.
        
               | mschuster91 wrote:
               | > There are a lot of reasons to be skeptical of this
               | claim. For one thing, it's not clear that trump voters
               | respect protestors in the first place.
               | 
               | They do respect one thing, just like their master does:
               | _strength_. Show up in force, in overwhelming numbers,
               | and all these  "don't tread on me" people suddenly find
               | out that, whoops, they aren't the top dogs any more. It
               | used to be the case that you got beaten up or worse for
               | showing up in KKK outfits, these days you got pseudo-edgy
               | kids on social media with them.
        
               | harikb wrote:
               | You are underestimating the risk to people who protest
               | and how bad it needs to get before people are pushed to
               | it.
               | 
               | Distribution is somewhat like this...
               | 
               | Say there are 10,000 people affected by this
               | 
               | 5,000 probably have skills to pivot to something else,
               | don't give a shit about future billionaire's kid's
               | problem. People wouldn't want to be scientists if they
               | can't also have a decent career.
               | 
               | 2,000 people have means to survive and can't afford to
               | fight the thugs on street
               | 
               | 2,000 people are desperate, but otherwise marginalized by
               | current admininstration (immigrant, mexican, black,
               | muslim,... whatever) but don't want to sacrifice their
               | extended family too.
               | 
               | 1,000 people are desperate, have the courage to fight
               | (probably white).
               | 
               | If the future of curing the billionaire's kid relies on
               | 1,000 people sacrificing their life... oh well....
        
               | immibis wrote:
               | Protests do not accomplish political change, have never
               | accomplished political change, and will never accomplish
               | political change. They are good for one thing and one
               | thing only: meeting other people who are just as angry as
               | you about something. From which you might decide to take
               | actions that actually cause some political change.
        
               | mschuster91 wrote:
               | > Protests do not accomplish political change, have never
               | accomplished political change, and will never accomplish
               | political change.
               | 
               | France's "yellow vests" or Germany's "Pegida" might
               | disagree with you on that one. Both were pretty darn
               | effective.
        
         | misja111 wrote:
         | Well as long as they carefully avoid phrases like climate
         | change or energy transition, they might be able to avoid the
         | wrath of the Trump administration.
        
           | whatshisface wrote:
           | That was what the NSF director may have thought during the
           | first 100 or so days of the administration, but he resigned
           | because he believed that the 55% budget cut wasn't possible
           | to overcome through negotiation.
        
         | dang wrote:
         | " _Eschew flamebait. Avoid generic tangents._ " -
         | https://news.ycombinator.com/newsguidelines.html
         | 
         | Why that last bit? Generic tangents supplant narrower/specific
         | topics with broader/generic ones that people tend to already
         | have opinions about, which they are eager to repeat. Because of
         | this, generic tangents--especially on divisive/indignant topics
         | --end up having two bad effects: (1) they take over the
         | conversation, and (2) they are repetitive.
         | 
         | It's similar to how weeds take over a garden. We want a garden
         | of unusual, interesting plants, not the most common ones that
         | take over everywhere if allowed to.
         | 
         | https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
        
           | munchler wrote:
           | I hear you, although I respectfully disagree that my comment
           | was either flamebait or a generic tangent. The topic is
           | (IMHO) appropriate for HN, and a concrete example like this
           | is a good way to highlight the issue. It seems quite far from
           | a common weed to me.
        
             | dang wrote:
             | It's generic in the sense that it masks out all the bits
             | about fusion energy, let alone this specific report of a
             | discovery, in favor of the much larger and more general
             | topic of what's happening with science and health funding
             | in the US.
        
       | lifeplusplus wrote:
       | I think it's time to say nobody in Congress can be older than 65
       | and has a dual citizenship
        
         | hornd wrote:
         | Is this comment on the right thread?
        
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