[HN Gopher] After years of doubts, hopes grow that nuclear fusio...
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After years of doubts, hopes grow that nuclear fusion is near
Author : jseliger
Score : 71 points
Date : 2021-12-25 17:15 UTC (5 hours ago)
(HTM) web link (www.bostonglobe.com)
(TXT) w3m dump (www.bostonglobe.com)
| leephillips wrote:
| "These advancements aren't incremental; they are quantum leap
| improvements." I hope that physicist Dennis Whyte was being
| misquoted here.
|
| We need to rapidly ramp down the use of fossil fuels and replace
| them with technology that works today, such as photovoltaics and
| nuclear fission (in the interim). Aspirational projects that
| might possibly have a working proof-of-concept in a decade or
| five are not part of the solution to the climate crisis.
| mlindner wrote:
| He is correct however. There's no possibility of replacing all
| power with renewables energy within 10 years, so having a 5
| year time scale for a working prototype is completely
| reasonable. We're not even going to have all cars converted to
| electric vehicles within 20 years even in countries with the
| most strict rules, let alone all power generation and fossil
| fuel use for other applications. (Even if fossil fuel sales
| were forbidden tomorrow, it would still take 20 years for the
| existing vehicles to be taken out of the used market.)
| willis936 wrote:
| Climate predictions end in 2070, but the world does not.
| "We're fucked" isn't a reason to throw our hands up and not
| try.
|
| Fusion is "too late" the same way every other decarbonization
| tool is too late. It doesn't matter. Do it anyway. In 200
| years the people who threw up their hands will be seen as
| short-sighted.
| andi999 wrote:
| Or just depopulate regions in the world which require heating
| to survive.
| echelon wrote:
| All of Canada and every state north of Kentucky?
| syspec wrote:
| What about places that require massive amount of cooling in
| the summer
| Jiro wrote:
| >I hope that physicist Dennis Whyte was being misquoted here.
|
| Why? Because quantum leaps are small? The metaphor is not
| comparing it to the size of the quantum leap; the metaphor is
| that quantum leaps are _discontinuous_.
| leephillips wrote:
| I thought he also believed that the advances were of
| significant size, but maybe I'm wrong and he did, in fact,
| mean to admit that this recent, discontinuous progress was
| minute.
| kiba wrote:
| If we are serious about ramping down the use of fossil fuels,
| we should start with the eliminations of vehicles that we don't
| need, such as cars.
|
| In order to eliminate cars, however, it will require a drastic
| readjustment of our urban planning policies. Land use policies
| are what made cars viable and public transport unviable.
| rindalir wrote:
| I would also like to see a more walkable future, but I've
| given up hope that such a big transition will happen within a
| timeframe small enough to make a difference for things like
| GHG emissions. I guess I've made my reluctant peace with a
| rapid electrification of the world's vehicle fleet (which,
| yes, isn't exactly clean either).
| pengaru wrote:
| How about instead we get rid of the people we don't need, so
| _everyone_ driving cars involves a much smaller multiplier
| and we can preserve a high quality of life without trashing
| the place.
| mlindner wrote:
| > If we are serious about ramping down the use of fossil
| fuels, we should start with the eliminations of vehicles that
| we don't need, such as cars.
|
| Whenever people state things like this it shows that this
| person is out of touch with reality.
| leephillips wrote:
| I totally agree. But another big contributor to the over-use
| of cars is the shared illusion that everyone has to "go to
| work". I think the extended pandemic is contributing to
| shattering that illusion.
| nopenopenopeno wrote:
| >I think the extended pandemic is contributing to
| shattering that illusion.
|
| Or, the opposite? How could you be so out of touch as to
| think society did not depend on all the masses of people
| who continued going to work continuing to go to work?
|
| Realize these are the low wage workers who will be tasked
| to pay for your carbon tax, and they won't blink an eye at
| re-electing Trump, who in such a case would be the left
| wing candidate regardless of his party affiliation.
| rindalir wrote:
| In 2017, only about 15% of vehicle trips in the US were
| taken for commuting [1], the rest are for shopping/errands
| (45%) and for socializing/recreation (the balance). So even
| if we eliminate half the commute trips, we still have a
| long way to go to reduce the miles traveled. [1]
| https://www.bts.gov/statistical-products/surveys/national-
| ho...
| SantalBlush wrote:
| >In 2017, only about 15% of vehicle trips in the US were
| taken for commuting
|
| This describes commuting as a percentage of total trips,
| but it would be more useful to find the percentage of
| total vehicle miles traveled. I imagine that would be
| higher than 15%.
| TheOtherHobbes wrote:
| It's not the number of journeys, it's the duration and
| consumption for each trip.
|
| A daily 55 min commute - which is the average both-way
| time - generates far more carbon than a daily 20 min trip
| to the store and back.
| leephillips wrote:
| I thought it was more; thanks for the information.
| Although 15%, or say half that after subtracting the
| people who actually need to be physically at work, is
| still significant. Also, note that 15% of miles will be
| more, probably much more, than 15% of the pollution,
| because those miles are the slowest ones that people
| travel.
| rindalir wrote:
| I also thought it was more (I remember reading about 30%
| in the early 2000's), so I was kinda surprised. I think
| you are right that miles traveled will be higher, so from
| an emissions perspective the decrease in commuting is
| good news. From the perspective of cars being everywhere
| and making environments unpleasant, as long as people
| don't think twice about hoping in the car to go Starbucks
| twice a day, we've got a huge problem.
| leephillips wrote:
| I grew up in NYC and don't regard cities, like Atlanta,
| covered in highways, to be cities. I never understood why
| places like this were built or how people enjoy living
| there, but clearly some do.
| Turing_Machine wrote:
| Different strokes.
|
| Other people don't understand why someone would pay
| $4,000/month to live in an NYC apartment that would maybe
| qualify as a large closet elsewhere.
| leephillips wrote:
| That they're willing to pay that should tell you
| something!
| fennecfoxen wrote:
| The major premise of such a city is generally that you
| own more space than you could ever get in New York.
| bparsons wrote:
| If you live somewhere that requires a long commute to
| work (ie. an exurb) you are likely completely dependent
| on a private vehicle for all other aspects of your
| lifestyle.
|
| Good transportation policy is actually good land use
| policy, and good land use policy is great climate policy.
|
| We don't need fusion reactors in space to stop climate
| change. We need walkable neighborhoods, an international
| carbon price and more trains.
|
| The harmful fantasy being sold to the public is that we
| can solve climate change while still having the vast
| majority of people living in far flung suburbs and
| driving a seven person truck 10km to go pick up a carton
| of eggs.
| mdp2021 wrote:
| > _we don 't need_
|
| It's not difficult to imagine a situation in which someone
| does not /strictly/ need a car (it also seems urban life is
| quite common these days). It should also be extremely easy to
| imagine having a car as extremely beneficial.
|
| (By the way: epidemics still being far from forgotten, it's
| really odd to paint collective, "public" transport as
| aproblematic.)
|
| Now, to attack the problem, one could also (and in some
| contexts primarily) hit house heating. There are voices
| recommending heating limited to 16degC/61degF. The issue is
| just about quality of life. Including enabling operations.
| Hacker should be attentive on their instruments, since they
| are instrument crafters.
|
| Since the control of resources has always been linked to
| their price (which is also equivalent to, or actually
| including, an externality tax) - so given a clear alternative
| -, I am not sure how the whole idea of "we will do without",
| restricting "freedom" (in abstract terms, as a primary value
| for constitutional decisors) and operation, came to be.
|
| (Up to not seeing "the car" as a life changing revolution...
| Reading just recently the first pages of a history text, the
| car was immediately mentioned as "expanding the possibilities
| for movement to unimaginable heights even for the richest of
| fifty years before". It has always been very clearly a most
| prominent gift of engineering, as if a third dotation of
| natural limbs: it's odd to now read about it as
| "negligible".)
| kiba wrote:
| _It 's not difficult to imagine a situation in which
| someone does not /strictly/ need a car (it also seems urban
| life is quite common these days). It should also be
| extremely easy to imagine having a car as extremely
| beneficial._
|
| Interurban rails and other form of mass transit gained
| prominence especially in the early 20th century. They were
| eventually outcompeted by cars on a wide variety of
| factors, including public support for funding of roads.
|
| It's not too difficult to imagine freight traveling on
| streetcar rails.
|
| _(Up to not seeing "the car" as a life changing
| revolution... Reading just recently the first pages of a
| history text, the car was immediately mentioned as
| "expanding the possibilities for movement to unimaginable
| heights even for the richest of fifty years before". It has
| always been very clearly a most prominent gift of
| engineering, as if a third dotation of natural limbs: it's
| odd to now read about it as "negligible".)_
|
| The car is simply not as viable without proper
| infrastructure and implicit subsidies.
| mdp2021 wrote:
| > _It 's not too difficult to imagine freight traveling
| on streetcar rails_
|
| So? What do you mean, what is your conclusion from that?
|
| You wrote that <<we don't need ... cars>>. I wrote that
| you don't "need" (much) heating either, relevantly to
| impact, but the impact on quality of life can be massive.
| Try performing intellectual (reduced motion, in general)
| activities in the cold. Try buying groceries without a
| car when living in a very low density, non urbanized
| area. Maybe you don't care about the advantages of a car:
| to others they are vital.
|
| > _The car is simply not as viable without proper
| infrastructure and implicit subsidies_
|
| So? What do you mean?
|
| You dismissed the car as expendable, I noted that it has
| been called an historical revolution with a massive
| impact in the quality of one's life, for good.
| toast0 wrote:
| > The car is simply not as viable without proper
| infrastructure and implicit subsidies.
|
| Cars work fine on dirt paths. Not as good as on roads,
| but they still work. Sure, it's tricky to go through a
| forest, but otherwise they're ok.
| tromp wrote:
| 12ft.io works as advertized:
|
| https://12ft.io/proxy?q=http://www.bostonglobe.com/2021/12/2...
| maccam94 wrote:
| There's not much new info here since the last time the project
| was discussed. The first two comments here link to informative
| videos about how the reactor works:
| https://news.ycombinator.com/item?id=24629828#24634733
|
| News since then:
|
| CFS has now raised $1.8B
|
| They have demonstrated a full-size magnet with a field strength
| of 20 Tesla
|
| They have started construction on the new SPARC reactor facility.
| ur-whale wrote:
| https://archive.ph/FbH0D
| anonuser123456 wrote:
| Getting fusion to happen is the easy part.
|
| Building a reactor that is economical is not so easy.
|
| Fast neutrons, tritium management, corrosive molten salts,
| beryllium supply constraints...whole lotta material science
| problems you gotta work out at scale and on budget.
| AtlasBarfed wrote:
| WHich reminds me of LFTR:
|
| http://transcriptvids.com/v/AHs2Ugxo7-8.html
|
| Molten salts, vessel degradation, etc all need to be dealt with
| there, but with a far clearer path for positive energy
| production.
| Animats wrote:
| It's forward progress, but nowhere near being useful.
|
| By "more energy out than they put in", they mean passing
| "theoretical breakeven", generating more energy as heat than they
| put in as electricity. Not converting that energy back to
| electricity and making the thing self-powered. Brief periods of
| theoretical breakeven have been achieved before.
|
| Ahead lies "sustained theoretical breakeven" - the thing can be
| kept running for a while. So far, other tokomak experiments have
| achieved 70 seconds of plasma containment (Korea) and 120 seconds
| (China). That's below ignition temperature, though. Then "self-
| sustaining breakeven" - the thing can power itself. Then,
| someday, "economic break-even" - it can pay for itself. Then,
| maybe, useful power generation.
|
| There's the problem of getting the energy out in some useful
| form. This begins with the "first wall" problem of finding
| something that can survive the conditions just outside the
| magnetic field. Those conditions include huge numbers of
| neutrons, which tend to split atoms in the first wall material
| and cause unwanted transmutation. This causes radiation
| embrittlement, which is not good for materials.
|
| It's going to be a long haul.
| david_draco wrote:
| Sabine Hossenfelder essentially called the nuclear fusion PR a
| fraud, because they do not report true (full-system)
| efficiencies. https://www.youtube.com/watch?v=LJ4W1g-6JiY
| mlindner wrote:
| She also overstated things and made things out to be worse
| than they actually are. Getting to fusion plasma power
| breakeven IS the hardest part. And it's always been so far
| away, setting and talking about realistic goals is better
| than trying to immediately jump to the far end goal.
|
| This is the difference between ITER and projects like SPARC
| though, they both plan to get fusion plasma power breakeven,
| but ITER's design has zero hope of ever being economical.
| leephillips wrote:
| As I recall her point about the deceptive reporting of gain
| figures was spot-on. It's something I'd observed throughout
| the 20 years that I followed the field fairly closely,
| being intermittently involved in several fusion-related
| projects. Especially in inertial confinement, claims of
| "break-even" are almost entirely devoid of meaning. So how,
| exactly, do you think she overstated anything?
| tsimionescu wrote:
| Extracting useful energy from the plasma, and protecting
| the reactor (magnets, control etc) from neutron bombardment
| are also hugely difficult problems.
|
| Not to mention, trying to fool public opinion about how far
| away we are from any chance of a fusion power plant is
| still ethically wrong. Let's not forget that even if ITER
| achieves all of its goals and milestones, we will be able
| to _start_ on the power extraction problem in 2030.
|
| And let's also not forget that inertial confinement fusion,
| while also being presented as a potential fusion power
| plant concept, with great fanfare occasionally, is simply a
| weapons research program with no imaginable way of
| progressing to economical power generation.
| gulikoza wrote:
| How about space propulsion? Maybe I'm naive, but inertial
| confinement fusion seems like a great candidate for a
| space engine.
| maccam94 wrote:
| CFS's ARC reactor design will use a FLiBe molten salt
| blanket to shield everything except the vacuum chamber
| itself, which is a steel doughnut with 2cm thick walls.
| They plan to build a proof of concept reactor by 2025
| that will have net energy gain (Q > 10), and then a full
| demo power plant by 2030. CFS believes they can move
| faster than ITER because the newer stronger magnets that
| they're using make smaller reactors viable. Smaller scale
| means cheaper to build, which means a nimbler private
| company can build it rather than a bureaucratic
| international project.
| maccam94 wrote:
| Commonwealth Fusion Systems plans to hit Q>10 net energy gain
| in their SPARC reactor in 2025, and then turn on a continuously
| operating ARC power plant around 2030. They plan to use a steel
| vacuum chamber which will need annual replacement. The rest of
| the ARC reactor will be shielded by a FLiBe molten salt blanket
| which will absorb neutrons and convert their energy into heat.
| mlindner wrote:
| IANANS (I Am Not A Nuclear Scientist)
|
| > Brief periods of theoretical breakeven have been achieved
| before.
|
| Source? I'm not aware of any reactor that has done that.
|
| > Ahead lies "sustained theoretical breakeven" - the thing can
| be kept running for a while. So far, other tokomak experiments
| have achieved 70 seconds of plasma containment (Korea) and 120
| seconds (China). That's below ignition temperature, though.
|
| Ignition temperature is not set just by the time you run it.
| The larger you go the longer you need to run before you can get
| to ignition. ITER will need something like 1000 seconds, but
| SPARC will only need 10.
|
| > Then, someday, "economic break-even" - it can pay for itself.
|
| For ITER-like designs that's impossible because the massive
| manufacturing cost.
|
| > This begins with the "first wall" problem of finding
| something that can survive the conditions just outside the
| magnetic field. Those conditions include huge numbers of
| neutrons, which tend to split atoms in the first wall material
| and cause unwanted transmutation. This causes radiation
| embrittlement, which is not good for materials.
|
| Radiation embrittlement is only a problem for certain types of
| materials. Some material types do not absorb neutrons at fusion
| energies and simply pass them through. This is a complex
| materials problems and you can't just use steel but there's
| already many designs that people are experienced with for this
| and it's well known because of the history of fision energy
| research with neutrons.
| pfdietz wrote:
| All materials have problems with fusion neutrons. The
| neutrons from DT fusion are sufficiently energetic to cause
| (n,alpha) and (n,p) reactions, causing hydrogen and helium
| gas to accumulate. Helium in particular is a problem, because
| it collects into tiny very high pressure bubbles that rip the
| material apart from the inside. Simple elastic scattering of
| neutrons off the atoms cause them to scatter many atomic
| diameters in the material, scrambling its crystalline
| structure.
|
| There are also just a few elements that do not produce
| unacceptably long lived radioisotopes under fusion neutron
| bombardment. This greatly limits the choice of elements from
| which to make the reactor structure. Right now, the best
| choice is RAFM steel, but it has a number of serious
| drawbacks.
| randmeerkat wrote:
| What are the serious drawbacks?
| Animats wrote:
| _Brief periods of theoretical breakeven have been achieved
| before...Source? I 'm not aware of any reactor that has done
| that._
|
| Not in a plasma reactor, yet. The laser Nuclear Ignition
| Facility at Lawrence Livermore Labs claimed "scientific
| breakeven" back in 2014.[1] That's the setup where they have
| a huge building full of pulse lasers focused on one tiny
| target.
|
| This is breakeven for a very weak definition of breakeven:
| "thermonuclear energy out" > "energy absorbed by the fuel
| capsule". Not "> energy required to run the lasers." That's
| for a _very_ brief period, nanoseconds. It 's taken Lawrence
| Livermore 45 years of zapping tiny targets with big lasers to
| get to this point.
|
| This was being touted as a potential approach to fusion
| energy back in the 1970s. It's not, really. It's mostly a way
| to study bomb-type fusion without setting off H-bombs. It's
| now part of "stockpile stewardship", keeping some people
| working on fusion to prevent forgetting how to make H-bombs.
|
| [1] http://www.hiper-laser.org/News%20and%20events/index.html
| leephillips wrote:
| And it's important to note that "energy absorbed by the
| fuel capsule" is not measured; it means the absorbed energy
| calculated by a model using a classified code that no one
| outside the program is allowed to see.
| danuker wrote:
| > and cause unwanted transmutation
|
| This is a syntagm I did not expect reading on Hacker News in a
| comment about technology, but about a roleplaying game.
| cletus wrote:
| The article doesn't really go into detail about this (it's
| mentioned in the video) but the key breakthrough they're
| referring to is increasing the magnetic field strength from HTS
| (high-temperature superconducting) magnets to 20 Tesla [1].
|
| It's hard not to come away from reading any of this without
| thinking what a huge boondoggle ITER was and is and there was
| plenty of reason to think that before now.
|
| A lot of talk here is given to net energy production. That is a
| key milestone but it's not by itself sufficient for commercial
| fusion power production.
|
| Example: imagine a plant costs $10B and products 100MW of net
| power. It has a lifespan of 30 years and requires $500m/year in
| maintenance and staffing. That capital cost and operating costs
| need to be amortized over the lifespan of the plant so even
| though it's 100MW of net power production, those numbers simply
| aren't commercially viable.
|
| I applaud these efforts but I remain skeptical on when (if ever)
| we'll have commercial fusion power production, for several
| reasons:
|
| 1. The issues of turbulence with a super-heated plasma;
|
| 2. Power loss through neutrons; and
|
| 3. Damage caused by neutron embrittlement of the reactor itself.
|
| Personally I think solar is still the frontrunner for the first
| renewable mass-scale power production method that will be cheaper
| than fossil fuels and thus replace fossil fuel plants for
| economic reasons.
|
| I'm glad there are a bunch of commercial enterprises focused on
| this. I hope at least some of them explore some of the
| alternative forms of fusion (ie other than hydrogen). For
| example: proton-Born fusion [2]. Aneutronic fusion would have
| huge advantages.
|
| [1]:
| https://www.popularmechanics.com/science/energy/a37924936/wo...
|
| [2]: https://en.wikipedia.org/wiki/Aneutronic_fusion#Boron
| maccam94 wrote:
| Commonwealth Fusion Systems has addressed all of those issues:
|
| 1. The higher field strength from the new HTS magnets
| eliminates turbulence.
|
| 2. The ARC reactor will use a FLiBe molten salt blanket to
| capture energy from neutrons and breed tritium to be used in
| the fusion reaction.
|
| 3. The ARC reactor is designed to have a swappable 2cm thick
| vacuum chamber, which is the component subjected to the most
| neutron radiation (everything else is shielded by the molten
| salt blanket). These chambers are expected to last a year, and
| while they are moderately radioactive waste, the amount of
| material is relatively small and they should become safe in the
| order of a decade.
|
| I highly recommend watching Dr. Whyte's talks on YouTube, he
| discusses the challenges, design, and performance in an
| approachable way. There's a timestamp index in the comments on
| this video:
|
| https://youtu.be/KkpqA8yG9T4
| sandworm101 wrote:
| And look at how much liquid helium is required for the cooling
| plant. There isn't enough on the planet to build many reactors
| like this.
|
| https://www.iter.org/construction/cryoplant
|
| >> In order to deliver the cooling fluids to the machine, a
| large cooling plant has been built at ITER that ranks as the
| most powerful single-platform cryoplant in the world.
| luckylion wrote:
| Isn't that to be expected during proof-of-concept builds?
| Once you can show that it's actually possible, you can start
| optimizing the process.
|
| Fusion could be a super breakthrough, even if it never gets
| super cheap and "we power the world by doing this one weird
| trick and all we need is one building". Provides reliable
| energy 24/7, is safe to use (as in no melt-down potential
| that people would be scared about) and does neither produce
| co2 nor blast coal dust particles all over the world.
|
| I'm sure we could do the same with nuclear power, but it's
| politically impossible in many countries, because the name
| short-circuits people's minds.
| tsimionescu wrote:
| > Provides reliable energy 24/7, is safe to use (as in no
| melt-down potential that people would be scared about) and
| does neither produce co2 nor blast coal dust particles all
| over the world.
|
| None of this is really plausible for any fusion plant,
| especially in the early phase. The first plants will likely
| be plagued by expensive time consuming periodic
| maintenance. They will be prone to catastrophic failures if
| plasma containment fails, easily killing everyone in or
| near the plant. They will be constantly spewing radioactive
| tritium. They will require fission plants to produce new
| tritium. They will require rare materials to create the
| superconducting magnets and others.
| luckylion wrote:
| Sure, I'm not claiming that they'll be there next year
| (or possibly ever). _If_ the predictions
| /promises/whatever you might want to call it, hold true,
| they'd be great, and it's not totally crazy like the
| perpetual motion people.
|
| If not, then we've spent a few billions and probably just
| learned a lot of interesting stuff and improved a bunch
| of scientific areas.
| heavenlyblue wrote:
| > They will be prone to catastrophic failures if plasma
| containment fails, easily killing everyone in or near the
| plant.
|
| I think that is impossible because plasma isn't actually
| that dense and if you turn off the magnets it immediately
| stops being plasma.
| sandworm101 wrote:
| >> if plasma containment fails, easily killing everyone
| in or near the plant.
|
| That couldn't be further from the truth. "Magnetic
| containment" doesn't mean the magnets are holding in the
| reaction. The magnets are compressing/heating everything
| to start and _sustain_ the reaction. Any containment
| failure will cause the reaction to stop instantly.
| Letting the plasma touch anything solid, any metal
| /wood/ceramic, would be like throwing a bucket of ice
| water on a burning candle.
|
| The far more dangerous aspects of this project are the
| same any any large industrial process: compressed gasses
| in big tanks. High power electrical lines. Fire. Confined
| spaces. Gas leaks resulting oxygen displacement. Normal
| industrial only dangerous to those persons inside the
| building. But I wouldn't want to have any metal fillings
| too close to those magnets when they power up. At 20
| teslas they might start moving though your head like a
| bullet.
| tekno45 wrote:
| Does anyone know of non energy generation related things we've
| learned doing this?
|
| Seems like space research in the same way that just trying will
| yield dividends.
| redis_mlc wrote:
| sandworm101 wrote:
| >> known as ITER, which the United States and other countries are
| building in southern France to generate 10 times more power than
| it took to generate the fusion reaction.
|
| ITER is a physics experiment, not dissimilar to the LHC. It is
| not going to generate "power" but _energy_. The goal is to
| provide a steady fusion reaction from which to then develop
| potential technologies to turn that energy into usable
| electricity. ITER is not a powerplant. It is a scientific
| reactor.
|
| https://www.iter.org/proj/inafewlines
|
| >> ITER will be the first fusion device to produce net energy.
| ITER will be the first fusion device to maintain fusion for long
| periods of time. And ITER will be the first fusion device to test
| the integrated technologies, materials, and physics regimes
| necessary for the commercial production of fusion-based
| electricity.
| maccam94 wrote:
| This article is not about ITER, it is discussing a new reactor
| being built by an MIT spin-off company called Commonwealth
| Fusion Systems. They plan to build a demo reactor by 2025, and
| a full scale power plant by 2030.
| _robbywashere wrote:
| Is nuclear fusion this centuries perpetual motion machine?
| rfrey wrote:
| No. There is nothing similar to perpetual motion except that
| both use the word "energy" a fair bit.
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