The cold fusion generator is ready, loaded with tons of heavy water. The scientists stand by ready to measure the energy output of the amazing new technology.

They turn it on, and as expected, get streams of helium and oxygen gas emerging from the reaction chamber, as two deuterium atoms fuse into one helium nucleus, leaving the oxygen atoms to sort themselves out.

Unfortunately, the expected power output fails to materialise. In fact, they record exactly zero energy released or emitted from the fusion reaction. Curious.

They also notice a plausible but unexpected contaminant in the gas output: radioactive fluorine-18, formed from the fusion of deuterium and oxygen. As they try to fathom how such a reaction could possibly occur, a precipitate starts to form in the water which turns out to be sulfur, formed from the fusion of two oxygen nuclei. While reaching for a cloth to mop up his spilled coffee, one of the engineers knocks the handwavium dial and the sulfur vanishes instantly along with a significant portion of the oxygen, leaving a cloud of atomised chromium and an overabundance of free hydrogen, which promptly overpressures and bursts the reaction vessel.

Once they put the pieces back together and work out how the plebotium works, the scientists realise they have built the first Elemental Transmuter. It can take in a batch of source elements, and perform any nuclear fusion reaction without consideration of conservation of nuclear binding energy. Charge and lepton number must still be preserved, so the same number of protons, neutrons and electrons must appear on each side.

Inevitably, the machine is then purloined by a Mad Businessman who intends to use it to maximise personal profit.

What are the most profitable reactions you could perform using this machine? By profitable I mean the market value of the end products greatly exceeds the cost of the raw materials.

The machine is capable of producing several kilos of output per hour, from a reaction vessel that is a few litres in volume. The cost of acquiring pure raw materials (or of processing any impurities which would be left in the output, if necessary) would be a factor.

  • 3
    $\begingroup$ No, I'm asking, at best, the most expensive element for which the raw materials are not horrifically expensive. I can make platinum by fusing two yttrium atoms, for instance, but unless I go and steal all fifteen tons of the US strategic reserve, I'll struggle to find enough to turn much of a profit. Is there a better way? $\endgroup$
    – Stephen
    Oct 17, 2019 at 14:39
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    $\begingroup$ As I recall, fusion yields energy up until you're producing iron; after that, it consumes energy; contrariwise, fission yields energy down until you're producing iron, after that, it consumes energy. Is this a consideration, or can I do any sort of fusion to any level? $\endgroup$ Oct 17, 2019 at 14:54
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    $\begingroup$ @Stephen so this is a perpetual motion machine, inasmuch as you can fuse stuff into fissile elements, fission them, and then glue them back together again for free? $\endgroup$ Oct 17, 2019 at 15:06
  • 8
    $\begingroup$ Any element can be made by a chain of fusion reactions starting with hydrogen-1: after all, this is how all the elements were actually made; so the cost of raw materials is completely irrelevant. $\endgroup$
    – AlexP
    Oct 17, 2019 at 15:59
  • 4
    $\begingroup$ What are the limits of what elements can go in and what can go out? Your example of two yttrium atoms to make a platinum atom make it sound like you have an arithmetic problem in mind. Can you use 195 hydrogen atoms to make a platinum atom? What about using two tin atoms to get a platinum atoms and some hydrogen? Are non-elemental inputs allowed? Is a bag of assorted garbage not allowed? $\endgroup$
    – Jetpack
    Oct 17, 2019 at 23:22

15 Answers 15


Maximizing short-term profits will be different than long-term profits. A rare element synthesized will lose value faster as the relative amount put into the market will depress the price faster as opposed so something less valuable but more common. It will probably involve some speculation and calculations of what is in demand and what you can get the best prices for.

The ideas below are likely not the most valuable, but they have low (or no) materials costs.

For reference, first is a list of what the device is observed to be able of, and as such, what the rest of the answers are based on.

What we know about the Device:

  • Any two atoms of a substance can fuse into a single output element comprising the entirety of the matter (22H -> 4He and 216O -> 32S)
  • Two different atoms can be fused into a single atom containing the entirety of the matter present (2H + 16O -> 18F )
  • Only one new product can be made in a reaction -- no side products are created. That or any side products that are created when molecules of the original product are split. Where the hydrogen came from the Oxygen/Sulphur reaction in the story is a bit nebulous.
  • The Transmuter cannot fuse protons and electrons into a neutron, ass evident by the starting product for helium being the rarer deuterium as opposed to the more common protium. It is also indirectly stated in the question itself.
  • We do not know the energy cost of elemental synthesis so ideally what we make should take a single step wherever possible.
  • It is stated that any reaction is possible, which means it could be possible for more than two atoms to be involved in a reaction, though that is not explicitly stated
  • It is unknown whether or not it transmutes an entire element or just a single isotope of an element.

This suggests that the limitation of what we can actually do is the neutron count of the atoms we want to make. While the lighter elements have a lower proton to neutron ratio, the higher up the periodic table we go the more neutrons we need in order to create a stable atom.

So our unwritten cost limitation is how cheap can we get elements with a higher neutron to proton ratio to get the capacity to synthesize the heavier elements.

Since we can't do the reaction 1H2 -> 21n as that violated the rules stated in the question regarding conservation of subatomic particles, it is actually a bit trickier than it looks as we can't just create what we feel like by zapping enough hydrogen into neutrons to solve our problems.

Easy Small Change

The atmosphere we breathe is primarily made up of nitrogen and oxygen, of which the primary isotopes are 14N and 16O. From those two, you can easily make Silicon, Phosphorus, and Sulphur by fusing the main components of air together. Silicon-28, Phosphorus-31 and Sulphur-32 are stable isotopes so you are likely sticking with Silicon or Sulphur for that one.

Your input materials are essentially free (atmosphere) so there is no worry about pesky questions about why one needs a large quantity of element X. Plus, your detritus of this is some noble gasses, carbon dioxide, and methane.

The downside is that this does not necessarily maximize profits by creating the most expensive thing. But this is something you can do in secret with only your energy bills and a large pile of silicon/sulphur to give you away. However, if the energy costs are too much, you won't actually be making a profit.

Nickel and Diming

Iron is cheap, and helium is not terribly expensive either. Nickel-60 is thus not an outrageous thing to create and can sell for a good price compared to the base cost of the materials. The primary reaction is 56Fe + 4He -> 60Ni.

Your primary benefit to this is that the other natural isotopes of iron, Iron-54, Iron-57, and Iron-58 also make stable isotopes of nickel through this process which means you do not care about what isotopes of iron are in your ingot, just that it is pure iron.

Again, you aren't likely making mad money doing this, but it is something you can do with little additional people or resources.

Previous Answer(s)

This previous answer mentioned Rhodium at a rather impressive selling price. I do not know if this is the most cost-efficient way to do it by the rules as I understand them, but you can transmute it using Krypton and Fluorine in the following: 84Kr + 19F -> 103Rh.

While there is only the one stable isotope of fluorine (19F), the krypton is a minor issue as the most common isotope is only a bit over 50% of the naturally occurring krypton.

A brief bit of research shows that the other isotopes of krypton will create rhodium isotopes that decays into either palladium or ruthenium.

Humourous Mad Science/Business

If you can crack molecules of something apart for your reactions, one can take the generally unwanted gas carbon dioxide, and fuse the carbon-12 atoms into magnesium-24 and have oxygen as your byproduct. Well, the magnesium might oxidize first, but you are still basically converting an unwanted greenhouse gas to a sellable metal and oxygen by the following reaction: 212CO2 -> 24Mg + 2O2

Magnesium is also stable at atomic masses 25 and 26, so if you happen to have carbon-13 or carbon-14 in there, you are still good for the most part. There is the option to fuse the newly created magnesium with a third carbon atom to make Argon-36 which is also stable if the noble gas is more your style.

This concept also works for methane, only you release hydrogen gas instead of oxygen. Alternatively, you can react the methane to make anything from nitrogen to neon, using some of that bonded hydrogen.

If you have some control over what form a transmuted element takes, then transmuting lithium into diamonds might be an option steeped in profit and madness. With a roughly 90/10 split of lithium-7 to lithium-6, there is the slight problem of getting almost half of your diamond as carbon-14, but the other two carbon isotopes (12 and 13) are stable. An interesting record for the future archaeologists.

On something that is a bit more Mad Science then Mad Business, with a machine that can fuse anything, you are in a unique position to research transuranium elements. The issue again is likely neutrons, but if you can directly make something in quantity, then it can be easier studied and a potential use for it could be found. Then you can corner the market on its production as only your plebotium-powered device can make it efficiently enough.

Ethics Optional

Depending on the exact interactions with molecules and other more complicated things, your Mad Businessman could have a rather shady business of body disposal. Just ensure that the chunks of body can fit in the machine and transmute its [Elements] into [Another Element]. I suspect it would be hard to find the body if all of its carbon was transmuted into magnesium for example. They pay you for disposal, and you can sell the resultant products.

This does depend on being able to break down molecules with the transmuter device though, which it might not do.

Minor Challenge

A thought is that by direct transmutation, the Mad Businessman will have pure samples of any element they desire without going through a complex manufacturing process. The most profitable thing might not be to sell the pure element directly to a consumer, but to use the created element in a process to synthesize something else. Depending on how the machine is powered and its consumption, you could market your product as "green" or "environmentally friendly", and potentially charge a additional markup for it

Nobody needs to know you make this product with the tears shed by the laws of physics when you run the machine.

  • $\begingroup$ This is absolutely fabulous. :-) $\endgroup$
    – Stephen
    Oct 18, 2019 at 10:41
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    $\begingroup$ A few notes: 1. The neutron limitation is less of a problem if neutron-short elements with less protons have reasonably long half-lives (e.g. more than a second); just shove some deuterium in there and fuse it in. 2. "Helium is not terribly expensive either" - but helium is sold as a gas. If you want to make solid nickel you'd need far more of it. Helium costs \$1200/kg, and you'd need 4kg of it to make 60kg of nickel, meaning you're producing nickel for \$80/kg. Raw nickel sells for half that price. $\endgroup$
    – Skyler
    Oct 18, 2019 at 15:14
  • $\begingroup$ My math or cursory research might have been off on that one. Well, if helium itself is too expensive, then fusing deuterium might be more economical. Also, deuterium does have a proton in it as it is hydrogen. just throwing deuterium at the problem might add more neutrons, but it does add protons, and thus you advance up the periodic table. $\endgroup$
    – Haylen
    Oct 18, 2019 at 17:07
  • $\begingroup$ I think deuterium is more expensive than helium. $\endgroup$ Oct 19, 2019 at 3:51
  • 1
    $\begingroup$ @Skyler Please disregard, my mistake! I inflated my figure by 35%, much different than 135%. So then \$1200/kg is reasonable. Hard to find current figures, seems nobody wants to advertise such prices. :-( $\endgroup$
    – Nolo
    Nov 17, 2019 at 15:09

Shorting gold

You don't actually need to make the gold, you don't strictly even need to have access to the machine. Just short the gold and then let people know the machine exists. The simple fact that someone now has an unlimited supply of gold will cause the market to crash and the profit is already made.

Note that if you do this with company stocks you'd be in big trouble for insider trading.

  • 3
    $\begingroup$ @immibis, stocks and commodities have different regulatory bodies with different approaches, though if you pulled this stunt they'd almost certainly find a way to make it apply. $\endgroup$
    – Separatrix
    Oct 18, 2019 at 9:10
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    $\begingroup$ @Separatrix: Interesting, I assumed that to be guilty of insider trading you had to be inside the company you were trading. Does that mean that if I invented a transporter (Star Trek) then I can't short Ford stock before I inform the world of the transporter's existence? $\endgroup$
    – James
    Oct 18, 2019 at 16:57
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    $\begingroup$ @James, you don't have to be inside you just need inside information. In this case you had hard information that the price of gold was about to tank before the market did and you acted on that. There's an argument that insider trading can't apply to commodities, but given you've just bent one of the favourite commodities over a table and had your wicked way with a broom handle on advance knowledge, they'll try to get you for something. But yes, I believe you could short Ford stock under those circumstances. $\endgroup$
    – Separatrix
    Oct 18, 2019 at 17:37
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    $\begingroup$ @Separatrix: Thanks! That's interesting information. Although I still don't really see the difference in the two examples: ILLEGAL: Shorting gold after inventing transmuter. LEGAL: Shorting conventional travel methods after inventing transporter. $\endgroup$
    – James
    Oct 18, 2019 at 17:58
  • 2
    $\begingroup$ @DanBryant, there's a quirk there that diamonds have effectively no value (try selling one) and the price is propped up by De Beers actions, there's no equivalent controlling cartel for gold. $\endgroup$
    – Separatrix
    Oct 18, 2019 at 18:39

Depending on the power requirement per kilogram,

You may have created an infinite energy generator.

From your question and one of your comments:

It can take in a batch of source elements, and perform any nuclear fusion reaction without consideration of conservation of nuclear binding energy.

The energy required to power the conversion of 1kg of source to 1kg of product is constant regardless of the reactions involved

If you can use the product of your transmuter (say, a very heavy radioactive element) as fuel in a reaction that (1) leaves as waste the same elements you transmuted your product from, and (2) yields more energy than it took to convert your source to your product, then you can perform this cycle over and over again, generating unbounded amounts of energy (and ultimately, matter).

If this is the case, then the most profitable thing you can do with it--at first, anyway--is to make more elemental transmuters. :)

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    $\begingroup$ This answer is just the logical conclusion of the hand-waved requirement. If energy is not a factor then that resource is automatically made infinite by this magical machine. $\endgroup$
    – Nelson
    Oct 18, 2019 at 3:30
  • 5
    $\begingroup$ The cost of fuel in real nuclear power reactors is small compared to the cost of the rest of the plant, so a source of (nearly) free fuel isn't especially exciting. $\endgroup$
    – Phil Frost
    Oct 18, 2019 at 6:41
  • 2
    $\begingroup$ No, it's more the workaround for dealing with the problem of entropy that would be important. (An answer to Asimov's "Last Question"!) $\endgroup$
    – Qami
    Oct 18, 2019 at 11:46

Do you have any ethical constraints? If not, consider building nuclear weapons (ideally immediately after secretly moving to, say, a nuclear bunker somewhere in Iceland). Uranium-235 is probably the best way to do this. While Plutonium bombs give you a bigger bang per kg of fuel, they also require complex arrangements of conventional explosives and extremely precise engineering. All you need for your Uranium-235 weapon is a way to smack two chunks of it together really hard.

It's not entirely clear to me precisely how your magic fusion device works, but in a comment, you mention combining two atoms of Yttrium to get Platinum. This seems to imply that your device simply corrects to a stable number of neutrons somehow. That means all you need to make your U235 is Lead and Neon. Or any other pair of elements that give you 92 protons. Heck, you could just use 92 Hydrogen atoms and build it up from single protons. Pb208 is a stable isotope of lead, and if you add 7 atoms of Deuterium and 3 of normal Hydrogen, you'll end up with some wonderful nuclear goodness without having to correct neutron number. Essentially, the stuff isn't hard to make if you have this device.

Since you're selling 100% pure U235, it's pretty difficult to get a market value for this stuff. Instead, we can look at the total wealth of ISIS and the net worth of Kim Jong-un, for a total of 7 billion US dollars for two weapons. Alternatively, you may be able to set up an exclusive contract with the US military. I feel they would probably be willing to pay you a few hundred billion $US per year for you to give them all of your weapons, as opposed to ISIS and North Korea. Essentially, at this point you are capable of blackmailing the entire world by just planting a nuke under every city over the course of a few months, so I don't think wealth is really a concept that applies to you anymore (as a side note, you now have the ability to provide extremely cheap power on a massive scale, as all your nuclear fuel is now free, and you can simply feed all that nasty, radioactive nuclear waste into your machine to turn it back into fuel).

You have an infinite source of nuclear weapons, so... do whatever you want with them. It's not like anyone is going to be able to stop you.

What happens when someone tries to stop you.  Source: https://www.ready.gov/nuclear-explosion

  • 5
    $\begingroup$ While that is an interesting twist, unfortunately (or, well, fortunately for us) nuclear weapons don't do much without advanced deliverance systems. Which is probably not much of a problem if that billionaire happens to have a space company already, of course. $\endgroup$
    – Alice
    Oct 17, 2019 at 14:50
  • 2
    $\begingroup$ @Alice if you can make a bomb, you can deliver it in a van. It'll be just as dangerous. $\endgroup$ Oct 17, 2019 at 14:56
  • 2
    $\begingroup$ @Alice Then do Moscow last, or keep them all in the country near their target city and move them in simultaneously. You now have an additional level of proof you can do what you say, and I doubt the authorities are going to attack someone they know has a nuclear weapon. And if they're idiots and do decide to attack, Moscow suddenly no longer exists. $\endgroup$
    – Gryphon
    Oct 17, 2019 at 15:01
  • 2
    $\begingroup$ @Alice the bomb doesn't have to be radioactive when it enters the city. It just needs to be ready to assemble. You can then fuse appropriate stable feedstocks together to make your fission fuel, slap it in the weapon assembly (you may as well just use something cheap and cheerful like a gun-type bomb) set the timer and leave. $\endgroup$ Oct 17, 2019 at 15:43
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    $\begingroup$ If you can produce arbitrary isotopes, there's no reason not to go with plutonium: isotopically pure Pu-239 works just fine in a gun-type weapon. The Manhattan Project dropped the gun-type Thin Man design in favor of the implosion Fat Man design when it was discovered that reactor-produced plutonium is contaminated with far more Pu-240 than cyclotron-produced plutonium is. $\endgroup$
    – Mark
    Oct 17, 2019 at 22:34


Synthesis will be a little tricky - Californium (Element 98) can be synthesized cheaply from two Indium atoms (Element 49), except we run into trouble. You see, Indium is stable as Indium-115, except Californium, an artificial element, starts being stable at Californium-248, meaning we need an additional 18 neutrons. Fortunately, I happen to know a remarkably good source for neutrons: deuterium, aka heavy hydrogen. A ration of 2 parts indium to 18 parts deuterium or just 1:9 will supply the proper amount of neutrons and leave over some Californium-248 and some normal hydrogen.

It's now that I note that you can make a more stable variant by adding more hydrogen (and thus more neutrons), just be forewarned to never produce Cf-251 in bulk, despite it being the most stable of the stable isotopes (half life of 898 years) - it has an estimated critical mass of 5kg. Honestly, from a business perspective Cf-254 would be best - a half-life of two months means a lot of repeat customers, and Cf-253's half-life of under three weeks will get people annoyed. But I'm sure a Mad Businessman would know more about exploiting scientists than I do.

Indium is rather cheap, only a few US dollars per gram. How much is Californium? 25,000,000 US dollars per gram. And Cf-248 is has a half-life of 333 days, making it stable enough to transport and sell in quantity. Unlike the actual most expensive element, Francium. Francium is theoretically 1 billion US dollars per gram - except since the stuff has a half-life of 22 minutes, good luck getting a gram of that stuff. And, unlike Californium which is a great portable neutron generator, it has no practical application, which means its price is really only a function of it's rarity and mass producing it will sink the price.

  • 8
    $\begingroup$ Cost to produce isn't quite the same as value. Californium is neat and all, but there's not much of a market for it yet. $\endgroup$ Oct 17, 2019 at 15:18
  • 2
    $\begingroup$ I wouldn't expect you to be able to sell it for that much, but there's enough of market for Californium. Like I said, it's a portable neutron generator, which makes it great for analysis in labs, and it works in a small enough quantity (literally micro-fractions of grams) which makes in affordable to labs. $\endgroup$
    – Halfthawed
    Oct 17, 2019 at 15:23
  • $\begingroup$ Are you sure that you need additional 18 protons to make Cf stable? $\endgroup$
    – L.Dutch
    Oct 17, 2019 at 15:59
  • 1
    $\begingroup$ This is the sort of answer I was hoping for :-) $\endgroup$
    – Stephen
    Oct 17, 2019 at 17:34
  • $\begingroup$ @L.Dutch According to Wikipedia, Cf-248 is the lowest stable number, and 115 is a high as Indium goes. I couldn't find any mention of Cf-230, but even if you made it, it'd probably have a half-life of minutes. $\endgroup$
    – Halfthawed
    Oct 17, 2019 at 23:21

Disaster Relief

I'm sure cleaning up someone else's mess can be profitable.

Until Next Disaster ...

Renew everyone's old fuel rods into new ones.

Now, will the (purposeful) impurities of your refurbished fuel rods cause the disaster?

  • $\begingroup$ How do you use this for disaster cleanup?? $\endgroup$ Oct 19, 2019 at 3:30

One of the biggest problems would be controlling the reactions with multiple isotopes present and with potential side reactions it would be easy to end up with a precious metal that was also contaminated by radioactive isotopes of the same element or of other similar elements as can be seen here:

Assuming that this is not an issue with your new process the First thing you must do is keep the discovery a secret! Then make sure you have good contacts amongst the dealers in precious elements so that you can dump an appropriate amount into the market from time to time.

You would also need a way to “fence” the materials so that they could be sold without attracting too much attention. It would probably be a good idea to involve the government to ensure that everything is as water tight as possible and prevent unwanted interest from the powers that be.

Then start production. Why not start with rhodium? At £40,000/kg and a world-wide annual production of 35,000oz it should be possible to dump a few hundred kilos into the market over a few years. But the secret would be not to concentrate on one element but to target a wide range of elements to prevent price supression. Nuclear reactions for forming some platinum group metals can be seen here:

Whilst the rhodium sales are under way you could use the proceeds to target the other platinum group metals and then branch out into a range of other expensive elements. Very large sums could be made if gold could be synthesized. The reason being the market for gold is huge as it played such an important part in world finance until as late as the 1970’s. Many thousands of tons are produced every year and hundreds of tons could probably be absorbed by the market over a few years without too much price impact. 100 tons of gold is worth around $4.8 billion.



I refer you to Watchmen, Iron Man, and Captain Marvel. All of them had energy and power sources at the heart of their plots. It was not dominant, but it was central.

One of the big causes of war today is argued to be oil, which cones back to energy.

ENRON was caught in a scandal of accounting, but it was all built on the idea that energy was imoortant enough to be able to barter. As the story notes, Tom White had interesting connections with ENRO 's manipulation of energy prices in California.

Today, we are in an energy race.

What energy?

If choosing a particular element is a problem, you could just use raw energy by disrupting the process. Just stop the process part way through, containing the raw energy output with a stabilizer based on quantum quark vibration theory. (This might require more research, but could be simple and could give your Mad Businessman an edge over the original researchers because they wouldn't have the full technology.)

  • $\begingroup$ How would one create energy with a transmutation device? $\endgroup$
    – zovits
    Oct 18, 2019 at 10:17
  • $\begingroup$ @zovits Just transmute into whatever energy supply would be most efficient, perhaps even photons... Or nothing at all! By not stopoung the transmutation process part way, one might have released atomic energy in the most efficient way. $\endgroup$ Oct 18, 2019 at 10:45
  • $\begingroup$ The only pure elements that are commonly used as energy supplies are hydrogen, carbon and fissile materials. Hydrogen can't be created as a result of fusion (see the question), carbon is not nearly valuable enough for this kind of mass production (several kilos an hour) and fissiles are covered in other answers (while still comprising only a tiny fraction of the price of nuclear power). Creating more complex molecules is out of the question, so no methane or gasoline (which are still not valuable enough at a few kgs / h). Photons are not even elements... $\endgroup$
    – zovits
    Oct 18, 2019 at 10:53
  • $\begingroup$ @zovits As I said, or none at all. Just stop the process part way through, containing the raw energy output with a stabilizer based on quantum quark vibration theory. $\endgroup$ Oct 18, 2019 at 11:19
  • $\begingroup$ While the question had handwavium in it, it explicitly asked to not add more handwavium, so you are answering a different answer than the one that was posted. $\endgroup$
    – toolforger
    Oct 20, 2019 at 7:02

Another angle that I don't see considered here (unless it's in the depths of TLDR Land) is that you have freed our mineral supply chain from the happenstance of where the various minerals are located, and for some minerals you have eliminated the hazards involved in mining.

The list of minerals on which any particular nation has a monopoly has greatly shortened.

Everything depending on these minerals is now cheaper, which means that everyone's money has more buying power.

Except for the people who were profiting from the scarcity of these elements, everyone is now richer.

An additional benefit is because certain elements are no longer scarce, the freer nations no longer have to play footsie with corrupt and/or oppressive governments of the nations where these formerly-scarce minerals were located.


For the people suggesting nuclear weapons--I think there's a different route here. This appears to be a fairly simple desktop machine. Thus, if I want to kill a city I don't build a nuke, I ship a transmuter to the city loaded with ordinary lead. When triggered the reaction is Pb + Pb, yielding a supply of element 164. This is going to be way past the proton drip line as well as way past anything that can hold together long enough to be seen outside an atom smasher. It will undergo a huge amount of radioactive decay in zero time on a human scale. The "end" product will probably be somewhere in the transuranics, but there will be no induced radioactivity. Note that a Geiger counter can't see this bomb as it's not radioactive until it's turned on.

There's also the issue that I can't figure out how to make fissionables with this device. You need the right number of neutrons and I see no way of supplying them. Just about everything in the lower part of the table is off limits unless you can get there from somewhere close nearby.

For a reaction that can be profitable for a sustained period, assuming the machine can crack elements:

1) O16 -> C12 + He4. C12 + C12 -> Mg24. Mg24 -> Ne20 + He4. Ne20 -> O16 + He4. (Note that you can't use C12 -> Be8 + He4 due to the exceedingly short half life, same as stars can't use He4 + He4 -> Be8.)

2) N14 -> C12 + H2, then as per #1.

Helium is expensive and has substantial ongoing demand, you can sell quite a bit of it without crashing the price.


Your device simply violates the first law of thermodynamics. It's a slightly less obvious variant of the perpetual motion device.

Actual fusion reactions have diminishing returns and stop releasing energy when they reach iron synthesis. Each heavier element requires heavier temperatures. Even before reaching iron synthesis, the device would hit some hard physical limit like power requirement or heat resistance.

As for creating gold or such precious elements, the kind of power delivery needed to synthesize nuclei heavier than iron only occurs during the few initial milliseconds of a supernova explosion.

A world where people would command such kind of power would simply have no need for money. They wouldn't even need nuclear fusion at all. They could use mechanical work and plain chemistry to procure and recombine any kind of existing atoms to their heart's content, for a tiny fraction of the energy cost of nuclear fusion.

Anyway, this magic world would very soon be blown to bits, either by absent-minded scientists botching an experiment or the military putting that energy to good use.



You have said Elemental Transmutter. Down there somewhere you can find how to make positrons and related stuff to produce antimatter OR you can keep it vague so that your audience can focus on story and not get too much into "technical" stuff which is handwavium anyway.

Coming back to the meat of your question, antimatter is the most expensive material, gram for gram, both economically and energytically speaking. Here is why:

1) When combined with ordinary matter it produce 100% mass to energy conversion. Antimatter is charged and so "want" to combine with ordinary matter (which almost always have some residual charge left in it, because molecules rarely fully "satisfy" each other electromagnetically) so no effort at all is needed for combining the two; just shut down the electromagnetic field in which you are containing your antimatter and it go and interact with walls of its container.

2) Antimatter is one of the perfect weapons, in line with micro blackholes. As stated above, antimatter can be used for total annhiliation. Ofcourse you have to deal with enormous amount of energy thats released, but if you are attacking enemy planet or want to destroy a pesky asteroid on course to hit your planet in 5 years (that is, if the planet and the asteroid are far enough) you dont have to deal with that massive release of energy.

We never produced antimatter in sufficient quantity to test whether it interacts with gravity same way as ordinary matter do, or oppositely. May be we discover antigravity once we have grams of antimatter.

Once we have antigravity sky is the limit, literally.


The real benefit for this sort of thing will be doing stuff on demand.

Consider a several stage machine set up to reduce Nitrogen to helium. A second machine to do the reverse. Now the operating costs of zeppelins is removed. You make helium on demand.

Look at space craft. Hydrogen has the best specific impulse. Take hydrogen accelerate it with a linear accelerator and spit it out at fractional light speed. Storing enough H2 for a long voyage is more difficult. So store the matter as sand. You have a several stage machine that processes sand into hydrogen.

Look at lunar colonies. The big problem is life support. Make enough H2 and O2 from dirt. Make water by reacting those two. Make carbon. React carbon and hydrogen to make methane, combine two methane to make ethylene. Now you have the starting material for a raft plastics.


It probably depends on how much money the people of the world are willing to pay to avert global warming. (You might want to wait until they get more desperate first).

Because you have the world’s best CO2 scrubber. Even if the device doesn’t let you go straight from gaseous carbon to solid carbon, it should let you go to something that is solid at room temperature like titanium (though you’d need to pick up some neutrons) or calcium (and some low weight gas).

  • $\begingroup$ Not really. It doesn't help you scrub carbon dioxide in the least. Heck, the problem with scrubbing CO2 from the atmosphere is just how incredibly tiny amounts of CO2 are in the atmosphere in the first place. You need to process huge amounts of air to get any meaningful amount of carbon dioxide out. And that's before you account for how tiny amounts of stuff the (presumably) expensive machine can process. $\endgroup$
    – Luaan
    Oct 18, 2019 at 7:49

money is a tool for controlling access to scarce resources through a social contract

this invention makes money obsolete as it solves the same problem better

actually, this invention breaks money because it breaks the supply side of most commodity markets, making price discovery meaningless

i suppose money could have a niche role in organising labour but this would get weird and the economy would quickly be unrecognisable relative to what we are used to now

  • 2
    $\begingroup$ The machine can only make raw materials, it's not a replicator. It cannot make itself, it cannot make any end products etc. Heck, it can't even make molecules, just atoms. So great for allowing us to use the best raw materials possible (rather than merely available), great for allowing us to only exploit the best mining sites possible, very disruptive to all those mining and manufacturing industries... but it cannot replace them. Stuff is still scarce, as is the machine itself. The only thing that drops in value, really, is the mining land and raw resources like gold. $\endgroup$
    – Luaan
    Oct 18, 2019 at 7:46

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