[lukan]

No, closer to alchemy is the actual creation of gold from other elements with nuclear physics.

Was demonstrated quite a long time ago, but is not really practical to get meaningful quantities out of it.

(That is why I always prefered physics over chemistry - my chemistry book in school started with the story of the alchimists and concluded that they were bound to fail as gold cannot be created.

And in my physics book was just the formula to create gold)

[pfdietz]

> No, closer to alchemy is the actual creation of gold from other elements with nuclear physics.

The place where this happens is in the liquid mercury target of the Spallation Neutron Source at Oak Ridge. Here, high energy protons shatter (spall) mercury nuclei, producing fragments that can include gold. An uncommon isotope of mercury can also be converted to gold by neutron capture.

[HappySweeney]

Is it the stable isotope? I understood that the only place to get that was neutron star collision but I would love to know more if wrong.

[pfdietz]

Yes, this can produce the single stable isotope of gold. Not in any practical way, though. It would be cheaper to just mine more of it.

[kragen]

> is not really practical to get meaningful quantities out of it.

you can build the entire neutron spallation reactor out of materials much cheaper than gold, and you can get unlimited quantities; the only impracticality is that the humans are still really bad at building machinery

[CamperBob2]

Well, there's the excuse I need to build a Farnsworth fusor, I guess.

[krisoft]

> not really practical to get meaningful quantities out of it.

It is quite practical. You just pour a big pile of hydrogen out, let gravity compress it until it starts fusing. Initially it will only create helium but near the end of the pile’s life you will get mountains of the other elements too.

Easy breasy. It just takes time and quite a bit of space and hydrogen. Much harder to scale it down of course. But think big and aim for a star as they say.

[mr_toad]

‘Natural’ fusion will only get you as far as iron. Supernovae may produce heavier elements, but the heaviest elements like gold are probably produced in neutron star collisions.

https://en.wikipedia.org/wiki/Nucleosynthesis#History_of_nuc...

[adrian_b]

Supernova explosions are good enough to make gold (and most other heavier elements until plutonium) by neutron capture.

Fusion, as you say, produces quantities that diminish very quickly for the elements beyond iron (iron 56 has the greatest binding energy of any nucleus and the binding energy decreases slowly after it), so that the last element that is produced in non-negligible quantities by fusion is likely to be germanium.