Last week, Marathon Fusion, a San Francisco-based energy startup, submitted a preprint detailing an action plan for synthesizing gold particles via nuclear transmutation—essentially the process of turning one element into another by tweaking its nucleus. The paper, which has yet to undergo peer review, argues that the proposed system would offer a new revenue stream from all the new gold being produced, in addition to other economic and technological benefits.
If it is possible to make small amounts of those elements on purpose as a byproduct, it can help to offset the costs of the reactor in some small way and help with isotopic/nuclear research in general. But that can be done in pretty much any fusion reactor design to some degree.
As for Alchemy of the future, If in a thousand years we can just built whatever materials we need (including potential ultra heavy stable elements) from raw subatomic particles we don’t even need mining, just gather up some hydrogen/helium from space and transmute it into whatever you need. food, fuel, structures, etc.
Believe it or not, this can actually be done without fusion alchemy.
It’s been explored in science fiction and I believe there are some actual theories and papers on the subject, but here’s the quick version:
The sun contains all the same elements found on earth in remarkably similar proportions (The exception being that all of earth’s hydrogen and helium were blown away long ago). But unlike earth, in the sun the heavy elements don’t separate and sink down to the core, everything just mixes together in one big suspension. Magnetic fields in the sun constantly eject charged particles out as solar wind and while these particles are mostly hydrogen, they actually contain every element found in the solar system. And because the particles are charged, this wind could be harvested using magnetic fields, it could be redirected and focused into a stream of matter for collection.
And it’s a lot of matter that could be collected this way… The sun loses 130 billion tons of matter in solar wind every day. For comparison, Mars’s moon Deimos masses about 1.5 trillion tons, so the sun loses a full Deimos worth of matter every 12 days. There would be more than enough of every element in that stream to satisfy humanity for the foreseeable future.
And my apologies for the long reply, someone mentioned space and I couldn’t help myself. 🤓
But how much can be caught?
From the sun, the angular diameter of the earth (12,756 km wide, 149,000,000 km away) is something like 0.004905 degrees (or 0.294 arc minutes or 17.66 arc seconds).
Imagining a circle the size of earth, at the distance of the earth, catching all of the solar wind, we’re still looking at something that is about 127.8 x 10^6 square kilometers. A sphere the size of the Earth’s average distance to the sun would be about 279.0 x 10^15 square km in total surface area. So oversimplifying with an assumption that the solar wind is uniformly distributed, an earth-sized solar wind catcher would only get about 4.58 x 10^−10 of the solar wind.
Taking your 130 billion tons number, that means this earth-sized solar wind catcher could catch about 59.5 tons per day of matter, almost all of which is hydrogen and helium, and where the heavier elements still tend to be lower on the periodic table. Even if we could theoretically use all of it, would that truly be enough to meet humanity’s mining needs?
Well there are a lot of factors defining how much usable material we could get, and how hard it would be to do it.
Yeah, about 98% of the sun is hydrogen and helium, with other elements making up the remaining 2%.
The machine used to generate the magnetic field would likely be a ring rather than plate, with the goal being to bend the trajectory of any matter that passes through the ring just a little. In effect it would work a lot like a lens, that could focus matter passing through it into a cone of trajectories, with collection happening at the point of the cone, possibly a point at a much higher in orbit. (This does introduce some complications in the different orbital speeds for the ring and collector, but without getting into it, there is a solution for that, it’s not the hardest part of this idea)
And how much you can capture depends a lot on how close to the sun you can put your magnet field ring. If it’s stationed closer to the sun it shrinks the size of the sphere you’re trying to cover. So if your ring could survive at 0.2 AU from the sun (about half the distance of mercury’s orbit), a ring of the same diameter would cover 25 times more area of the sphere than if it was stationed at 1 AU.
So your 59.5 tons collected turns into 1487.5 tons, 2% of which is 29.75 tons of usable material (which I’ll be honest, is not great considering the magnitude of the construction project). It’s probably a better deal if you’re using the hydrogen towards fusion power, but it’s still not great.
The good news is that it scales well, the larger you make the ring, the better your ratio of materials gathered vs materials needed to build the ring, which makes the optimal diameter of the ring about the same as the diameter of the sun. So… yeah, this is not a project in our immediate future.
Tea, earl gray, hot.
And a gross of self-sealing stem bolts.