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.
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?