In Series …
THE APERIODICALS
Local (personal, potentially shallow, and subject to change) outlooks on science, technology, growth, and occasionally culture and history. The goal is to write something every week, but whether it can make its way to FWPhys is random. Hence the series title.
A few months ago, when I was preparing to demonstrate one of our few physics experiments that deal with radioactive sources — Co-60, for our use case, a good source of gamma rays and electron-positron pairs — I remember reading about the concept of low-background steel, the magical metal they required to build the radioactive castle and all our Geiger counters.
The term “Low Background” is one of the more interesting technical terms. It does not generally refer to a particular manufacturing technology, not a certain grade of chemical resilience, nor some special mechanical performance. Rather, it refers to a priceless quality, a timestamp on their manufacturing time: before humanity’s first nuclear tests.
From mid-19th century, humanity has been reliant on atmospheric gases to lower the carbon level in molten iron alloys, a crucial step in steel manufacturing. With the successful nuclear tests starting in the 1940s, especially when the Americans thought detonating nuclear bombs mid-air or next to an island nation were good ideas, a huge amount of radioactive byproducts have remained in atmospheric circulation ever since, some naturally find their way into our metals, and back to ourselves.
“High Background” steel manufactured afterwards of course isn’t worthless. Other than precision scientific and healthcare scenarios, they are around in abundance, supporting every bit of modern life.
What I do wish to remark, with decades of hindsight and speculative wisdom, is that the “background” distinction was an unforeseen consequence. To me, there is a general lack of evidence that Americans in the 1940s, or anybody else, stockpiled steel with foresight of this particular kind of threat, only realizing the lasting impacts of those free nucleotides after our geiger counters malfunctioned or photographic films exposed to random dots.
This one little example actually marks the end of my essay this week.
Whether I am insinuating that I feel concerned about what has transpired recently in the Northern Pacific, is up to your own comprehension. I have zero knowledge about real-world nuclear fallouts or power plant failure management, and understand that my opinion, if any, can effect little change in a world where “being transparent” earns oneself more praise than actually doing anything.
That something is logical but unforeseen usually leads to the painful realization that humanity has little chance to do anything about it when it arrives, even if it is we who set it in motion. What are our generation’s unforeseen consequences? I am actually quite keen to know.
Footnotes
I am not to imply that nature before the nuclear age was particularly bucolic — the radioactive isotopes in all the metal forests humans inhabit come from more places than the steel. Radon, for example, mostly come from the radioactive decays within the earth itself. Potassium has an abundant radioactive cousin, K-40, let alone the lighter ones such as C-14 and H-3 that are replenished by a diverse range of natural processes.
Yourong Frank Wang 