Skip to main content

The Kamioka mines: from silver to supernovas

Part of the Kamioka zinc mining and smelter complex
Just after posting about the Kamioka Railway another photo from that 2006 set piqued my interest. Up there in the mountains the landscape looked blasted not just by winter but by something more. It was the kind of lonely place where you would not expect to find major industry, so this sight was quite surprising. Even more surprising is the history associated with this photo.

According to some sources mining and refining of ores in Kamioka dates back to 710 AD and only closed in 2001. Undoubtedly the mine was a major reason for the existence of the Kamioka Railway. Refining of zinc still continues to this day under the parent Mitsui Kenzoku zaibatsu.

Gold, silver, copper, zinc and lead were all dug out of the rock here. Unfortunately, the process released cadmium into the river, which, when taken up by the rice that was grown in the river, caused the terrible itai-itai disease - meaning "It hurts! It hurts". Cadmium poisoning has a number of terrible effects on the body, including the softening of bones and kidney damage. The corporation and government were forced to engage in a large clean up operation which primarily involved preventing the escape of further cadmium contamination at the source.

But the history of the mine doesn't end there. Hidden away a kilometre underground in the mine is a huge tank of ultra-pure water and extremely sensitive photodetectors. Called the Super Kamionkande Experiment, its purpose is to detect subatomic particles called neutrinos. These particles only interact very weakly with matter, but when one does collide at very high speed with an atomic nucleus or electron in the water it can accelerate it to beyond the speed of light in water and produce a detectable flash of Cerenkov radiation.

Super Kamionkande has detected neutrinos generated by fusion within the Sun and by the supernova 1987a.

So this is a story of curiosity, discovery, wealth, suffering and enlightenment.

Comments

Popular posts from this blog

My first overseas trip: Singapore and Malaysia

I've always loved to travel. My first memory is of sitting in a an aircraft, aged 18 months or so. Yet I never believed that I could travel overseas. To me, it seemed like something you did when you retired, or if you were rich. That all changed when I met B. She had not only travelled overseas, she was from overseas . B was born in Malaysia and arrived in Australia, with her family, in 1988. She still had relatives and friends in Malaysia and Singapore and she, along with the remainder of her family, planned to return for a visit during the Australian summer of 1995. At the time I was staying in B's mother's house while we were studying at university. After B's father passed away the year before I was the nominal "man" of the house and its high maintenance garden; her brother Michael was studying up in Queensland. B and I were quite inseparable and her mother kindly offered to pay for me to join them on their vacation. So it was that I obtained my very firs...

One night in Canberra

It's the April school holidays and we are too busy to have a break but need one because of that. And because it's the Easter weekend the options are limited, so we just drive down to Canberra for the night. No, this isn't our first trip for 2023. I wrote about Japan on another site .  I refuse to wake up early so we depart after 8.30 AM. There is not much to say about the drive except that the clouds seem so low and Lake George is very full. We stop at a rest area and at the lookout up the hill to take it all in. Everyone is hungry so we first stop in Dickson and then can't think of anything to eat, so I drive us to Civic, where we can't decide and end up eating at the Singaporean Killiney Kopitiam branch.  The Canberra Centre has nice shops. I dream of getting an iPad from the Apple Store, we buy a blanket and toothbrushes from Muji and wish that Lego wasn't so expensive. Nothing we can't get in Sydney, but then we rarely go out shopping in the city. It...