I guess most of us now are familiar with the concept of Peak Oil. At some point (maybe about now) oil production will peak, then it will be in decline as reserves run out. The only way around this issue is to reduce our use of it, which means, for example, reconsider our transport options.
At cafe scientitique last week, Shaun Hendy drew our attention to some other resources that are looking decidedly finite. The specific ones he drew on are platinum and palladium, which are used for high-tech applications. Since demand for high-tech equipment is growing rather faster than our demand for oil, one might speculate we could be hitting peak platinum before peak oil, and perhaps even that peak platinum might hit our civilized western mobile-phone-and-ipod-and-general-gadget-loving cities harder than peak oil. The price of platinum certainly has gone up sharply in the last few years, and nearly all of it comes from a single source in South Africa (imagine the politics if nearly all our oil came from a single source…) We may have to become more clever in recycling high-tech equipment.
Another ‘peak’ example, though of a slightly different form, I read about in this month’s Physics World magazine. The world is running short of Helium 3. (That’s the isotope of helium that has two protons and one neutron in its nucleus.) Helium 3 has previously been in abundant supply as a by-product of nuclear weapons development – tritium (an isotope of hydrogen), which is produced in nuclear-weapons reactors, decays into Helium 3.
Why is this an issue? Well, helium 3 has some seriously odd properties when it gets cold (e.g. see Wikipedia) which means that amongst other things it can be used to cool systems to very low temperatures (much less than 1 Kelvin). And low temperatures are important for investigating basic physics, such as quantum effects – for example there is minimum thermal noise to mask what is going on. Some condensed matter physicists are getting a little worried that not enough is being produced. Recently, supplies have been sidetracked into screening the US borders for smuggling of nuclear material (ironically, the very stuff that produced the helium 3 in the first place; helium 3 captures neutrons very easily so can be used as the basis of a detector).
The most pessimistic condensed matter physicists might even go as far to say that we have reached ‘peak physics’, unless we are able to get a decent supply of Helium 3 back to the physics labs. It’s not an issue I’d thought about until reading the article. I suspect there may be several other materials that also fall into this ‘peak’ category; you might be able to think of a few.