This is in response to the economics teacher who laughs at the concept of investing in gold or silver. You'll note that this sentiment is shared by nearly every teacher, practitioner and proponent of modern Keynesian economics (the real destroyer of Europe and the US).
Your economics teacher laughs at silver because he does not live in reality. He lives in the ivory tower of Keynesian economics, where reality can be whatever a bureaucrat (or a college professor) deems it to be. But reality can only be evaded at the cost of destruction to those who evade it.
In reality, silver and gold are real--and paper is not. In reality, wealth (and all human values) must be produced, the most basic example of which is a mining company digging gold and silver out of the ground. Paper is a child's fantasy based on the idea that you can magically wish a printing press to represent a valid, earned value; reality says you cannot.
It is for this reason that the value of precious metals appreciate every time the printing presses are turned on--there exists a class of investors who prefer to live in reality, which means: they prefer to take the paper money they are issued and use it to buy something real.
Keynesianism is to economics what astrology is to astronomy. Yet these are the economics that have seduced mainstream intellectuals and bureaucrats the world over, for the reason that the political corollary of Keynesianism is statism. Keynesian economics grant to governments unheard, unreal, irrational powers to regulate interest rates and the value of money at a whim. If you look into it, you will discover that Keynesianism is the economics of fascism, in it's specific and literal definition. It was through economics, not politics, that fascism was smuggled into America--and it was the political left, not the right, who was the smuggler.