State-money box

It seems to be a regular money box with a transparent wall. However, when we throw a coin inside, the money somehow disappears.

Thanks to a mirror reflection we get an illusion that we see the whole box inside. But in the middle, a mirror is placed on a diagonal. Such a construction makes the other half of the box invisible and there is where the coin goes.

This magic money box can be used not only to explain the laws of physics but also those of economy. It is a very good model of budgets of many countries.