A little bit closer

http://www.thebigview.com/buddhism/emptiness.html

What is emptiness then? To understand the philosophical meaning of this term, let's look at a simple solid object, such as a cup. How is a cup empty? We usually say that a cup is empty if it does not contain any liquid or solid. This is the ordinary meaning of emptiness. But, is the cup really empty? A cup empty of liquids or solids is still full of air. To be precise, we must therefore state what the cup is empty of. Can a cup be empty of all substance? A cup in a vacuum does not contain any air, but it still contains space, light, radiation, as well as its own substance. Hence, from a physical point of view, the cup is always full of something. Yet, from the Buddhist point of view, the cup is always empty. The Buddhist understanding of emptiness is different from the physical meaning. The cup being empty means that it is devoid of inherent existence.

What is meant with non-inherent existence? Is this to say that the cup does not ultimately exist? - Not quite. - The cup exists, but like everything in this world, its existence depends on other phenomena. There is nothing in a cup that is inherent to that specific cup or to cups in general. Properties such as being hollow, spherical, cylindrical, or leak-proof are not intrinsic to cups. Other objects which are not cups have similar properties, as for example vases and glasses. The cup's properties and components are neither cups themselves nor do they imply cupness on their own. The material is not the cup. The shape is not the cup. The function is not the cup. Only all these aspects together make up the cup. Hence, we can say that for an object to be a cup we require a collection of specific conditions to exist. It depends on the combination of function, use, shape, base material, and the cup's other aspects. Only if all these conditions exist simultaneously does the mind impute cupness to the object. If one condition ceases to exist, for instance, if the cup's shape is altered by breaking it, the cup forfeits some or all of its cupness, because the object's function, its shape, as well as the imputation of cupness through perception is disrupted. The cup's existence thus depends on external circumstances. Its physical essence remains elusive.