Originally Posted by

**brewbuck** When you cover one slit the interference disappears because the wave function isn't interfering anymore, it still doesn't mean the electron is a wave. This is in contradiction to what you read in introductory quantum texts, but not contradictory with what you read in the more advanced texts. It becomes clearer when you start considering systems of more than one particle.

There is a great lecture by Feynman which was videotaped, and it's on Youtube. He addresses this exact question at the end of the lecture. When I get home I can post a link. For now, it basically goes like this (paraphrased):

Student: "You just spent all this time telling me that things are particle, but then you show me all these equations that look like the equations of waves. So, aren't you just being sneaky and trying to hide the fact that your theory of matter is really just a wave theory?"

Feynman: "It's true that *for a single particle* the equations are wave equations. A wave is a function of position and time. But things change when you consider systems of more than one particle. There is a wavefunction for the system, and it is a function of *multiple* positions and time. That is *not* a wave. Further, if a single wavefunction describes more than one particle, how can it be said that this wavefunction represents *this* particle or *that* particle? You can't."