But once again, if we have many of these molecules in close proximity, Vanderwald forces, lunaspersion forces begin to play a very substantial role in holding the molecule together, as we'll see in the structure of DNA. So London dispersion forces are forces that exist because these electrons fluctuate over time. So the electron density around atoms is not static, but rather fluctuates with time. The asymmetric distribution of one molecule, as shown here, can cause the electron density of a nearby molecule here to basically change in accordance with the law of repulsion. So we have these electrons repelling these electrons, creating a partial positive charge here, and these can interact a moment in time. And this is what we mean by an instantaneous interaction, which is another way of saying London dispersion forces.