Thus we can get the correct answer for the probability of partial reflection by imagining (falsely) that all reflection comes from only the front and back surfaces. In this intuitively easy analysis, the 'front surface' and 'back surface' arrows are mathematical constructions that give us the right answer, whereas .... a more accurate representation of what is really going on: partial reflection is the scattering of light by electrons inside the glass.

The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

Nature does not care what we call it, she just keeps on doing it.

I love to think. I once considered taking drugs as an attempt to better understand an altered state of mind; however, I decided not to. I didn't want to chance ruining the machine.

We cannot define anything precisely. If we attempt to, we get into the paralysis of thought that comes to philosophers, who sit opposite each other, one saying to the other, "You don't know what you are talking about!" The second one says, "What do you mean by know? What do you mean by talking? What do you mean by you?"

You can’t say A is made of B or vice versa. All mass is interaction.

The other thing that gives a scientific man the creeps in the world today are the methods of choosing leaders - in every nation. Today, for example, in the United States, the two political parties have decided to employ public relations men, that is, advertising men, who are trained in the necessary methods of telling the truth or lying in order to develop a product.