Probability (1963)
Sorry, Feynman, whatever else he did, on probability he gets a grade of flat F.  Here is why:  In his book <i>Lectures on Physics</i> he states that a particle of unknown location has a probability density uniform over all of space.  No it doesn&#x27;t.  No such density can exist.  Done.  Grade flat F.<p>I tried to be a physics major but could not swallow all the daily really stupid mistakes such as this one by Feynman I got each physics lecture and I didn&#x27;t have time both to learn the physics AND to clean up the sloppy math.  So, I majored in math.<p>As I learned the math, from some of the best sources, I came to understand just how just plain awful the math of the physics community is.<p>Then in one of the Adams lectures on quantum mechanics at MIT I saw some of the reason:  The physics community takes pride in doing junk math.  They get by with it because they won&#x27;t take the math seriously anyway, that is, they insist on experimental evidence.  So, to them, the math can be just a heuristic, a hint for some guessing.<p>Students need to be told this, in clear terms, early on.<p>It went on this way:  In one of the lectures from MIT a statement was that the wave functions were differentiable and also continuous.  Of COURSE they are continuous -- every differentiable function is continuous.<p>The lectures made a total mess out of correlation and independence.  It looks like Adams does not understand the two or their difference clearly.<p>There was more really sloppy stuff around Fourier theory.  I got my Fourier theory from three of W. Rudin&#x27;s books.  It looks like at MIT they get Fourier theory from a comic book.<p>I got sick, really sick, of the math in physics.  Feynman on probability is just one example.