It's good! I would watch your use of the passive voice, e.g. "being the recipient of" = receiving, "resulting in a physics paper of mine being published" = resulting in the publication of my physics paper. Look for more places where you used "being" and try to replace it with an action verb instead.Although it's very relevant to your PS, a lot of ad comms have expressed disdain for the slew of statements they have received that mention September 11th.
I think that if you feel like you can effectively make your point without it, go ahead and take it out. Perhaps reference the recent activation of the military without saying September 11th -- everybody knows it happened, and by now the mere words are politically charged.
I would also say to watch out for run on sentences- I noticed a few. Some sentences were a little convoluted, and could be said more clearly in fewer words.Also, I might make some changes in regard to the amount of emphasis you place on the importance of your family's approval when making major decisions in your life. I think it fit well at the beginning, when you discussed how you felt like you were betraying your family by doing something outside of the norm for what they typically would do... but at the end when you write "the familiar sense of guilt and avoidance of duty began to creep back into my conscience. Once again, my fears and uncertainties were assuaged by my family voicing their support in me..." it doesn't convey a strong sense of how much you grew and developed a sense of purpose/mind of your own throughout college. It seems like you started out w/those feelings, and overcame them once you realized your family was proud of you, but then you went right back to where you were 4 yrs prior as you neared graduation...Overall, I think it's very good, just some minor changes here and there.