Stan Marsh said:
If you check the information of the physics faculty of top 10 college in the US, you will find that most of them are top 10 phds, with only few exceptions. Universities with lower ranking 11-30 are also filled up with top 10 phds.
Some observations:
1) the higher ranked universities also happen have the larger programs.
2) there's also the timing element. For example, there is an entire generation of mid-western astrophysics departments that were started by Harvard grads in the 1970's, which means that if you look at those schools, they are staffed by Harvard people
3) there is something of an "hiring network." We once had the President of our university give a talk in which he talked about how his Harvard connections helped his career, and the point of the talk was to get us to set up a network from our school so that we could help each other with our careers. Hiring at post-doc and faculty levels tends to be highly personal.
This phenomenon is quite alerting: if you are not a graduate from a top notch college, the career path may be very difficult for you. Possibly you will end up in some 50+ college, with enough luck and hard work.
Actually the odds are that you won't. Even with the Ph.D.'s from big name school, the odds are that you will not be a professor at any school. The other thing is that if you do end up as faculty in a no-name school, it's not that hard to make that school a big name in some small part of physics. All you need to put together a top-notch department in money and a small number of people.
One piece of advice that I give people that are considering doing a Ph.D. is that you *should* *NEVER* think of physics as a career. It will only end up in disaster if you do.
If this is the general fact, entering a lower rank school may be quite frustrating. (though not a total disaster, if you work hard)
If any of this matters you really shouldn't be getting a Ph.D. at all. You should go into a Ph.D. program with the assumption that you aren't going to be able to make a career out of it, and if that turns out off, you really should be doing something else. Don't assume that hard work is going to save you. Everyone works hard.
I first got interested in astrophysics when I was eight years old, and one thing that keeps me going is that there is still that eight year old inside of me that is fascinated about how the universe works. That eight year old isn't particularly interested in glory or career, and he is still giddy about learning something new about the universe. What I've found is that I seem to be rather unique. Yes, I'm a little cynical, a little bitter, and a little angry, but in the end it really doesn't matter.
At some point, I just had to accept the fact that I'm not going to be able to make a career out of astrophysics, and I'm just not going to get any glory out of it, and that's a realization that most people that go into physics have to make. For a lot of people, once they make that realization then there is nothing left, but for me you still have that little boy that is curious about how things work, and that's enough.