Technical phd after 33 Is it a good idea to get a math/stats/theoretical cs phd after 33 in the hope of becoming a professor? I am an electrical engineer who did his phd in EE at a low ranked school. I have been working in industry with a lost soul. I did enjoy my research and published quite a few papers. I have taken courses till Algebraic number theory and audited lectures on etale cohomology. I am thinking of a decent school like UCLA or UC Berkeley to pursue a second doctorate.
 A: My impression is that the main challenge for a Ph.D. student in mathematics, whether older or younger, is being able to focus enough of one's time and energy towards learning and doing mathematics. If an older student tends to have more difficulty, it is often because an older person has too many other responsibilities and/or interests.
So if you have the financial resources and the flexibility in your life to shove everything else aside and really focus for, say, five years on learning and doing mathematics, then I think you stand a chance. In particular, you should not be holding any job beyond the usual teaching assistantship that most graduate students get.
Beyond that, it is rather important to get into a strong graduate program or, if you attend a lower ranked school, get guidance from one or more professors who are active participants in the research community.
A: I know quite a few people who received their first Ph.D. after the age of 30, and some who received their M.D. after the age of 40.  Their success hinged on their desire to do the work that comprised their Ph.D. research, or their desire to become medical doctors and perform clinical medical duties.  It's not your age that matters as much as your motivation and intention does.  However, note that a theoretical Computer Science degree and a Mathematics degree are very different beasts, even if at the base of both lie the same thing in the theory of automata.
And don't even think of lumping Statistics and Mathematics in the same pool -- :) -- without expecting to get some raised eyebrows and arguments.  Do you notice that statistical questions on this web site get told to ask the question over at a different website?  
You probably need to find your focus first.
What do you really want to do: computer science, mathematics, or statistics?  Then figure out where you can go to further your specific interests and work with someone else who works in that domain.
What questions are burning in your head?  What do you want to figure out and understand better?  What is it that you can figure out which no one else could probably do, due to the unique confluence of talents and skills and interests which you possess?  
A: That is a little old, but not outlier-level old. Most students who get PhDs at that age do not become professors, although the reason for that is a little hard to identify. Here are two serious (possible) reasons that come to mind.
1) Maybe it's harder when you're older to deal with the stress of moving several times, possibly to extremely random geographical locations, as you make your way to a permanent job. That takes its toll even on people in their late 20s and early 30s, and it may get harder for older people.
2) You may encounter some agism. I don't know much about agism in mathematics (I think it's not a huge problem but maybe I just haven't seen it). My hunch is that some advisors may prefer younger students because they are more intellectually malleable, but if you shop around you will find an advisor who appreciates your background. At that point, if the advisor is impressed with you, your career will go more smoothly.
Just for some context I'm a postdoc in my late 20s.
A: In my opinion, people are not giving the OP enough credit for already having a PhD in a related field.  This means s/he has a better grasp of what it means to get a PhD than 99% of the general population, has already shown considerable technical skill, the drive to complete a task which requires years of hard work, and so forth.  
So far as I know, by far the most common reason for someone to drop out of a doctoral program in math (or any discipline) is that they just didn't really know what they were getting into: they had no way of properly gauging the scope and amount of work involved.  
I am currently involved in graduate admissions at UGA.  I have only been doing this for a little while, so my ideas may change, but at the moment if I saw a candidate who had a decent undergraduate background, test scores within the normal range of our successful applicants (e.g., greater than 50% on the math subject GRE) and already had a PhD, I would be tempted to put them towards the top of the list.  Thinking it through as a hypothetical admissions decision, my only major concern would be that the candidate's undergraduate background may not be as fresh or relevant as that of our other strong applicants.  Thus I would recommend taking a few math classes at the advanced undergraduate level.  With good performance on those, I see no reason not to count the candidate's previous experience as an advantage, rather than his/her age as a disadvantage.
A: Yes, Berkeley or UCLA would be decent schools, I guess...
Getting into either school is very challenging. But kidding aside, I know some people who started 
late, got hooked, did their PhD in decent schools, and have been enjoying since then a really good academic career. I'm sure there's also examples of people who did not fare so well, but then again that comes with the territory when you enter a graduate program. But to put your mind at rest, it's definitely feasible.
