soft question - Starting a physics Ph.D. at 60?

Decades ago I was in a physics Ph.D. program, made a hash of things, and quite rightly was dropped from the program. Since then I've had a very satisfying career as a computer programmer, and picked up an M.S. in Applied Math. I'm currently working in a bioinformatics research lab, and really enjoying myself.

I think I might want to retire in five or six years, and lately I've been daydreaming about returning to my first love, and entering a physics Ph.D. program. This would be entirely for my personal satisfaction. I have no intention of seeking a further career in physics, I'd just like to spend a few years working in a physics research group. I've been out of physics too long to really know what area I'd like to work in, but I'm thinking quantum computing or quantum optics.

While I wouldn't require any financial support, I recognize that taking on a Ph.D. student is still a major investment of resources for a researcher. My hope is that my years of experience in software development would be enough of an asset to make it worth their while.

I'm just curious if there is anybody in the audience who's done something similar, or any faculty who can give an opinion about whether this is a realistic notion.

Update:

Thanks to all for your answers and comments. I think nibot's comment that the thing to do is to establish relationships with some faculty I might like to work with is the most "actionable" answer. I really appreciated all the other anecdotes and advice though.

Answer

The point of PhD programs is to produce future scientists; it seems unlikely that any decent department would admit someone who indicates that they "have no intention of seeking a further career in physics."

Since you do have a background in physics, math, and computing, it does seem like you could earn your keep in a physics lab. Assuming you are interested in experimental physics, I suspect your best bet would be to get a half-time job in a physics lab with an informal agreement that you can also audit the department's courses. Actually taking a spot in a formal PhD program would probably be seen as unfair to the person you would be displacing, who would actually need the PhD for their career.

Theoretical physics would be more difficult, since it is much more difficult to "earn your keep" as a novice theorist. I think it would be difficult to find an advisor in theoretical physics who would have the patience to mentor someone who explicitly did not intend to continue in the field--unless that person was manifestly brilliant.