## July 31, 2008

### Getting Started Early

#### Posted by John Baez

You may have heard of the Mathematics Genealogy Project. This is a wonderful database that lets you look up the Ph.D. advisor and students of almost any mathematician. This is how I traced back my genealogy to Gauss back in week166.

I was feeling pretty proud of myself, too — until I found someone who had two Ph.D. students before he was even born!

Yes indeed: our friend and café regular Tom Leinster is listed as having two Ph.D. students: Jose Cruz in 1959, and Steven Sample in 1965. At the time he was teaching at the University of Illinois at Urbana-Champaign. Later he took an extended sabbatical, got born in England, and transferred to kindergarten. After a lively second career as a youth, he returned to academia and got his Ph.D. at Cambridge under Martin Hyland in 2000. He now has a permanent position at the University of Glasgow. But who can say what he’ll do next?

Check it out soon, since it may go away.

Tip ‘o the hat to Alissa Crans for pointing this out.

Posted at July 31, 2008 7:26 PM UTC

TrackBack URL for this Entry:   http://golem.ph.utexas.edu/cgi-bin/MT-3.0/dxy-tb.fcgi/1756

### Re: Getting Started Early

That is hilarious!

I noted with pleasure that within 2-3 days after me adding myself through the submission form, I was actually up in the database.

Posted by: Mikael Vejdemo Johansson on July 31, 2008 7:59 PM | Permalink | Reply to this

### Re: Getting Started Early

Mikael said

I was actually up in the database.

You’re actually up in the database as my first cousin once removed, I see.

Here’s my relation to the other people in this thread: Tom is an eighth cousin once removed; John and Scott are both seventh cousins twice removed; Bruce is not related to me as he has not been yet been born; and Jamie is of indeterminate lineage, his forebears being of another denomination and so not registered in the parish records.

Note 1 If $x$ and $y$ have a lowest common ancestor $z$ where $z$ is the great$^n$-grandparent of $x$ and is the great$^m$-grandparent of $y$ then, $x$ and $y$ are $(min(n,m)+1)^{{th}}$ cousins $|n-m|$-times removed (for $n,m\ge 0$ and $z\ne x$ and $z\ne y$).

Note 2 I have a big family tree sitting in front of me, so I didn’t have to trawl through the database to figure this out.

Posted by: Simon Willerton on August 1, 2008 1:47 PM | Permalink | Reply to this

### Re: Getting Started Early

We always knew that Tom was an evil genius, but this confirms our darkest fears. Stars, hide your fires! Let not light see his black and deep desires.

Posted by: Bruce Bartlett on July 31, 2008 9:58 PM | Permalink | Reply to this

### Re: Getting Started Early

You’re hardly innocent of using cheap tricks to bump up your descendent number!

Posted by: Jamie Vicary on July 31, 2008 10:02 PM | Permalink | Reply to this

### Re: Getting Started Early

They don’t call me the Wizard for nothing!

Posted by: John Baez on July 31, 2008 10:07 PM | Permalink | Reply to this

### Re: Getting Started Early

You may laugh, but I’m very proud of those two. Jose is now Distinguished Professor of Engineering at Ohio State, while young Steve went on to become President of the University of Southern California. I taught them everything they know.

Posted by: Tom Leinster on July 31, 2008 11:56 PM | Permalink | Reply to this

### Re: Getting Started Early

I guess we need to re-read Time enough for love and its sequels to find out which time thread Tom is on. Having not met him I wonder is that he singing I’m my own grandpa ??!?

One might think with all that experience in 4-d he might like knotted surfaces ;-)

Posted by: Scott Carter on August 1, 2008 1:39 AM | Permalink | Reply to this

### Re: Getting Started Early

I trace back via Piron, Stueckelberg and Pauli to Lagrange, Euler and Leibniz, which is somewhat a weird match. If the base would be complete, wouldn’t everyone trace back to one of those monster mathematicians, as we also all trace back to Adam and Eve?

Posted by: bob on August 1, 2008 1:32 PM | Permalink | Reply to this

### Re: Getting Started Early

If the base would be complete, wouldn’t everyone trace back to one of those monster mathematicians … ?

It seems that fails to happen more than you’d guess, and not just because of incompleteness in the database. Well, depending on how narrowly you define “monster mathematician”. There certainly are modern giants who turned out to be much more famous than their own advisors (and advisors’ advisors, etc.). They end up with lots of descendants who don’t necessarily trace back to the 18th and 19th century monsters.

There are other issues, too. The database will trace my lineage back to plenty of monsters, but only if you believe their claim that Banach’s advisor was Steinhaus. Even granting that the concept of the student/advisor relationship has evolved over time, from this biography it seems more accurate to say that Banach didn’t actually have an advisor; or else his advisor was Lomnicki, who doesn’t appear in the database.

Posted by: Mark Meckes on August 1, 2008 4:04 PM | Permalink | Reply to this

### Re: Getting Started Early

Gauss is one of my ancestors too, but I suspect that half the people in the database have that privilege.

Now I’d like to be able to say what my relationship is to other people with mathematics PhDs. But I haven’t quite grasped the procedure for determining the names of kinship relationships in the English speaking world (despite being a native English speaker). If my mth ancestor is your nth ancestor, and we have no more recent ancestors, what are we to each other, for all m and n?

Posted by: Dan Piponi on August 1, 2008 5:08 PM | Permalink | Reply to this

### Re: Getting Started Early

See the algorithm that Simon Willerton gave higher up. The way I get it, Gauß is your 8th grandparent (9 clicks up in the database), and he’s my 9th grandparent, so you’d be my 9th cousin, once removed.

I haven’t yet checked rigorously that Gauß is our earliest intersection, but it illustrates the theory.

Posted by: Mikael Vejdemo Johansson on August 1, 2008 5:17 PM | Permalink | Reply to this

### Re: Getting Started Early

Nine generations up means that Gauss is Dan’s great7-grandparent; similarly he is Mikael’s great8-grandparent. So the two of you are 8th cousins, once removed (if not closer).

Posted by: Mark Meckes on August 1, 2008 6:20 PM | Permalink | Reply to this

### Re: Getting Started Early

Dan said

Gauss is one of my ancestors too, but I suspect that half the people in the database have that privilege.

A good proportion of the people I know either go back to Gauss or else to Euler and Lagrange. (At least to judge by the big departmental family tree, due to Andrew Stacey, which we have in the corridor.)

John and Dan go back to Gauss; Bob, Tom, and Scott go back to Euler; however, Mikael and I go back to both of them via Klein who had both Plucker (Gauss) and Lipschitz (Euler) as supervisors.

Posted by: Simon Willerton on August 1, 2008 7:43 PM | Permalink | Reply to this

### Re: Getting Started Early

Anyone without physical access to Sheffield can see the Sheffield genealogy graph off my homepage; somewhere around here. It’s an applet since the graph is rather large (hope it works for everyone interested). Although I started with the MGP, I found quite a bit missing - particularly with UK-based people. Many links are extremely tenuous, particularly as one goes back into the murky mists of time. Soon after WWII there were several orphans which made life harder (one of my goals with this graph was to make it connected, sadly I left before I could achieve it).

Around the same time I also did the Sheffield collaboration graph - linking the Sheffield mathematicians by collaborations. This was much easier to get the data for (all via the AMS), but harder to figure out how to lay out the data (not being directed, for example). I don’t have this one on-line (it, also, is out of date).

It might be fun to do a cafe graph - of either type - but I’m not volunteering.

Anyone interested in doing a graph of this type should check out the Genealogy Graph Generator and Graphviz (a bit of perl knowledge doesn’t come amiss - the GGG program only searches for ancestors and needs a bit of careful modifying to look for descendants as well; a word of warning: don’t look for ancestors and descendants at the same time!)

Posted by: Andrew Stacey on August 7, 2008 10:25 AM | Permalink | Reply to this

### Re: Getting Started Early

Dan wrote:

Gauss is one of my ancestors too, but I suspect that half the people in the database have that privilege.

Indeed — I enjoy showing off, but it’s absurd that Wikipedia has a chart of my genealogy going back to Gauss, as if that were something special. If I were a normal person I’d be quite embarrassed.

Posted by: John Baez on August 1, 2008 11:02 PM | Permalink | Reply to this

### Re: Getting Started Early

John wrote:

Later he took an extended sabbatical, got born in England, and transferred to kindergarten.

This being England, I think he would have transferred to nursery school.

And furthermore:

But who can say what he’ll do next?

But clearly we know what he’ll do next: build a time machine, go back to some time before 1959, get stuck there, and start a new career amazing people with his mathematical prescience!

Posted by: Tim Silverman on August 1, 2008 8:35 PM | Permalink | Reply to this

### Another Gauss-descendent; Re: Getting Started Early

In several disciplines, it is standard practice to tell students who their teacher’s teachers’ teachers’ were, such as in Music, Theatre, Martial Arts. In others, it depends on how illustrious in the lineage, or how people-oriented the teacher. Note also that one’s social network (a la Erdos number) of coauthors, coauthors’ coathors, and the like, can go back far into one’s past. Light cone =/= ink cone.

PROFESSIONAL “GENEOLOGY”: MY TEACHERS’ TEACHERS’ TEACHERS

Posted by: Jonathan Vos Post on August 2, 2008 7:24 PM | Permalink | Reply to this

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