When I became chairman of my department a few years ago, I moved from my office far down at the end of the hall to one much closer to the center of action: the tea room! I make a lot more visits there than I used to, and began to notice a frustrating pattern:

Far more often than seems reasonable, there’s not even a full cup of coffee in the coffee pot! Once again, someone has left a nearly empty pot with no regard to the next person (me, whine)!

This seems to happen so often I began to wonder what kind of boors I’ve been working with all these years. They seem like nice people and all, but…?

And then I realized: there’s a perfectly logical reason, a mathfactor puzzle, if you will, that explains this phenomenon perfectly, no boors required, no special tricks, just sensible activity by all. My faith in my colleagues has been restored.

Why is it that on average I see an emptier rather than fuller coffee pot?

PS let us know what works for when we return…

Well, it’s been quite a while, and I guess the important news is that the M.F. is coming back soon! Look for new segments starting around the end of the year!

All those encouraging emails, prodding emails, whining emails have had their effect—but I have to say, in the end, it was the Juniors Fabulous cheesecake that probably made the difference.

Meanwhile, a steady accumulation of great ideas and on top of that, when we do come back, we’ll be listed on the National Science Foundation’s app/site, Science 360. Thanks to all those that have hung around waiting—your patience is valued. 

One question: Over the years we’ve experimented with a lot of formats (short, long, interviews, deep stuff, light stuff, book reviews, puzzles, Kyle and me shooting the breeze.) What format works best for you?

It’s been a while since I posted a puzzle and happened upon a nice one today.

You find yourself babysitting a friend’s marble collection while he’s away at a conference of collectors.  The housekeeper, being an honest type, admits to having disturbed one of the displays.  She assures you that she returned all the marbles and shows you ten marbles laid out thus:

* * * * *

* * * * *

That looks fine, but the note to the side of it says five lines of four marbles each.  Since this is two lines of five marbles, must there be marbles missing or can they be laid out in a manner consistent with the note?