Bees Are Smart, But Let’s Get Some Facts Straight

Today, a colleague of mine sent me a link to a news article entitled Tiny Brained Bees Solve a Complex Mathematical Problem, which appeared on the Queen Mary, University of London web site and on the Guardian web site. Here’s what it says:

Scientists at Queen Mary, University of London and Royal Holloway, University of London have discovered that bees learn to fly the shortest possible route between flowers even if they discover the flowers in a different order. Bees are effectively solving the Travelling Salesman Problem, and these are the first animals found to do this.

I think this is actually pretty cool, and I had no idea that bees were capable of this kind of “optimization”. However, the article contains a couple of incorrect statements that are really vexing:

Incorrect Statement 1: “The Travelling Salesman must find the shortest route that allows him to visit all locations on his route. Computers solve it by comparing the length of all possible routes and choosing the shortest.”

If that were true, we wouldn’t be able to solve the TSP’s with thousands of cities that we can solve today. OR is about being much smarter than simply enumerating all the possible solutions to a problem.

Incorrect Statement 2: “In nature, bees have to link hundreds of flowers in a way that minimises travel distance, and then reliably find their way home – not a trivial feat if you have a brain the size of a pinhead! Indeed such travelling salesmen problems keep supercomputers busy for days.”

Wrong again! According to published results (e.g. see here), many 1000-city TSP’s can now be solved in a matter of minutes on a standard desktop computer.

Ten Freshmen + 46 Slides = 1 Hour of OR Fun

I just finished my presentation to business undergraduate students and, from what I could tell by looking at them, I think it was successful. Of course the real test will be whether someone stops by my office saying “I love OR! Can I work with you?”. I want to thank our vice dean for this opportunity and I am looking forward to doing it again next year.

I closed the presentation with a little “quiz” based on a very nice paper by Brown, Klein, Rosenthal and Washburn entitled Steaming on Convex Hulls. Here’s how it goes (you can open the image on a new window to make it larger):

An aircraft carrier can run with 2 or 4 engines online. The graph below shows gallons of gasoline used per hour versus possible speeds for each engine configuration. How would you run the ship to cover 100 miles in 4 hours?

According to the article, the Navy spends over 1 billion dollars a year on surface combatants alone. An officer who became a ship commander after graduating from the academy was smart enough to solve the above problem the right way. His ship was saving so much fuel that it had to be inspected under the suspicion that it was violating safety regulations. But we all know it wasn’t. It was just a case of using analytical techniques to make better decisions.