Uh, sorry, I don't have the answer here. But I know who might.
Next week, some of the brightest tech thinkers will gather near Boston to brainstorm solutions to the world's toughest and most important problems in areas like energy, environment, health, security, and learning.
The summit, to take place on Wednesday, 21 April, at Wellesley College, in Wellesley, Mass., is part of the Grand Challenges for Engineering, a program of the U.S. National Academy of Engineering (NAE).
A few years ago, NAE convened an international group of technologists -- including inventor Dean Kamen, Google's Larry Page, MIT's Robert Langer, and others -- to identify the world's most pressing engineering challenges. The result was a list of 14 formidable tech problems.
Now it's time to find the solutions.
NAE and other organizations, with input from the public and a host of experts, are organizing summits to discuss the challenges and ideas on how to tackle them.
Next week's event, organized by Babson College, Olin College of Engineering, and Wellesley College, is a regional event. You can see the whole program and lineup of speakers at http://grandchallengesummit.olin.edu.
A national summit will take place in October at the University of Southern California.
Below is the list of 14 tech challenges. You can find accompanying explanations, essays, videos, and discussion forums at the Grand Challenges for Engineering web site.
* Make solar energy economical
* Provide energy from fusion
* Develop carbon sequestration methods
* Manage the nitrogen cycle
* Provide access to clean water
* Restore and improve urban infrastructure
* Advance health informatics
* Engineer better medicines
* Reverse-engineer the brain
* Prevent nuclear terror
* Secure cyberspace
* Enhance virtual reality
* Advance personalized learning
* Engineer the tools of scientific discovery