Haifa-born Prof. Hod Lipson and his colleagues have created a computer program that generates mathematical formulas which explain various scientific phenomena. In essence, he argues, it can accelerate the process of scientific discoveries.
The beeping of the mobile phone awoke Prof. Hod Lipson in the middle of the night. “We found the equation!” his research student, Michael Schmidt, announced. The equation Schmidt was referring to has been known to every physicist since the 19th century. It describes the Law of Conservation of Energy – not exactly an earthshaking discovery. Nevertheless, as Prof. Lipson laid his head of disheveled hair back on the pillow, he did so with a smile.
A few days earlier, Lipson and his students at Cornell University had carried out a simple mechanical experiment. They attached two pendulums to one another in a way that generated complex patterns of movement. They then connected that oscillating system to a computer program they have been developing these past five years. The program is intended to take data from different systems – in this case, data concerning the movement of the pendulums – and use it to generate mathematical formulas that describe the mechanisms producing the data. To put it more provocatively – which is how Lipson likes to describe it – this computer program is supposed to identify laws of nature.
The experiment with the pendulums was intended to test the program’s capabilities with regard to identifying laws already known to scientists. The result was impressive. Within one day – and without being fed any algorithmic knowledge in physics, geometry, kinematics or from any other area of research – the program was able to come up with one of the most famous equations in the field of science: F=ma, the mathematical representation of Newton’s Second Law. A few days later, the program, extrapolating from the data, came up with the equations that describe the Law of Conservation of Momentum and the Law of Conservation of Energy.
The program is named Eureqa, after Archimedes’ famous bathtub exclamation (meaning: “I have found it!” ) – invoking the moment of euphoria that accompanies great new discoveries or insights. (The “q” replaces the “k” in “Eureka” as an allusion to the word “equation.” )
In April 2009, Lipson and Schmidt published their findings in the Science journal. Alongside their paper – entitled “Distilling free-form natural laws from experimental data” – a research team headed by Ross King from the University of Wales published a paper about a similar program called Adam, which focused on biological experiments. The two papers immediately generated intense media buzz. Although automation of the processes of producing, collecting and storing research data is not unusual, this time the researchers purported to automate the distillation of scientific knowledge. The Guardian newspaper’s science correspondent was not alone with his dramatic assertion that, “The work marks a turning point in the way science is done.”
Lipson and Schmidt were soon deluged with requests from people who wanted to use the program, and they decided to make it available online for free download. At present, Eureqa is being used by more than 20,000 people – scientists and enthusiasts alike – around the world.
I met with Prof. Hod Lipson late last year at the Weizmann Institute of Science in Rehovot, where he was lecturing on Eureqa during his annual visit home. Haifa-born Lipson, 44, has been in the United States since 1998, after obtaining a Ph.D. in engineering and artificial intelligence from the Technion – Israel Institute of Technology. He first went to the U.S. to pursue his postdoctoral studies, but stayed after getting tenure from Cornell. His prolonged residence in the United States has left a distinct impression on his mannerisms and dress code. He radiates serene vitality and quiet self-confidence, along with open friendliness. Lipson is married to Melba Kurman; they have two sons, Lahav, 14, and Eitan, seven.
Lipson presented Eureqa to me as the next big thing in science, asserting that,”Within less than 20 years, programs like Eureqa will be as commonplace as calculators. In fact, you can already see that today. At the moment people don’t give machines credit for discoveries or inventions, but that might have to change.”