New artificial intelligence program discovers alternative physics
NEW YORK — Can artificial intelligence discover a new type of physics? A team of roboticists from Columbia Engineering decided to put this question to the test. They developed an AI program that detected physical phenomena and discovered relevant variables, which are a necessary precursor to any physical theory.
To conduct the study, the researchers gave the AI program raw video footage of phenomena for which they already knew the answer. The video showed a swinging double pendulum that has four “state variables” – the angle and angular velocity of each of the two arms. The AI system gave an almost correct answer of 4.7 variables after several hours of analysis.
“We thought this answer was close enough,” Hod Lipson, director of the Creative Machines Lab in Columbia’s mechanical engineering department, said in an academic statement. “Especially since all the AI had access to raw video footage, without any knowledge of physics or geometry. But we wanted to know what the variables really were, not just how many.”
The researchers report that two of the variables chosen by the AI program roughly corresponded to the angles of the arms, but the other two remain a mystery.
“We tried to correlate the other variables with everything we could think of: angular and linear velocities, kinetic and potential energy, and various combinations of known qualities,” notes Dr. Boyuan Chen, assistant professor at the Duke University. “But nothing seemed to fit perfectly.”
Dr Chen believes the program found a valid set of four variables, because it made good predictions, “but we don’t yet understand the mathematical language it speaks”.
The AI system has discovered new ways to describe the universe
Researchers have begun feeding computer program videos of systems whose explicit variable response scientists don’t know. The first video showed an “air dancer” moving up and down in front of a used car parking lot. The AI program returned eight variables from this video. The program gave the same number of variables after receiving a video from a lava lamp. The program then returned 24 variables after analyzing a video clip of flames from a chimney loop.
The study found that the number of variables was the same each time the AI program was restarted. However, the specific variables were different. This proves that there are other ways to describe the universe.
“I always wondered if we encountered an intelligent extraterrestrial race, would they have discovered the same physical laws as us, or could they describe the universe in a different way?” notes Lipson. “Perhaps some phenomena seem enigmatically complex because we are trying to understand them using the wrong set of variables.”
Researchers believe this AI system can help scientists uncover complex phenomena in fields ranging from biology to cosmology.
“Although we used video data in this work, any type of network data source could be used – radar networks or DNA networks, for example,” explains the study’s co-author, Dr. Kuang Huang.
Scientists still don’t have all the answers
Since scientists may not have a decent set of variables to describe phenomena, Lipson says, scientists can misinterpret or misunderstand many phenomena.
“For millennia, people knew about fast and slow moving objects, but it was not until the notion of speed and acceleration was formally quantified that Newton was able to discover his famous law of motion F=MA”, explains Lipson, proving that variables are a precursor. to any theory.
The study is published in the journal Computational science of nature.