Featured Research

from universities, journals, and other organizations

Being Isaac Newton: Computer Derives Natural Laws From Raw Data

Date:
April 3, 2009
Source:
Cornell University
Summary:
If Isaac Newton had access to a supercomputer, he'd have had it watch apples fall -- and let it figure out the physical matters. But the computer would have needed to run an algorithm, just developed by researchers, which can derive natural laws from observed data.

Cornell University doctoral student Michael Schmidt makes adjustments to an automated research system. Using the digital mind that guides a self-repairing robot, Hod Lipson, a researcher at Cornell, and Schmidt have created a computer program that uses raw observational data to tease out fundamental physical laws. The breakthrough may aid the discovery of new scientific truths, particularly for biological systems that have, until now, eluded detection. Such automation in scientific research is becoming more common, raising questions about its impact on science.
Credit: Jonathan Hiller, Cornell University

If Isaac Newton had access to a supercomputer, he'd have had it watch apples fall – and let it figure out the physical matters. But the computer would have needed to run an algorithm, just developed by Cornell researchers, which can derive natural laws from observed data.

The researchers have taught a computer to find regularities in the natural world that become established laws – yet without any prior scientific knowledge on the part of the computer. They have tested their method, or algorithm, on simple mechanical systems and believe it could be applied to more complex systems ranging from biology to cosmology and be useful in analyzing the mountains of data generated by modern experiments that use electronic data collection.

The research is published in the journal Science (April 3, 2009) by Hod Lipson, Cornell associate professor of mechanical and aerospace engineering, and graduate student Michael Schmidt, a specialist in computational biology.

Their process begins by taking the derivatives of every variable observed with respect to every other – a mathematical way of measuring how one quantity changes as another changes. Then the computer creates equations at random using various constants and variables from the data. It tests these against the known derivatives, keeps the equations that come closest to predicting correctly, modifies them at random and tests again, repeating until it literally evolves a set of equations that accurately describe the behavior of the real system.

Technically, the computer does not output equations, but finds "invariants" – mathematical expressions that remain true all the time.

"Even though it looks like it's changing erratically, there is always something deeper there that is always constant," Lipson explained. "That's the hint to the underlying physics. You want something that doesn't change, but the relationship between the variables in it changes in a way that's similar to [what we see in] the real system."

Once the invariants are found, potentially all equations describing the system are available: "All equations regarding a system must fit into and satisfy the invariants," Schmidt said. "But of course we still need a human interpreter to take this step."

The researchers tested the method with apparatus used in freshman physics courses: a spring-loaded linear oscillator, a single pendulum and a double pendulum. Given data on position and velocity over time, the computer found energy laws, and for the pendulum, the law of conservation of momentum. Given acceleration, it produced Newton's second law of motion.

The researchers point out that the computer evolves these laws without any prior knowledge of physics, kinematics or geometry. But evolution takes time. On a parallel computer with 32 processors, simple linear motion could be analyzed in a few minutes, but the complex double pendulum required 30 to 40 hours of computation. The researchers found that seeding the complex pendulum problem with terms from equations for the simple pendulum cut processing time to seven or eight hours.

This "bootstrapping," they said, is similar to the way human scientists build on previous work.

Computers will not make scientists obsolete, the researchers conclude. Rather, they said, the computer can take over the grunt work, helping scientists focus quickly on the interesting phenomena and interpret their meaning.


Story Source:

The above story is based on materials provided by Cornell University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael Schmidt and Hod Lipson. Distilling Free-Form Natural Laws from Experimental Data. Science, 2009; 324 (5923): 81 DOI: 10.1126/science.1165893

Cite This Page:

Cornell University. "Being Isaac Newton: Computer Derives Natural Laws From Raw Data." ScienceDaily. ScienceDaily, 3 April 2009. <www.sciencedaily.com/releases/2009/04/090402143457.htm>.
Cornell University. (2009, April 3). Being Isaac Newton: Computer Derives Natural Laws From Raw Data. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/04/090402143457.htm
Cornell University. "Being Isaac Newton: Computer Derives Natural Laws From Raw Data." ScienceDaily. www.sciencedaily.com/releases/2009/04/090402143457.htm (accessed July 29, 2014).

Share This




More Computers & Math News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Teen's Phone Ignites Under Her Pillow; How Real Is The Risk?

Teen's Phone Ignites Under Her Pillow; How Real Is The Risk?

Newsy (July 28, 2014) A Texas teen's Samsung phone apparently ignited while she slept, but what was the real problem here? Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
Powered by NewsLook.com
Cellphone Unlocking Bill Clears U.S. House, Heads to Obama

Cellphone Unlocking Bill Clears U.S. House, Heads to Obama

Reuters - US Online Video (July 27, 2014) Congress gets rid of pesky law that made it illegal to "unlock" mobile phones without permission, giving consumers the option to use the same phone on a competitor's wireless network. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Congress OKs Unlocking Phones From Carriers

Congress OKs Unlocking Phones From Carriers

Newsy (July 26, 2014) A bill legalizing "unlocking," or untethering a phone from its default wireless carrier, has passed Congress and is expected to be signed into law. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins