Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Planet Earth

Mathematicians See Within

Proof allows mapping of an interior object without cutting it open.

By Devin PowellFebruary 1, 2018 6:00 AM
Mikkel Juul Jensen/Science Source


Sign up for our email newsletter for the latest science news

Jules Verne might be disappointed to learn that we still can’t journey to the center of the Earth. But those curious about what’s down there — metal or monsters? — can take heart from a mathematical proof nearly four decades in the making.

The proof, posted online in February, demonstrates that an object’s insides can be mapped exactly without cutting it open. All you need to know is how quickly waves travel between every possible pair of points on the object’s surface.

Strictly speaking, the proof applies only to certain mathematically perfect objects. “The Earth is far from mathematical idealization,” says Stanford University’s András Vasy, one of three mathematicians behind the proof. Still, he hopes their work will lead to better tools for geology, which already investigates Earth’s interior by studying seismic waves, and medical imaging, which infers the internal details of bodies from electromagnetic waves like X-rays.

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.


Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%


Already a subscriber? Register or Log In