Ultima Thule

In ancient times the northernmost region of the habitable world - hence, any distant, unknown or mysterious land.

Wednesday, April 19, 2006

Black holes thrown in Einstein's blender

By Aussiegirl

A very interesting article on the importance of correctly translating mathematical equations into computer-speak.

Black holes thrown in Einstein�s blender - Space.com - MSNBC.com

Black holes thrown in Einstein’s blender
Scientists simulate relativity’s recipe for massive mergers

The types of black hole mergers predicted by general relativity have been accurately simulated in a computer model for the first time.

The new three-dimensional model provides a direct test of Albert Einstein's theory and could guide the hunt for gravitational waves, one of the most elusive and sought-after forms of energy in the universe.

"In the past, we've always shown animations or artists' conceptions of gravitational waves, but now we have Einstein's conception," said Joan Centralla, head of the Gravitational Astrophysics Laboratory at NASA's Goddard Space Flight Center and a member of the team that created the model. [...]

Black holes are regions of space where matter is packed so tightly that the resulting gravity ensnares matter and even light.

Einstein's general theory of relativity predicts that when black holes merge, they will emit gravitational waves that distort the fabric of space-time like ripples spreading across a pond.

"These mergers are by far the most powerful events occurring in the universe, with each one generating more energy than all of the stars combined," Centralla said. "If our brains could detect gravitational waves like light waves, we'd be blinded by black hole mergers."

Even though gravitational waves are thought to be ubiquitous throughout the universe, they have yet to be detected directly because even the strongest gravitational waves would interact with matter only very weakly.

Previous simulations of black hole mergers were plagued by crashes because they used translations of Einstein's general relativity equations too complex for even the most sophisticated computers.

Einstein's theory of general relativity uses tensor calculus, a type of mathematics that can't be programmed directly into computer code. The equations must be translated, but as in the translation of a book from one language to another, the process leaves some room for interpretation.

Just as some translations of Leo Tolstoy's "Anna Karenina" read better than others, certain renditions of Einstein's equations are easier for computers to understand. [...]

"When LIGO and LISA detect gravitational waves from merging black holes, we'll know whether Einstein's theory is right or wrong," Hertz said.

LIGO, short for Laser Interferometer Gravitational-Wave Observatory, is a currently operational ground-based detector designed to detect these subtle waves. The Laser Interferometer Space Antenna is a mission planned by NASA and the European Space Agency with similar goals.



Post a Comment

<< Home