General relativity, the geometric theory of gravity developed by Albert Einstein in the early 1900's, is today considered one of the twin pillars of modern physics. Along with quantum mechanics, it is fundamental to our understanding of the universe.
Yet despite its importance, general relativity doesn't always get the classroom attention it deserves.
"Is general relativity in the state standards? No. Probably the crowning achievement of science not in the state standards," Dan Burns, a physics teacher at Los Gatos High School in California, says in the video above. But that didn't stop Burns from coming up with an ingenious demonstration to help students understand concepts that are notoriously tricky.
As Burns explains in the video, which was posted by apbiolghs on YouTube, matter bends space. He demonstrates that idea with the help of a stretched sheet of lycra, a pair of weights, and a few marbles. When set in motion on the lycra, the smaller marbles circle the much heavier weights, coming closer with each turn until they connect.
The video helps students wrap their minds around a number of complicated concepts. Class is in session!