Remember that time Stephen Colbert brought physicist Brian Greene on The Late Show to demonstrate the concept of gravitational waves with green lasers? Yeah, that was pretty awesome. Now there's a handy DIY demonstration for those of us without access to that kind of technology, courtesy of science presenter Steve Mould. For those who haven't been following the biggest science story of the year, gravitational waves are light-speed ripples in the fabric of spacetime caused by such epically violent events as exploding stars and black hole mergers. They're incredibly tiny and difficult to detect, but the Laser Interferometer Gravitational Wave Observatory (LIGO) did just that, announcing the first direct detection in February. They announced a second detection in June.
But Mould felt something was missing in the deluge of explainers, graphics and animations spawned by the discovery. "In all the graphics that I've seen, there's a kind of disconnect between the objects and the waves that they produce," he explains in the video. "There's no way to see how one causes the other, and I think we can fix that with an actual physical demonstration of gravitational waves."
First, build your own spacetime warping demo with stretched spandex lycra, marbles and weights. Then mount a couple of little wheels onto a wooden plank to simulate a pair of binary black holes, and use a drill to set them rotating at the requisite 18 times per second. Voila! Ripples in the fabric of your two-dimensional spacetime.