Photo credit: Julian Stratenschulte/European Pressphoto Agency
By Lawrence M. Krauss
With presidential primaries in full steam, with the country wrapped up in concern about the economy, immigration and terrorism, one might wonder why we should care about the news of a minuscule jiggle produced by an event in a far corner of the universe.
The answer is simple. While the political displays we have been treated to over the past weeks may reflect some of the worst about what it means to be human, this jiggle, discovered in an exotic physics experiment, reflects the best. Scientists overcame almost insurmountable odds to open a vast new window on the cosmos. And if history is any guide, every time we have built new eyes to observe the universe, our understanding of ourselves and our place in it has been forever altered.
When Galileo turned his telescope toward Jupiter in 1609, he observed moons orbiting the giant planet, a discovery that destroyed the Aristotelian notion that everything in heaven orbited the Earth. When in 1964 Arno Penzias and Robert Wilson of Bell Laboratories detected radio waves emitted by celestial objects, they discovered that the universe began in a fiery Big Bang.
One hundred years ago, Albert Einstein used his newly discovered general theory of relativity (which implies that space itself responds to the presence of matter by curving, expanding or contracting) to demonstrate that each time we wave our hands around or move any matter, disturbances in the fabric of space propagate out at the speed of light, as waves travel outward when a rock is thrown into a lake. As these gravitational waves traverse space they will literally cause distances between objects alternately to decrease and increase in an oscillatory manner.
This, of course, is far from the realm of human experience. In the absence of alcohol, your living room doesn’t appear to shrink and grow repeatedly. But, in fact, it does. The oscillations in space caused by gravitational waves are so small that those ripples in length had never been seen. And there was every reason to suspect they would never be seen.
Yet on Thursday, the Laser Interferometer Gravitational-Wave Observatory, or LIGO, announced that a signal from gravitational waves had been discovered emanating from the collision and merger of two massive black holes over a billion light-years away. How far away is that? Well, one light-year is about 5.88 trillion miles.
Continue reading by clicking the name of the source below.