10 fast radio bursts have been detected in the past 15 years that all have the same unusual characteristic of an arrival delay close to a multiple of 187.5. There is no known natural process to explain this. Initially the bursts appeared to be coming from billions of light years away, far outside of our own galaxy. But recent analysis suggests that they may be coming from a group of objects in the Milky Way. Michael Hippke of the Institute for Data Analysis in Germany and John Learned at the University of Hawaii say that if the pattern is real, it is very hard to explain. There is a 5 in 10,000 probability that the line up is a coincidence. If it is a natural process, perhaps in some way involving pulsars, it is the result of a physics that we don’t yet understand. It is also possible that the signals are from something manmade such as a a spy satellite which is designed to mimic signals from deep space.
Even if the signals come from within our galaxy, fast radio bursts require an enormous amount of power–far more, for example, than we could presently generate. To generate such powerful signals, a civilization would need to be able to harness energy output equivalent to that of a star.
The beauty of this story is that it almost certainly means that an as yet undiscovered physical process of extraordinary power and complexity is at work, or we have detected signals from another civilization that is far more advanced than our own. The answer? Stay tuned!