Fast Radio Waves in a Short Burst? What’s up with that?
Fifteen years ago astronomer Duncan Lorimer at West Virginia University was startled to tune in to a burst of rapid radio waves. They were very strong, and originated from deep outer space. His radio telescope recorded these bursts off and on for several days. Lorimer couldn’t make heads nor tails of the phenomena.
Not that there wasn’t a lot of noisy radio waves already emanating from outer space. But so far, all the bursts that had been discovered and recorded were repeating and predictable in their patterns. This is what a pulsar does – sends out the same pattern of signals over and over again.
But a random burst of radio waves? Scientists were at first skeptical about Lorimer’s claims, dismissing them as a mere fluke or one trick pony – never to be seen (or rather heard from) again. The likeliest explanation, thought scientists, was some kind of interference from a powerful radio or television tower here on Earth. Lorimer just didn’t have his snooperphone (not a real scientific term, but fun to use) tuned very well.
But scientists, especially astronomers and astrophysicists, are nothing if not open minded. Since Lorimer refused to back down about his discovery, researchers began taking a closer look at these fast radio bursts – and found that they did indeed exist, and were coming from as far away as 3 billion light years. Not a local neighborhood bedlam at all! And they happened all the time, but with no set schedule.
In the electromagnetic spectrum these short intense bursts of radio waves show up as light. But they’re not light. They’re really sound waves that are so intense that they . . . well, scientists are still not sure why they transform from sound waves to what appears to be light waves to our telescopes.
If you’re thinking of a career in astrophysics, or a hobby to drive you crazy in retirement, you might want to consider devoting your life (what’s left of it, seniors!) to investigating this still mysterious phenomena to discover how it happens.
Scientists refer to fast radio bursts, which last only a few seconds at a time, as FRBs. In the past 20 years they have only tracked a few dozen of ‘em.
Their use, or threat, to the human race is next to non-existent right now. Although some scientists have postulated that if and when their source can be found and their mechanism explained, it might be possible for us to turn regular radio waves into light. It takes much less energy to produce standard radio waves than to produce artificial light. The savings in money and the environment could be substantial. But that idea is still pretty much pie in the sky right now.
Some astronomers think that FRBs come from neutron stars, and since they can track neutron stars it just might be possible to track FRBs as well. The theory runs that as the shrinking neutron star spins faster and faster it throws out trillions of charged particles past its magnetic field. These charged particles create sound waves and grow incandescent at the same time. But so far researchers haven’t been able to catch any of the known neutron stars in the act of creating an FRB. But scientists are a patient bunch, and don’t mind spending years waiting and watching for their theory to be proven correct – as long as someone provides coffee and ham sandwiches every once in a while.
What researchers do know for sure about FRBs is that they require a tremendous amount of initial energy to be created. Like the energy produced when two stars crash into each other. Or two black holes collide. Such intergalactic catastrophes happen all the time out in deep deep space, where our telescopes and satellites have hardly penetrated at all. It’s like comparing the street that runs by your house with the entire network of highways in the United States. Your local street may never see a car crash at all, but nation-wide they’re happening all the time.
For those who are tired of reading about explosions and collisions in outer space, who think there’s entirely too much violence in astronomy nowadays, you can take comfort in the fact that a few scientists think that FRBs don’t come from any sort of violent encounter. No, they come from a peaceful and quiet magnetar. A neutron star with an especially strong magnetic field that spins so silently and quickly that it appears only as a blur. Fast radio bursts pop out of these magnetic stars like a grasshopper pops out of the dry grass. And nobody gets hurt.
Lack of hard data always frustrates scientists, because it leads to theories but no hard and fast rules that govern specific phenomena. So it’s heartening to learn that up in Canada scientists are using something called the Canadian Hydrogen Intensity Mapping Experiment, known as Chime, to explore large swathes of the heavens in search of FRBs. The CHIME system consists of long open cylinders with dozens of antennas in them that can search large sections of outer space all at once. What researchers are hoping to prove is that FRBs are much more common than previously thought. Right now the number of FRBs that probably hit the Earth is around one every ten seconds. If this can be proven by the CHIME, then further studies will undoubtedly be initiated to find out if such frequent high energy bursts are doing any good, or harm, to the Earth.