Some people can actually hear shooting stars
Scientists may have cracked a puzzle that's been confusing people for centuries.
I've never heard a shooting star, and apparently I've been missing out. For centuries, people have been saying that they can hear hissing as stars shoot across the sky.
For a while, people scoffed at this claim. Light travels much faster than sound, after all. Even if shooting stars do make sounds that travel to Earth, the sounds should come minutes after the stars burn out. How could anyone ever see and hear a shooting star at the same time? They must be either mistaken or lying, say the critics.
But thanks to scientists from Israel's Tel Aviv University and New York's Cornell University, we've got even more reason to believe these "star listeners."
To understand what these star listeners are hearing, you need to know something about shooting stars: they aren't actually stars. What we call shooting stars are meteors – pieces of metal or rock from space. They break off from comets, the moon and other big space stuff. When they fall into the Earth's atmosphere, they burn up, which is where you get that burst of starry light.
Meteors are actually pretty small. That glorious shooting star you see may actually be a few grains of dust.
So as these pieces of rock and dust are burning up in the atmosphere, they're making a lot of light waves. And according to this new theory, they're also making other kinds of waves.
Shooting stars "produce radio waves that travel at the speed of light, together with the light we see, to the observer," explained Colin Price, an environmental science professor at Tel Aviv University and co-author of the new study. Price, a native of South Africa, moved to Israel three decades ago to study geophysics and atmospheric science.
So can people hear these radio waves? As it turns out, no. Humans can only hear certain kinds of sounds, and these radio waves are out of our range. But the waves don't just disappear into the air when they reach the Earth. They often hit something that conducts electricity – like metal fences, hair, glasses or a billion other things we've got on this planet. When a radio wave knocks into your glasses, it makes them vibrate. And then some people can hear the vibration.
"The conversion from electromagnetic waves to sound waves … is exactly how your radio works,” Price told Science Magazine. “But in this case nature provides the conversion between electromagnetic waves and acoustic waves.”
This theory explains how you could see a shooting star and hear it at the same time even though light waves are so much faster than sound waves: sound waves aren't the waves traveling to your ears. The waves travel to Earth in a different, faster form. They only turn into sound waves when they knock into something.
The scientists believe this theory can also explain something about northern lights, those beautiful bursts of color that sometimes wash over Arctic skies. Some have long said they've heard "clapping" sounds while watching the northern lights. For a long time, people didn't believe them, but the scientists think the same process might be at work.
“Auroras also create radio waves that can easily reach the ground,” pointed out Michael Kelley, an engineering professor at Cornell University and coauthor of the study.
This is still a theory, not a fact. Meers Oppenheim, an astronomer at Boston University not involved in the study, told Science Magazine that he finds this theory "reasonable." But it's a pretty tough one to test, since we don't conveniently have a mini universe in a box we can experiment on. “The devil lies in the details, and no one seems to have truly worked through those,” Oppenheim said.
Of course, you can always test it yourself. Next time you catch a shooting star, don't just ask people around you if they saw it. Ask them if they heard it.
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