Buzz
Sound recording technology has made tremendous advancements since its inception in the 1800s. While it is commonly used for enjoying music and podcasts, it also plays a pivotal role in a variety of scientific fields, helping researchers capture unexpected sounds that aid in their discoveries.
Here are ten unusual and captivating examples that will leave you astonished, especially since some of these sounds seem impossible!
10. Melting Glaciers
With rising global temperatures, scientists need to gauge the rate at which glaciers melt to better understand the impact on sea levels. While photography and satellite imagery have been the go-to methods, a more recent approach involves using hydrophones—specialized underwater microphones—to listen to the glaciers, providing a unique insight into the changes occurring beneath the ice.
It turns out that the sound of a melting glacier is reminiscent of firecrackers or sizzling bacon! The popping noises are caused by bubbles escaping into the water. The goal is to track the ratio of bubbles popping to those trapped within the glacier, providing valuable insight into the rate at which glaciers are melting. This research is critical: rising sea levels due to melting glaciers could have catastrophic consequences for millions of people worldwide.
9. Silent Animals Revealed
We’re all familiar with the sounds made by birds, cats, and frogs, and perhaps even the calls of foxes. However, the sounds of many other animals—especially amphibians and marine life—remain a mystery. Gabriel Jorgewich Cohen, a Ph.D. student from Zurich, has been exploring whether some of these species make sounds at all, and as it turns out, many do. You can even hear them in his recordings.
The recordings were captured using a hydrophone, just like those used for studying glaciers. Cohen traveled across five countries to various research institutions, recording sounds from animals previously thought to be mute, such as fifty species of turtles and lungfish—air-breathing fish. He discovered that none of these animals were silent. Every single one produced sounds. Furthermore, the research suggests a shared ancestor for sound-producing species dating back around 407 million years.
8. The Earth’s Entire Soundscape
In 2014, sensors were activated in Indiana, USA, to record every sound on Earth for a whole year. Yes, every sound: from birds chirping and bats emitting ultrasonic whistles to ocean waves, earthquakes, and much more. This ambitious project was led by Bryan Pijanowski, who identifies as a 'soundscape ecologist.' Unlike traditional ecologists who study the sounds of a single species, Pijanowski focuses on understanding how the sounds of various species interact with each other and the environment.
In his research, Pijanowski listens for the natural rhythms and patterns of the world, such as the increasing sounds at dawn and during specific seasons. Identifying these patterns could provide scientists with crucial information about the planet's well-being.
7. The Sound of a Single Bacterium
An interesting discovery is that every living cell generates sound through tiny vibrations, referred to as 'nanomotion.' The development of graphene, an ultra-sensitive material, enabled scientists to amplify these nanomotion sounds, allowing them to detect the sounds produced by bacteria. Remarkably, they were able to differentiate between living and dead bacteria using this method.
Curiously, graphene was so sensitive that scientists could listen to a lone bacterium swimming in water. However, the significance of this research goes beyond curiosity: it holds potential in combating infectious diseases and addressing antibiotic resistance.
6. Martian Storms
The Perseverance rover carried the first operational microphone to Mars. Although it only recorded for three minutes every few days, it made significant discoveries, including capturing the sound of a Martian whirlwind. The team had already observed nearly 100 dust devils since the rover's landing, but they considered themselves fortunate the first time one passed by while the microphone was active.
The sound recordings helped scientists gain a deeper understanding of the Martian atmosphere and weather. Along with other instruments, such as air pressure sensors and time-lapse cameras, they discovered that Martian dust devils possess a similar force to those on Earth. This means future astronauts need not be overly concerned about gale-force winds damaging their equipment.
5. A Black Hole
In space, no one can hear you scream, right? Well, not entirely. While it’s true that sound requires a medium, like air or water, to travel, space is a vacuum and lacks these mediums, so it should be silent. However, in 2022, NASA revealed that space isn't a perfect vacuum and isn’t completely silent. Galaxy clusters contain gases that allow sound waves to travel through them.
Thanks to this, NASA managed to capture the sound emitted by a black hole. The sound was so low in pitch—57 octaves below middle C—that it was inaudible to the human ear. To make it audible, the sound had to be amplified 57 times, which might sound like a lot, but in terms of frequency, it was scaled up by an astounding 288 quadrillion times. And just to put that into perspective, a quadrillion has 15 zeros!
4. Mysterious Creatures of the Deep Sea
As ocean temperatures rise along with sea levels, scientists fear that these changes could cause irreversible damage to marine ecosystems and lead to the extinction of various species. In response, a team of marine biologists from around the world launched a project called GLUBS, the Global Library of Underwater Biological Sounds. Their goal is to capture and catalog the wide range of sounds produced on the ocean floor, which could help in identifying and studying different species.
Dolphins and whales aren’t the only animals that create noises in the ocean. Among the surprising sounds recorded are sea urchins scraping algae off coral reefs. Many other sounds remain unidentified, and the researchers are hoping that advanced algorithms will help match these sounds to the species responsible for making them.
3. The Sun’s Sound
The Sun is a dynamic and tumultuous place, filled with eruptions, waves, solar flares, and more. However, these events are invisible to the human eye. Even with advanced visual technologies, scientists still can’t directly observe what's happening within the Sun. Instead, they rely on the vibrations caused by the Sun’s waves and eruptions, which they convert into sound to better understand the inner workings of our star.
This research has been spearheaded by the European Space Agency and NASA, who have been recording vibrations from the Sun's activity for over two decades. The data is cleaned to eliminate unwanted noises, like the sounds of spacecraft. Then, the frequency of the vibrations is amplified by a factor of 42,000 to make them audible. You can actually listen to the haunting, pulsating hum of our nearest star on the NASA website.
2. The Sound of an Atom
The interaction of atoms with light is a well-established concept in physics, but the interaction between sound waves and atoms has been less understood. In 2014, scientists achieved a groundbreaking feat by using sound to communicate with an artificial atom for the first time. Like a regular atom, an artificial atom can be charged with energy, which it then releases in the form of a particle, usually light. However, researchers at Chalmers University in Sweden created an atom that could absorb and emit energy as sound instead. The sound it produced was incredibly faint—at the edge of detectability. This pioneering work aims to open new doors in the study of quantum phenomena, as sound travels more slowly than light, offering scientists more time to manipulate and study quantum particles.
1. The Earth's Magnetic Field
In 2022, scientists at the Technical University of Denmark (DTU) successfully converted magnetic data collected by the European Space Agency’s (ESA) Swarm satellites into sound. These satellites, launched in 2013, recorded creaking-like noises as they measured Earth's magnetic field, which serves as a protective shield against cosmic radiation.
The magnetic data was transformed into an auditory representation of the Earth's core magnetic field. Although the sound wasn’t captured directly, it was generated by using the data characteristics from the satellites. The resulting audio illustrates the magnetic field created by Earth's core interacting with a solar storm. This research aims to enhance our understanding of space weather and further knowledge about Earth’s magnetic field.
