Sound and Last Week's News and Research

Sound is a type of energy in the form of a wave that travels through a medium, such as a guitar string, air, or water. Just as some waves have alternating peaks and valleys, sound waves have alternating regions of high density (compressions) and low density (rarefactions). These regions result from the energy pushing particles away from a source and into surrounding particles, where they collide, transfer energy, and thus propagate the sound wave before bouncing back.

> See how particles move due to sound with this collection of animations. (More)
> ... and how you can visualize sound waves with fire using a Rubens tube. (More)

The rate at which particles vibrate forward and back—the frequency—corresponds to pitch, while the severity of vibrations corresponds to loudness. Because sound requires the movement of matter particles, it cannot exist in the vacuum of space, and its properties vary according to the medium it travels through. For example, sound travels faster in denser, hotter materials, where closely packed, fast-moving particles can quickly collide and transfer energy.
 

> You can shatter glass with your voice, but you need to make it sound like the glass. (More) 

> The bullwhip was the first human-made object to break the sound barrier. (More)

> Sound can be used to implode fluids so fast that they produce light. (More)

Virtually all animals hear via specialized structures that convert the energy of sound waves into electrical signals for the nervous system, provided the structures are sensitive enough to feel the vibrations. As with other waves, sounds can be absorbed, reflected, and interfere with one another, with overlapping vibrations producing unique sounds or canceling one another out.

> Why do noise-canceling headphones need microphones to work? (More)

> Watch how acoustic levitation systems use sound to make objects float. (More)

Discover more: 

> From planets to galaxy clusters, explore a library of "sounds" from across the universe. (More)

> Test your hearing and make beats with this online tone generator. (More)

> ... and take an auditory adventure to learn how every sound imaginable can be created by combining multiple vibrations of air. (More)

Keep learning by exploring all our findings on Sound here.

News in Context 

1440 brings you the knowledge and context behind the week's stories:

Space-based wildfire-detection system, FireSat, launched its first three operational satellites. (More)

> Track active wildfires, floods, and more natural disasters across the US in real time.

> Containment, control, and other terminology related to firefighting, explained.

Astronomers discovered an apparent moon outside the solar system, but the exosatellite has sparked debate over what makes something a moon. (More) 

> The exosatellite orbits a brown dwarf, whose definition has also been debated.

> ... and follows other naming debates in the astronomical community, such as the one that led to Pluto's demotion. 

China's new heavy-ion accelerator began trial operations after completing construction and passing technological review. (More)

> Scientists collide particles in accelerators to probe subatomic structure through controlled nuclear experiments.

> Learn about five of the world's largest particle accelerators.

The Solar Car Challenge celebrated its 30th anniversary, with solar-powered cars built by high school students competing in a five-day, 630-mile race. (More)

> Solar panels generate electricity by displacing electrons using sunlight.

> ... while concentrated solar power systems use sunlight to boil water before generating electricity.

Research Spotlight

Like all great researchers, we love spending time learning about the latest breakthroughs across science and technology. Here's what we found this week.

Space weather may be detectable about 12 times earlier with a new instrument.

Royal Astronomical Society | Staff. Set to be placed in space as part of a 2027 European Space Agency mission, MAGIC—MAGnetometer from Imperial College—measures the sun's magnetic field farther upstream than current real-time space weather monitors, which give forecasters about 15 minutes of warning time. (More)

> View a breakdown of space weather, including solar flares and coronal mass ejections. 

> Magnetism originates from an alignment of a quantum property of electrons.

A laser-based system spots toxic chemicals in alcohol without opening bottles.

Adelaide University | Candy Gibson. Using Raman spectroscopy, the technology can read the unique chemical "fingerprint" of a liquid through its packaging to identify contaminants, such as methanol. Researchers are investigating the system's potential use for testing in food quality and product safety systems, including detecting counterfeit wines and perfumes, as well as contaminated olive oil. (More)

> How does Raman spectroscopy use molecular vibrations to identify counterfeits?

> ... and how do similar techniques help scientists find life beyond Earth?

An AI tool helps find that bursts of bird evolution often coincide with climate shifts.

University of Michigan | Morgan Sherburne. An analysis of data collected by Skelevision, which scanned and measured the skeletons of over 15,000 specimens, helped track the history of bird body shape across about 45 million years. Rapid bursts of body-shape evolution were found to coincide with major geological events in Earth's history—findings consistent with hints in the fossil record. (More)

> Evolution, or the change in the abundance of specific genes within a population, is driven by five key mechanisms.   

> Explore an interactive timeline of major events in Earth's 4.5-billion-year history.

Scientists develop a method to map heat-induced distortions in LIGO's mirrors.

University of California, Riverside | Iqbal Pittalwala. Gravitational wave observatories rely on light reflecting off mirrors, but minute absorptions of this light alter the mirrors' shape, reducing the detector's sensitivity. These distortions can now be measured more precisely via thermal imaging, which researchers can address by applying controlled heating patterns to the mirrors, thereby enabling the detection of more distant phenomena, including black holes and neutron star collisions. (More)

> See a visualization of how the Laser Interferometer Gravitational-Wave Observatory detects astronomical phenomena.

> Albert Einstein predicted gravitational waves a century before they were first detected.

Etcetera 

> Airplanes need longer runways and take longer to land and take off from high-elevation airports.

> Dogs use a dedicated organ distinct from their noses to smell each other's butts.

> Across the animal kingdom, the efficiency of human travel falls between that of a cow and a horse.

> NASA lost a $125M spacecraft in 1999 because it overlooked converting imperial units to the metric system.

> It took turfgrass scientists about eight years to design the World Cup pitches.

> Visualize the scientific differences between plant milks and cow's milk.

> After a new species is discovered, how does it get named?
 

> Watch the first artificial solar eclipse in space.

> Although about 99.999% of the world's deep ocean is unexplored, existing datasets can be used to rank the deepest location in each of the world's oceans.

> From butterflies and corals to snails and sparrows, several organisms benefit from the presence of typically harmful invasive species.

> How do ZIP, JPEG, MP3, and other file formats compress data to shrink file sizes?

> Explore an interactive timeline of the world's biggest data breaches and hacks.