Research collaboration between Queen Mary University of London, Cambridge University and the Institute for High Pressure Physics in Troisk has found the fastest possible speed of sound.
The result – about 36 km. Per second – almost twice as fast as the speed of sound in diamonds, the hardest material in the world.
Waves, such as sound or light waves, are disturbances that move energy from one place to another. Sound waves can travel through different mediums such as air or water and move at different speeds depending on what they are traveling. For example, they move faster than solids flowing through liquids or gases, which is why if you hear the sound spread on the railway tracks instead of going through the air you will be able to hear the approaching train much faster.
Einstein’s special theory of relativity determines the absolute speed limit at which a wave can travel, which is the speed of light, and it travels about 300,000 km. Is equal to per second. However, it is not yet known whether sound waves also have high speed limits when traveling through solids or liquids.
The study, published in the journal Science progress, Shows that the prediction of the upper limit of the speed of sound is based on two dimensional basic stability: excellent composition constant and proton-to-electron mass ratio.
These two numbers are already known to play an important role in understanding our universe. Their micro-consistent values govern molecular reactions such as proton decay and molecular synthesis in stars and the balance between the two numbers provides a narrow ‘habitable field’ where stars and planets form and life-supporting nuclear structures can emerge. However, new findings suggest that by setting limits to specific material properties, such as these two basic static sound speeds, other fields of science, such as materials science and condensed matter physics, may also be affected.
Scientists tested a wide range of their theoretical predictions and addressed a precise prediction of their theory that the speed of sound should keep decreasing with the mass. Atom. This prediction suggests that noise is the fastest in solid atomic hydrogen. However, hydrogen is only atomic solids at very high pressures above one million atmospheres, which is a comparable pressure to the core of gas giants. Jupiter. At that pressure, hydrogen becomes an attractive metallic solid electric current just like copper and is projected to be a superconductor at room temperature. Therefore, to test this prediction, the researchers performed advanced quantum mechanical calculations and found that the speed of sound in solid atomic hydrogen is close to the theoretical fundamental limit.
Chris Picard, a professor of materials science at Cambridge University, said: “Soundwaves of solids are already very important in many scientific fields. For example, seismologists use sound waves initiated by earthquakes to understand seismic events and the properties of the earth’s formation. They are also of interest to material scientists because sound waves are related to important elastic properties, including the ability to resist stress. “
Costa Trechenko, a professor of physics at Queen Mary, added: “We believe that in finding and understanding the limitations of various properties related to high temperature superconductivity, such as viscosity and thermal conductivity, we may have more scientific applications in the findings of this study. Plasma And also Black hole Physics. ”
Reference: k. Trechenko, b. Monsart, CJ Picard and V.V. Brazkin, 8 October By October 2020 “Sound speed from basic physical stability” Science progress.
DOI: 10.1126 / sciadv.abc8662
