Latest news with #PhysicalReviewResearch
The Independent
5 days ago
- General
- The Independent
Scientists finally crack mystery of how clapping generates sound
Scientists have finally unravelled the complex process that generates sound during handclaps, a discovery that shows how even simple acts can be rich with physics. The research, published in the journal Physical Review Research, shows that the characteristic ' pop ' sound of a clap is not just from two hands smashing into each other but a much more complex phenomenon. The key to generating sound from clapping is a cavity of air that is compressed and pushed out of a small space. Scientists followed an interdisciplinary approach to understand clapping, using live experiments, theoretical modelling and silicone replicas of human hands. They modified the volume and duration of claps by changing the speed, the shape of the hands and even the skin softness. 'We clap all the time but we haven't thought deeply about it. That's the point of the study,' said study co-author Yicong Fu from Cornell University, 'to explain the world with deeper knowledge and understanding.' 'The point was not to look just at the acoustics, or the flow excitation or the collision dynamics, but to look at them all simultaneously,' Likun Zhang, another study author from the University of Mississippi, said. 'That's an interdisciplinary effort that allows us to really understand how sound relates to hand clapping.' The study shows that when hands come together during a clap, they create a pocket of air between the palms. This pocket is rapidly expelled from the narrow opening between the forefinger and thumb, causing the air molecules to vibrate. Scientists liken this vibration to the Helmholtz resonance principle, which is behind the tone heard when blowing across the mouth of an empty bottle. 'Traditional Helmholtz resonators have rigid walls like the glass walls of a bottle. This produces a long-lasting sound that attenuates very slowly because most of the energy contributes to the acoustic signal,' Dr Zhang explained. 'But when we have elastic walls – let's say our hands – there is going to be more vibration of the solid material, and all of that motion absorbs energy away from the sound.' This is why clapping generates a single short 'pop' as opposed to a longer noise, researchers say. Scientists hope their research can help inform music education, where handclaps are often used for rhythm timing. The study also shows that every person's clap has a different sound and a different frequency, indicating that clapping can be used in the future as an identification method, like how we use fingerprints. 'One of the most promising applications of this research is human identification. Just through the sound, we could tell who made it,' Guoqin Liu, another author of the study, said.
Yahoo
22-03-2025
- Science
- Yahoo
Scientists Build Device to Generate Electricity Using the Earth's Rotation
In a controversial experiment, a team of physicists investigated whether we could harness the Earth's rotational energy to generate electricity. It's a deceptively simple idea that researchers have only started to grapple with over the last decade. But whether the concept will ever turn into a feasible source of renewable energy remains to be seen, with the team's peers noting their skepticism of the results. As detailed in their paper published in the journal Physical Review Research, the team led by Princeton University physicist Christoper Chyba, aligned a special device made up of a weak manganese-zinc ferrite conductor and electrodes at each end, at a 57 angle, making it perpendicular to our planet's rotational motion and its magnetic field. They observed that the device generated 17 microvolts of electricity, which as Nature points out is a fraction of the voltage released by a single neuron firing. It's a "controversial but intriguing" result, as researchers told the science journal, especially considering the minuscule voltage is extremely difficult to isolate from other physical influences. "The idea is somewhat counter-intuitive and has been argued since Faraday," University of Wisconsin–Eau Claire emeritus physicist Paul Thomas, who wasn't involved in the research, told Nature. Retired physicist Rinke Wijngaarden, who found the effect didn't work in his own 2018 experiments added that he's "still convinced that the theory of Chyba et al. cannot be correct." The device could theoretically work by having the generator pass through the Earth's magnetic field, parts of which remain static, producing a current. However, as the journal points out, electrons could end up rearranging themselves as a result to create an opposing force, negating the effect. Chyba and his team claim to have corrected for this by coming up with a special material that isn't prone to rearranging itself in this way by maintaining the same electrostatic force inside the device. In short, plenty of research has yet to be done before we can definitively say that we could harness the Earth's rotational energy to generate power. But the team of physicists is planning to do just that, attempting to scale up their experiment to generate an actually useful amount of energy. Intriguingly, assuming that the system would work and would be scaled up to meet the demands of the entire planet, the Earth's rotational spin would only slow by seven milliseconds over the next 100 years, the researchers found — which is in the same ballpark as the amount the Moon's pull slows the Earth's rotation over the same period. More on renewable energy: Capitalists Alarmed as Renewables Keep Making Electricity Temporarily Free
Yahoo
22-03-2025
- Science
- Yahoo
Scientists Build Device to Generate Electricity Using the Earth's Rotation
In a controversial experiment, a team of physicists investigated whether we could harness the Earth's rotational energy to generate electricity. It's a deceptively simple idea that researchers have only started to grapple with over the last decade. But whether the concept will ever turn into a feasible source of renewable energy remains to be seen, with the team's peers noting their skepticism of the results. As detailed in their paper published in the journal Physical Review Research, the team led by Princeton University physicist Christoper Chyba, aligned a special device made up of a weak manganese-zinc ferrite conductor and electrodes at each end, at a 57 angle, making it perpendicular to our planet's rotational motion and its magnetic field. They observed that the device generated 17 microvolts of electricity, which as Nature points out is a fraction of the voltage released by a single neuron firing. It's a "controversial but intriguing" result, as researchers told the science journal, especially considering the minuscule voltage is extremely difficult to isolate from other physical influences. "The idea is somewhat counter-intuitive and has been argued since Faraday," University of Wisconsin–Eau Claire emeritus physicist Paul Thomas, who wasn't involved in the research, told Nature. Retired physicist Rinke Wijngaarden, who found the effect didn't work in his own 2018 experiments added that he's "still convinced that the theory of Chyba et al. cannot be correct." The device could theoretically work by having the generator pass through the Earth's magnetic field, parts of which remain static, producing a current. However, as the journal points out, electrons could end up rearranging themselves as a result to create an opposing force, negating the effect. Chyba and his team claim to have corrected for this by coming up with a special material that isn't prone to rearranging itself in this way by maintaining the same electrostatic force inside the device. In short, plenty of research has yet to be done before we can definitively say that we could harness the Earth's rotational energy to generate power. But the team of physicists is planning to do just that, attempting to scale up their experiment to generate an actually useful amount of energy. Intriguingly, assuming that the system would work and would be scaled up to meet the demands of the entire planet, the Earth's rotational spin would only slow by seven milliseconds over the next 100 years, the researchers found — which is in the same ballpark as the amount the Moon's pull slows the Earth's rotation over the same period. More on renewable energy: Capitalists Alarmed as Renewables Keep Making Electricity Temporarily Free
