The lead reader | Seven Lemon · Anchor | Li Bin
Resonance refers to the situation that the physical system will vibrate at a larger amplitude than other frequencies at certain frequencies, and these specific frequencies are called resonance frequencies by the world.
In fact, simply put, resonance is the vibration of an object caused by the vibration of other objects, at the resonance frequency, because the system stores kinetic energy, so a small periodic vibration can produce great vibration.
In life, resonance is also everywhere.
Human beings' own breathing, heartbeat, blood circulation, etc. have natural frequencies, and the brain waves produced by the brain when carrying out thinking activities will also resonate.
In addition, the reason why our throat can make sounds is because when the vocal cords vibrate under the friction of the air, each vibration resonates with the air, forming a syllable, through the nasal cavity, throat and other parts of the vibration to amplify the sound.
In nature, resonance is also everywhere.
A rare bird in South America, the male plum-winged grebe uses resonance for courtship. This bird grows with 9 inner wing feathers, and the feathers at the innermost part of the wings have enlarged hollow feathers. When courting, the male rubs at the correct frequency, and the inner feathers cause 9 feathers to vibrate at the same time, continuously making a sound close to the violin to show favor to the female.
The ozone layer relies on resonance to protect the planet from excessive ultraviolet damage. In addition, resonance can also maintain the earth's proper temperature to ensure the survival of living things.
Hello friends with books. Today we continue to read the book "Tides, The Waves and Wonders of the Stars of the Universe", and today we will tell you about Chapter 7. This time we will come together to understand the great power of resonance.
Before reading together, let's think about it together: What role does resonance play in tidal phenomena? And what are the principles that lead to these effects?
Mr. Jonathan White once experienced falling into an ice cave in Angava Bay, Quebec, Canada. Although a thick layer of ice forms on the edge of the bay in winter, the tides can still affect the coast, with high tides forcing the ice to float twice a day, while low tides can set the ice stranded. Sometimes ice caves form at the edge of the coast. Ice caves appear only a few hours before the low tide arrives, and as soon as the tide starts, they close immediately.
Jonathan followed the local villagers into the ice cave and spoke loudly, which was absolutely not allowed. Talking too loud can resonate in a cave — just as plucking a guitar string creates a resonance inside the guitar to make a sound. This can cause the ice to move or the cave to collapse. Previously, a large tide in the local Aungava Bay was caused by loud resonances.
Just like when we take a bath and sing, we will feel the resonance of the sound, the clearer the signal on the radio, the stronger the resonance, driving through the uneven section of the road, once the speed is completely synchronized with the ground bulge, the car will vibrate.
In the 17th century, Kepler and Galileo alluded to the enormous influence of resonance on tides. Each ocean has its own rhythm, and the celestial body stimulates this rhythm. When the sun or moon plays a certain "tone", this "tone" will also resonate at a certain point in the ocean, which in turn will have an enhancing effect on the tides.
Such discoveries provide a new dimension for humans to think about tides. Scientists originally thought that the sun or the moon was moving around the earth in the push-pull ocean, but now we all understand that this is actually a joint cooperation of the sun and the moon. The moon and the sun call, and the ocean calls back, not passive listeners, but participants in a lively conversation—resonance.
In places like Venice, the resonance caused by the blowing of the wind is also one of the causes of the occurrence of tides. I believe everyone has heard that in a South American Amazon rainforest, an ordinary butterfly, occasionally flapping its wings, can cause a tornado in Texas two weeks later.
The reason is that the movement of the butterfly flapping its wings causes the air system around it to change and produce a weak air flow, and the weak air flow will cause the surrounding air or other systems to resonate, which causes a chain reaction, and eventually leads to great changes in other systems.
Tides are complex, and in a changing environment, the resonant characteristics of the ocean change over time. With geological movements, the impact of human activities, the retreat of glaciers in some bays, and the rise of sea levels in others, their oscillation cycles change, and the scale and timing of tides will naturally be different from before.
Today we learned together about the relationship between resonance and tidal occurrence. Next time, we'll move on to chapters eight and nine of the book, which focus on how people use tidal energy to drive production and development from the past to the future, and how humans live in harmony with the tides.
Before reading together, consider the question, do you support the large-scale use of tidal energy? And what will the tidal energy market look like in the future? The next time I have a book to read together, I look forward to seeing you.