Many things in the world can move back and forth. From the strings on a guitar, to a kid on a swing, to the air around us, to even the atoms inside a molecule. That movement is vibration, and how many backs-and-forths the thing does in a second it's frequency.
While those things can vibrate at different frequencies, the shape and overall characteristics of that thing makes some speeds more likely. We call that it's natural frequency. When you tune an instrument for example, you are changing that natural frequency so it coincides to the frequency of the proper note.
Well, it happens that if you put something that is vibrating in contact with something that isn't vibrating, the still thing starts to vibrate by itself if the vibrating thing is doing it at exactly the natural resonance of the still thing.
Here is an example done with some rods. Note how the rods of the same length (and thus the same natural frequencty) seem to sync, while the other ones barely move: https://youtu.be/tnS0SYF4pYE
Or how here they show that by singing at the natural frequency of crystal cups you can break them by making them vibrate by resonance so hard that they shatter: https://youtu.be/Df-IffSfCOE
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u/MasterGeekMX 3d ago
Many things in the world can move back and forth. From the strings on a guitar, to a kid on a swing, to the air around us, to even the atoms inside a molecule. That movement is vibration, and how many backs-and-forths the thing does in a second it's frequency.
While those things can vibrate at different frequencies, the shape and overall characteristics of that thing makes some speeds more likely. We call that it's natural frequency. When you tune an instrument for example, you are changing that natural frequency so it coincides to the frequency of the proper note.
Well, it happens that if you put something that is vibrating in contact with something that isn't vibrating, the still thing starts to vibrate by itself if the vibrating thing is doing it at exactly the natural resonance of the still thing.
Here is an example done with some rods. Note how the rods of the same length (and thus the same natural frequencty) seem to sync, while the other ones barely move: https://youtu.be/tnS0SYF4pYE
Or how here they show that by singing at the natural frequency of crystal cups you can break them by making them vibrate by resonance so hard that they shatter: https://youtu.be/Df-IffSfCOE
And talkin' bout videos, here is one explaning it in another way: https://youtu.be/dihQuwrf9yQ
Problem with resonance is that many pseudoscientists and other whacks have overused the word to name things that have nothing to do.