if you think on a worm hole thats not far away from the correct view.
as I said, first you have to create an undamped oscillation,
If you had already managed to do this, then you understand how this is being done.
Bessler has had not the possibility as you have today, he only could use pendulums. Nowadays you have the electronic way to create an amplification of an wave.
Bessler had only the way of a mechanical amplification of a wave.
i give you here again the sentence in german and highlight the specific words
two different types of energy storage.Beispiele für ungedämpfte Systeme
Resonanzfrequenzen treten in Systemen mit mindestens zwei verschiedenartigen Energiespeichern auf. Bei einfachen (theoretischen) Systemen ohne Dämpfung ist die Resonanzfrequenz gleich der ungedämpften Eigenfrequenz (Kennfrequenz) {\displaystyle f_{0}}f_{0}. Bei gedämpften Systemen ist die Frequenz bei der die maximale Amplitude auftritt stets kleiner als die ungedämpfte Eigenfrequenz.
And now you see Bessler with his words, the weights act in pairs.
Two Pendulums are two different energy storages,
Pendulum1 a has the energy m1*g*h1 and pendulum 2 has the energy m2*g*h2
Depending on the length of the rope you will get the frequency of the pendulum swing.
Same length --> same frequency
The next step is to listen to Bessler again, one weight is arranging the other
This is meaning that the weights are coupled.
The trick is how they are coupled.
You will find a lot of coupled mechanical oscillation in the internet but not Besslers one.
