Vibration can, in principle, be used as a propulsion technology, no?[1]
> Woodward’s MEGA drive is different. Instead of propellant, it relies on electricity, which in space would come from solar panels or a nuclear reactor. His insight was to use a stack of piezoelectric crystals and some controversial—but he believes plausible—physics to generate thrust. The stack of crystals, which store tiny amounts of energy, vibrates tens of thousands of times per second when zapped with electric current. Some of the vibrational frequencies harmonize as they roll through the device, and when the oscillations sync up in just the right way, the small drive lurches forward.
That drive would need extensive testing, because it violates Newton's third law. Similar reactionless drives like the EM drive also warrant skepticism. Occam's razor, it's more likely the tests measuring their thrust were not accounting for a background element, even the article acknowledges this.
No, the levitating frog is exactly what you'd expect if you had a strong enough magnetic field.
https://www.ru.nl/hfml/research/levitation/diamagnetic-levit...
"Lesson #1: Everything can levitate
It is possible to levitate magnetically every material and every living creature on earth. Molecular magnetism is always present, although it is very weak and usually remains unnoticed. It might give you the impression that materials around us are mainly nonmagnetic. But this is not true. They are all magnetic. We call them ‘diamagnetic’. With magnetic fields high enough you can levitate all diamagnetic materials. At our lab, we develop and build magnets that have a very high magnetic fields. We use it to investigate molecules and materials. And show the world a levitating frog."
> Woodward’s MEGA drive is different. Instead of propellant, it relies on electricity, which in space would come from solar panels or a nuclear reactor. His insight was to use a stack of piezoelectric crystals and some controversial—but he believes plausible—physics to generate thrust. The stack of crystals, which store tiny amounts of energy, vibrates tens of thousands of times per second when zapped with electric current. Some of the vibrational frequencies harmonize as they roll through the device, and when the oscillations sync up in just the right way, the small drive lurches forward.
[1] https://www.wired.com/story/mach-effect-thrusters-interstell...