Would love to learn more about Sonar. Since the Hall effect sensor converts a magnetic field into electrical form, and piezoelectric crystals convert pressure changes into electrical form, could that be put to work for a transducer?
And is it Snell's law or Fermat's principle that governs light traveling the path that takes the least time? With Maxwell's equations for electromagnetic radiation, could Snell's law be derived?
I'm sure frustrated with the changes I see here in the midwest. For one thing, the sky is covered up somehow. Objects keep hitting my house. Nobody goes outside. Trees are leaning north. Everything is so wrong.