There is a class of solids called "quasicrystals" that were big news in the 1980's. these showed up with an x-ray diffraction pattern with 5 fold symmetry

–why was this a surprise?

–what would the mechanical properties of such a material be?

–how was the quandary resolved?

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this

statement #3 on andre"s list is false.

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me