For physicists, ASEP candidates
For students of Schools of Positive Sciences

This book had multiple objectives:
1. We wanted to gather the seemingly endless material of General and Modern Physics in a methodical, concise way, and above all, without neglecting its fundamental parts.
2. We wanted to highlight the unifying principles that govern all of Physics, such as the conservation principles, within which one can interpret a multitude of different phenomena.
3. We did not want to hide the mathematics, nor "whatever is difficult" under the rug or discard them. On the contrary, we insisted more on highlighting, commenting, interpreting, and understanding every "difficult" issue, always of course at the level of General and Modern Physics.

While writing the book, we had in mind the educator, whether a candidate in competitions or not, the student, the graduate of Schools of Positive and Technological Sciences, who has been taught or is being taught Physics, but somewhere feels lost, either in its extent or, more importantly, in its "translation". In other words, we wanted to answer the question of what exactly Physics says and why it says it. And mainly, we focused on the issues around which there are the most difficulties or misinterpretations in application or understanding.
We wanted, for example, to see what the difference is between conservative and non-conservative forces, from a physical perspective (beyond the known definitions for closed paths), what the difference is between gravitational and inertial mass in our daily life, what the difference is between υ = ωr of circular motion and υc.m.=ωR of rolling. We wanted to clarify the issue around thermodynamic changes that are reversible only for the gas and those that are reversible for both the gas and the environment, so that we understand what is special about the Carnot cycle and why everyone is concerned with it. We thoroughly applied Gauss's and Ampere-Maxwell's laws to specific examples and preferred to introduce the rather "advanced" vector potential in Electromagnetism, to show how the changing magnetic field "magically" generates current, even at great distances from where the change occurs. We insisted on what General Relativity says and how it substantiates what it says, and even more so, we insisted on what Quantum Mechanics says and how Schrödinger's equation is applied in a multitude of different cases, and finally, we mentioned what the elementary particles are, when and why they decay, and when they exert forces on each other. We do not hide that we aspired to formulate on behalf of the reader and then answer all those questions that sometimes escape us, sometimes we do not dare to formulate, sometimes we formulate but answer them incorrectly, and sometimes their answer has been indefinitely postponed.
Certainly, to keep this book concise, we sacrificed a few things: Lengthy proofs of relationships when they had no physical content or methodological usefulness, the units of mass, and generally all known units, the relationship of hours to seconds, and all that Physics which is known, and in our opinion, would only tire the reader's eyes if we added it.