Galilean physics in six interesting statements and movies

Christoph Schiller, MOTION MOUNTAIN, the adventure of physics – vol.I, Fall, flow and heat.

The study of everyday motion, Galilean physics, is already worthwhile in itself: we will uncover many results that are in contrast with our usual experience.

For example, if we recall our own past, we all have experienced how important, delightful or unwelcome surprises can be. Nevertheless, the study of everyday motion shows that there are no surprises in nature.

Motion, and thus the world, is predictable or deterministic.

The main surprise of our exploration of motion is that there are no surprises in nature.

Nature is predictable. In fact, we will uncover six aspects of the predictability of everyday motion:

1. Continuity. We know that eyes, cameras and measurement apparatus have a finite resolution.  All have a smallest distance they can observe. We know that clocks have a smallest time they can measure. Despite these limitations, in everyday life all movements, their states, as well as space and time themselves, are continuous.

2. Conservation. We all observe that people, music and many other things in motion stop moving after a while. The study of motion yields the opposite result: motion never stops. In fact, three aspects of motion do not change, but are conserved: momentum, angular momentum and energy (together with mass) are conserved, separately, in all examples of motion. No exception to these three types of conservation has ever been observed. In addition, we will discover that conservation implies that motion and its properties are the same at all places and all times: motion is universal.

3. Relativity.We all know that motion differs from rest. Despite this experience, careful study shows that there is no intrinsic difference between the two. Motion and rest depend on the observer. Motion is relative. And so is rest. This is the first step towards understanding the theory of relativity.

4. Reversibility. We all observe that many processes happen only in one direction. For example, spilled milk never returns into the container by itself. Despite such observations, the study of motion will show us that all everyday motion is reversible. Physicists call this the invariance of everyday motion under motion reversal (or, sloppily, but incorrectly, under ‘time reversal’).

5. Mirror invariance. Most of us find scissors difficult to handle with the left hand, have difficulties to write with the other hand, and have grown with a heart on the left side. Despite such observations, our exploration will show that everyday motion is mirrorinvariant (or parity-invariant). Mirror processes are always possible in everyday life.

 6. Change minimization.We all are astonished by the many observations that the world offers: colours, shapes, sounds, growth, disasters, happiness, friendship, love.The variation, beauty and complexity of nature is amazing. We will confirm that all observations are due to motion. And despite the appearance of complexity, all motion is simple.

Our study will show that all observations can be summarized in a simple way:

Nature is lazy. All motion happens in a way that minimizes change. Change can be measured, using a quantity called ‘action’, and nature keeps it to a minimum. Situations – or states, as physicists like to say – evolve by minimizing change. Nature is lazy.

These six aspects are essential in understanding motion in sport, in music, in animals, in machines or among the stars.This first volume of our adventure will be an exploration of such movements. In particular, we will confirm, against all appearences of the contrary, the mentioned six key properties in all cases of everyday motion.

movies:
1. Types of Motion: movie
2. Earth's Magnetism:  movie1
    movie
3. Akatsuki movie
4. Keplers Law: movie
5. Projectile od motion: movie
6. Free fall  movie
7. Forces and Motion REVISION PODCAST movie