Physics - Introduction
To fathom what physics is all about can only go wrong. We try it anyway, not in general, but on the probably most important topic of the natural sciences, namely the origin of the world.
Although physics is actually only about the 'physis' (Greek). So if someone asks you how you are doing, he could also formulate as a partial question how your physis is doing, that is your body, and then immediately
ask about your psyche. But certainly, the concept of the body is now significantly expanded and one concludes the entire nature.
Physics obviously feels at home in the middle of the natural sciences. And we also begin directly with the so-called natural philosophy of Aristotle (384-322 BC). It is the geocentric view of the world in which the earth is
the center of the universe. Gravity is explained in such a way that everything inevitably flows towards its center.
It's taken for granted, conceived by people recognized as wise. It is interesting to note that in the theory of flowing there is already the assumption of the earth as a globe. Nevertheless this world view is of course wrong.
We'll come back to that. But we do Aristotle wrong when we assume that he has not already learned from observations. Much more physics is, however, caused by Aristarch (picture above, 310-230 BC), who
presumably observed a little more intensively.
A second important prerequisite for physical knowledge is arithmetic. Aristarch started from the data of the solar and lunar eclipses, continued to observe and calculate, and finally came to the conclusion that not the
earth was the center, but the sun.
If you now have in mind that this was discovered in the 16th century by Galileo Galilei, then you are absolutely right, because first of all they did not believe in Aristarchs theory and second his theory has been forgotten.
But already this part of the story shows, besides the necessity of observing nature, the calculations as a prerequisite for physics.
With Galileo, another important factor is added, namely that of the experiment. As a rule, a model comes out at the end. What is important here is that it is not reality itself, but actually just a tool to explain reality. It can be
totally or even only in parts wrong, like the one represented by Aristotle.
In physics, one cannot actually declare a model to be correct, but only try to describe parts of it or the whole thing as wrong. Of course you don't do that just like that, but you prove it which in turn is achieved by
experiments and further calculations. High demands are made on these, e.g. that they are precisely performed and described, and thus without major problems. comprehensible.
The first additional areas for physics were created early on in the field of mechanics. Until the end of the millennium, magnetism, sound, light, electrics and thermodynamics were added. And when had thought that now
everything had been largely researched, it was people like Plank, Röntgen, Einstein, Heisenberg and the later atomic researchers who turned classical physics upside down.
In the meantime, it only applies within certain limits, e.g. certain speeds. Einstein is now attributed not only with his theory of relativity, but also with his much further publications, to have contributed decisive e.g. also to
the explanation of the origin of the universe. By the way, some of Einstein's assumptions were proven by experiments only later.
In this phase of physics, the so-called ingredients of the cosmos, matter, energy and space were related to each other. The first two were already defined by Einstein himself, i.e. mutually replaceable - but by no means
minimizable. The so-called big bang, to which one fixes the origin of everything, can be explained in the meantime with 13.8 billion years quite exactly determine.
How did they find that out? By re-calculating the progressive drifting apart of the universe. Very important for the explanation of the Big Bang are the so-called black holes. From a documentation of ntv we take an
Suppose someone wants to dig a hole on a level without anyone. What he gets at the end is a hill next to the hole. So you can imagine matter and antimatter. Where before a plane, thus a nothing was, so both were
created. One could thus proceed from the Big Bang of nothingness.
The question remains, what was in the time before the Big Bang? Here, too, the surprising realization that there was no time before that. It only began to count with the Big Bang. By the way, such starting points in
physics are nothing unusual. Just think of the lowest possible temperature of -273°C.
May be we can increase the speed of land vehicles from Mach 1 at the moment to Mach 2 in the future, but we can never reach a speed below 0 km/h.