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Historical Overview #7

In 1996, roughly 28 years ago I started with "My Homepage" and again it is time to give an overview of what I have done.

• In 2002 Years ago I wrote my first Historical Overview. To read it go to: Historical Overview #1
• In 2009 Years ago I wrote my second Historical Overview. To read it go to: Historical Overview #2
• In 2015 I wrote my third Historical Overview. To read it go to: Historical Overview #3
• In 2016 I wrote my fourth Historical Overview. To read it go to: Historical Overview #4 This seems a rather short time. The primary reason is my current interest in Numerical Relativity. For an overview of the documents I'm studying read this: Numerical relativity documents
• In 2017 I wrote my fifth Historical Overview. To read it go to: Historical Overview #5
• In 2019 I wrote my sixth Historical Overview. To read it go to: Historical Overview #6 The main reason of this review are current physical discussions related to SR and the behaviour of clocks.
• In 2022 I wrote my seventh Historical Overview. To read it go to: Historical Overview #7 The main reason of this review is a deeper discussion of the meaning of: Understanding of the 'physical world' surrounding us.
• This one is my eigth Historical Overview. The main reason of this review is to have an even more philosophical dicussion about 'understanding the physical world and the evolution of the Universe'

Contents

• 1. Introduction
• 1.1 Observations
• 1.2 Universal time
• 1.3 Determinism versus indeterminism
• 2. Experiments
• 3. Mathematics, Equations and Laws

1. Introduction

The purpose of this document to have a phylosophical discussion of what means understanding something. In this particular case understanding the processes in the universe. How do you do that and what is involved. Remember this is mainly my personal opinion. The reader can agree or disagree. Specific if they disagree I like to here from them, such that I can learn something and adapt my opion.

IMO understanding starts with writing in a clear as possible language.
Almost immediate followed with:

Understanding starts with defining a certain set of concepts.

Almost immediate followed with:

Understanding starts with that we all agree and accept these concepts

The following text describes certain concepts in use: There exists one Universe. This Universe exists now. We humans realize that we can define a concept called time. The universe is constantly changing. Every change defines an event. All events happening now, anywhere in the universe, are happening simultaneous. The universe is not empty, in the sense that it contains objects. Objects, like the unverse, exists now. The existance of each object defines a sequence of events.

1.1 Observations

Understanding starts with observations. Observations will learn us you that there exists a day and a night. That birds can fly. The best example to understand observations is Charles Darwin when he made his observations on board the Beagle and when he travelled in South America. What he found that isolated systems have their own birds. An even more important observation was that for each insolated systems the birds were different, but comparing different isolated systems the the only conclusion was that animals have common ancesters.

To perform observations is a human conduct, which teaches us something, but performing these observations in principle should not interfer of what we are observing. That means the act of observations primarily raises questions which can be answered by performing more observations under different circumstances. Observations also require certain specific tools. For example Galilea Galileo required a telescope to observe the planet Jupiter. But with Galileo his observations through his telescope was something special involved. What Galileo saw through his telescope, where not events happening now, but events happening in the past. That means he saw the surface of Jupiter not the situation as it is now, but in an earlier epoch.
The important aspect of these tools is that you can do better observations with the emphasis that you do not want to disturb what you are observing.

1.2 Universal time

One very important issue is when you make observations of a physical event that you know the physical time of that event. To explain what is meant, it is important to go back to the concepts. It is important to agree upon that there exists now, at present, only one physical universe. This physical universe, in its totality, is constantly changing, like the planets revolving around the Sun throughout the universe. We humans have nothing to do with this. What happens in the universe at every instant are events and all these events are happening simultaneous. All these events have the same time stamp. This time stamp we call universal time. That all the events with the same time stamp are also happening simultaneous.
What is physical important that two events with the same time stamp, happening at two different locations in the universe (simultaneous), that these two events cann't influence each other.

1.3 Deterministic.

An important concept in physics is determinisme. The question in that respect is: based on observations is it possible that when you study any process in detail that that process is 'in some sense' deterministic?
The problem is I myself have a problem with this concept. IMO a concept to be of any value, should make a clear distinction between situations where this concept is applicable and situations when not. The same situation exists with concepts like absolute and relative related to observations

In order to answer the question depents on what you want. Suppose you want to know how does it come that many stars have planets. Current observations reveal that this is the case. For more detail select these links:

1. https://en.wikipedia.org/wiki/Planet-hosting_star
   
2. https://arxiv.org/pdf/1608.00764.pdf New prospects for observing and cataloguing exoplanets in well detached binaries
   
3. See page 9 of document #2: http://www.openexoplanetcatalogue.com/ In link "Cataloque". Select: "Planets in Binary Systems". (*)
4. BH merging. http://www.nicvroom.be/VB2019 BHmerger operation.htm Select figure 2C and Figure 2D

What link #3 shows is that there are 181 binary systems, which have multiple planets. My interpretation is that the actual evolution of these binary systems, including the planets involved, starting of the moment that the stars were born, is physical completely different. Implying that the concept like determinisme does not make sense. The only thing that can be said is that all the objects (large and small) which are part of a binary system, existing now, are influenced by all the other objects in the universe, existing now, in due time.

2. Experiments

The next step to improve understanding is to perform experiments, mostly in a laboratory.
The most important aspect of an experiment is to learn the physical details of the evolution of a process or a reaction in a controlled environment, such that the same experiment can be repeated by other groups or that the same experiment can be repeated by using slightly different parameters.
For example, Laboratory experiments are the basic tool to perform the chemical reactions which are used to define the elements of the Periodic Table.

It should be mentioned that performing experiments is the best way to learn about the evolution of physical processes using all different circumstances.
It can be used for almost all chemical, biological, mechanical, medical and physical processes. The most difficult are cosmological processes.
One important step in understanding a process is to start with a more simple case and to slowly make the process more complex. Suppose you want to understand why can birds fly and secondly and what is involved for an airplane fly.

2.1 Understanding why birds can fly.

In order to understand why and how birds can fly you can start with a ballon, next a hot air ballon and finally a kite. To understand these examples will introduce new concepts.

• In order to understand why a ballon can 'fly' you must blow the ballon up, you must release the air and the balloon will move in the opposite direction.
• In order to understand why a hotair balloon can fly you must heat the air inside the balloon.
• In order to In order to understand you have to introduce new concepts, like being at rest, moving and force.
  Being at rest can be defined as that the (observed) position of object, on the surface of the earth does not change.
  Being at rest is also physical the same as a point fixed to the surface of the earth.
  Next we can define moving as that the (observed) position of an object on the surface of the earth, every time is different, compared with a fixed point.
  Using both these concepts we can define the concept force. An action, more specific a force is required to change the state of an object from at rest to moving. More detail is required about the object what the force is. For example an airplane requires an engine and a propeller to move the airplane on the runway.
  For more detail why an airplane can fly use this link: ScientificAm February 2020 The enigma of aerodynamic lift A force is one of the most important concepts to understand physical processes.

2.2 Astronomical systems.

In order to For astronomische systems, one of the simplest to study is a binary system, constisting of two stars. To study such a system you need a third object, which can be considered at rest and a coordinating system. This coordinating system can be used as the bassis to observe the position of both stars during a certain period. But that is not the point here. Two types of observations are important:

• When the two objects are of the same size, the trajectories of both objects are the same, and they will rotate around a point half way between both objects.
• The larger one object the more the smaller object seems to rotate around the larger object.

3. Mathematics, Equations and Laws

The third step to improve the accuracy of our understanding of the evolution of the universe and the individual processes that take place by using mathematics.
Starting point are the observations and experiments discussed previously, which give a physical explanation
Starting point of using mathematics is that we want to describe the universe and predict the future using numbers and the physical evolution of the universe and certain processes by means differential equation and difference equations.
If you want to use mathematics, the first step is to define a coordinate system. The second step is to perform measurements.

However a more philosophical issue is at stake: How important is mathematics in order to understand astromical, biological and chemical processes
In general the answer is: not.

3.1 Chemical processes

When you study chemical processes (reaction) the most important issue are the chemical elements involved in the chemical reaction. For some detail select: https://en.wikipedia.org/wiki/Chemical_reaction">https://en.wikipedia.org/wiki/Chemical_reaction. In general you can claim that these reactions take place here on earth. Much more complex chemical reactions take place between astrophysical objects and specific when they come in close context. In these cases there is also mass transfer between the different objects involved.

3.2 Astronomical processes

For astronomische problemen a whole other situation exists.