Comments about "Space" in Wikipedia

This document contains comments about the article Space in Wikipedia
In the last paragraph I explain my own opinion.

Contents

Reflection


Introduction

The article starts with the following sentence: Space is a three-dimensional continuum containing positions and directions.[1]
Space at any moment in time only contains objects.
In classical physics, physical space is often conceived in three linear dimensions.
Okay.
Modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime.[2]
Spacetime is a mathematical concept in a mathematical 4D system.
The concept of space is considered to be of fundamental importance to an understanding of the physical universe.
Space is a important concept in the 3D physical world. Of more importance are the objects in the Universe.
However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.
This sentence is not clear.
The most important point of our understanding is to identify the events that happened simultaneous.

1 Philosophy of space

In Isaac Newton's view, space was absolute—in the sense that it existed permanently and independently of whether there was any matter in the space.
That is a tricky sentence. To understand the concept absolute space you must also define the concept relative space.
From a physical point of view it is important to ask the question if it makes sense to make a difference between space with or without matter?
IMO to discuss physics (including space) without matter does not make sense.
Later, the metaphysician Immanuel Kant said that the concepts of space and time are not empirical ones derived from experiences of the outside world—they are elements of an already given systematic framework that humans possess and use to structure all experiences.
That is a clever definition.
Kant referred to the experience of "space" in his Critique of Pure Reason as being a subjective "pure a priori form of intuition".
This is requires a definition of the words subjective and intuition.

1.1 Galileo

1.2 René Descartes

1.3 Leibniz and Newton

Newton took space to be more than relations between material objects and based his position on observation and experimentation.
Observations and experiments are the starting point of understanding the behavior of physical objects. I.e. the dynamics involved.

1.4 Kant

1.5 Non-Euclidean geometry

Euclid's Elements contained five postulates that form the basis for Euclidean geometry.

1.6 Gauss and Poincaré

1.7 Einstein

2. Mathematics

3 Physics

3.1 Relativity

Before Albert Einstein's work on relativistic physics, time and space were viewed as independent dimensions.
The problem is that time and space are completely different concepts. It is important to agree that there are two types of space: Physical space and Mathematical space.
Physical space exists and is not empty. The Universe as such consists of physical objects and space. All object in the universe have a position identified by 3 coordinates x,y, and z. Each coordinate identifies a physical dimension.
Time is not such a dimension. You can multiply with a speed and then is becomes a length, the distance of train travelled during a certain period. Mathematical space does not exist.
Einstein's discoveries showed that due to relativity of motion our space and time can be mathematically combined into one object–spacetime.
By introducing the concept relativity of motion the whole of physics

3.2 Cosmology

4 Spatial measurement

5 Geographical space

6 In psychology

7 In the social sciences

8. See also

Following is a list with "Comments in Wikipedia" about related subjects


Reflection 1 Philosophy of science, Philosophy of physics

One important consideration when you want to do science or physics etc, all the concepts used should be clearly defined.
One of almost the first subjects to discuss is the role of mathematics in physical science.
My own understanding if you want to do science, that means if you want to understand the evolution of the physical processes in the universe you don't need mathematics. The reason is that the evolution of the universe involves all different types of physical processes i.e. gravitational, chemical, electrical, magnetic, mechanical and biological processes which all are based on physical products which change and interfere which each other in the course of time.
That leads to the conclusion that the understanding is similar. That also leads to the conclusion that the way how processes interfere within each and between each other follows similar lines.
One type of systems that can be studied are mathematical systems. These systems don't exist and operate and are described in mathematical space or frame.
What also can be said that physical systems are described in physical space or a physical frame.
In Mathematical space we can speak of lines and points. In physical space lines and points don't exist, only 3D objects. This sometimes leads to wrong conclusions. For example: in physical space the distance between two objects (calculated from the centre of these objects) can never be zero. This leads two the wrong conclusion in case of Newton's law (division by zero).
That does not mean that in physics no mathematics and equations can be used. Mathematics used can be tricky because it is based on accurate measurements.

To perform science you must start with a certain world view. This world view describes the bassic concepts about the evolution of the universe. Such a world view gives a certain common starting point to describe the universe in all its details and complexity.
For me the starting point should be that at any moment during the evolution of the universe we define a now (also called universal time). In the universe there exist objects (small and large) i.e. atoms and molecules and the rest is physical space. From a human perspective we can call physical space empty, but from a physical point this is not true, because it contains photons and fields. It should be understood that in whole of the universe there are gravitational fields, implying that the universe is not empty.

At each now all the objects atoms and molecules in the Universe have a certain position. All these positions also identify events, which all happen simultaneous.
You can also consider one specific object and define its position as a sequence of equally spaced events. All these points define the trajectory of the object through space.


Reflection 2 - Newton and a rotating object.

Perform the following experiments.
  1. Connect a heavy stone with a thin rope and hang it against a fix point to the ceiling.
    What you will observe is that the line between stone, rope and fix point, is a vertical straight line.
    What you also can observe that the rope will break and the stone will fall to the floor.
  2. In that case use a double rope and the rope will not break. If not add a third rope etc.
  3. Next turn the stone 4 times clock wise. And leave the stone loose.
  4. The stone will start to move counter clock wise. Its spead will increase, stop and decrease.
  5. After it stops the stone will clock wise. After it stops the stone will again move counter clock wise. Untill all movement stops.
  6. Next remove the stone and replace the stone with a basket filled with water.
  7. Next turn the basket 4 times clock wise. The water level should be flat. And leave the basket loose.
  8. The basket will start to move counter clock wise. Its spead will increase, the water level should become concave, stop and the spead decrease.
What is happened next with the level of the water is not completely clear. The point is that all (?) of the behaviour can be explained by means of forces.


Reflection 3


Feedback


If you want to give a comment you can use the following form Comment form
Created: 17 April 2024

Go Back to Wikipedia Comments in Wikipedia documents
Back to my home page Index