The idea of an omnipresent ether as carrier of light, and thus of any electromagnetic wave comes from Aristotle and was
later taken up by Newton. Since Newton, the space has been viewed as a "container" in which all physical processes take
place. Even if it was not provable, Newton was convinced that there is a substance that permeates the entire universe and
connects it with each other. He called this invisible substance "ether" and described it as a living, spiritual element.
Also, James Clerk Maxwell, the founder of the electromagnetic theory believed in ether, calling it "a material substance
that is more subtle than the visible body, and which exists in those areas of space, which appear to be empty."
The notion of space, however, has changed dramatically in the continued development of physics and at least was
challenged by Einstein. Since then, formal properties of mathematical spaces are used for its physical description.
As a seemingly disused physical concept, the ether hardly is treated by a scientific theory today. Although it is still
discussed today if it is possible to quantize the space, however even in this matter the space considered as a mathematical
or geometric object.
It was failed to prove ether around the turn of the century, and also in several later experiments. Albert Einstein could then
solve the difficulty by banishing ether from his equations and replaced it by the speed of light as a universal constant. Thus,
the failure of attempts to prove the ether gave Einstein the impetus to develop the theory of relativity.
In one of his speeches, Einstein summarized the former idea of the ether, and he expressed his views in detail about this
" Recapitulating: we may say that according to the general theory of relativity space is endowed with physical
qualities; in this sense, therefore, there exists ether.
According to the general theory of relativity space without ether is unthinkable; for in such space there not only
would be no propagation of light, but also no possibility of existence for standards of measuring rods and clocks,
nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with
the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The
idea of motion may not be applied to it.
When talking about the subject of ether it is often asserted that Einstein would have abolished it. But how one can see in
his speech, he did not abolish the ether, but he has redefined it according to his theory. So, he has modernized the ether
concept during that period.
It is interesting to experience what considerations are hidden behind the fact that at the beginning of the last century the
debate in relation to ether was brought to an end. Not just because the fact that it is not provable, but also because there
was no theory with which one could equally explain the physical phenomena in the micro and macrocosm explain using
the properties of the room. In his speech, Einstein also called attention to the following fact:
"Of course it would be a great advance if we could succeed in comprehending the gravitational field and the
electromagnetic field together as one unified conformation. Then for the first time the epoch of theoretical
physics founded by Faraday and Maxwell would reach a satisfactory conclusion. The contrast between ether and
matter would fade away, and, through the general theory of relativity, the whole of physics would become a
complete system of thought, like geometry, kinematics, and the theory of gravitation."
The above-quoted speech of Einstein is very interesting for the subject of this book, and therefore it is included in the last
chapter of the book. In this speech, we get to know the real reasons why the former idea of “material" ether, was
abandoned in a justified way.
Why can the ether not be measured?
Since last century, the ether hypothesis is considered dead. In later experiments it also was not possible to prove the
ether. In the many discussions on ether at the beginning of the last century and even later, no one seems to have
considered that the one thing they were looking for was simply too small to be detected in experiments.
Apparently ether is considered as an element, which is large enough to be proven. However already at the beginning of
the last century Max Planck -after the discovery of the quantum of action-, has derived the units which were named after
him and has defined a tiny quantized quantity of the space as a Planck length. Latest after this recognition, the researchers
should have actually been aware that it is not possible to measure physical effects at these small scales.
For centuries, the ether was defined with different, sometimes even bizarre theories. However, the new world model is
not based on the old ideas of space and the ether, so I will not use that term.
In the following chapters we will see that the "empty" space has a structure, which previously was unknown. Even if the
properties of the "empty" space can not be detected directly, there is enough evidence for the existence of a " substance
that permeates the entire universe and connects it with each other " as Newton had described.