Fields permeating spacetime - aether?

[jnorman]

i recall einstein idicating that there was no longer a reason to posit an aether after special relativity was published, but later wrote a short paper indicating that there was, in effect, an aether after all. ref - http://www.aetherometry.com/Electronic_Publications/Science/einstein_aether_and_relativity.php

so, is he indicating that there is an electromagnetic field which permeates spacetime, and that photons are simply excitations of that EM field? is that the erstwhile "aether" now?

do all fields likewise permeate spacetime, such as the gravitational field, and is the graviton an excitation of the gravitational field?

how many fields are there according to the standard model, and do they all permeate spacetime?

is there anything other than fields, considering that all particles are merely illusionary manifestations of underlying fields? are all particle interactions the result of interacting fields?

thanks.

 

[Whovian]

So, is he indicating that there is an electromagnetic field which permeates spacetime, and that photons are simply excitations of that EM field? is that the erstwhile "aether" now?

Nope. This is from misinterpreting the analogy and taking it too far, methinks.

 

[dipstik]

according to quantum field theory, which the standard model uses, yes... there is a dirac field, a gluon field, a higgs field, em field...

i'm not sure how many different fields there are, but i think quantum chromo dynamics has a field for quarks being excitations of a field the same way electrons are excitations of the dirac field.

i remmeber reading another lecture/essay he did saying if there is an aether, but it doesn't do anything that the theory doesn't already address.

 

[Mark M]

They have nothing to do with the aether. The aether was a proposed medium through which electromagnetic waves propagated. No such medium exists.

 

[pmacias]

I would say that the concept of an aether has been a topic of debate in physics for centuries. Historically, it was believed to be a medium that filled the entire universe and was responsible for the propagation of light and other electromagnetic waves. However, with the development of special relativity, the concept of an aether became unnecessary and was discarded.

In his later years, Einstein did write a paper discussing the possibility of a "new kind of aether" that is consistent with special relativity. This idea was based on the concept of a spacetime metric, which is a mathematical representation of the geometry of the universe. This metric can be affected by the presence of matter and energy, and Einstein suggested that this could be considered a type of aether.

In modern physics, the term "aether" is not used in the same way as it was historically. Instead, we now understand that fields permeate spacetime and are responsible for the interactions between particles. These fields, such as the electromagnetic and gravitational fields, are described by mathematical equations and are fundamental to our understanding of the universe.

In the standard model of particle physics, there are currently four fundamental forces: the electromagnetic, weak, strong, and gravitational forces. Each of these forces is associated with a field, and they all permeate spacetime. The graviton, which is the hypothetical particle responsible for the gravitational force, is considered an excitation of the gravitational field.

It is important to note that fields are not the only aspect of the universe. There are also particles, such as quarks and electrons, which are considered to be fundamental building blocks of matter. These particles are not illusions, but rather they are manifestations of the underlying fields. Particle interactions, such as the exchange of photons between electrons, can be described as the interaction of these underlying fields.

In summary, the concept of an aether has evolved over time in physics, and it is now understood that fields permeate spacetime and are responsible for the interactions between particles. While the term "aether" is no longer used in modern physics, the idea of a medium that fills the universe and affects the behavior of particles is still relevant in our understanding of the universe.