Ether

**joychandra** · Jun9-09, 07:22 AM

”According to the general theory of relativity space without ether is unthinkable; for in such space there not only wonld be no propagation of light, but also no possibility of existence for standards of space and time“..........this in an statement given by einstein.........please tell me what is the ether according to general relativity.

**fatra2** · Jun9-09, 08:04 AM

Hi there,

From what I remember, Einstein had a hard time believing that light can travel in the empty space. Therefore, it was thought that their was an invisible material, without any mass, without any smell, without anything, that would allow light to travel through it.

Since then, many experiments were made to discover that ether, without success. The unsuccessful attempts to detect ether could be explain with some god d*** theory that was as complicated as it was ridiculous. Therefore, after a while, scientist decide to apply a simple procedure which says that if you have two theories that can explain the same thing, the simplest one is the most probable. Since then, the idea of ether has been dropped.

I hope I did not make any mistakes. This is what I rememebr from some class in University.

Cheers

**turbo-1** · Jun9-09, 08:38 AM

If you will go to a library and check out Saunders and Brown's "The Philosophy of Vacuum", you will find that chapter 1 is a translation of Einstein's 1924 "On the Ether". He laid out his case in that writing more thoroughly than in his Leyden address. In essence, he claimed that "empty" space has properties that are modified by the presence of embedded matter. The idea was not well-accepted at the time, or presently.

**ZikZak** · Jun9-09, 08:38 AM

Einstein was not a god. We do not blindly follow anything and everything he had to say just because he said it. That is not the way things work in science. There is no ether in general relativity.

**George Jones** · Jun9-09, 08:41 AM

Originally Posted by joychandra

”According to the general theory of relativity space without ether is unthinkable; for in such space there not only wonld be no propagation of light, but also no possibility of existence for standards of space and time“..........this in an statement given by einstein.........please tell me what is the ether according to general relativity.

For any particular spacetime, there is a (tensor) field defined at each event (point) of spacetime that is used to tell whether paths in spacetime are timelike, lightlike, or spacelike. This field, known as the metric (tensor), seems to be what Einstein had in mind in the above.

**fatra2** · Jun9-09, 08:47 AM

Hi there,

Originally Posted by ZikZak

Einstein was not a god.

But very close to it. Let's say that he was one of the scientist that could explain very complex theories with little trains other simple objects. There has not been many like him (which I am thinking of Faraday as another one).

Cheers

**ZikZak** · Jun9-09, 09:38 AM

Originally Posted by fatra2

But very close to it.

No.

He was a man, with all of the follies, foibles, and failures of that kind. We remember him for his truly inspirational achievements, but should also remember that he did not make them in a vacuum, and was wrong about many other things besides. To deify a scientist rather than appreciating the science is dangerous. It tends to lead people into exactly the OP's fallacy: argument from authority, which is the one thing, above all others, the process of science seeks to avoid.

**fatra2** · Jun9-09, 10:02 AM

Originally Posted by ZikZak

and was wrong about many other things

Not that many other.

He was certainly not a god, but let's give to Einstein what he deserve. He was an outstanding scientist, sometimes close enough to insanity, like others. Don't forget that the man brought into light some theories that are still completely misunderstood.

He was given a nobel price, but not for his special relativity, but for the brownien movement. I mean, the man was not only gifted in one field but in many.

Cheers

**DaleSpam** · Jun9-09, 07:57 PM

Originally Posted by fatra2

He was given a nobel price, but not for his special relativity, but for the brownien movement.

No, Einstein won the Nobel prize for his work on the photoelectric effect.

**russ_watters** · Jun9-09, 08:07 PM

Originally Posted by fatra2

From what I remember, Einstein had a hard time believing that light can travel in the empty space. Therefore, it was thought that their was an invisible material, without any mass, without any smell, without anything, that would allow light to travel through it.

Since then, many experiments were made to discover that ether, without success. The unsuccessful attempts to detect ether could be explain with some god d*** theory that was as complicated as it was ridiculous. Therefore, after a while, scientist decide to apply a simple procedure which says that if you have two theories that can explain the same thing, the simplest one is the most probable. Since then, the idea of ether has been dropped.

I hope I did not make any mistakes. This is what I rememebr from some class in University.

Cheers

Your description of the history is incorrect: Einstein did not propose nor accept the classical version of the ether and, in fact, SR is (one of?) the first theory to discard the idea. What he proposed in the quote was something completely different. He's just saying that space still has properties, even if not the same properties previously believed.