What “is” a radio signal-?

[Justatruthseeker]

It's just an analogy, not a perfect analogy. Waves have sources. The classical source of electromagnetic waves (including radio waves) is electrical charges that accelerate.

That said, radio waves have energy. Therefore they have relativistic mass. This is why light (including radio waves) is affected by gravity.

No, according to the epicycles it is simply following a force free path...... and has zero mass....

http://curious.astro.cornell.edu/ab...-do-they-feel-the-effects-of-gravity-advanced

"You are right that according to Newton's gravity, the force of gravity on particle that has 0 mass would be zero, and so gravity should not affect light. In fact, according to Newton's gravity Black holes should not exist: no matter how strong gravity is, light would always be able to escape!

However, we know that Newton's gravity is only correct under certain circumstances, when particles travel much slower than the speed of light, and when gravity is weak... This is certainly not the case near a black hole! When we try to understand how black holes work we need to consider the more general law of gravity which is Einstein's General Relativity...

According to General Relativity, gravity is not a force! On the contrary, gravity just affects how distances are measured, and says what shape has the "shortest" path from one place to another... All particles then follow these "shortest path" routes in their motion. Notice that nowhere so far have I mentioned mass, this rule applies for all matter and energy, whether they have mass or not!

It turns out that very close to the black hole, these shortest paths never cross the event horizon... As a result neither light nor anything less can escape from the gravity field of a black hole!"

 

[Dig4truth]

No, according to the epicycles it is simply following a force free path...... and has zero mass....

http://curious.astro.cornell.edu/ab...-do-they-feel-the-effects-of-gravity-advanced

"You are right that according to Newton's gravity, the force of gravity on particle that has 0 mass would be zero, and so gravity should not affect light. In fact, according to Newton's gravity Black holes should not exist: no matter how strong gravity is, light would always be able to escape!

However, we know that Newton's gravity is only correct under certain circumstances, when particles travel much slower than the speed of light, and when gravity is weak... This is certainly not the case near a black hole! When we try to understand how black holes work we need to consider the more general law of gravity which is Einstein's General Relativity...

According to General Relativity, gravity is not a force! On the contrary, gravity just affects how distances are measured, and says what shape has the "shortest" path from one place to another... All particles then follow these "shortest path" routes in their motion. Notice that nowhere so far have I mentioned mass, this rule applies for all matter and energy, whether they have mass or not!

It turns out that very close to the black hole, these shortest paths never cross the event horizon... As a result neither light nor anything less can escape from the gravity field of a black hole!"

However, it has been observed that " black holes" are spitting out material.

https://blogs.scientificamerican.co...omers-catch-black-hole-spitting-out-material/

Makes one wonder if they really know anything at all.

 

[Ophiolite]

Some might say that there must be a medium to travel through and some have even given it a name, aether.

There are some classic experiments that support this theory but they are generally suppressed in the classroom.

Long refuted arguments that have no place in modern science. Pay attention to the above post only if you are members of that sad group who believe there is an atheist conspiracy suppressing the truth through corrupt science. Otherwise take some quality physics course at your local college or use reputable online resources.

 

[Dig4truth]

Long refuted arguments that have no place in modern science. Pay attention to the above post only if you are members of that sad group who believe there is an atheist conspiracy suppressing the truth through corrupt science. Otherwise take some quality physics course at your local college or use reputable online resources.

Sorry, I didn't get your objection to the material. All I heard was don't listen to this.

Was there something specific you had a disagreement with?

 

[Ophiolite]

Sorry, I didn't get your objection to the material. All I heard was don't listen to this.

Was there something specific you had a disagreement with?

The consensus, made up of practically all physicists, astronomers, cosmologists and other relavent specialists, is that the aether does not exist. Glibly asserting it does, without noting this is an outfield view, is intellectually dishonest. Implying that this is some conspiracy, rather than a sensible rejection of a long and solidly refuted hypothesis, is at best silly, certainly paranoid and at worst simply crazy. Doing this without an ounce of supporting citations is amateurish, or worse, suggests a disrespectful view of the intellect of your target audience.

Is that sufficient for you?

 

[Dig4truth]

The consensus, made up of practically all physicists, astronomers, cosmologists and other relavent specialists, is that the aether does not exist. Glibly asserting it does, without noting this is an outfield view, is intellectually dishonest. Implying that this is some conspiracy, rather than a sensible rejection of a long and solidly refuted hypothesis, is at best silly, certainly paranoid and at worst simply crazy. Doing this without an ounce of supporting citations is amateurish, or worse, suggests a disrespectful view of the intellect of your target audience.

Is that sufficient for you?

No, that’s not sufficient. Science is not established by a consensus.

I will give you the benefit of the doubt and assume that you didn’t see my reference to Sagnac’s and Michaelson Morley’s experiments.

For information on Sagnac:
https://en.m.wikipedia.org/wiki/Sagnac_effect

For information on Michelson Morley:
https://www.google.com/amp/s/www.th.../michelson-morley-the-great-failure-63642/amp

 

[Ophiolite]

No, that’s not sufficient. Science is not established by a consensus.

Yes, it is: a consensus of experts working on observations, hypotheses and experiments before reaching a provisional conclusion, typically expressed as a theory. (All scientific conclusions are provisional.)

I'll give you the benefit of the doubt and assume you didn't understand the material you presented on the Sagnac effect. From the wikipedia article you linked to: "Sagnac believed that his results constituted proof of the existence of a stationary aether. However, as explained above, Max von Laue already showed in 1911 that this effect is consistent with special relativity."

I'll give you the benefit of the doubt and assume I wrote unclearly. Let me clarify: to claim that the Michelson-Morley experiment did not refute the notion of the aether, or to imply that there have not been other experiments validating this conclusion, without mentioning that the consensus view of science is that the aether does not exist, is either profoundly ignorant, or seriously dishonest.

Is that sufficient? It is for me. You are welcome to your own opinions, not your own facts.

 

[essentialsaltes]

There are some classic experiments that support this theory but they are generally suppressed in the classroom.

---

For information on Sagnac:
https://en.m.wikipedia.org/wiki/Sagnac_effect

For information on Michelson Morley:
https://www.google.com/amp/s/www.th.../michelson-morley-the-great-failure-63642/amp

M-M is the classic experiment taught in all relativity texts that demonstrates that there is no aether. The Sagnac effect is well-understood in relativity, as your reference indicates.

 

[FrumiousBandersnatch]

However, it has been observed that " black holes" are spitting out material.

https://blogs.scientificamerican.co...omers-catch-black-hole-spitting-out-material/

Makes one wonder if they really know anything at all.

The material ejected comes from the orbiting disk of accreted material outside the event horizon, not from inside the BH itself.

 

[Tom 1]

Well, let's take it back a step. What is a wave?

 

[FrumiousBandersnatch]

The consensus, made up of practically all physicists, astronomers, cosmologists and other relavent specialists, is that the aether does not exist. Glibly asserting it does, without noting this is an outfield view, is intellectually dishonest. Implying that this is some conspiracy, rather than a sensible rejection of a long and solidly refuted hypothesis, is at best silly, certainly paranoid and at worst simply crazy. Doing this without an ounce of supporting citations is amateurish, or worse, suggests a disrespectful view of the intellect of your target audience.

Is that sufficient for you?

Einstein did make comparison between traditional aether and the requirements of Special and General Relativity. He basically suggested that if you must have some concept of an aether, then it would be the spacetime of GR, but it's very different from the traditional ideas of an aether.

"... we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an 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 space and time (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."
Ether and the Theory of Relativity​

 

[Ophiolite]

Einstein did make comparison between traditional aether and the requirements of Special and General Relativity. He basically suggested that if you must have some concept of an aether, then it would be the spacetime of GR, but it's very different from the traditional ideas of an aether.

"... we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an 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 space and time (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."
Ether and the Theory of Relativity​

Indeed. I was, perhaps, being overly concise. The ether has had multiple definitions, some of which have existed in parallel. Your clarification is welcome.

 

[Dig4truth]

The material ejected comes from the orbiting disk of accreted material outside the event horizon, not from inside the BH itself.

How was this observed or established?

 

[Dig4truth]

Yes, it is: a consensus of experts working on observations, hypotheses and experiments before reaching a provisional conclusion, typically expressed as a theory. (All scientific conclusions are provisional.)

I'll give you the benefit of the doubt and assume you didn't understand the material you presented on the Sagnac effect. From the wikipedia article you linked to: "Sagnac believed that his results constituted proof of the existence of a stationary aether. However, as explained above, Max von Laue already showed in 1911 that this effect is consistent with special relativity."

I'll give you the benefit of the doubt and assume I wrote unclearly. Let me clarify: to claim that the Michelson-Morley experiment did not refute the notion of the aether, or to imply that there have not been other experiments validating this conclusion, without mentioning that the consensus view of science is that the aether does not exist, is either profoundly ignorant, or seriously dishonest.

Is that sufficient? It is for me. You are welcome to your own opinions, not your own facts.

I'm sorry, but in science consensus means nothing. Empherical evidence is the definition of science and not what a bunch of people believe or want to be true.

In both examples I gave of empherical evidence it was only "overturned" by theory. Theory does not beat empherical evidence. You know, observable, testable and repeatable?

Einstein wanted to do away with the aether so he theorized that the measuring ruler shrank. How did he test that? Can you show me the demonstration of this effect? You are aware that this is why he came up with SR, right?

 

[essentialsaltes]

Einstein wanted to do away with the aether so he theorized that the measuring ruler shrank.

Wrong! Because the Michelson-Morley experiment showed no aether, FitzGerald hypothesized length contraction as a way to save the aether theory.

How did he test that?

Einstein was not much of an experimentalist. However, he presented the correct way of thinking about the result based on the Lorentz invariance of the laws of electromagnetism.

Can you show me the demonstration of this effect?

Certainly. The fact that cosmic ray muons reach the surface of the earth in measurable numbers is an easy example. From the perspective of the muon, our rapidly moving atmosphere is contracted making it easy to traverse during the short lifetime of the muon. [From our perspective, the rapidly moving muon has a slower clock making it easy for it to traverse the atmosphere during its dilated life time.]

You are aware that this is why he came up with SR, right?

Einstein didn't have a grudge against the aether. It had already been largely dissipated by the Michelson-Morley experiment.

 

[Dig4truth]

Wrong! Because the Michelson-Morley experiment showed no aether, FitzGerald hypothesized length contraction as a way to save the aether theory.



Einstein was not much of an experimentalist. However, he presented the correct way of thinking about the result based on the Lorentz invariance of the laws of electromagnetism.



Certainly. The fact that cosmic ray muons reach the surface of the earth in measurable numbers is an easy example. From the perspective of the muon, our rapidly moving atmosphere is contracted making it easy to traverse during the short lifetime of the muon. [From our perspective, the rapidly moving muon has a slower clock making it easy for it to traverse the atmosphere during its dilated life time.]



Einstein didn't have a grudge against the aether. It had already been largely dissipated by the Michelson-Morley experiment.

Ether lives on in the sense in which Einstein understood and used it. He views it as physically real in some sense and sets it on equal footing with matter. It is not too great a leap to interpret his ten gravitational potentials in terms of dimensions and/or quantum states, not necessarily equivalent to these but somehow related. In the end, when all is said and done, we have an Einsteinian space-time that is unabashedly and intricately geometrical, one which finds room for matter/energy and the ether too.


https://www.quora.com/Why-do-so-many-physicists-oppose-the-ether-and-Einsteins-idea-of-the-ether

 

[essentialsaltes]

Ether lives on in the sense in which Einstein understood and used it.

"To hear him speak of this gravitational ether, it is difficult to discover any distinction drawn between it and space-time itself."

 

[FrumiousBandersnatch]

No, that’s not sufficient. Science is not established by a consensus.

In fact, it is the science that establishes the consensus...

 

[FrumiousBandersnatch]

How was this observed or established?

The physics of such accretion discs has been studied, and observed around other celestial bodies, e.g. neutron stars; the material accreting at extremely high velocities can generate very high temperatures, powerful jets of radiation from the 'poles', and intense magnetic fields that twist and rupture, spewing material into space (similar magnetic torsion and breakage happens around our sun, causing coronal mass ejections). Other mechanisms may also be involved, but - by definition - nothing escapes the event horizon (bar Hawking radiation).

 

[FrumiousBandersnatch]

"To hear him speak of this gravitational ether, it is difficult to discover any distinction drawn between it and space-time itself."

Quite. His 1920 lecture was to a group of aetherists, so he described spacetime in terms of an analogy familiar to them.

What's in a name? spacetime by any other name would be as relativistic...