The Speed of Light is Not Constant

[PhysBang]

OK, so let's watch as Farsight again tries to blatantly lie to all of you:

All: PhysBang said this on another forum:

"In a sense, this was done in 1905, when Einstein developed special relativity. This constancy of the speed of light is a postulate of the theory, so it is "shown" through the effectiveness and practicality of the theory. The same is true for general relativity, developed in 1915, which holds that the speed of light is constant at any infinitesimal region of a coordinate system".

Note that the speed of light is constant in an infinitesimal region. That means it isn't constant in the room you're in.

Note that Farsight is here trying to get you to ignore the words "coordinate system", just like he wants you to not actually read the Baez article, but rather take his out-of-context word for it that Baez is endorsing the Farsight-Relativity claim that the speed of light in infinitesimal regions is slower.

 

[OnlyMe]

I really don't understand in what context OnlyMe could have found such a statement by Einstein. But, I don't understand Farsight's objection to the purported paraphrase unless Farsight accepts that Einstein's General Relativity requires a constant and isotropic local physical speed of light.

Some while back I lost almost all of my digitally marked up documents/papers and books, during an OS reinstall, so it is difficult without more effort than I am willing to commit at this time to recover a specific reference.

That said, the reference was most likely from a second or third party account within a paper from the Stanford Encyclopedia of Philosophy. It was not from any published paper of Einstein's. Best recollection.., it was from an accounting of an early debate on the issue of a variable speed of light... Einstein defended the constant speed of light, but was attributed with a statement, that even should the speed of light be variable, it would have no adverse affect on GR.

 

[danshawen]

first,
" This article needs attention from an expert in Physics. "

>> Authority actually means very little in science. Fortunately, authority is not a physical law.

and second,
" The experiments have been repeated many times since then, with increasing accuracy.

" the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potetial "
passing through a medium causes the path/direction to change.

Calculating time delay

" the effect may be considered as a special case of gravitational time dilation "

All very true. But in order for the speed of light to be constant in all cases, the person measuring it would indeed need to be confined to a negligibly small amount of space traveling with it in order to measure it. @krash661: That idea is brilliant, and also something I did not expect, even if you didn't express the idea in those terms.

Let us stipulate: The observer(s) cannot travel with the beam of light or stationed at small intervals of space along its trajectory in order to measure the speed of its propagation.

And under those terms, to an inertial observer sufficiently far removed from gravitation influences, it appears that the speed of light in a straight line is a constant, just as it is for sufficiently small scales.

Does this cheat the premise of the thread? Basically then, all it is saying is that gravity exists. So, what?

 

[danshawen]

Some while back I lost almost all of my digitally marked up documents/papers and books, during an OS reinstall, so it is difficult without more effort than I am willing to commit at this time to recover a specific reference.

That said, the reference was most likely from a second or third party account within a paper from the Stanford Encyclopedia of Philosophy. It was not from any published paper of Einstein's. Best recollection.., it was from an accounting of an early debate on the issue of a variable speed of light... Einstein defended the constant speed of light, but was attributed with a statement, that even should the speed of light be variable, it would have no adverse affect on GR.

Ugh! Philosophy again. One of the things I find most irritating about Sean Carroll's blog, among others, is a predisposition to enter into philosophical debates about science. Philosophy is as old as most scripture and shares with many of those, the property of not saying anything that is much deeper in content than the large numbers of words in their infallibly lengthy essays. Yes, it is possible to play with words, bandy them about, and not say anything at all. Popper, for instance was full of it. He co-opted natural selection as indispensable to science (not a bad idea), and then went on to trash the idea of induction being part of the scientific method simply because he had no clue. The gift that keeps on giving for philosophers; a way to sabotage the scientific method to resemble the workings of pseudoscience (or more to the point, philosophy). Without induction, science can use no instruments at all. That would be induction, you see? Try getting a philosopher to convey that idea in as few words.

 

[krash661]

first,
" This article needs attention from an expert in Physics. "

>> Authority actually means very little in science. Fortunately, authority is not a physical law.

and second,
" The experiments have been repeated many times since then, with increasing accuracy.

" the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potetial "
passing through a medium causes the path/direction to change.

Calculating time delay

" the effect may be considered as a special case of gravitational time dilation "

All very true. But in order for the speed of light to be constant in all cases, the person measuring it would indeed need to be confined to a negligibly small amount of space traveling with it in order to measure it. @krash661: That idea is brilliant, and also something I did not expect, even if you didn't express the idea in those terms.

Let us stipulate: The observer(s) cannot travel with the beam of light or stationed at small intervals of space along its trajectory in order to measure the speed of its propagation.

And under those terms, to an inertial observer sufficiently far removed from gravitation influences, it appears that the speed of light in a straight line is a constant, just as it is for sufficiently small scales.

Does this cheat the premise of the thread? Basically then, all it is saying is that gravity exists. So, what?

there was a time when i thought this poster(#723) was actually one of the non cranks/crackpots.
now, after reading this post,
it has been shown i was competently wrong.
even with obvious statements with these links,
it's still not comprehended or it's completely ignored for an incorrect personal preference.
i give up.

 

[PhysBang]

Ugh! Philosophy again. One of the things I find most irritating about Sean Carroll's blog, among others, is a predisposition to enter into philosophical debates about science. Philosophy is as old as most scripture and shares with many of those, the property of not saying anything that is much deeper in content than the large numbers of words in their infallibly lengthy essays. Yes, it is possible to play with words, bandy them about, and not say anything at all. Popper, for instance was full of it. He co-opted natural selection as indispensable to science (not a bad idea), and then went on to trash the idea of induction being part of the scientific method simply because he had no clue. The gift that keeps on giving for philosophers; a way to sabotage the scientific method to resemble the workings of pseudoscience (or more to the point, philosophy). Without induction, science can use no instruments at all. That would be induction, you see? Try getting a philosopher to convey that idea in as few words.

While I agree that Popper was full of it, that's not good evidence that philosophy of science is bad, since most philosophers of science have moved on from Popper. However, to say that he had no clue is merely to do bad philosophy.

Additionally, it's not good evidence that philosophy is bad simply because they write a lot about the problem of induction; it simply is the case that the problem of induction is a very complicated ans sophisticated subject. Ignoring the details helps few people.

 

[danshawen]

there was a time when i thought this poster(#723) was actually one of the non cranks/crackpots.
now, after reading this post,
it has been shown i was competently wrong.
even with obvious statements with these links,
it's still not comprehended or it's completely ignored for an incorrect personal preference.
i give up.

Likewise, again, just what I was trying to say. Uncanny.

 

[danshawen]

While I agree that Popper was full of it, that's not good evidence that philosophy of science is bad, since most philosophers of science have moved on from Popper. However, to say that he had no clue is merely to do bad philosophy.

Additionally, it's not good evidence that philosophy is bad simply because they write a lot about the problem of induction; it simply is the case that the problem of induction is a very complicated ans sophisticated subject. Ignoring the details helps few people.

If using the scientific method really meant that scientists could not use any previously established results (induction), I would ignore all of my science textbooks, and never use a scientific instrument. Oh, wait, isn't that what a pseudoscience does?

Induction works well in mathematics, even for proofs. Isn't mathematics a science?

 

[krash661]

Likewise, again, just what I was trying to say. Uncanny.

well, i actually have the education, experience, and career.
i'm not the one spewing on the forum with only a basic physics education(without moving higher)
about higher levels of physics that has not even been touched with education, claiming what is establish is wrong.

this is massively typical and amusing with a touch of pathetic.

 

[PhysBang]

If using the scientific method really meant that scientists could not use any previously established results (induction), I would ignore all of my science textbooks, and never use a scientific instrument. Oh, wait, isn't that what a pseudoscience does?

What you write is funny because you think you are making a point.

Not all inductive arguments are the same.

Induction works well in mathematics, even for proofs. Isn't mathematics a science?

No.

 

[danshawen]

well, i actually have the education, experience, and career.
i'm not the one spewing on the forum with only a basic physics education(without moving higher)
about higher levels of physics that has not even been touched with education, claiming what is establish is wrong.

this is massively typical and amusing with a touch of pathetic.

If I have ever suggested that established science is wrong, I apologize I didn't mean to say or write anything like that.

But it is hardly complete.

 

[origin]

If I have ever suggested that established science is wrong, I apologize I didn't mean to say or write anything like that.

But it is hardly complete.

Oh really? So we have not discovered everything there is to know. Gee, how profound of you.

 

[danshawen]

What you write is funny because you think you are making a point.

Not all inductive arguments are the same.

No.

Glad it amused you; that was actually my intention. Mostly, philosophy simply bores me; same old tired arguments, nothing ever resolved. In philosophy 101, we went the entire semester going over Berleley's arguments about what people believe, and then on the last day the prof tore his core arguments literally to bits. It made me wish never to repeat the experience, which was nothing but a waste of time and my (and some scholarship) money.

I would have expected an answer of "No" to the question about whether math is a science or no, from a philosopher.

Math is:
the singularly most successful and meaningful symbolic language ever devised by human beings
the best language for the expression of quantitative relationships in any science
a language in which it is next to impossible to actually vet or debate any philosophical concepts concerning its subject matter, which suits me just fine.

 

[PhysBang]

Glad it amused you; that was actually my intention. Mostly, philosophy simply bores me; same old tired arguments, nothing ever resolved. In philosophy 101, we went the entire semester going over Berleley's arguments about what people believe, and then on the last day the prof tore his core arguments literally to bits. It made me wish never to repeat the experience, which was nothing but a waste of time and my (and some scholarship) money.

I don't need the story; I already knwo you didn't learn anything.

I would have expected an answer of "No" to the question about whether math is a science or no, from a philosopher.

You might not realize that I have a math degree.

Math is:
the singularly most successful and meaningful symbolic language ever devised by human beings
the best language for the expression of quantitative relationships in any science

The language of science is not science. Just like English is not Moby Dick.

a language in which it is next to impossible to actually vet or debate any philosophical concepts concerning its subject matter, which suits me just fine.

Sure. It's not like the philosophy of mathematics was central to philosophy in the 20th century.

(PS. that was sarcasm.)

 

[danshawen]

I don't need the story; I already knwo you didn't learn anything.


You might not realize that I have a math degree.


The language of science is not science. Just like English is not Moby Dick.

Sure. It's not like the philosophy of mathematics was central to philosophy in the 20th century.

(PS. that was sarcasm.)

Surely, you jest? There is a philosophy of math alright; I checked it out, and it's just as bad as Berkeley.

Here's the rub; what you have there seems to be a philosophy about A LANGUAGE
Worse: You aren't discussing it IN THE LANGUAGE IN WHICH IT IS WRITTEN

You don't have a problem with that? There was no one qualified even to teach it when I went to school in the 1970s; that's why they gave us Berkeley. If Berkeley wasn't available, it most assuredly would have been someone else as ancient as they were Greek.

I don't think it even merits serious study, and that was not sarcasm.

 

[krash661]

Math is:
devised by human beings

you should think seriously about this.
in my opinion, it's not true.

 

[zgmc]

you should think seriously about this.
in my opinion, it's not true.

I think discovered would be more appropriate.

 

[danshawen]

Many mathematicians feel the same way, because math gifts you insight for relationships you would have difficulty finding any other way. There is beauty there. Possibly Emmy Noether's insight into symmetry is the most beautiful in recent memory. Without it, we would be nowhere near the understanding we currently have of particle physics.

I have two sons with PhDs; one in math, and the other in physics. I love them both dearly and marvel at what each of them can do with their gifts and tools provided them.

@PhysBang; Please don't take my comments on my personal philosophy about philosophy personally. I mean no disrespect, but philosophy has never taught me anything that I could actually use.

 

[river]

Many mathematicians feel the same way, because math gifts you insight for relationships you would have difficulty finding any other way. There is beauty there. Possibly Emmy Noether's insight into symmetry is the most beautiful in recent memory. Without it, we would be nowhere near the understanding we currently have of particle physics.

I have two sons with PhDs; one in math, and the other in physics. I love them both dearly and marvel at what each of them can do with their gifts and tools provided them.

@PhysBang; Please don't take my comments on my personal philosophy about philosophy personally. I mean no disrespect, but philosophy has never taught me anything that I could actually use.

Thats good

But how does one think outside the box ?

 

[paddoboy]

Thats good

But how does one think outside the box ?

By first standing on the shoulders of giants of the past.