Dear csteele,
>>However using your strict definition <<
I have certainly not defined “constant velocity” or other terms that are found in any first year textbook on physics or applied mathematics.

>> where in the universe would we ever find “two … planets or stars moving at constant velocity with respect to each other”? <<
I certainly don’t know. You will have to ask the author of the strange article http://en.m.wikipedia.org/wiki/Speed_of_gravity#section_5 that you yourself brought up here. I cannot understand what it is trying to say, but I can understand first year material on mathematics and physics.

As to http://www.metaresearch.org/ I could not put it better than Poirot. The author, Thomas Van Flandern, is arguing against the majority view among theoretical physicists, perhaps not unlike people like William A. Dembski who argue against evolution and natural selection against the majority view among biologists.

I cannot follow Dembski’s arguments using advanced mathematical statistics as I cannot follow Van Flandern’s arguments from astronomy and experimental physics. So in both cases I rather trust the overwhelming majority of specialists in the particular fields. Especially since what I know and understand about the matter coincides with that majority view.

Poirot,

Thanks for the entertaining quotes (concerning Special Relativity) from the book by Brian Greene. Perhaps you would be interested in his recent article “Is mathematics the root of reality?” (http://www.newscientist.com/article/mg21729062.400-physics-crunch-is-mathematics-the-root-of-reality.html).

Thanks, George - I will check it out : )

csteele,

"I suppose that for a layman like myself comprehensible explanations are often found in less than specialist sites."

I suppose they are - but there's a reason for that. Things like the constancy of the speed of light seem counter-intuitive. But these things are also mathematically proven. Time and time again mathematicians and physicists find it to be true.

My take is if you're a layman and having trouble digesting things which are counter-intuitive, you should start with the basics and work your way up - aiming toward the understanding that physicists and mathematicians possess - rather than starting out at skeptical sites (which you might like to visit if, having garnered a good insight into those disciplines, you still think the theory is wrong)

An interesting article on "spinning" black holes.

http://theconversation.edu.au/cutting-through-the-spin-on-supermassive-black-holes-12528

Poirot,

>> Things like the constancy of the speed of light seem counter-intuitive. But these things are also mathematically proven. Time and time again mathematicians and physicists find it to be true.<<

Mathematics cannot “prove” anything about the physical world. It is the physicists, both theoretical and experimental, who decide that this or that mathematics “adequately” - in the sense of making experimentally verifiable predictions - models (the part of) physical reality (that they are concerned about). Mathematics can only prove statements like A implies B, and until Goedel it was assumed that mathematics was just part of formal logic.

“As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality” (Einstein)

Many years ago, as an undergraduate student, I was also puzzled and disturbed when first trying to understand the consequences - as I saw them - of Einstein’s (special) theory of relativity. The whole world seemed to come down, everything in that theory seemed to be against common sense or even logic.

It was not until I came across a book that properly explained the mathematics behind the theory that I realised, that what I held to be common sense was simply the setup of Newtonian physics that needed to be abandoned, or rather extended, not common sense (though common sense at this level became somehow irrelevant). And certainly not mathematics which remained the clear symbolic frame of reference compatible with both the old and the new physics.

So what you referred to as “counter-intuitive” is perhaps in fact just “counter” our being used to Newtonian physics (and the strict separation of “absolute” space and time).

I once read somewhere a speculation that for Aquinas it would have been easier to understand Einstein than Newton. Well, I am not sure to what extent was this philosopher able to put himself into Aquinas’ intuition about what today we call physics, but still.

Yes, George,...thanks for that. Right you are.

I remember you and I swapped that quote by Einstein in a thread once before. It's a wonderful quote.

Thanks for elucidating your feeling on understanding the mathematics and how it helped you understand the shift. I can only glean the incredible extension from Newtonian physics from a layman's point of view.

I'm spellbound by the kind of things that Einstein intuited. Of course, the simplicity of his realisations rested upon his prior knowledge, and also the knowledge he gleaned from his contemporaries. So both the simplicity and the complexity needed to be in the same person at the same time - a lot of circumstances came together to place him in the patent office in space and time to allow him the freedom to let his mind roam.

I'm also struck by the humanity and humility that comes through in his writing. It's that, as much as anything else, I think, which draws me to him.

Dear Poirot,

Sorry, came close to being sucked into a black hole it seems.

Thank you for your post. I consider myself suitably chastised. Guilty pleasures are sometimes hard to give up but I will endevour sticking to reputable science sites from now on.

For quite a few years I have had on my phone 3 podcasts on Einstein from 'Einstein & the Mind of God' by Speaking of Faith with Krista Tippett. They are titled Einstein's Ethics, Einstein's God, and The Mind of Einstein and I commend them to you.
https://itunes.apple.com/us/itunes-u/einstein-the-mind-of-god/id387565038

Truly a great and inspirational man and I try to remember to re-listen to these every few months, particularly the one on his ethics. We all need centring and reminding of a standard on occasion and this does the trick for me.

I hope you get a chance to enjoy them.