It is a nice game: Pretend that c, the speed of light in the vacuum, were a global constant of nature. Then the Einstein equation assumes a more compact form. And black holes acquire radically new properties. One should not try to produce them down on earth, for example.
Fortunately, this simple game is pure fiction. Presently, Stephen Hawking’s safety guarantee to the planet – the rapid “evaporation” he described – renders miniature black holes innocuous, his recent modifications notwithstanding.
There are some voices that c is indeed globally constant (http://eujournal.org/index.php/esj/article/view/2608/2469 ). Would this be a reason to look at the issue anew for Hawking and others?
Otto -
Einstein first mentioned variable speed of light around 1907, and a few years later (1911?) elaborated on this, on the hypothesis that that the speed of light in a gravity field is a function of position — though he soon gave up on these ideas. And although a very recent paper suggestes that the speed of light in a vacuum may not afterall be constant — varying slightly (The quantum vacuum as the origin of the speed of light — Urban, Couchot, Sarazin, Djannati-Atai, March 2013, European Physical Journal http://www.popsci.com/science/article/2013-03/speed-ligh…tudy-finds), the constant c in a vacuum has been pretty much standard and accepted. A constant c in a vacuum is not questioning mainstream physics http://en.wikipedia.org/wiki/Variable_speed_of_light, or have I missed your point somewhere?
-Tom.\
Otto — Despite your silence on comments, I’ve reasoned you are referring to relativity here and not absolute speed of light, which of course is constant. I will respond in due course, but the gist is that you are claiming Einstein’s General Relativity is incorrect that light appears to vary with the intensity of the gravitational field to the outside observer?
Dear Tom:
Forgive me tha I had not responded to the misunderstanding you had posted about c being a global constant in physics in your mind.
Physicists will not agree with this.
“Absolute” constant is not the same as “global” constant.
Also I do not claim general relativity is incorrect. It is the most marvelllous and improbable finding of history. It only needs to be re-scaled properly. This will be easy to do. Nevertheless only someone who comes from the outside has a chance to succeed. Maybe no one is better equipped than you yourself.
Take care,
Otto
Otto my friend — you put a lot of expectation on me. Am not as well versed in relativity as I should be. I must dig further on the subject matter. Another tune for you — https://www.youtube.com/watch?v=NhjSzjoU7OQ
- Tom.
Thank you for the soul-lifter.