🚀 go-pugleaf

On Jun 21, 1:07 am, Pentcho Valev <pva...@yahoo.com> wrote:
> http://www.nature.com/news/2010/100617/full/news.2010.303.html
> NATURE: "Gravity is mercilessly impartial - on Earth, it accelerates
> light and heavy objects alike with a tug of 9.8 metres per second
> squared. That property is the cornerstone of Albert Einstein's theory
> of general relativity, which states that gravity is indistinguishable
> from any other type of acceleration."
>
> That gravity "accelerates light and heavy objects alike with a tug of
> 9.8 metres per second squared" is true but this is Newton's emission
> theory of light developed by John Michell in the 18th century and
> temporarily adopted by Einstein in 1911. If NATURE's editors were both
> honest and knowledgeable they would have published the following text:
>
> "Gravity is mercilessly impartial - on Earth, it accelerates light and
> heavy objects alike with a tug of 9.8 metres per second squared. That
> property is the cornerstone of Newton's emission theory of light; it
> is equivalent to the fact that, in the absence of a gravitational
> field, the speed of light varies with the speed of the emitter, v, in
> accordance with the equation c'=c+v."
>
> Although in 1911 Einstein was on the right track, in 1915 he spoiled
> everything by making light accelerate faster than cannonballs by a
> factor of two:
>
> http://www.mathpages.com/rr/s6-01/6-01.htm
> "In geometrical units we define c_0 = 1, so Einstein's 1911 formula
> can be written simply as c=1+phi. However, this formula for the speed
> of light (not to mention this whole approach to gravity) turned out to
> be incorrect, as Einstein realized during the years leading up to 1915
> and the completion of the general theory. In fact, the general theory
> of relativity doesn't give any equation for the speed of light at a
> particular location, because the effect of gravity cannot be
> represented by a simple scalar field of c values. Instead, the "speed
> of light" at a each point depends on the direction of the light ray
> through that point, as well as on the choice of coordinate systems, so
> we can't generally talk about the value of c at a given point in a non-
> vanishing gravitational field. However, if we consider just radial
> light rays near a spherically symmetrical (and non- rotating) mass,
> and if we agree to use a specific set of coordinates, namely those in
> which the metric coefficients are independent of t, then we can read a
> formula analogous to Einstein's 1911 formula directly from the
> Schwarzschild metric. (...) In the Newtonian limit the classical
> gravitational potential at a distance r from mass m is phi=-m/r, so if
> we let c_r = dr/dt denote the radial speed of light in Schwarzschild
> coordinates, we have c_r =1+2phi, which corresponds to Einstein's 1911
> equation, except that we have a factor of 2 instead of 1 on the
> potential term."
>
> http://www.speed-light.info/speed_of_light_variable.htm
> "Einstein wrote this paper in 1911 in German (download from:http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/191...
> ). It predated the full formal development of general relativity by
> about four years. You can find an English translation of this paper in
> the Dover book 'The Principle of Relativity' beginning on page 99; you
> will find in section 3 of that paper Einstein's derivation of the
> variable speed of light in a gravitational potential, eqn (3). The
> result is: c'=c0(1+phi/c^2) where phi is the gravitational potential
> relative to the point where the speed of light co is measured......You
> can find a more sophisticated derivation later by Einstein (1955) from
> the full theory of general relativity in the weak field
> approximation....For the 1955 results but not in coordinates see page
> 93, eqn (6.28): c(r)=[1+2phi(r)/c^2]c. Namely the 1955 approximation
> shows a variation in km/sec twice as much as first predicted in 1911."
>
> Nowadays Einsteiniana's marauders do not give a sh-t about either
> Newton's emission theory of light or Einstein's relativity and teach
> anything:
>
> http://www.amazon.com/Brief-History-Time-Stephen-Hawking/dp/0553380168
> Stephen Hawking, "A Brief History of Time", Chapter 6:
> "Under the theory that light is made up of waves, it was not clear how
> it would respond to gravity. But if light is composed of particles,
> one might expect them to be affected by gravity in the same way that
> cannonballs, rockets, and planets are.....In fact, it is not really
> consistent to treat light like cannonballs in Newtons theory of
> gravity because the speed of light is fixed. (A cannonball fired
> upward from the earth will be slowed down by gravity and will
> eventually stop and fall back; a photon, however, must continue upward
> at a constant speed...)"
>
> http://www.hawking.org.uk/index.php?option=com_content&view=article&i...
> Stephen Hawking: "Interestingly enough, Laplace himself wrote a paper
> in 1799 on how some stars could have a gravitational field so strong
> that light could not escape, but would be dragged back onto the star.
> He even calculated that a star of the same density as the Sun, but two
> hundred and fifty times the size, would have this property. But
> although Laplace may not have realised it, the same idea had been put
> forward 16 years earlier by a Cambridge man, John Mitchell, in a paper
> in the Philosophical Transactions of the Royal Society. Both Mitchell
> and Laplace thought of light as consisting of particles, rather like
> cannon balls, that could be slowed down by gravity, and made to fall
> back on the star. But a famous experiment, carried out by two
> Americans, Michelson and Morley in 1887, showed that light always
> travelled at a speed of one hundred and eighty six thousand miles a
> second, no matter where it came from. How then could gravity slow down
> light, and make it fall back."
>
> http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_o...
> Steve Carlip: "Is c, the speed of light in vacuum, constant? At the
> 1983 Conference Generale des Poids et Mesures, the following SI
> (Systeme International) definition of the metre was adopted: The metre
> is the length of the path travelled by light in vacuum during a time
> interval of 1/299 792 458 of a second. This defines the speed of light
> in vacuum to be exactly 299,792,458 m/s. This provides a very short
> answer to the question "Is c constant": Yes, c is CONSTANT BY
> DEFINITION!....Einstein went on to discover a more general theory of
> relativity which explained gravity in terms of curved spacetime, and
> he talked about the speed of light changing in this new theory. In the
> 1920 book "Relativity: the special and general theory" he wrote:
> ". . . according to the general theory of relativity, the law of the
> constancy of the velocity of light in vacuo, which constitutes one of
> the two fundamental assumptions in the special theory of relativity
> [. . .] cannot claim any unlimited validity. A curvature of rays of
> light can only take place when the velocity of propagation of light
> varies with position." Since Einstein talks of velocity (a vector
> quantity: speed with direction) rather than speed alone, it is not
> clear that he meant the speed will change, but the reference to
> special relativity suggests that he did mean so. THIS INTERPRETATION
> IS PERFECTLY VALID AND MAKES GOOD PHYSICAL SENSE, BUT A MORE MODERN
> INTERPRETATION IS THAT THE SPEED OF LIGHT IS CONSTANT in general
> relativity."
>
> Pentcho Valev
> pva...@yahoo.com

And the ignorance fest continues...