You cannot talk about the speed of light without defining your frame of reference. The measured speed of light in local inertial frames is 299792.458 km/sec. So if you want to make a comparison with "299792.458 km/sec" then you have to make it in a "local inertial frame".

Special Relativity requires the frame of reference to be inertial (travel in a straight line). Since Earth (our local frame of reference) is orbiting the sun then it is not traveling in a straight line, hence it is non-inertial. So when we compare the nominal speed of light with 12000 Lunar Orbits / Earth Day inside the gravitational field of the sun (non-inertial frame) we get 11% difference; however when the geocentric frame is inertial we get zero% difference.

As long as Earth is not traveling in a straight line then any geocentric frame is not inertial, hence NASA's measurement of the lunar orbit is made in a non-inertial frame. So we have to calculate the lunar orbit in an inertial frame starting from the measured one in this non-inertial frame. We need to calculate 12000 Lunar Orbits / Earth Day when the geocentric frame travels in a straight line, on the other hand we already know that outside sun's gravity it would travel in a straight line. But from the equivalence principle we know that these two experiments are equivalent, that is, whenever Earth is inertial you will get the same results as if Earth is outside sun's gravity. We chose to calculate the lunar orbit outside sun's gravity because it is easier to calculate however these two experiments are absolutely identical.

In a local frame non-rotating with respect to sun the moon speeds up when it heads towards the sun and then slows down by the same amount when it heads away from the sun. However in a local frame non-rotating with respect to stars the sectors where the moon speeds up and slows down are actually moving forward inside the orbit by the same angle Earth orbits the sun. In this frame there is a rotational force around Earth. This means that the lunar orbit is influenced by a torque-like force around Earth (twist, assist). As the distance to the sun increases to infinity the lunar orbit loses this twist. When we remove the energy gained from this twist we can calculate the total energy and hence the length of the lunar orbit outside gravitational fields. When the Earth-moon system exits the solar system the geocentric frame travels in a straight line (becomes inertial) and 12000 Lunar Orbits / Earth Day becomes equivalent to the speed of light. The difference in this local inertial frame is 0.01%.

Have you noticed that when you spin on your toes your clothes fling outwards? And that when your spin slows down your clothes settle back inwards? This is what also happens when the Earth-moon system gains or loses rotational kinetic energy, the distance to the moon changes (hence the length of the lunar orbit changes).

Do you know why the same half of the moon always faces Earth? The moon has been facing Earth like this for more than 4 billion years. Just like Earth rotates on its axis once every day with respect to stars, the moon also rotates on its axis with respect to stars. Since the moon keeps facing Earth this means that the moon needs to travel 360 degrees around Earth with respect to stars in order to rotate 360 degrees on its axis with respect to stars. When the moon first formed it was very close to Earth and it orbited Earth once every few hours, today this period is 27 days, and as the moon continues to recede this period will continue to increase; the greater the distance from Earth the greater this period becomes. When this period becomes 50 days, for example, this also means that it will take the moon 50 days to rotate 360 degrees on its axis with respect to stars. So as the moon recedes from Earth its spin with respect to stars slows down, that is, it loses rotational kinetic energy (this is different from moon's kinetic energy due to moon's motion around Earth). If the distance to Earth increases to infinity, the moon would stop spinning with respect to stars and hence its rotational kinetic energy decreases to zero. This proves that the moon's rotational kinetic energy is a function of the distance from Earth. Similarly the total energy of the Earth-moon system is a function of the distance from the sun, that is, as the distance to the sun changes the total energy of the Earth-moon system changes, hence the length of the lunar orbit changes. Since the distance to the sun is not a constant then a definition using Lunar Orbits/Earth Day inside the gravitational field of the sun is impossible. However when the Earth-moon system exits the solar system (becomes isolated) 12000 Lunar Orbits/Earth Day becomes equivalent to the speed of light.

Inertial Geocentric Frame 12000 Lunar Orbits/Earth Day = SPEED OF LIGHT

Speed of Light: 

Lunar Orbits/Earth Day is common to all observers; Km/sec is not.

Suppose that you have a clock and a ruler (which is not rotating with respect to stars) and that you are not accelerating (inertial). Locally (where you are) you will always measure the speed of light at 299792.458 km/sec. However in the presence of gravity if I am at a different location than yours then I could measure the speed of light at your location to be any value smaller than or greater than 299792.458 km/sec. It depends on where I am and where you are (it depends on locations). So in the presence of gravity the speed of light becomes relative (variable depending on the reference frame of the observer). This does not mean that photons accelerate or decelerate. This is just gravity causing clocks to run slower and rulers to shrink. 12000 Lunar Orbits/ Earth Day = 299,792.458 km/s is the speed of light for observers standing outside gravitational fields and looking at light also traveling outside gravitational fields. But an observer near a black hole for example sees the speed of light outside gravitational fields a zillion km/s. This is because the velocity of light appears to vary with the intensity of the gravitational field (See proof at footnote [7]).

From General Relativity we know that an observer standing outside gravitational fields looks at events inside gravitational fields and sees them in slow motion. When he steps inside those gravitational fields he sees them in normal speeds. But now he looks back at where he was outside gravitational fields and sees the events there in fast motion. In our case the event is the moon orbiting Earth. When an observer in stronger gravitational fields, near a black hole for example, looks at the Earth-moon system he does not see the moon orbiting Earth once every month; instead he sees the moon orbiting Earth once every few seconds; he also sees the length of the lunar orbit to be much longer than we see it. This is because the gravitational field that he is in causes his clock to run slower and his ruler to shrink.

Not only observers in different gravitational fields will not agree on the time period for the lunar orbit but also they will not agree on the length of the lunar orbit either. By using classical orbital mechanics we discovered that all observers will see the speed of light outside gravitational fields equal to 12000 Lunar Orbits/Earth Day; but from General Relativity we know that they will never agree on a value in km/sec. An observer near a black hole for example sees the speed of light outside gravitational fields a zillion km/s, but still equal to 12000 Lunar Orbits/Earth Day! This means that if the speed of angels outside gravitational fields were defined in km/sec then it will appear to vary for observers in different gravitational fields; however since this speed was defined in Lunar Orbits/Earth Day then it will never appear to vary to anyone because 12000 Lunar Orbits/Earth Day is common to all observers. Hence the Quran gave us a better definition for time and distance: A definition common to all observers, forever!!!

Muslims ask how could an illiterate man who lived 1400 years ago have figured out the three-body problem, speed of light and general relativity?

[1] It is the angels who execute God's orders:

"Mudaberat" in Arabic means execute and "Amr" means order. These exact two words are also used in describing the rate at which God's orders are executed:

Both these verses use the same words and both refer to angels. "Araj" means a man with a lame leg; "Yaruj" means a man stepping. This verse particularly says "Yaruj" describing angels taking steps. The measure of these steps is called distance. The distance traveled by angels in one day is 12000 lunar orbits.

About the Preserved Tablet:

^{[Quran 85.21-22]} But it is a Glorious Quran. ²² Inscribed on a Preserved Tablet.

Muslims believe that Archangel Gabriel got the Quran to their prophet from this Preserved Tablet:

^{[Quran 15.8-11]} We only send down the angels in Truth; if they were not (in truth), no respite would they have. We have sent down the Message and We will preserve it. We did send Messengers before you among the religious sects of the old, but never came a Messenger to them but they mocked him.

The Quran and all the instructions to all angels were inscribed on this Preserved Tablet before the creation of Earth started. They commute to and from this Tablet to get their orders from God. The angels were originally made of light (they are not light anymore just like we are not clay anymore), and the speed at which they commute to and from this Tablet turned out to be the known speed of light.

[2] What would happen if Earth suddenly stopped in its track while orbiting the sun? Earth would plummet into the sun, right? If it were not for distant stars then how would you know that Earth is orbiting the sun? Maybe it is the sun that is orbiting Earth. Or better yet, maybe Earth and sun are both fixed in their positions. So how do you know? It is the background of distant stars that tells you which is orbiting which.

Our physics today simply does not work with the synodic system. For example, this equation gives you the distance to the moon by simply knowing the sidereal lunar month (27.3 days):

If you use the time for synodic lunar month (29.5 days) it gives you the wrong distance to the moon (consequently wrong energy, wrong momentum...). But what you should keep in mind is that the equations in the sidereal system have no counterpart in the synodic system.

Although the moon keeps facing Earth it is actually spinning with respect to distant stars. Since the moon is spinning then it should bulge at the equator, right? However an observer on Earth sees the bulge but does not see the spin of the moon. When we calculate the bulge from spin with respect to Earth we get the wrong value (does not match observation). When we calculate the bulge from spin with respect to the sun we also get the wrong value. However when we calculate the bulge from spin with respect to distant stars we get the correct value. This should tell you that the bulge is a consequence of the spin with respect to distant stars (neither with respect to Earth nor with respect to the sun). This is why classical orbital mechanics (and general relativity) are based on the sidereal system, that is, rotation (and precession) are with respect to stars.

Some skeptics argue that due to Earth's motion around the sun the length of the lunar orbit is longer for an observer on the sun, however this is also false. Why? Because the distance between Earth and the moon (R) is the same whether measured from Earth, from the sun or from the center of another galaxy... And since the length of the lunar orbit is simply 2πR then the length of the lunar orbit is the same for an observer on the sun, on the moon, Andromeda... Actually you should deduce from the above equation that R is measured the same for any observer in the Newtonian limit (non-relativistic).

The sidereal system is a local frame non-rotating with respect to stars. The difference between a local frame non-rotating with respect to stars and a local frame non-rotating with respect to the CMB is extremely negligible and cannot change the result. The effect of our galaxy is also too small to make any difference. The only thing that really matters is the effect of sun's gravity on our local frame of reference.

[3] Consider a spherical mass of weakly-interacting particles (say a gas) and a spherical gravitational source (say the moon). The gravitational force is stronger on the particles of gas closer to the moon than on the particles of gas farther out. The difference in forces makes the sphere of gas to be stretched into an ellipsoid. (General relativity explains why the actual tidal effect generated by a spherical gravitational source is stretching in the radial direction and additional squeezing in the transverse direction). In our case the moon stretches the oceans into an ellipsoid while Earth is too rigid to change shape; so we end up with two tidal bulges one facing the moon and another one opposite to it. This is why we have two high tides a day instead of one.

You might ask why does the much stronger gravitational force of the sun actually produce much smaller tidal bulges than the moon? Well it is not the magnitude of the forces that causes the stretching but rather the difference in forces. Although the sun's gravitational forces are stronger in magnitude, the much bigger distance to the sun causes this difference in forces to be much smaller; hence the weaker stretching and smaller bulges. If the radius of the oceans (or the sphere of gas) was as big as the radius of the lunar orbit then the sun's average gravitational force on the particles closer to and farther out from the sun would be the same as it is today but the increased difference in forces would stretch this sphere into an ellipsoid with bulges thousands of kilometers high. This ellipsoid will always be oriented towards the sun; but as Earth goes around the sun the position of the sun relative to Earth with respect to stars changes. This means that with respect to stars this ellipsoid will always be rotating in order to point to the sun again; this rotation with respect to stars is rotational kinetic energy. As the distance to the sun increases to infinity the position of the sun relative to Earth with respect to stars remains the same, hence as the distance to the sun increases this sphere of particles will lose this twist. This means that sun's gravitational field along with Earth's motion around the sun produce a net rotational force on this sphere of particles (gravitational twist). So the sun exerts gravitational twist on the Earth-moon system in the same way that Earth exerts gravitational twist on the moon.

[4] Sun's gravitational field along with Earth's motion around the sun produce a net rotational force on the lunar orbit (like torque around Earth). Without this gravitational assist the moon's isolated orbital length would only be L' = Lcos�:

In a geocentric frame non-rotating with respect to sun the moon speeds up when it heads towards the sun and then slows down by the same amount when it heads away from the sun. However in a geocentric frame non-rotating with respect to stars the sectors where the moon speeds up and slows down are actually moving forward inside the orbit by the same angle Earth orbits the sun. In this frame there is a rotational force around Earth; a twist or gravitational assist.

This rotational force is evident in the NASA animation of Swift J1644+57, a star consumed by a black hole: 

This means that without the energy gained from this twist Earth day increases to = 86170.43114 seconds (6 seconds increase from 86164.0906 sec).

[6] Have you heard about the solar wind? This is actually mass ejected from the surface of the sun. Also mass is converted to energy at the core of the sun. But when this happens the mass of the sun decreases. Lower solar mass leads to weaker gravitational force between the sun and Earth. Earth that was at the right velocity around the sun now becomes a little bit too fast for this weaker gravitational force (excess kinetic energy). To compensate for this imbalance, Earth recedes a bit from the sun (trades excess kinetic energy with potential energy above the sun). After receding a bit from the sun, Earth slows down a bit and returns to equilibrium. But again more and more mass is ejected from the sun, weaker gravitational forces... and the cycle repeats itself.

Actually any star that loses half its mass loses all the planets around it (its planets fly off). You can find the solution for circular orbits in:

'High Energy Astrophysics', S. Rosswog & M. Bruggen, Cambridge University Press (2007).

This means that any star that loses half its mass will become gravitationally unbound to the planets around it. All the planets around it will simply fly off. In conclusion, the distance to the sun (a star) is not a constant.

[7] Recalling the very famous second postulate of Special Relativity declared by Einstein (1905):

Einstein's theory of special relativity says that the speed of light in vacuum is always measured the same (at 299,792.458 km/s) however this is only true locally for systems that are inertial, which means not accelerating. From Newton's second law: if forces exist implies acceleration exists; this means that if you are in a spaceship and fire your rockets then you are not inertial.

The other factor besides acceleration is gravity. Albert Einstein himself emphasized in his paper in 1917:

In 1915 (10 years after special relativity) Einstein developed another theory called General Relativity that deals with gravitational fields and according to this latest theory the velocity of light appears to vary with the intensity of the gravitational field. For example, an observer outside gravitational fields measures the speed of light locally (in his location) at 299792.458 km/s but when he looks towards a black hole he sees the speed of light there to be as slow as a few meters/sec. At the same time an observer freefalling into that black hole (zero-g) measures the speed of light locally (in his location) at 299792.458 km/s; when he looks towards the black hole he sees the speed of light there much slower; when he looks away from the black hole he sees the speed of light there much faster. If he tries to resist his freefall into that black hole (by firing his rockets for example) he will not measure the speed of light locally anymore at 299792.458 km/s; instead the stronger the g-force that he feels the faster light appears to him. Again when he looks towards the black hole he sees the speed of light there much slower; when he looks away from the black hole he sees the speed of light there much faster. In any case, freefalling or not, he will never see the speed of light outside gravitational fields at 299792.458 km/s. Finally, there is no difference between the effects of g-forces experienced from these rockets and the effects of g-forces experienced when standing on planets, stars... hence an observer standing on a black hole measures the speed of light locally (in his location) much faster than 299792.458 km/s; when he looks towards outside gravitational fields he sees the speed of light there a zillion km/s.

In the presence of gravity the speed of light becomes relative. To see the steps how Einstein theorized that the measured speed of light in a gravitational field is actually not a constant but rather a variable depending upon the reference frame of the observer:

'On the Influence of Gravitation on the Propagation of Light', Annalen der Physik, 35, 1911.

Einstein wrote this paper in 1911 in German (download from: http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1911_35_898-908.pdf). 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:

Whereis the gravitational potential relative to the point where the speed of light c_o is measured. Simply put: Light appears to travel slower in stronger gravitational fields (near bigger mass).

You can find a more sophisticated derivation later by Einstein (1955) from the full theory of general relativity in the weak field approximation:

'The Meaning of Relativity', A. Einstein, Princeton University Press (1955).

See pages 92-93, eqn (107); the variable velocity of light expressed in coordinates is:

Simply put: Light appears to travel slower near bigger mass (in stronger gravitational fields). A non-mathematical discussion of this can be found in:

'The Riddle of Gravitation', Peter G. Bergmann, Charles Scribner's Sons, NY (1987).

See pages 65-66. Bergmann takes the deflection of light by the gravitational field of a star as evidence of the decreased speed of light in a gravitational field.

You can also find modern direct derivations that lead to the same results by Einstein:

'Relativity, Gravitation, and Cosmology', T. Cheng, Oxford University Press (2005).

For the 1911 results see pages 48-49, eqn (3.39):

For the 1955 results but not in coordinates see page 93, eqn (6.28):

Namely the 1955 approximation shows a variation in km/sec twice as much as first predicted in 1911.

Km/sec is a scalar, however gravitational length contraction and time dilation make it impossible to represent the speed of light by a scalar. (Discuss in forum: There is a difference between the radial speed of light and the tangential speed of light. The effects of gravitation can only be accurately represented by a tensor field).

Contrary to Special Relativity, the measured speed of light in a gravitational field is not a constant, but rather a variable depending upon the reference frame of the observer; what one observer sees as true another observer sees as false. The only observers that can actually agree that the speed of light outside gravitational fields is 299792.458 km/s are those who are themselves outside gravitational fields.

[8] The Christian Bible says that in the beginning God said "Let there be light" Genesis 1:3. Well it turned out that in the beginning photons couldn't travel at all. After the Big Bang the universe was primarily Hydrogen, Helium and a tiny bit of Lithium. However when a gas is too hot it becomes ionized (loses the electrons) and becomes opaque (like today's smoke). In the beginning the universe was opaque to visible light (non-transparent). After 380,000 years the universe cooled enough and it became transparent to visible light. For other wavelengths it was opaque for a billion years. So "Let there be light" turned out to be false.

Also the Christian Bible says that the universe was created six thousand years ago. Science says that the universe was created 13.7 billion years ago. We can actually observe galaxies 13 billion light years away; that is, light already traveled 13 billion years before it reached us. This alone proves their Bible wrong. To fix this problem, they need the speed of light to decay (to slow down over time); that is, light was faster and covered that distance in much shorter time. But the theory of relativity says that the speed of light is constant over time (no decay)... Since the theory of relativity contradicts their Bible, they need the theory of relativity to be wrong for their Bible to be correct.

Some Christians claim that Quran 32.5 (angels travel in one day the same distance that the moon travels in a 1000 lunar years) is a restatement of this Bible verse:

^{(2Peter 3:8)} But do not forget this one thing, dear friends: With the Lord a day is like a thousand years, AND A THOUSAND YEARS ARE LIKE A DAY. ⁹ The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance.

Obviously this verse is talking about God's patience, but some Christians say that it predated the scientific miracles of the Quran.

The first problem with this Christian claim is that the Quran is referring to the angels moving and not to God moving. Here in this Bible verse God has to be moving. And assuming that God is moving, not only this verse does not talk about any distance traveled but also Christians and the Jews before them used solar years. The solar year is the revolution of Earth around the sun with respect to distant stars (not related to the lunar orbit).

The Christian solar year is simply the revolution of Earth around the sun with respect to distant stars. So 1000 Earth's Orbits around the sun / Earth Day is 36.5 times faster than light. Moreover during a solar year there are 12.37 lunar months. The Jews used to add a 13th lunar month every few years to make up for the difference between the lunar and the solar calendar. So a year in the Bible is by no means related to the moon.

Second problem, this verse describes time vs. time (and not time vs. distance). So if this time difference (time dilation) is due to the mass of God's Throne then the Bible got it wrong as well: 1 day at God's Throne should measure 2.28 billion years on Earth; instead the Bible says "With the Lord a day is like a thousand years". Here the Bible missed by a whole 2,280,000,000 years! The other part says "AND A THOUSAND YEARS ARE LIKE A DAY", that is, 1000 years by God measures 1 day on Earth. Here the Bible got it in reverse! So how small is God's Throne? Even if God's Throne is microscopic, Earth is not massive enough to generate this time dilation.

Third problem, if this verse was referring to time dilation due to God's movement then it got it all wrong as well. For an object to move it needs to accelerate. But acceleration causes clocks to run slower, the stronger the acceleration the slower the clock; hence the faster moving object experiences slower time and not the other way round. In this verse in the Bible it is man who experiences the slower time hence travels faster than God! Man experiences less time of 1 day (travels fast) and God experiences more time of 1000 years (travels slow). This verse practically says that once God travels faster than man but immediately follows it with a fatal mistake that man travels faster than God. So no, the Bible got it wrong in every possible way.

But the Bible did indeed describe sunlight: Common sense says that sunlight illuminates Earth and that without sunlight darkness will cover Earth. Is there anything simpler? But the Bible says something else: In Genesis 1:1-31, the Bible explains how the sun is related to day and night. The Bible says that on the first day God created the light and darkness on Earth. The first evening came and the first morning followed. But God did not create the sun until the fourth day, specifically after three evenings and three mornings. So three evenings and the three mornings occurred on Earth before there was a sun. So according to the Bible daylight occurs without the sun!

Our sun is a very small star. Actually our solar system (including the atoms that you are made of) came from a dying star 100 times more massive than our sun. Some stars are even bigger than our solar system, so you can imagine how large stars are. However according to the Bible these stars are so small that they could fall on Earth: In Mark 13:24-30 Jesus said that stars will fall on Earth before his second coming. Actually he said that stars will fall on Earth before even that generation pass away. However that generation passed away a long time ago and no star ever fell on Earth nor ever will. Do you know why? Because Earth will vaporize before it even contacts a star; so the events prophesied in the Bible are supposed to occur on Earth when Earth is already vaporized!

The Christian Bible says that the sky is "hard as a mirror of cast bronze" Job 37:18. So the Bible insists on a static universe, non-expanding non-contracting. Actually Albert Einstein's famous blunder, the cosmological constant, was to explain the static universe. Although at that time no scientific evidence existed to support that claim, Einstein gave the Bible the benefit of the doubt and went for a static universe, non-expanding non-contracting. Later, when Edwin Hubble discovered the expansion of the universe, Einstein retracted this cosmological constant and called it the biggest blunder of his career. By trusting the Bible Einstein got it wrong by the order of 10¹²⁰.

While today's scientists have confirmed that animals inherit their colors and stripes from their parents (through DNA), the Bible says something else: In Genesis 30:37-42, the Bible explains how baby goats get their streaked colors: If their parents were mating AND LOOKING at upright rods then the baby goats will have stripes; while if their parents were mating BUT NOT LOOKING at upright rods then the baby goats will not have stripes!

^{[Quran 2.23-24]}  And if you were in doubt about what We have revealed to Our servant, then bring forth a book like the Quran; and call your witnesses (scientists) to prove it contrary to Allah, if you were truthful. ²⁴ But you cannot and will never (be able). So beware of a fire whose fuel is men and stones prepared for blasphemers.

^{[Quran 42.14]}  They only disbanded after they received knowledge (of their Bible) fallaciously among them. And if it were not a word from your Lord [Allah] that postponed it to a later date, it would have been all settled among them then. And those who inherited the Book (the Bible) from them are in great suspicion of it. ¹⁵ Therefore call them (to the Quran) and straighten your ways as you are ordered and don't follow their passions and say: "I believe in what Allah revealed of the Book (The Quran) and I was ordered to be just among you (both Christians and Jews); Allah is our Lord and your Lord, we have our actions and you have your actions, no argument between us and you, Allah brings us together and to Him we are (all) destined."

To Muslims:

^{[Quran 6.108]}  Do not curse those who call (to worship) other than Allah, so that they don't curse Allah out of spite and ignorance. This is how We [Allah] appealed to each people its own actions; then they will be brought back to their Lord [Allah] who will inform them of what they have been doing.