Chapter 3


The Hafele-Keating Experiment



“I particularly noted a regular practice of not re-examining the fundamental assumptions underlying a theory once it gained ‘accepted’ status, almost no matter how incompatible some new observation or experiment might be.  And I saw powerful vested interests in a ‘status quo’ develop around certain accepted theories.”

Tom Van Flandern



Description of the Experiment


The next experiment to be discussed is the Hafele-Keating ("H-K") experiment of 1971, which was introduced in the first chapter.  In this experiment, the location of the "at rest" observer (i.e. "at rest" reference frame or coordinate system) is much more significant than it was in the SLAC.  This is because the velocities of the objects in the H-K are no where near the speed of light, thus unlike the SLAC, the location of the "at rest" reference frame is very important.  In fact, the velocity of the objects in the H-K is slower than the rotation velocity of the earth.


Hafele and Keating flew four cesium atomic clocks around the world in commercial jet airplanes; first all 4 clocks were flown eastbound around the world, then they were flown westbound around the world.


After the experiments, Hafele and Keating published two articles in the same issue of Science.  In the first article, there are detailed predictions of the time changes in the atomic clocks due to both kinematic (SR) and gravitational (GR) affects. It was impossible to make these predictions until after the experiments were completed because they had no way of knowing in advance how fast the jet airplanes would be flying or at what altitudes they would be flying, etc.


In the second article they have the actual data of the experiments.  In this article it was impossible to segregate the actual time differences in the clocks between gravitational and kinematic (i.e. velocity and direction) affects because it was impossible to have separate clocks measuring separate effects.  Thus their predictions include a separation between the gravitational effects and the kinematic effects, but their actual data cannot make this separation.  Here is the predicted data, based on the actual jet airplane flight data:


Predicted Data

Direction of Airplanes





144 +/- 14

179 +/- 18


-184 +/- 18

96 +/- 10


-40 +/- 23

275 +/- 21


The actual data is as follows: the eastbound clocks lost 59 +/- 10 nanoseconds and the westbound clocks gained 273 +/- 7 nanoseconds.  The authors felt the experiment was very successful - and it was.


Note especially that the atomic clocks in the westbound plane actually operated at a faster rate than the stationary clock due to kinematic effects, but that the eastbound plane operated at a slower rate than the stationary clock due to kinematic effects.  Direction had no affect on the gravitational part of their predictions except that the jets flying westbound must have flown at a different average altitude (no doubt higher) than the jets that flew eastbound.  Or other factors could have come into play, such as latitude.


Now let's elaborate on why the rotation of the earth was the real issue behind the importance of the direction the airplanes flew.


A drawing in an article by Hafele, which was undoubtedly sent to the publisher before his experiments were performed in October of 1971, clearly demonstrates what he meant by his "nonrotating observer looking down on the North Pole from a great distance."[9] This same drawing explains why direction was so important.  I will describe the same concepts using the center of the earth as the "at rest" reference point.  Actually, any point on the elongated, imaginary axis of the earth could have been used as the "at rest" reference point.


If a nonrotating person were sitting at the center of the earth looking up at the stars (let us assume the earth is hollow), the person would think he is stationary and that a stationary atomic clock sitting on the surface of the earth was in motion.  From the North Pole the earth rotates counterclockwise.  From the center of the earth the person would be at the center of a rotating disk (the equator would represent the edge of the disk), and the stationary atomic clock would appear to move in a direction defined to be "east."


For example, using "round numbers” (i.e. approximations in order to focus on concepts), suppose the earth rotated at exactly 1,000 mph on the equator.  If a nonrotating person were sitting at the center of the earth looking up at the stars, a stationary atomic clock on the equator would appear to be traveling at 1,000 mph eastbound due to the rotation of the earth.  It would look much like a satellite.


Thus, if the westbound jet traveled at 350 mph, on the equator, then the person at the center of the earth would see the westbound clock moving at 650 mph eastbound.  That is, the earth would rotate the westbound jet at 1,000 mph eastbound, but the westbound clock and jet would fly westbound at 350 mph, thus giving a net velocity of 650 mph eastbound (1,000 mph east minus 350 mph west).


Because the clocks in the westbound plane appear to move slower than the stationary clock (650 mph eastbound versus 1,000 mph eastbound), relative to this observer, according to the SR, the clocks in the westbound plane would operate at a faster rate (i.e. faster actual time) than the stationary clock.  That is what Hafele and Keating observed.


Likewise, to a person at the center of the earth, the eastbound plane (i.e. the clocks in the eastbound plane) would appear to be moving at 1,350 mph (1,000 mph rotation of the earth velocity plus 350 mph ground velocity, both eastbound).  Thus, the eastbound clocks would operate more slowly than the stationary clock because of their faster relative velocity.  This is also what was observed.


The SR formulas were applied to 650 mph (westbound plane, the fastest clock), 1,000 mph (stationary clock) and 1,350 mph (eastbound plane, the slowest clock).  These are my very simplified numbers, not the actual data as shown above.


What their experiments prove is that a jet airplane's velocity and direction have a predictable affect on "actual time" changes recorded by atomic clocks inside of the airplanes.  Planes that fly eastbound decrease their "actual time" and planes that fly westbound increase their "actual time," both relative to a "stationary" atomic clock.  But remember that the "stationary" clock is also in motion relative to the center of the earth.  For now I am ignoring the factors that involve general relativity, namely altitude.


Hafele and Keating applied the special relativity formulas to two types of coordinate systems.  The first type was the nonrotating "at rest" coordinate system which consisted of a point on the extended axis of the earth ("a nonrotating point high above the North Pole").  According to Einstein, the axis of a rotating disc should be the one and only "at rest" reference frame of a rotating disc.[12]  This was not in his original 1905 paper, but it came later.  Thus, Hafele and Keating used a point on the axis of the rotating earth as their "at rest" reference frame.


The second type of coordinate system was the atomic clocks, which were part of the experiments.  Each atomic clock, even the stationary clock, was considered to be a coordinate system that was in motion relative to the "at rest" reference frame, or reference point to be more accurate.  In the original SR there was only one type of coordinate system, the objects in the experiment, and the "at rest" reference frame was any of those objects.



Introduction to Ether and the H-K


If we consider Michelson's model of ether drag, since all of the ether inside the ether drag is at rest, and does not rotate with the earth, the axis of the rotating earth is at rest because it is not in motion relative to the ether drag.  In other words, the axis of the earth is not spinning with the earth (it is the center of a rotating disc), thus it is not in motion relative to ether drag.  Thus, the velocity of all objects relative to the stationary ether in the ether drag has the same velocity (of these objects) relative to the axis of the rotating earth.  Thus, the special relativity "at rest" reference frame is effectively the same as the ether drag "at rest" reference frame (i.e. the ether drag itself).  In fact, Hafele and Keating could have used either the PRM (Photon/Relativity Model) "at rest" reference frame or the "bubble" of ether drag and the velocity of the objects in their ambient ether.


If ether causes resistance to the SLAC electrons, it also caused resistance to atoms inside of the atomic clocks.  Exactly how the ether might affect the frequency of the atomic clocks is not known, but most likely it has to do with resistance to the cesium atom electrons (which would be more affected by the ether than the very heavy nucleus).  The velocity of an atomic clock, relative to the stationary ether, will have a direct affect on how much resistance is experienced by the cesium atoms.  Thus, if the jet goes "relatively" faster in the ether drag (i.e. faster in the ambient ether) the atoms will be affected by additional resistance and the frequency change will cause "actual time" to slow down.  It the airplane goes "relatively" slower in the ether drag the clocks will speed up because of lessened resistance.


The H-K experiment is very similar to the SLAC experiment, in the sense that ether is causing resistance to electrons, but there are two differences.  The first difference is that in the H-K each electron is part of an atom.  The second difference is more complex and needs some explanation.


In the SLAC, the velocity of the electrons could be controlled by human beings by simply increasing or decreasing the amount of energy that was applied to the electromagnets.  When an electron is attached to an atom, that is not possible to do in the same kind of way.


When an electron is attached to an atom, it is generally assumed by scientists that the electrons in atoms move at the same velocity at all times.  Suppose an electron has resistance applied to it.  In order for this electron to maintain the same velocity in the atom, there must be something in the atom that detects the change in resistance and there must be some mechanism in the atom that can physically change the energy to the electron so that the electron can maintain a constant velocity.  The energy must be added, if resistance is increased, or must be reduced, if resistance is reduced.


For example, let us suppose one person spins a globe.  Suppose another person pushes their hand against the globe causing resistance to the globe's surface.  In order for this globe to continue spinning at a constant velocity the resistance must first be detected and then another force must offset the resistance to the globe's surface.  The same thing must happen in an atom if an electron is to spin at a fixed velocity.  But there is nothing in an atom to detect a change in resistance and there is nothing, that we know of, that can adjust the energy to the electron so that it will spin at the same velocity.


The only logical conclusion to draw is that when the resistance to electrons increases or decreases, the electrons physically slow down or speed up, respectively, and the "time" measured by the atomic clock slows down or speeds up, respectively.


Even if an airplane were flying such that the ambient ether wind was zero (i.e. it was flying westbound at the exact rotation speed of the earth), ether would still be surrounding each atom and would still be providing resistance to the electrons.  In other words, ether is always applying resistance to electrons, even if the atoms are "at rest" relative to their ambient ether.


However, if one airplane is flying slower than another airplane, relative their ambient ether, the slower plane (i.e. the atoms in the slower plane) will experience less resistance due to the ether than the faster plane.  This means that its electrons will be moving faster and its time will measure time faster.  Note that the electrons in human bodies experience resistance to ether, thus "actual time" as measured by human beings would also speed up and slow down, though such a change could not be measured at the velocities of jet airplanes.


In summary, if there are three planes, and they are all moving at different velocities, relative to their ambient ether, they will measure time differently.  The slowest plane, relative to ambient ether, will measure the fastest time and the fastest plane, relative to ambient ether, will measure the slowest time.


(Note: In this book I talk about electrons physically "speeding up" and "slowing down."  This is based on the model of atoms currently in use.  Should the model of atoms change, such as the discovery of "ether drag" at the atomic level, or the discovery of some new type of substance that surrounds each atom and stores the energy in atoms, the concept of "speeding up" and "slowing down" could very easily become outdated.)


(Note: I should also mention that it has been shown that all atomic clocks on the surface of the earth experience the same "actual time," even for atomic clocks at different latitudes.  In simplistic terms, the gravitational differences on the surface of the earth offset the kinematic differences on the surface of the earth due to latitude.[18])


As mentioned in Chapter 1, the concept of "relative reference frames," that every reference frame can be considered to be "at rest," is false (i.e. it is false to claim that every reference frame can be considered "at rest" relative to any other reference frame).  Every reference frame must be compared to its ambient ether, which is essentially a local URF or local ARF.  Ether, of course, is not uniformly stationary throughout the universe, thus the concept of "ambient ether" has yet to be well understood.


In the "old SR" any two moving reference frames could be directly compared to each other.  In the ether theory, two reference frames can only be compared to each other indirectly, meaning each reference frame must first be compared to its ambient ether and then it can be calculated how the two reference frames relate to each other indirectly.  It is a two step process.  First, determine how each reference frame compares to its ambient ether, then step two is to compare the two reference frames indirectly to each other.  Thus the ether theory has no problems with the "clock paradox" or the "twin paradox."


(Note: What if the ether surrounding an atom were removed (physically or effectively) and the atom was sitting in an ether vacuum?  Would its electrons spin so fast that they would literally fly off of the atom or would the electrons collapse into the nucleus?  This, and many other questions, are very interesting to think about with respect to ether.)


(Note: It is also possible that it is the ether that is causing the electrons to spin in the first place, either directly or indirectly, by applying energy to the atom.  I have often wondered how electrons get their energy.  In other words, why is it that electrons can continuously spin around a nucleus for billions of years?  Where does their energy come from, meaning how does an electron spin at roughly the same speed for billions of years?  The answer is certainly not inertia.  It is not likely that a nucleus contains enough energy to support its electrons for that length of time.  Something from outside of the atom probably supplies the energy to either the nucleus or to the electron during the lifetime of an atom.  It is very logical to think that this outside energy source is ether.  This would imply, and ponder this carefully, that the ether might be an energy source!  Alternatively, it is possible some source of energy elsewhere in the universe is transmitting energy through the medium of ether.  It has been stated by multiple people that in a vacuum, even the size of a coffee cup, there is an enormous amount of energy.  It is clear that Tesla tapped into that energy source, though to what degree this is true is not clear.)



What is the Direction of the Ether Wind?


In this first example imagine you are sitting on a flatbed train car.  Suppose there is no wind and you are sitting perfectly still.  Suppose the train, and you, are facing east and that the train is moving at 60 kph.  You will feel a 60 kph wind in your face.  Now let us suppose the train, and you, are facing east, but the train is not moving.  In what direction would the wind have to move in order for you to have exactly the same wind in your face?  The answer, of course, is westbound.  If both you and the train are facing eastbound and are stationary, and if a 60 kph wind is moving to the west, you will have the same feeling on your face as if there were no wind and the train were moving eastbound at 60 kph.


In this second example remember that with ether drag, the earth rotates underneath the ether in the ether drag.  Let us compare this second example to the first example.  The motionless wind in the first example is equivalent to the motionless ether in the second example.  Suppose you are facing east in both examples.  Now let us compare the moving train in the first example to the rotating (surface of the) earth in the second example.  In other words, just as the moving train pushes you trough the motionless air, the rotating earth is pushing us through the motionless ether because the earth rotates underneath the motionless ether.  If you could feel the ether wind (which you can't), and you were on the equator, you would feel it hit your face at a 1,600 kph clip.  Therefore, in what direction does the ether wind effectively move?  Just as in the first example, it effectively moves westbound.


Even though the ether is motionless, or almost motionless, the rotation of the earth through this ether has the same effect as if the earth were stationary and the ether was moving at 1,600 kph westbound on the equator.


Now let us consider the jet airplanes in the H-K.  The westbound flights would have been flying in the same direction as the ether wind, causing less resistance (than a stationary clock) and would measure faster time (than a stationary clock).  Likewise, when the flights were headed eastbound, they would have been flying into the ether wind, thus causing more resistance and slowing time down.


Since we are assuming that the earth rotates at exactly 1,000 mph at the equator, an atomic clock on the equator would have the equivalent of a 1,000 mph ether wind applied to it.  The westbound clock would be flying with the ether wind, thus its speed relative to ambient ether would be 650 mph (1,000 mph minus 350 mph since both the wind and plane are moving in the same direction).  The eastbound clock would be flying into the ether wind, thus its speed relative to ambient ether would be 1,350 (1,000 mph plus 350 mph because they are moving in opposite directions).  These are the same simplified numbers we calculated above.


Thus the ether theory makes exactly the same predictions as the SR as to whether the clocks speed up or slow down relative to a stationary clock, and by how much.  This should not come as a surprise because both the H-K "at rest" reference frame and the ether drag reference frame generate exactly the same coordinate system.


Assuming the ether drag theory, the H-K proves the existence of the ether wind and it proves that the earth rotates underneath the ether drag as stated by Michelson!