Chapter 10
Lunar Laser Ranging Experiments
"It
is easier to find a score of men wise enough to discover the truth than to find
one
intrepid enough, in the face of opposition, to stand up for it."
A. A.
Hodge
The Tilt of Aberration for the Interior Planets
One of
the things I really wanted to know was the “tilt of aberration" for light
from
the
interior planets. It didn’t take long to realize that this determination is
impossible
because no one really knows the actual or exact location of any
planet.
We only know their apparent positions, meaning we only know the
direction
they appear to be as we look at them. It is somewhat of a
paradox. If
we
knew where they were, we would know the tilt of aberration. Or if we knew
the
tilt of aberration, we would know where they are. But we don't know either.
Celestial
mechanics formulas only predict the apparent positions of planets
and
are
unconcerned with their actual locations. Because spacecraft make
numerous
course adjustments during flight, not even NASA or the JPL knows the
exact
position of any of the planets. In fact, no one even knows the exact
location
of the moon because no one knows the tilt of aberration of lunar light,
even
though humans have walked on its surface.
(Note:
Actually, it was known prior to the Lunar Laser Ranging experiments that
aberration
of moonlight was zero, thus they knew the moon was where it appears
to be,
but this was not common knowledge. I will not assume a prior knowledge
of
that fact, I will calculate it anew.)
Fortunately,
Lunar Laser Ranging experiments, which have been done since
1969,
and continue to be done today, provide key information about light and the
moon.
Its value, in the context of this book, is that we know exactly where the
light
from specially designed mirrors on the moon is being aimed.
Introduction to Lunar Laser Ranging
The
experiments that that will now be discussed are called: Lunar Laser Ranging
("LLR")
experiments and are currently being done at facilities such as the
McDonald
Laser Ranging Station facility in Texas ("MLRS").[25] These
experiments
consist of powerful laser beams being bounced off of special types
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of
mirrors, called “retro-reflectors”, that have been placed on the
moon (retroreflectors
will
be discussed in a moment).
The
reason such experiments are important to this book is that we know exactly
where
these mirrors are located on the moon, and just as importantly, we know
exactly
where the returning light is "aimed" by the reflected laser beams!
In
1969, the Apollo 11 astronauts placed a small box on the moon's surface.
This
device was a very special type of mirror: a retro-reflector. Because it was
placed
on the moon it is frequently called a "lunar retro-reflector."
What is
special
about a retro-reflector is that it reflects light back to its point of
origin.[26.27.28]
To
understand this, note that a normal mirror will reflect a 15-degree light ray
away
from the point of origin, meaning the light will exit the mirror at 15-degrees
away
from the point of origin. But a retro-reflector, which actually consists of an
array
or grid of "corner cubes" or "corner reflectors" of
mirrors, returns light back
to the
point of origin. The Apollo 11 retro-reflector contained 100 "corner
cubes."
To make
sure there is no misunderstanding as to what a retro-reflector does,
suppose
you are standing 15 degrees from a vector that is normal to the surface
of a
retro-reflector. If you fired a laser at the retro-reflector, the beam would
come
back and hit you! A retro-reflector does not reflect light at an angle,
as a
normal
mirror does, a retro-reflector is specially designed to send light back to
where
it came from. That is why we know exactly where a retro-reflector is
aiming
its reflected light.
In
total, there were 5 retro-reflectors placed on the moon between 1969 and
1973,
but only 4 of them are functional. The largest of these retro-reflectors, and
the
one most often used in LLR experiments, was left by the Apollo 15 astronauts
in
1971. Retro-reflectors are generally about the size of a small suitcase.
The
major purpose of LLR experiments is to determine various facts about the
relationship
between the moon and the earth and to learn specific facts about the
earth.
For example, measuring the time it takes the laser pulse to make the
round
trip between the earth and moon, at different times of the day, can yield
very
accurate measurements of the distance between the moon and earth. This
assumes
the speed of light is a constant during the trip, which is an assumption
that
will be discussed much later in this book.
In a
LLR experiment, a very short pulse of laser light is fired through a telescope
at one
of the retro-reflectors. The reason the laser is fired through a telescope is
to
"collimate" the laser pulse, which will now be
explained. When light normally
leaves
a laser the angle at which the light leaves the laser is frequently very high,
perhaps
as high as 30 degrees or more, depending on the laser. This angle is
called
“beam divergence”
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Think
of a flashlight. If the angle of light from the flashlight (the angle formed by
the
two sides or edges of the outside of the main beam) was zero degrees
(meaning
the edges were parallel), then 100 yards away the width of the
flashlight
beam would be the width of the flashlight lens. But that is not the case,
the
light from flashlights, and some types of lasers, is very broad, meaning at 100
yards
away the beam might be 30 yards wide or more. When the angle of light
that
leaves a laser is too high, lenses or mirrors can be used to make the beam
divergence
angle smaller. When that happens the size of the beam is wider, but
the
beam divergence is smaller. That is the trade-off, you can have a narrow
beam
coming out with high beam divergence or you can use a collimator and
have a
wide beam coming out, but with small beam divergence.
With
lasers that are shot at the moon, it is very important that the minimum beam
divergence
possible be achieved. This is because only a very, very small
percentage
of this laser light actually hits the small retro-reflector and is returned
to the
earth. Telescopes are used to collimate these laser beams so that the
smallest
possible beam of light (and thus the most intense beam of light on the
moon's
surface) hits the moon. Even though telescopes make the beam very
wide
at the time the beam is shot, the collimation more than makes up for this
wide
beam when the beam hits the moon.
Shooting
through a telescope also provides another benefit. Telescopes have
tracking
mechanisms that are very, very accurate. Thus by shooting a laser
through
a telescope, the pointing of the laser is very accurate. When the beam
gets
to the moon it is about 7 km in diameter and when it returns from the moon it
is
about 20 km in diameter.[28] Only a
very, very small percentage of the 7 km
diameter
laser beam actually hits the retro-reflector, thus only a minuscule
amount
of light actually returns to the earth. Furthermore, only a minuscule
amount
of the 20 km wide returning light actually hits the sending telescope.
Needless
to say, extremely sensitive detection equipment is needed to detect the
returning
light.
The
returning lightwaves are measured by a detection device such as a
photomultiplier
or
photo-diode, which is coupled to the same telescope that fired the
laser.
A telescope is used to capture the returning light because it has a large
diameter
to gather in more light than other devices. Nevertheless, considering
the
ratio of the surface area of a telescope, compared to the 20 km diameter of
the
returning beam, it is clear than an unbelievably small percentage of the light
that
is sent is actually detected after returning from the moon.
In an
LLR, there are three key things to understand:
1) The
optical viewing of the moon through the telescope (which is subject to the
full
370 kps secular aberration of starlight that all light from all other objects
in the
sky is
subject to - assuming the photon theory),
2) The
shooting of the laser through the same telescope that is optically viewing
the
moon,
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3) The
receiving of the laser light after hitting the retro-reflector, by the same
telescope.
In
other words, the same telescope does the optical viewing, the
firing of the
laser
and the receiving of any light that returns from the moon.
To
better understand the significance of LLR experiments, consider this
metaphor:
Two Parallel Car Metaphor
Think
about two automobiles driving nose-to-nose, 30 feet apart, at the same
high
velocity down a highway. Assuming a vacuum, suppose a ball is thrown
from
one car to the other. At the instant the ball is released from
the first car by
one
person, a second person in the first car paints a small mark on the pavement
underneath
the car. In other words, one person releases the ball and a second
person
in the same car simultaneously paints a small mark on the
pavement.
Suppose
that in the time the ball moves from the first car to the second car, both
cars
travel 100 feet. Thus, when the ball is received in the second car, both cars
are
about 100 feet from the mark on the pavement.
As soon
as the ball arrives at the second car, someone (who is in the second
car)
catches the ball and immediately throws the ball so that it lands on the
mark
on the
pavement that was painted by the second person in the first
car. In other
words,
the ball is thrown to where the first car was when the ball was originally
released
from the first car. By the time the ball returns to the mark on the
pavement,
suppose both cars have moved an additional 100 feet away from this
mark
(this is obviously not accurate, but this is a metaphor). This means that
when
the returning ball hits the mark on the pavement, both cars will be about
200
from the ball.
Note
that when the ball lands on the pavement, both cars, and we are most
interested
in the first car, are 200 feet from where the ball lands. This means that
no one
in the first car is going to catch the ball when it lands after being thrown
by
someone in the second car.
Introduction to the Problems Introduced by Lunar Laser Ranging
Let us
consider an infinitely long imaginary line that passes through the sun and
the
point in Leo that the sun is currently headed for. We will define the direction
from
the sun towards Leo as "north." We will draw a second line
perpendicular to
this
line that also passes through the center of the sun. We will further draw this
imaginary
line on the “ecliptic” plane, which is the two dimensional plane formed
by the
sun and our orbit plane around the sun. Actually, we could draw this
91
second
imaginary line on the earth-moon 2D plane, which is very close to being
on the
ecliptic plane.
We
have timed drawing this second line so that it goes through both the center of
the
earth and the center of the moon (or as close as possible because the two
planes
are not the same). In other words, we waited until the earth and moon
were
in the correct positions before we drew this line. The portion of this line to
the
left of the line to Leo (from our viewpoint from above the north pole with our
head
pointed towards Leo) will be defined as “west” and the portion of a similar
line
on the other side of the sun, to the right of the sun, will be defined as
“east.”
This
scenario means that the earth and moon are “nose-to-nose” as they are
both
headed towards Leo. (Note: we can ignore the orbit velocity of the moon
around
the earth and the rotation velocity of the moon because they are so slow).
With
this scenario, let us visualize what happens when a LLR experiment is
done.
First, a laser beam is shot at the moon and retro-reflector. During the time
it
takes this laser beam to travel to the moon and back (about 2.5
seconds), both
the
earth and moon (as part of the solar system) move about 948 km towards
Leo
(474 km while the beam is headed to the moon and 474 km while the beam
is
headed back to earth). Since the retro-reflector sends light back to its
point
of origin, and because the returning beam is only 20 km wide
when it
returns,
then the returning laser beam should miss the telescope (that shot the
laser
beam) by at least 928 km (948 km minus 20 km). This is because both the
earth
and moon have moved 948 km towards Leo while the laser beam was "in
the
air." But in fact the laser beam is detected by the same telescope that
shot
the
laser in the first place!
With
this scenario, the LLR is a type of experiment virtually identical to the “Two
Parallel
Car Metaphor.” The line between the sun and Leo is represented by the
path
of the two parallel cars. The person in the first car that throws the ball is
represented
by the telescope that shoots the laser beam. The person in the
second
car, who throws the ball back to the spot on the pavement, represents a
retro-reflector
that returns light back to where it came from, meaning to where the
telescope
was when the laser was originally fired. The returning laser beam
should
miss the originating telescope by at least 928 km. I will come back to this
example
later in much more detail. For now, I want to present a "big picture"
of
what
is going on.
More About the LLR Experiments
The
actual process of doing an LLR experiment begins with an observer
"finding"
the retro-reflector on the moon. By "finding" the retro-reflector it
is
meant
that they can detect returning light from the moon after firing the laser and
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the
detected light is not "noise." I cannot talk about all of their challenges,
but I
will
mention three of the problems they face:
1) The
most significant problem is "image motion," caused by hot and cold
cells
in the
earth's atmosphere. The hot and cold cells cause the image to weave
back
and forth and up and down.
2) Secondly,
"seeing" problems are encountered when a point of light on the
moon,
or from a star, is "blown-up" or enlarged by either temperature cells
or
particles
in the atmosphere.
3)
Third, "dither" problems are jerks in the image caused by the finite
mechanical
equipment
in the telescope drive system.
An
observer begins by pointing the telescope, as accurately as possible, to
where
the retro-reflector is located on the moon. I call this initial pointing of the
telescope,
whether successful or not, "ground zero."
Obviously,
no telescope on earth can see an object the size of a suitcase on the
moon
(not yet anyway), but when the sunlight is hitting the section of the moon
where
the retro-reflector is located, the observer can see various lunar features
in the
landscape near the retro-reflector they are going to aim at, thus allowing
accurate
pointing.
When
the retro-reflector is in the shadowed part of the moon, the observer must
first
calibrate the telescope and computer for several well-known reference
craters
on the moon that are in the sun's light. But even that is not easy because
the
shadows cast by the cliffs that are on the sides of the craters vary in length
depending
on the angle of the sun to the cliffs. Once these reference craters are
used
to calibrate the computer, the computer moves the telescope to where it
thinks
the chosen retro-reflector is in the dark section of the moon.
When
ground zero is first attempted, either by the observer or the computer, the
observer
may not have "found" the retro-reflector on the first shot and he or
she
may
need to start "clicking" the telescope controls to "find"
the retro-reflector.
Frequently,
however, it is not necessary for the observer to "click" the controls
because
the laser light is returned and is detected in the first laser firing.
When
"clicking" is necessary, each "click" makes a 1/10 of one
arcsecond
adjustment
(an "arcsecond" is 1/3,600 of a degree, thus a "click" is
1/36,000 of a
degree)
in where the telescope is pointed. It is frequently a process of "hunt-andwait-
and-peck"
trying to find the retro-reflector.
Hitting the Retro-Reflector and Looking at "Old Light"
Now
let's get down to the details. When a telescope is looking at a galaxy
100,000,000
light years away, it is looking at light that left the galaxy 100,000,000
years
ago. It is also looking at where that galaxy was located in the
sky
93
(ignoring
aberration, etc.) 100,000,000 years ago. The same holds true when a
telescope
is pointed at the moon.
When
an optical telescope is pointed at the moon, because it takes 1.25 seconds
for
moonlight to get to the earth, the telescope is really looking at where the
moon
was located approximately 1.25 seconds earlier. This means that the
telescope
is pointed or looking at a spot that is 474 km (i.e. about 1.25 seconds
times
the average 370 kps motion towards Leo) behind where the moon is
actually
located when the light arrives at the telescope. This is based on the
assumption
that the earth and moon are headed nose-to-nose towards Leo at
370
kps. In other words, the light the optical telescope is seeing is "old
light,"
meaning
that by the time the lunar light arrives at the telescope, the moon has
traveled
474 km, meaning the telescope is constantly looking 474 km behind
where
the moon is when the light arrives.
It
gets worse, because in the time it takes the laser beam to get to the moon, the
moon
has moved an additional 474 km. This means that the laser beam, which
is
only 7 km wide when it gets to the moon, will miss the retro-reflector by 948
km. To
explain, the telescope (i.e. the laser) is pointed (i.e. aimed) 474 km
behind
where the retro-reflector is located (because of "old" light) when it
fires
the
laser. Further, it takes 1.25 seconds for the laser beam to get to the moon. If
this
were the case, the observers would never be able to "find" the
retro-reflector
(this
will be discussed in a moment).
Now
let us consider what would happen if there was a tilt of aberration of the
laser/telescope
based on 370 kps. If this were the case, at the instant the laser
was
fired, the telescope would be pointed directly at where the retro-reflector is
located
on the moon at the instant the laser is fired. This is because of two
offsetting
errors. The first error is that the light the telescope sees is 1.25
seconds
old, meaning the laser is pointed behind where the
retro-reflector is
located
by 474 km. However, there is a second error in which the "apparent"
location
of the retro-reflector would be 474 km ahead of its
"old" location. Thus,
because
the light is 1.25 seconds old, the telescope will point behind the
retroreflector,
but
because of aberration, it will point ahead of the retro-reflector,
meaning
there is a net result that at the moment the laser is fired, the telescope
is
coincidentally pointed exactly at the retro-reflector.
However,
this does not solve the problem. By the time the laser beam gets to
the
moon, the moon has moved 474 km, thus the 7 km wide beam will miss the
retro-reflector
by 474 km. Again, if this were the case the observers would never
be able
to "find" the retro-reflector. This I will now explain in detail.
1) Let
T0 be the moment light leaves the moon. T1, which is 1.25 seconds later,
is
when the light gets to the earth from the moon, during which time the earth and
moon
have moved 474 km towards Leo. T2, which is 1.25 seconds later than
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T1, is
when the laser beam gets to the moon, and between T1 and T2 the earth
and
moon travel another 474 km towards Leo.
2)
Because of "old light," the telescope is actually looking at where
the moon was
located
1.25 seconds earlier. However, with tilt of aberration of 370 kps, if the
photon
theory were correct, the telescope would be tilted so it would point 474
km
ahead. Thus, these two things accidentally offset each other and at T1 the
laser
is pointed exactly where the moon is located at T1. However, in the time
the
laser beam is traveling to the moon, the earth and moon move another 474
km and
the laser beam will miss the retro-reflector by 474 km.
3) A
"click" (i.e. 1/36,000th of a degree) moves the image in the
telescope 186.4
meters
(remember that the light pulse is about 7 km wide by the time it gets to
the
moon). Note: the simplest way to calculate this is to know that the moon has
an
angular diameter of 0.5181 degrees (which is 18,652 "clicks") and the
diameter
of the moon is 3,476 kilometers.
4) The
average distance to the moon is 384,400 kilometers.
With
these statistics in mind, and knowing that the software that drives the
computer
can also be used for purely optical viewing, the ground-zero shot of an
observer
would miss the retro-reflector by 2,543 clicks (474,000 divided by
186.4)
to the left or right of ground zero (this is the maximum number of clicks
needed
if the moon happened to be directly "east" or "west" of our
path towards
Leo).
At an
average of 1 click every three seconds, it would take an observer up to 127
hours to
find the retro-reflector. This assumes he or she is perfectly efficient at
knowing
which direction to click. As mentioned above, observers frequently
"find"
the retro-reflector without a single click! Most of the time they find
the
retro-reflector
within 5 minutes. If they don't find it within 10 minutes, they may
take a
"coffee break" and then start over.
Thus,
there is simply no possible way that the laser/telescope could ever hit the
retro-reflector
with or without secular aberration of moonlight.
A
person might think that if moonlight had path momentum, that the problem
would
be solved. Actually, if moonlight had path momentum, the problem would
get
worse because the laser/telescope would point even further behind the
location
of the moon at the time the laser is fired. We would be back to the 948
km
miss, even with aberration.
How
about path momentum of the laser beam? My experiment proves that
lasers
must have path momentum, meaning the light leaves the laser at an
angle.
If the laser beam had path momentum, is there a scenario in which the
laser
beam could hit the retro-reflector? Actually, yes. If there was laser
path
momentum
of the laser, and there was aberration of moonlight (i.e. tilt of
aberration),
and if moonlight did not have path momentum (moonlight is
reflected
light
from the sun, just like retro-reflectors reflects laser beams), then the
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observer
could "find" the retro-reflector in short order, perhaps on the first
try. In
summary,
because moonlight is "old light" when it gets to the telescope, there
is
only one
combination of events that could explain why observers ever
"see" the
retro-reflector:
1)
Path momentum of laser beam light (LPM is true).
2) Aberration
of moonlight (tilt of aberration)
3) NO
path momentum of reflected sunlight (MPM is false).
Without
any of these items, and with the photon theory of light, the observer
could
never "find" the retro-reflector because of the "old" light
issue. I will get
back
to this issue later in the chapter.
The Returning Laser Beam
So far
we have only talked about the observer finding the retro-reflector. Let us
for a
moment ignore the problems with actually hitting the retro-reflector. Let us
talk
about the returning laser beam hitting the telescope. We are absolutely
certain
where the returning laser beam is aimed, it will return the laser beam in
the
exactly opposite direction it came in at. That is what a retro-reflector is
designed
to do. We don't need to worry about hitting the retro-reflector, we are
now
assuming the retro-reflector is being hit and our concern is where the
retroreflector
is
sending its light.
If the
mirrors in the retro-reflector did not add path momentum to the laser beam,
the
returning beam would miss the telescope by 948 km per the 2-car example.
The
simplest way to comprehend this is to think of the retro-reflector as being the
origin
of the light beam. In other words, we don't care about
the process of
getting
the light to the retro-reflector, we are only concerned here with what the
retro-reflector
does with the light. We know exactly where the reflected light from
the
retro-reflector is aimed. It is aimed at the exact location of where the light
source
came from (where the telescope was when the beam was fired), without
regard
to any aberration of earthlight (the retro-reflector is not looking at the
earth
through
a telescope so "aberration of earthlight" is irrelevant), path
momentum of
laser
light, etc. Consider this scenario:
T1) (the
same T1 as above) The laser beam is fired. This instant in time
identifies
where the laser/telescope is in 3D CMBR space at the instant the laser
is
fired. This is the exact location in 3D CMBR space that the retro-reflector
will
send
the returning laser beam.
T2)
(1.25 seconds after T1) The laser beam arrives at the moon and is instantly
"fired"
back by the retro-reflector. Between T1 and T2, as above, the earth and
moon
have both moved an additional 474 km towards Leo. Thus, when the
retro-reflector
"fires" the laser back to the point in 3D CMBR space where the
laser/telescope
was at T1 (T2 is the origin of the retro-reflector light), it is aiming
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the
light 474 km behind where the telescope is located at T2. In other words, T2
is the
time the retro-reflector "fires" the returning beam, but at T2 the
telescope is
already
474 km away from where the retro-reflector is aiming.
T3)
(1.25 seconds after T2) The laser beam returns to earth. Between T2 and T3
the
earth and moon travel an additional 474 km. Thus the returning beam will
miss
the telescope by a total of 948 km because the retro-reflector is aiming the
beam
at where the telescope was at T1 (I am ignoring the width of the returning
beam
because it is insignificant).
Because
of the fact that the retro-reflector is aiming at where the telescope/laser
was at
T1, it is clear that the photon theory of light cannot be true.
However,
now let us look at this scenario. Suppose the laser light hits exactly
two
mirrors in each corner cube, and that each of the corner cube mirrors adds
one
path momentum unit to the light. In this case the retro-reflector would add
two
units of path momentum to the laser beam, and the same telescope that fired
the
laser beam would also be able to receive the laser beam.
In
other words, because of the Two Parallel Car Metaphor, the light from the
retro-reflector
to the earth would never hit the sending telescope unless exactly
two
mirrors in each corner cube added one path momentum unit each (this
assumes
exactly two mirrors in each corner cube are hit).
Four More Paradoxes
Let us
summarize what we have learned, if we assume the photon theory is
true:
The
Observer Trying to Find the Retro-reflector:
1)
Path momentum of laser beam light. LPM is true.
2)
Aberration of moonlight (tilt of aberration) is true, based on 370 kps.
3) NO
path momentum of reflected sunlight. MPM is false.
The
Returning Light From the Retro-reflector To the Telescope:
1)
Path momentum of light bouncing off of mirrors, light must hit two mirrors in
each
corner cube and each mirror must add one path momentum unit. MPM is
true.
My
First Experiment:
1)
When I used a telescope, I was looking at light reflected from a piece of
paper.
This
light clearly had to have path momentum in order for me to see a dot, thus
MPM is
true for reflected light.
My
Second Experiment:
1) The
light from mirrors must not have path momentum, thus MPM is
false.
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We
thus have four major paradoxes resulting from this analysis.
Paradox:
Because observers are able to quickly "find" the "retro-reflector"
it has
been
shown that moon dirt (which is reflected light) cannot add path
momentum
to
light. However, the returning light from the retro-reflector cannot hit the
sending
telescope unless the reflected light (from the retro-reflector mirrors)
adds two
path momentum units. Thus, MPM is false and MPM is true.
Paradox: In
my second experiment it was evident that MPM was false.
However,
the returning light from the retro-reflector cannot hit the sending
telescope
unless the reflected light (from the retro-reflector mirrors) adds two
path
momentum units. Thus, MPM is false and MPM is true.
Paradox:
In my first experiment, when a telescope was used to look at a paper
target,
it was clear that because I got a dot, that light being reflected off of a
piece
of paper does have path momentum. However, the light being reflected off
of the
surface of the moon cannot have path momentum. Thus, MPM is true and
MPM is
false.
Paradox:
In my first experiment, as just mentioned, MPM must be true, or else I
would
not have seen a dot. In my second experiment, MPM must be false, or
else I
would not have seen a dot. Thus, MPM is true and MPM is false.
These
paradoxes are proof that the "tilt of aberration" of lunar light is
actually
zero
kps. This means the moon is where it appears to be when we look at it.
This,
by itself, is a proof that the photon theory of light is false.
These
experiments on the "path of light" also prove that the aberration of
terrestrial
light is also zero. I could prove this directly if I had the right equipment.
I
could also prove that laser light does not have path momentum if I had the
right
equipment.
Lunar Laser Ranging and Ether Drag
There
are actually several scenarios in which the ether theory could easily
explain
the above paradoxes:
1) If
the earth's ether drag extends beyond the orbit of the moon around the
earth,
then both the earth and moon would be in the same ether drag. In this
case
it wouldn't matter if the moon had its own ether drag, only "moving
target"
leads
(that apply only to the orbit velocity of the moon around the earth while the
laser
beam is "in the air") would apply because all light between the earth
and
moon
would be dragged together. The "moving target" lead is not
aberration, it is
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simply
an application of the MTLs within the same ether drag. The orbit velocity
of the
moon around the earth is about 1 km per second. This means that in the
time
the laser pulse travels between the earth and moon the moon only travels
about
1.25 km. This is still within the 7-km radius of the arriving laser light.
The
best way to visualize how ether drag works with lunar light is to imagine a
string
between the retro-reflector and the telescope. The string is dragged with
the
earth and moon towards Leo. The string represents the path of the light
beam
from the moon (i.e. from the vicinity of the retro-reflector), because
everything
is dragged together. Thus this is the direction the telescope thinks the
retro-reflector
light is coming from, and thus it is also the direction the laser is
pointed,
and it is the path of the laser beam that travels to the moon. When the
laser
beam gets to the moon, this is also the direction the retro-reflector thinks
the
laser beam is coming from, and thus it is the direction the retro-reflector
aims
the
light, and thus it is the path of the retro-reflector light back to the
telescope.
2) If
the moon had its own ether drag and if the earth's ether drag and the moon's
ether
drag overlapped, then the earth and moon would essentially be in the same
ether
drag because all lightwaves during the round trip would be dragged with
the
earth/moon system towards Leo. It is very similar to case #1.
3) If
the earth and moon both had ether drag, and if the ether drag of the earth
and
the ether drag of the moon did not overlap, but their edges or boundaries
were
"close" to each other ("close" will be defined in a
moment), then the LLR
data
could be explained.
4) If
the moon did not have ether drag but the boundary of the earth's ether drag
came
"close" to the moon, the LLR data could be explained.
How
"close" does the earth's ether drag need to be to the moon's ether
drag (or
the
moon itself if the moon does not have ether drag)? It depends on whether
the
sun's ether drag extends beyond our earth's orbit distance from the sun. If
the
ether drag of the sun does not reach the earth's orbit distance, then
"close"
probably
means less than several thousand kilometers, or else the observers
would
have to "lead" the retro-reflector consistently during certain times
of the
lunar
month (this is simplified). If the ether drag of the sun does extend beyond
our
earth's orbit distance (which is highly likely) then there is far more
tolerance
for
how "close" the gap (between the earth's ether drag and the moon or
its ether
drag)
needs to be - perhaps up to a 50,000 kilometer gap.
Because
LLR observers frequently need to use some "trial and error" when
trying
to
"find" the retro-reflector, their data is not accurate enough
(actually for several
reasons)
to determine an exact number as to how "close" the gap must be. Also,
their
data is not accurate enough to determine which of these options is the
correct
choice. However, their data is accurate enough to assure that one of
these
options is the correct choice!
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The
LLR experiments provide critical data as to how large the earth's ether drag
must
be in order for the LLR experiments to work. The earth's ether drag
probably
extends over 330,000 kilometers above the earth and the moon
probably
has some ether drag of its own. This height, in fact, is the best
evidence
that the sun's ether drag does extend beyond the earth's orbit distance.
The
bottom line to all of this is that because of ether drag, the moon is exactly
where
we think it is. In other words, we do know the exact location of a celestial
body
other than the earth - the moon! (OK - to be technical lunar light is
"old"
light,
but we can take that into account if we need to.)
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