As a boy, I was fascinated with aircraft. I remember how overjoyed I was when I first understood how an aircraft flew. The bottom of the wing surface is flat while the top surface is curved. This means that, as the wing slices through the air, the air must travel faster over the top of the wing than it does over the bottom. The result is that there is more pressure on the bottom of the wing than on the top and when the aircraft is going fast enough to get to the point where this difference in pressure on the wing exceeds the weight of the plane, it lifts off into the air.
Now, I would like to see if I can add something to the field of aviation. I only thought this up within the last 24 hours but I think that I really have something here.
We know that a hurricane travels westward actually because the circular motion of the air causes the hurricane to gain some independence from the earth's gravity and the earth rotates eastward under the hurricane. We could actually measure a hurricane's independence from the earth's gravity relative to the sorrounding air that was not part of the hurricane by the time it takes the hurricane to cross the ocean divided by the time it takes the earth to rotate that distance. It is also clear that the very high winds in the stratosphere are due to relative independence from the earth's gravity.
The rotation of the earth affects so many things as I have described extensively in these online writings. It affects rivers, the courses of glaciers, winds and, ocean currents. I got to wondering, why wouldn't the rotation of the earth have an effect on aircraft also? Nowadays, aircraft fly high enough to gain a lot of independence from the earth's gravity.
Let's begin by thinking of an aircraft as actually a spacecraft and considering the absolute distance that it travels during a flight. This absolute distance is not the same as the apparent ground distance due to the rotation of the earth. For example, you can sit still in a chair and you are still moving rapidly in terms of absolute space because the earth that you are on is rotating and revolving around the sun. An aircraft is actually a spacecraft except that it is more influenced by the earth and cannot leave earth's atmosphere because it depends on outside oxygen for fuel combustion.
An aircraft flying eastward must travel a far greater absolute distance than one travelling westward for the same ground distance yet the flight takes no longer. In a flight from New York to London, for example, the earth's eastward rotation is actually moving London away from the plane and thus stretching out the flight, while the return flight from London to New York has the earth's rotation actually bringing New York toward the plane and so shortening the flight. Yet, the flight time either way is the same. (Doesn't this sound like relativity?)
The reason for this is that the eastbound flight, while stretched out, is also assisted by momentum from the earth's rotation while the westbound flight has it's advantage of having New York brought toward the plane negated by forcing the plane to work against the momentum of earth's rotation over the shortened flight. Since no new energy is introduced, the flight times remain the same.
Someone on the ground or in the plane will notice none of this. But suppose that a person on the moon or far out in space was watching or tracking the flight. It would seem that the westbound flight to New York was travelling a much shorter distance than the flight to London but was doing so at a much slower speed so that the flight times were the same.
Imagine that the earth is not there and picture how far each flight travels in terms of absolute space instead of ground distance. In eastbound flights, and diagonal flights with an eastern element, the total flight distance is the surface distance plus the distance the earth rotated during the flight. In westbound flights, the total flight distance is the surface distance minus the distance the earth rotated during the flight. Since the flight times are the same, it is clear that the eastbound flight must be going considerably faster in terms of absolute space and the only way to explain the added velocity is the eastward rotation of the earth.
In summary, we have a trade-off that comes out even. Eastbound flights must cover more distance because the rotation of the earth is moving the destination away from the aircraft but in return these flights are assisted by the momentum of the earth's eastward rotation. Westbound flights get the "gift" of having the earth's rotation bring their destinations closer to the plane but the price is that the momentum of this eastward rotation works in opposition to the motion of the plane.
Now, why not apply our knowledge of spaceflight to aircraft in a way that I cannot see has yet been done? Suppose we could find a way to make the earth's rotation work for us by maximizing the benefit of this rotation for eastbound flights while minimizing the hindrance of the same rotation for westbound flights. The obvious way to do this is by altitude selection since the earth's influence will be greater the closer we are to it. The actual absolute distance that flights must travel cannot be changed, but that does not mean we cannot alter the influences of the earth's rotation.
Plainly and simply, we can take advantage of the earth's rotation by establishing air corridors based on flight direction and altitude. Eastbound flights should fly low to maximize the assistance given by the earth's rotation and westbound flights should fly high to minimize the hindrance of the momentum of the earth's eastward rotation.
The systems of flight corridors in use today does nothing to make use of the earth's rotation. In the U.S. flights heading east or west must fly at odd or even thousands of feet in altitude and I cannot see that any other country exploits this potentially great advantage either. It cannot be said that flying west at a higher altitude will have any such benefit negated because it will travel a wider circle higher above the earth. Aircraft gain altitude gradually, not by a vertical rise, so the same proportion of the "corner cut off" will occur as on lower, eastbound flights.
When flying diagonally with an westbound element to the flight vector, the same principle applies. If the plane were to have less eastward momentum than the destination city, the rotation will "deliver" the city to the plane and the plane can thus course a lesser angle relative to the north-south line and thus travel less distance. But when flying eastward, we want to gain the maximum momentum possible. In direct north or south flights, with no east or west element, we want the rotational momentum to be as close as possible to that of the destination city on the ground so flights in these directions should be as low as practical.
Thus flights in any direction have an optimum altitude, considering that corridors of space must be reserved for flights going in every direction. From the top down, westbound flights should be at the highest altitude, diagonal flights with a westbound element in the vector should be below those with the more westbound higher, flights north or south should be next and, eastbound flights should be at the lowest practical altitude because the earth's rotation is pulling their destinations away the most yet they have the most to gain from the earth's rotation. Basically, the more the westbound element in a flight, the higher in altitude it should be for maximum efficiency.
(Note- By the way, international agreement defines that flights going north or east have even flight numbers and flights going south or west have odd flight numbers.)
This concept makes practical use of the Equatorial Force that I described in my geology blog. The earth's rotation not only affects very large objects but also those travelling a long distance across the earth's surface in a short time, relative to the time of rotation. This will have minimal effect on low-level flight in the denser air nearer the earth's surface. It would not have been an important factor in the early days of aircraft development, but that has certainly changed.
Aircraft fly by playing a simple trick on the air and getting it to lift the plane. Why not play a similar trick on the rotating earth and get it to give aircraft an extra boost? We see this opportunity more clearly when our frame of reference is the absolute space and not the rotating earth.
In selecting appropriate flight altitudes, this is certainly not the only factor. Also to be taken into account are winds, weather and, the altitude at which the engines are designed to operate best since air gets thinner as well as colder as we get higher. But I am certain that this idea will save a fortune in fuel costs every year.
The same principle will apply to any type of missile. Usually a 45 degree angle, halfway between horizontal and vertical, is considered the aiming point to acheive maximum range. But if we consider the earth's rotation, we will find that actually for eastbound missiles it is a little bit below 45 degrees to gain assist from the earth's rotation and for westbound missiles, it is a little bit above 45 degrees to minimize hindrance from the contrary rotation.
I notice that proof of this effect can be seen in where Cape Canaveral is located. This is the launching site on the east coast of Florida from which spacecraft are launched.
There is a certain amount of risk that something will go wrong whenever a rocket is launched, as with the unfortunate destruction of the space shuttle Challenger in 1986. If that should happen, it is preferable that the rocket not be over a populated area. U.S. military rockets were tested in open spaces in the western part of the country, and the Russian launch site was in a remote area of what is now Kazakhstan.
So why was Cape Canaveral constructed on the east coast of Florida, when the U.S. has much more open space in the western states? Part of the reason is the weather, a launch in the winter would not have to deal with ice and snow. Another reason is the latitude, it is easier to launch a spacecraft into orbit if the launch site is not too far from the plane of the equator.
But it seems to me that the main reason for the site of Cape Canaveral is the earth's rotation. With the rocket launched directly upward, the momentum from the earth's rotation would pull the rocket eastward, so that it would orbit the earth in the same direction as it's rotation the same as the moon does. But, with the launch site on the east coast, this would also mean that the rocket would be over the ocean if a mishap should occur. The probable reason that it was not located further south in Florida was to avoid putting the Bahamas at any risk.
But this shows that my idea of saving fuel by organizing air corridors to take advantage of the earth's rotation must be correct.
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