Effects on Ballistic
Eotvos effect
The Eotvos effect is caused by the rotation of the earth, but this is not to be confused with the Coriolis effect. While Coriolis is related to the effects caused by the earth, it is on a horizontal plane. Eotvos effect is a vertical change in target position that at long distances could cause a miss on a target. The following examples explain the Eotvos effect.
Notice that when shooting eastwards that the effect causes the impact to move up. However, while shooting westwards the impact has a tendency to move down.
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February 5, 2011, 8:47 am
Sorry first post was not proof read
The Eotvos effect as I understand it is different from the Coriolis effect as the Coriolis effect is a question of the earth’s movement between the time the round is fired and when it arrives as it does not rotate with the earth while in flight, Eotvos effect on the other is a little harder to visualize. When moving eastward there is LESS apparent gravity pulling the projectile toward the earth as opposed to MORE apparent gravity pulling the projectile towards the earth when moving westward. Why? The earth is rotating and at the equator the earth is rotating at about 1000 miles an hour while it is rotating in place at the poles.
This rotation causes gyroscopic force that counteracts some of the earth’s gravity at the equator. (While our mass is the same everywhere we weigh slightly more at the poles than at the equator).
Firing a rifle round eastward adds to the gyroscopic force counteracting some of the earth’s gravity and causing less “pull” towards the earth while firing westward negates some of this gyroscopic force allowing more of the earths gravity’s to take effect causing more “pull” towards the earth.
Think a the fair grounds ride “round up” where you are spun around inside the ride and pinned to the sides by gyroscopic force, if you were inside the ride and were able to run in the opposite direction of the rotation at the same speed as the ride you would feel no gyroscopic force, if you could run in the same direction of the rotation you would add more gyroscopic pushing you to the sides of the wall than already provided by the ride.
It’s effect is greater the closer you are to the equator.
Fascinating effect.
Great web site.