The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity. Shooting eastbound, the Eötvös effect will cause the bullet to impact high, and shooting westbound will cause the bullet to impact low. The way I remember this is from the movie Lean On Me, with Morgan Freeman. It's a little unorthodox, but the name of the school in the move is Eastside High. So, shooting east the bullet will impact high. Something that might be important to be aware of, even if you don't fully understand (like me) is the Coriolis effect vs Eötvös effect. In my studies, I have found 2 components to the Coriolis effect: Horizontal displacement (Northern and Southern hemisphere dependent but independent of direction of fire) and Vertical displacement (east and west bound dependent) There's a mathematical equation for both of these elements. The Eötvös effect is also dependent on direction of fire (east and west bound). However, Eötvös is often referred to as Coriolis, or is said to be the vertical component of Coriolis, but has a different formula. Horizontal Displacement Formula: F = 2 * m * v * ω * sin(α) (Ω * Range ft2 * sin(Lat)) / V ave Vertical Displacement Formula: 1+2*Ω*MV/-32.2*cos(Rads(Lat))*sin(Rads(Azimuth)) Eötvös Formula: 2Ωucos(ϕ)+u2+v2/R a->2ωvcosλsinθcosϕz⃗ So, what does all this mean? I don't know. I at least wanted to present that Coriolis and Eötvös are two separate components that should/can be calculated for, whether or not there is a vertical component to coriolis or if Eötvös is the vertical component. The effects of Eötvös are minor, but can be adjusted for. Depending on many factors, Eötvös will affect the bullet's impact about 4 inches high or low at 1000 yards, with the greatest affect at the equator when shooting due east or due west. 4 inches at 1000 yards is just under 1/2 MOA. 1/4 MOA is 2.5 inches, and you would be closer to adjust 1/2 MOA. If we take 1/2 MOA and convert it to Miliradian (.5 ÷ 3.5 = .14 Mils), we can make this adjustment on our turret. Lets try 1/4 moa or 2.5 inches at 1000 yards. .25 ÷ 3.5 = .071 Mils This we can't adjust for unless we round up to .1 mils. We will have less error by adjusting .1 mil than not adjusting at all. Lets see if we can get a little more precise. The formula to use to see how many inches one click (.1mil) will move our bullets impact is: Distance in 1/100 yards / 2.777 x number of clicks = Distance in inches the round will move 10 ÷ 2.777 x 1 = 3.6 inches Now that you know you can calculate and make an adjustment for the Eötvös effect, log your direction of fire in your dope book and see if you can notice a difference between east and westbound impacts. #TheOverwatch
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