User talk:Mdekok3000

From Wikipedia, the free encyclopedia

The approximate distance between the two locations on the planet can be determined with their geographic coordinates and this formula

d = \sqrt{\left ( \frac{r\pi(\mbox{Lat}_2 - \mbox{Lat}_1)}{180} \right )^2 + \left ( \frac{r\pi(\mbox{Long}_2 - \mbox{Long}_1)}{180} \right )^2}.

The radius r in this instance is the radius of the earth. The units that the final distance d is measured in is the same as that you used for the radius.

The formula above is not 100% accurate. That would be impossible, because the earth is not a perfect sphere and the exact radius of the earth is not known. The radius of the earth has been estimated to be about 6,378.135 km (\approx3,963.189 mi; \approx3,443.917 nm).

[edit] Derivation of the Formula

First, all you should have are the sets of coordinates. The latitudinal angle between each location is Lat2 − Lat1 and the longitudinal angle is Long2 − Long1.

If you were to slice a thin layer of the earth out at the equator, you would have a circle. To find the arc length on a circle given an angle and the radius, the following formula can be used to find the latitudinal and longitudinal distances

\begin{matrix}s = r\theta.\end{matrix}

These distances also form the legs of a right triangle on a flattened surface. To use this formula, your angles must be in radians. To convert the angles from degrees to radians the concept

\angle (\mbox{radians}) = \frac{\pi\angle^\circ}{180}

will work.

Since the following equations summarizing the above equations are the formulas for the lengths of legs of a right triangle

\begin{matrix}s & = & r\theta \\ s_1 & = & \frac{r\pi(\mbox{Lat}_2 - \mbox{Lat}_1)}{180} \\ s_2 & = & \frac{r\pi(\mbox{Long}_2 - \mbox{Long}_1)}{180}, \end{matrix}

the distance formula will give the length of the hypotenuse, or the geographic distance between each location.

[edit] Earth Distance Formula

A proposed deletion template has been added to the article Earth Distance Formula, suggesting that it be deleted according to the proposed deletion process. All contributions are appreciated, but this article may not satisfy Wikipedia's criteria for inclusion, and the deletion notice should explain why (see also "What Wikipedia is not" and Wikipedia's deletion policy). You may prevent the proposed deletion by removing the {{dated prod}} notice, but please explain why you disagree with the proposed deletion in your edit summary or on its talk page.

Please consider improving the article to address the issues raised because even though removing the deletion notice will prevent deletion through the proposed deletion process, the article may still be deleted if it matches any of the speedy deletion criteria or it can be sent to Articles for Deletion, where it may be deleted if consensus to delete is reached. Do you want to opt out of receiving this notice? Fabrictramp (talk) 23:55, 23 April 2008 (UTC)