## violation of the 360⁰ rule Edit

On the TOS episode "Day of the Dove", at about 13:20 in, Sulu reports a heading of 902 mark 5. Kirk responds "that'll take us out of the galaxy."– *The preceding unsigned comment was added by* 76.107.152.138 (talk).

- While clearly based on 99.999% of the uses of headings and "Datalore", there was a 360-degree system used, my interpretation of the at least three instances from TOS-VOY of 9XX-mark-XXX headings is that there was an alternative system/way of describing headings (such as 180-mark-0 is 900-mark-0 in the other system) that was used rarely. At least until we have a clear statement from the producers of the series that all these instances were production mistakes. --Pseudohuman (talk) 01:28, October 20, 2013 (UTC)

does this call for at least a mention (with citations of what episodes feature this other scheme), whether or not your theory is given by way of explanation? I for one have noticed that a lot of fringe details are not only mentioned but also treated in this wiki yet stuff like this (which, according to your report, at least three instances have appeared) goes unmentioned. 76.107.152.138 17:15, October 20, 2013 (UTC) never mind. I see that it is indeed mentioned. 76.107.152.138 17:18, October 20, 2013 (UTC)

## Removed Edit

Opinion and not in-universe, I removed the following text. Tom (talk) 12:08, November 23, 2013 (UTC)

- Imagine the ship at the center of two circles marked in degrees, one horizontal, and one vertical. The "Zero" of the 'horizontal' component of the heading, termed the azimuth (the circle on the xy-plane) is a horizontal vector pointing directly in front of the ship, and the angle is measured counter clockwise from the positive x-axis, meaning a azimuth angle of 90 degrees corresponds to a heading pointing directly to the left (port) of the star ship. This angle is often denoted using the greek letter Theta.

- The "Zero" of the 'vertical' component of the heading, termed the altitude or elevation (the circle on the xz-plane) is a vertical vector pointing directly up from the ship, and the angle is measured downwards from the positive z-axis, meaning an elevation angle of 90 degrees corresponds to a heading pointing directly in front of the starship, while an elevation angle of 180 points directly down. This angle is often denoted using the greek letter Phi.

- In practice, the elevation angle is always bounded between 0 and 180 degrees, because an elevation angle outside of this range has the effect of reversing the direction of the horizontal heading from that would be intuitively expected from the given azimuth angle, in effect changing the 'horizontal heading' from that which was stated to an angle directly opposite, in effect adding/subtracting 180 degrees from the azimuth. While it is mathematically sound to allow this angle to vary outside of this range, it creates unnecessary confusion for humans visualizing the desired heading.

- i.e. heading "0 mark 185" would actually point down and behind the ship, as opposed to down and infront of the ship as might be Naively expected.

- The writers almost always ignore this fact, probably due to lack of mathematical understanding of the spherical coordinate system. (typically not encountered by most people until multivariate calculus)