The shorter jump

This post is about trigonometry in the hex-maps used for Traveller subsectors. The summary for those who hate maths is that a jump-4 is actually only 3.46 parsecs if you take the shortest route.

3.46 pc

As you can see in the image above is that if you want to go from point X (0503) to point Y (0101) it is a jump-4. The distance is 4 parsecs.

But if you wants to go from point  X (0503) to point Z (0103) it is also a jump-4, but the distance is actually shorter since you are zigzagging  when you are counting the hexes following the dotted orange line.

How much shorter is it? If we use Pythagoras, then:
a2 + b2 = c2
b2 = c2 – a2
b2 = 16 – 4 = 12
b = 3.46

If we use trigonometry, b = 4 * cos(30) = 3.46.

In the Adventures of the Starship Notorious the crew meets a very talented jump-drive scientist that helps the crew improve and calibrate their J-3 drive so that it can do 3.46. This will only work if the ship is unloaded and if a special jump-program is run.

Subsector from a Map

I have been asked how I made the maps of Lancaster and Chambersburg Subsectors. In this post I will describe how I did it.

(I have also done the same for Ireland. I work on a version of Denmark and south Sweden.)

First I find the area I want to map on Google Maps (or any other map). I zoom to the level I like. 10-20 towns (or places) in the area is about right. Make a screenshot of this.

I use a transparent subsector map that I have made using quickhex.

I use a good image editor that can handle layers. (I use GIMP, which is free.) Then I open my screenshot and place the transparent map on top of it as a layer. (I can move it a bit until I am happy where the towns are in the subsector.) This is what it could look like.
Continue reading Subsector from a Map

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