Wednesday, September 24, 2014

Straight vs Curve : Understanding Distances

Today we rolled out some fixes to the site as well as a couple little side simple tools utilizing Scribble Maps. The first is a distance calculator and the other is an area calculator. So we thought we would take a little bit of time and explain some important considerations when drawing lines on maps over great distances. Particularly what is the difference between a straight line, which is a Rhumb line on Google Maps, and a curved line.

There is a common misconception that if you were to walk in one direction without wavering and then drew a line of all the places you stopped it would appear as a curve on a map. While it is true you would actually walk in a curve, on a Google Map which uses what is called a Mercator projection, the line would actually be straight. This is because the projection Google uses stretches the latitude (y-axis) to make travelling in a straight line appear as a straight line on a map.

Travelling in one direction on a globe

On a Google Map

If you're unfamiliar with this, it might be a little mind bending. The important thing to remember is that when working with a map like Google a straight line is associated with moving in a straight line.

So now, to make every more confusing, let's talk about flight lines also known as great circle lines.

At first glance one might actually assume something that is incorrect and that is if you were to walk in a straight line you would actually follow this curve. However, this is wrong. As we established before, walking in a straight line actually appears as a straight line on a Google Map. So what is this?

The quickest route between two points for something like an airplane on a globe is not a straight line and by straight I mean keeping the same bearing. To save time and distance (which is important for jet fuel) the planes travel on a curve which actually takes less time. I will not go into this in this post, but if you're interested in why you can look up information on the "great circle."

So this bring us to the rub, when calculating the distance between two points, what should you use? The answer is usually a straight line unless you want the shortest distance between two points in the case of flight.

This is important because there are tools out there that utilize great circle curves to estimate the distance between two points and this is not actually accurate if you're planning to walk or move while maintaining the same bearing.


  1. Thanks for an exceptional presentation of this info. I would also like to contribute by sharing this web-page with you.

  2. Lots of thanks for sharing this amazing article and i think you know about lucky patcher apk free download and i think it works fine.

  3. Awesome quality of writing. You may also want to check this website to learn more on this topic.

  4. Hello everybody! My name is Patrik and i am 26 years old girl from Europe. But anyway i still work at english writing service SpeedyPaper. I really love my work and i know that this is one of the best writing services in internet. If you need some help with essay or other study work then just join our site and SpeedyPaper will help you.

  5. When you must switch to the World Wide Web to search for some Assignment help. Our high expert's professionals who have extensive experience in writing assignment will not only make you avail with the quality assignment, but you will also get plagiarism free assignment within the given time. Assignment Help

  6. Assignmentservicerating is best reviews site.We at Top Quality Assignment believe that there is no shortcut to success and to attain success, hard work, dedication, and commitment must be reviews  best reviews site.
    AllAssignmentHelp reviews 

  7. Get the best MBA assignment help service at Students Assignment Help by our in-house experts and academic professionals’ writers who always assist students with their assignments and homework covering all educational qualifications.

  8. Here are some easy implications of Clairaut's Theorem. See whether you can prove them all:

    The equator must be a geodesic.
    All meridians are geodesics.
    No line of latitude, other than the equator (and the poles, if you want to include them), can be a geodesic. Not even a small part of a line of latitude can be geodesic.
    Loxodromes (aka rhumb lines), which are lines of constant bearing, cannot be geodesics unless they are meridians or the equator. Not even a small part of such a loxodrome can be geodesic. In other words, if you sail or fly in a fixed compass direction, then--with a few obvious exceptions--your path is constantly curving!

  9. This writer is very talented and write the best books ever! Thank you for the wonderful article! Leadership Assignment Help

  10. To start defining the difference between the straight shaft vs curved shaft weed trimmer, we have to start with what exactly the shaft is. The shaft is the part of the weed eater that transfers power from the motor or engine to the lines which cut the grass via an internal drive cable.

  11. TvTap is totally free to use. You do not need to pay single penny to use this application. If somebody is charging to use TvTap application the report us.

  12. So it is interesting and great composed bearing is the specific way you need to go to get started with one place, then onto the next separation is a proportion of the space between one place and another deliberate in things like meters, kilometers yards or miles you can utilize a guide to make sense of the separation between two spots utilizing something many refer to as the scale. Thank you for sharing them. Sara Gilbert The Conners Jacket