3 ms·
Many of you will be well aware that you can't have a distance-preserving "map", that is a projection from the globe to a segment to of the plane where the lengt
by Y_Y 3y ago
Many of you will be well aware that you can't have a distance-preserving "map", that is a projection from the globe to a segment to of the plane where the length of an arbitrary path is preserved. Hence you can't measure real-world distances using string and a paper map.
That said you can preserve distance in special cases, for example any two chosen points. For example you can go to https://www.jasondavies.com/maps/two-point-equidistant/ https://www.jasondavies.com/maps/two-point-equidistant/ and put your points at the Suez Canal and the Cape of Good Hope. While that still won't let you measure wiggly ship routes along the coast, it does a better job than Mercator.
Failing that you can use Gall-Peters which does a better job of conveying the vastness of Africa, since it's area preserving.
- rightbyte 3y ago> Hence you can't measure real-world distances using string and a paper map. You very much can. The scale of longitude and latitude is just not the same so you need to do Pythagoras (usually by approximation rules). There are usually lines to allow for that.
- Y_Y 3y agoIf you only use rigid string and sail in strange curves that map to straight lines in 2d then that's true. Or maybe by "do Pythagoras" you meant to calculate the metric tensor for your projection and integrate that along your shipping route?
- bevenhall 3y agoIs measuring distances in Google Earth misleading? Why bother with ancient flat maps?
- deleted 3y ago[deleted]
- kube-system 3y agoThe measuring tool is accurate. The way it appears on your screen is always misleading in some way, because your screen is flat.
- OscarCunningham 3y agoThey actually curve the line of the measuring tool so that it follows the geodesic.