Projections & Scale

Question 1

map projection

Answer 1

is a set of mathemetical formulas and equasions that enables Earth’s curved surface to be shown on a flat map

Question 2

the accuracy of map projection

Answer 2

• only a **globe **can accurately represents all of the Earth’s metric properties
• Projected on a flat surface,only some of these properties can be accurately respresented: Every map has some sort of distortion

Question 3

we can categorize projections based on:

Answer 3

*** Projection surfaces

* Types of projection(metric properties)

Question 4

Projection surfaces

categrophers found that 3 surfaces were sutible for projecting an image of earth without significant distortian:

Answer 4

1. Cylindrical projection
* the earthis projected on a cylinder
* whole-world maps are rectangular
* distortion in the poles

2. Conic projections
* the Earth is projected on a cone
* good for representing parts of the earth

3. Plenar projection
* The earth is projected on a plane(circle)
* lots of distortions towards the edges

Question 5

Types of projections

Answer 5

1. Conformal
* Angles between positions are preserved
* convenient for sea navigation
* distortion of countries/continents areas( how big it is )
* ex: Mercator (cylindrical projection)

2. Equivilant/Equal areas
* The area of countries/continients is preserved
* enable direct surface comparisons within the map
* the** shape**of countries/continients is distorted( how it looks like )
* ex: Mollweide,Gall-Peters

Question 6

Types of projections

Answer 6

3.Equidistant
* all distance from a point(the projection center are correct
* distance between any other points are incorrect/distorted
* convenient for radio communication,radar
* ex: Azimuthal Equidistant(Plenar projection)

4.Compromise
* Balances the distorton of shape and area
* produces visually appealing maps
* no metric properties: areas,distance,and shapes cannot be measured
* example:Robison

Question 7

what are some issues with having a map which has distortion?

Answer 7

l
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Question 8

Eurocentic mapping and africa

Answer 8

the hypothasis about how Africa’s importance has been diminhshied in the western consciousness in part due to map projections making the continent appear smaller

Question 9

eurocentric mapping and prime meridian

Answer 9

the location of the prime meridian has been claimed as an example of eurocentric

Question 10

sooo….

how the Mercator projection has historically perpetuated Eurocentricism in institutions?

Answer 10

Historically the Mercator projection has been most commonly used in educational institutions, and that the distortion of size or area is increasing in the Mercator projection towards the pols.

1.the distortions increase towards the polls areas at higher latitudes so further north countries/continents appear much larger than they actually are , that means that some of these countries up north may appear more dominant and more important than countries closer to the equator, this is fundamentally perpetuated Eurocentric with the Mercator projection.

2.The other note is that the Mercator projection also has the prime meridian located through Greenwich England, making it the centre of the map also potentially perpetuating eurocentrism

Question 11

Measuring what er observe

Answer 11

original mesurements metrics were derived from the human body or common travel distance

problem:not everybodies bodies are the same

Question 12

normalization:the meter

Answer 12

• after the french revolution a new normalized decimal metric system was proposed
• The metre was originally defined in 1793 as one ten-milionth of the distance from the equator to the north pole
• since 1983 it is defined based on the speed of light: lenght of the path travelled by light in vacuum during a time interval of 1/299…. of a second

Question 13

metric system

Answer 13

international agreed decimal system of mesurment

although they dont use it at usa because the president though it was ‘’ too frech’’

Question 14

how we observe different scale

Answer 14

• electron microscope
• optical microscope: a little bit bigger
• camera
• telescope

Question 15

how we represent scales on maps?

Answer 15

• map scale is defines as the ratio of the distance between two points on the map to the corresponding distance on the ground

**small/corse scales maps **cover a large area with coarse detail(zoom out)

* large/fine scale maps cover a small area with great detail and accuracy(zoomed all the way in)