Placeholder Image

Subtitles section Play video

  • This is space.

  • No, I don't mean the part filled with stars and satellites.

  • This image of the world is letting us see part of geographic space.

  • The Earth is covered in features and relationships that we can measure and study in a variety

  • of ways to better understand our environments.

  • For example, if I were to zoom in to your community, I might measure the space by counting

  • the buildings to get a sense of how big it is.

  • But this is your community, so you know where the place to catch up with a neighbor is,

  • like an eclectic coffee shop or walking the sculpture park.

  • I only see the physical buildings, while you understand the importance of each building.

  • We're looking at the space in two different ways.

  • But there are more ways to discuss space, and they each add a new layer of understanding

  • -- from measuring it, to defining it, to understanding the relationship between places.

  • Just as all historians study events in time, based on what's going on or what's normal

  • for a time period, all geographers study events in space.

  • No matter the topic, we end up contextualizing places or human-environment interactions based

  • on the space they exist in.

  • I'm Alizé Carrère and this is Crash Course Geography.

  • Intro

  • In geography, we ask questions to understand what is where, why it's there, and how it's

  • changing.

  • So when we're trying to interpret why glaciers melt or disease outbreaks happen in certain

  • places, we want to both measure space (to get thelay of the landif you will),

  • and try to understand the significance space has to what's happening.

  • As geographers, we can think about space in four broad categories that emphasize different

  • aspects and use a suite of tools and techniques to help us with measuring and understanding

  • our world.

  • In its simplest form, we can think of space as a container, like a box or an extra-large

  • Tupperware container for delicious banana bread.

  • We want to know where stuff is -- basically, what's inside or outside the container.

  • The Earth is like a stage, and everything from cool rock formations to political protests

  • happen on that stage.

  • Studying space as a container helps us answer the questionwhat is where?”, by measuring

  • and locating physical features or borders or boundaries.

  • To do this, geographers and other people who work with distances and points, like surveyors,

  • use a coordinate reference system.

  • Like overlaying a square grid on the globe.

  • Even our phones can be used to tell us what is where.

  • When we open Google Maps on our phones, the phone connects to a Global Positioning System

  • or GPS, which pinpoints the location of an object on the ground using radio from satellites.

  • When a receiver on Earth -- like our phones -- receives a radio wave from three or more

  • satellites, the phone can translate those signals into a precise location, and know

  • where we are.

  • These days all the satellites launched by the US, China, Russia, the EU, India, and

  • Japan are called the Global Navigation Satellite System.

  • While it's great to know where things are, as geographers we want to go beyond that.

  • Even our phones tell us more than just where the sculpture park is.

  • Once we know where things are in space, we can understand how they're related, or their

  • spatial relationships.

  • In fact, humans are hardwired to think about spatial relationships and how we're related

  • to the space container around us.

  • To describe those spatial relationships, we need to recognize topological space, which

  • measures and analyzes how the features in space are arranged and connect to each other.

  • This term comes from the word topology, which refers to how the pieces of something are

  • related or arranged.

  • We also see topological space in action every time we ask our phones to route us somewhere.

  • We're really asking Google Maps to look at how our beginning and ending locations

  • are related and find the most efficient connection based on what's physically in the area.

  • Spatial analysis is a blend of geography and math that identifies and analyzes those patterns

  • and relationships in space using a range of techniques including imaging technology, statistics,

  • and geometry.

  • To see those spatial patterns, and understand how space changes over time, sometimes it

  • helps to zoom out and stand back.

  • Remote sensing, or studying something without physically contacting it, is an entire subfield

  • of geography that lets us do just that.

  • Photogrammetrists a nd other remote sensing professionals compile

  • and analyze images from satellites, airplanes, or drones that have sensors that record energy

  • reflected from the Earth's surface.

  • The reflected energy is sensed by a device that records the wavelength as a number and

  • turns that number into a pixel in an image.

  • Remote sensing has been particularly helpful in Antarctica, which is incredibly hard to

  • study in person.

  • Covered in ice and snow, this frigid continent has been one of the least mapped areas on

  • Earth.

  • And for good reason.

  • Antarctica is considered the coldest place on Earth and the windiest.

  • Conditions are so extreme that hiking around and recording the terrain in a ground-based

  • mapping effort is nearly impossible.

  • So in 1997, researchers collaborated with NASA and the Canadian Space Agency to use

  • remote sensing satellites with radar capabilities known as Radarsat to scan the surface of Antarctica.

  • They generated accurate images of the surface ice and snow on Antarctica by measuring the

  • echo of radio waves sent from a RADAR satellite.

  • With this data, we can start by defining the boundaries of features in Antarctica, like

  • the location of large cracks in the ice called crevasses.

  • We're defining the space, or container, that is this polar continent.

  • But definitions of any kind are really just the initial building blocks.

  • In Antarctica, we can use that information to analyze our relationship to those features.

  • Crevasse zones are dangerous to cross and difficult to see from the ground, so knowing

  • where they're located can help create safe travel routes.

  • This can save time and lives when trying to navigate this dangerous terrain.

  • But our spatial relationships are more than just routes.

  • The radar dataset is also used to measure how quickly glaciers are moving, which gives

  • us insight into the physics of glaciers and lets us better predict how glaciers change.

  • We can build a more complex understanding of a space when we ask not just where is the

  • crevasse but how is it changing? or where is that ice moving?

  • Now containers and topology are informative, but they don't let us talk about the more

  • subjective things we know about a space.

  • In geography we can also talk about socially constructed spaces, or those spaces we create

  • and give meaning to as communities.

  • Like that coffee shop or sculpture park.

  • In fact, the socially constructed space doesn't even have to be physical.

  • The way we develop and define virtual spaces -- like the fan communities we form and participate

  • in online -- is a whole sub-field of geography.

  • But let's stay in the physical realm, in - for example - Harbin, China.

  • Each January, blocks of ice from the Songhua River that flows through the city are carved

  • into sparkling sculptures as part of the annual Harbin International Ice and Snow Sculpture

  • Festival.

  • Originally, ice lanterns were mostly used at night on the river by fishermen.

  • They gradually became an artform and, eventually, a major social and cultural event.

  • Now the wonder of the Ice and Snow Festival is synonymous with Harbin.

  • By studying socially constructed spaces, we learn how space is carved out and a place,

  • or location with meaning, is created and can become sites for social, political, or economic

  • activity.

  • Individuals, not just communities, can also create meaning in space.

  • We study individually perceived space to incorporate the idea of place and see how the perception

  • of a space can change person to person or culture to culture.

  • Like a teenage girl living in Harbin might hold a mental map of her neighborhood that

  • includes points of interest to her, like the curb she almost twisted her ankle on while

  • jogging.

  • That's her perception of that space, just like we all have our own perceptions of our

  • individual spaces.

  • And we can see how the perception of individuals or groups has changed over time.

  • Today, Harbin is the 8th largest city in China.

  • But its name was originally a Manchu word meaning “a place for drying fishing nets

  • which hints at how past inhabitants perceived and used this space.

  • Any space can be studied through any of these four lenses: as a container, topologically,

  • socially, or how we individually perceive it.

  • Let's go to the Thought Bubble.

  • In January 2010, a magnitude 7.0 earthquake shook the nations of Haiti and the Dominican

  • Republic creating massive damage and killing hundreds of thousands of people.

  • But things could still get worse.

  • Relief efforts in Haiti were delayed because aid workers didn't know where to go or how

  • to get there.

  • Clear maps of neighborhoods and remote regions of the island before the quake just didn't

  • exist, so international aid workers had no sense of space and no fast way of learning.

  • But the locals did know the area -- what was there, how it was organized, and what it meant

  • for their communities.

  • So that collective knowledge -- or perceived space -- was put to work.

  • In two weeks, Haiti went from no map to a complete map in the first crowdsourced mapping

  • effort for humanitarian purposes.

  • A team of mappers organized people around the world to help digitize photos, which means

  • tracing images to create 2D shapes and attaching coordinates that can be plotted on a map.

  • These humanitarians input aerial and satellite images into a mapping platform called OpenStreetMap.

  • With OpenStreetMap, volunteers can look at space as a container and use those images

  • to trace buildings, parks, roads and more to create a basic digital map.

  • That map can then be used by anyone in the world with access to OpenStreetMap.

  • In Haiti, those maps meant relief workers could see where buildings should be and could

  • use that to help identify where people might be trapped.

  • Now they could find efficient routes to points they needed to get to and engage with the

  • topology, or organization, of the space.

  • The global effort to map Haiti was such a success because it brought together those

  • who had technology to digitize the building boundaries and roads, and those who knew the

  • significance of those boundaries and roads.

  • With crowdsourcing, the sense of space could be complete.

  • Thanks, Thought Bubble!

  • Since 2010, communities around the world have worked within OpenStreetMap digitizing their

  • buildings, roads, and other features.

  • Local citizens imbue the map with meaning, like which of these buildings are houses,

  • or where there are important community gathering places, hospitals, and businesses.

  • Local groups and humanitarians can then create the maps they need to achieve their goals

  • -- from identifying areas at risk for disease spread, to identifying safe areas for persecuted

  • groups, to helping locate people quickly after a natural disaster.

  • Because anyone can update the map as spatial features change, the data is always fresh

  • and ready to be used.