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Hey BrainStuff, I'm Jonathan Strickland.

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So you've probably seen geographic coordinates like these before.

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Maybe on a GPS device, or maybe scrawled in a mysterious note you found in the glove box

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of a rental car.

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But if you never knew exactly what they meant, fear not.

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It's actually pretty simple, and we are here to make it all clear.

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When you see a set of geographic coordinates looking like this, or like this, you're reading

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latitude and longitude.

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Latitude represents north-south location, and longitude represents east-west location,

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usually listed in that order.

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By combining them, you can pinpoint any spot on the surface of the Earth.

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These coordinates aren't expressed in units of distance, but in degrees.

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Why?

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Because the Earth is a sphere.

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Imagine a line running from the equator to the center of the Earth, and then another

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line running from the center of the earth to the north or south pole.

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These two lines make a 90 degree angle.

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All latitudes in each hemisphere can be represented by drawing a third line somewhere between

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them.

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So the equator would have 0 degrees latitude, and the north pole would have 90 degrees north

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latitude, and a location halfway between the north pole and the equator would lie at 45

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degrees north.

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Same thing for the southern hemisphere, except you'd call it degrees south.

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For more precision, each degree of the Earth's surface

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is divided evenly into 60 minutes,

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and each minute is divided into 60 seconds.

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If you need to get even more specific,

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you can just add decimals to your seconds.

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Alternately, you can write the whole coordinate

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in decimal notation.

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To do this, you have to convert minutes and seconds,

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which are base 60, into our regular base 10 counting system

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by dividing each unit by 60 and then summing them up.

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The results sometimes look counterintuitive,

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But if you're skeptical, you can pause the video

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and check out the math.

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Lines of longitude, also called meridians,

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run north-south and are used to measure position

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along the east-west axis.

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While the lines of latitude run parallel to each other,

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meridians converge at the poles

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and spread farthest apart at the equator,

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like the segments of an orange.

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Longitude is also measured in degrees,

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but its zero degree line is known as the prime meridian,

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and it runs from the North Pole to the South Pole

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through Greenwich, England.

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So, if the prime meridian is zero degrees,

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the opposite side of the Earth is 180 degrees,

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and lines in between are expressed as degrees east

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or degrees west, between zero and 180.

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Since the lines of latitude are parallel,

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each degree covers about the same distance the world over,

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roughly 111 kilometers.

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But because meridians converge at the poles,

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the distance covered in each degree of longitude

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varies hugely depending on your latitude.

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At 20 degrees north, which is about the latitude

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With Cuba and Hawaii, one degree of longitude is approximately 104 kilometers.

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At 80 degrees north, the latitude of Svalbard and Northern Greenland, it's only about 19

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kilometers.

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So, let's say I wanted to go dig up a stash of hot loot from some coordinates I found

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written in a mysterious note.

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Even without looking at a map, we can start to make a guess where this would be.

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Since it's 43 degrees north, it's almost halfway between the equator and the North Pole, again

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and halfway being 45 degrees.

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And since it's 89 degrees west,

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it's almost halfway west between the prime meridian

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and the opposite side of the globe,

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halfway being half of 180 degrees or 90 degrees.

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Based on this alone,

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you can guess it's probably somewhere in North America.

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But if we use a map or a digital tool like Google Earth,

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we can zoom in and see these coordinates lead us to

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U.S. National Mustard Museum in Middleton, Wisconsin?

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Huh.

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But what's the weirdest landmark you've ever found on Google Earth?

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Paste the coordinates in the comments so everybody can check it out.

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If you liked this video, hit that thumbs up button and subscribe for more.

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And as always, for answers to all kinds of questions like this, head over to HowStuffWorks.com