I was lost
and a little bit scared.
Women and men were swerving and shoving, not even looking at each other, their eyes downcast toward crossed-off lists. Where the hell was I? Wishing for a trail of breadcrumbs was only a mockery since I couldn't find my way to the bread aisle. I was in the cereal aisle, near all the boxes with white beady eyes of cartoons taunting me , I did the only thing an eight-year-old could: I yelled for my mother. Needless to say, about ten women looked right at me. Jewel is a land of rationed rows and columns that have been intrinsically designed with a pattern that consistently loses children , although somehow mothers across this city have deemed kids fine company to take along on these Saturday afternoon errands.
Yes, my mother did find me. She did it by following my voice. She had a reference point to latch onto, a tool that told her where she was going and where she had been: my screaming. The answer to never being lost is reference. So if you're lost, as in you live in your parent's basement and you cried at the end of Friends , then this will not help you. You in fact need a lot more then reference to help you out. But if you've lost your way in the woods or lost your way in your local Jewel, then here goes the basics of a compass and the Global Positioning System.
Low Tech: Compass
A magnetic compass is about as simple a device as one could build. The compass consists of a small, lightweight magnet balanced on a nearly frictionless pivot point. The magnet is generally called a needle. One end of the needle is often marked "N," for north, or colored in some way to indicate that it points toward north.
The needle on the compass always points north, thus giving you that all-important reference. When talking about magnets although this theory crumbles with people opposites attract. So if the needle on a compass always point north, then it's as if there is a large bar magnet that stretches through the center of the earth with its south end at the North Pole. But there is in fact no large magnet stretching through the Earth, even though the way a compass acts would dictate this.
There are theories about molten iron at the earth's core doing stuff, but really, for our purposes, who cares? The point is a compass is generally attracted to north. Now it's time to learn how to use that compass, so get out your favorite map. The map does most of the work, but it is the compass that gives you the reference.
So you are at the corner of Division and Halsted Streets and you've just heard a gunshot. You see a bunch of guys running at you, yelling at you to take off that white hood. Needless to say you're confused but you know there is a safe house on Augusta Boulevard and Milwaukee Avenue . Take out your map and mark Division and Halsted as A. Mark Augusta and Milwaukee as B. Now draw a line connecting A and B.
Every map worth its salt comes with two very important features that you've probably never used. The first are orientating lines that point north on the map. Lay the compass on the map and point the arrow north. You want to do this with the compass edge near the mark of A. By the way, hurry up because the guys are getting closer and they don't look pleased. The arrow will be now lined up with the map's orientating lines. The compass will have a dial on it turn it so the arrow is parallel with the line connecting A and B. Now put your map away, dodge that next bullet , find north with your compass and run as fast as you can in the direction of the dial's arrow. That's it.
The other feature that most maps have is called the level of declination. Remember when I said a compass always points north? A compass really always points to magnetic north. That magnet that runs through the center of the earth? Even though it isn't real, to be completely accurate, the fake bar magnet does not run exactly along the Earth's rotational axis. It is skewed slightly off center. This skew is called the declination.
So depending on where you are in the world, north and magnetic north are not always the same, and it is the map that must tell you how far off your compass is. Now that sucks. What if you don't have a map, or what if you need to coordinate 100 vehicles around the globe with pinpoint accuracy? Because we all need that ability from time to time, hello GPS.
High Tech: GPS
The Global Positioning System is actually a constellation of 27 satellites with 24 in operation and three extras for replacement. The U.S. military developed and implemented this satellite network in the late 1970s as a military navigation system, but opened it up to everybody else in 1993. The orbits are arranged so that at any time, anywhere on Earth, there are at least four satellites visible in the sky.
The GPS receiver is a small device that listens into the radio signals given off by these 24 satellites. A GPS receiver's job is to locate four or more of these satellites, figure out the distance to each, and use this information to deduce its own location. This operation is based on a simple mathematical principle called trilateration . Here comes that geometry.
So you're standing on the corner, lost. Completely without a clue of where you are, you ask a stranger. He, being confused himself because of a pending divorce, doesn't know where you are either but knows you are 660 feet from The Alley on Clark Street and Belmont Avenue. You can draw a circle with a diameter of 660 feet around the Alley and you know you are somewhere on that circle. You ask a second person the same question and again, she is also lost because her three kids have been yelling in her ear all morning long. She does know, however, that you are 329 feet from the bar Sheffield 's. Again you can draw a circle with a diameter 329 feet and you see it intersects with the first circle at two points. So you're at one of those two points.
Finally in desperation, you ask a third gentleman the same question but his mind is foggy from the 50 cent Pabst Blue Ribbons from last night but he assures you that you're 100 feet from the Vic Theater . Again with the circle and you now see that the three circles intersect at on point. You're standing at the corner of Belmont and Sheffield Avenue ! Hurray for you. This is only a two-dimensional example of how GPS works. In real life, GPS is three-dimensional and the circles you just drew become spheres. Your GPS receiver does the same process. It asks the questions and the satellites give the answers. The earth itself acts as a fourth sphere so that the receiver can tell you where in the world you are.
So using radio waves sent from the satellites, the receiver can measure the distance from one satellite to another and if you add a fourth to the mix, it can tell you exactly how high you are as well. Beyond this, all the information a receiver can tell you is handled in the software of your receiver, which can calculate speed, direction and even the nearest Chinese restaurant.
Conclusion:
Like I said, it comes down to a point of reference. A compass tells you which way is north and with that reference you can find any direction or path. A GPS receiver tells you how far away you are from three points and with those references you can again find your way. My mom found her reference when I screamed for her like a little girl in the middle of Jewel.
I wish that for every other time I was lost in life, I had a better sort of reference than the one I use. It's not as advanced as a compass and not nearly as accurate as GPS but its worked so far. My reference? In the poker game of life, women are the fucking rake.
It's not really my reference, I just love that line .