Step 1: I. Notice About Copyright
Techniques used in celestial navigation follow the standard course of planets and stars, as well as the physics behind that governs those courses, which are laws of nature. U.S. and international copyright law forbid the copyright, patent, trademark, etc of natural laws. Just because you discovered it, doesn't mean you own it.
The reason I include this is that some of these techniques are several thousand years old, while a few have only been discovered recently with current technology. But again, the same principle applies, you can't own it.
Step 2: What You Need
- An *accurate watch
- Your hand
- Some sticks (should be easily found)
*I define an accurate watch as one that has had its time set to an atomic clock within the last 4 weeks. The reason for this is that most watches use the oscillations of a quartz crystal, to keep time many times more accurately than a mechanical clock. However, it still can lose or gain 5 seconds a week. To get the most accurate calculations, the watch should be within 30 seconds of the actual time.
NOTE: The watch will not always gain or lose time at the same rate. Odds are, you will barely be off by 2-3 seconds most of the time. However you should get in the habit of setting the watch every month or so.
By the way, the calculations that you will be doing here are nothing like typical celestial navigation. Nothing more than simple multiplication, division, addition, and subtraction.
Step 3: Measuring With Handspan
- One finger is approximately 2 degrees.
- The width of your hand at the knuckles is approximately 10 degrees.
- With you hand fully spanned, they measure approximately 20 degrees.
By using these, you can get a rough estimate of the angle between the horizon and any stars you need to measure. But remember, you must hold your hand out at arm's length.
*To all of you who are going to make a sexual comment, please grow up. I'm trying to teach you ways to save your life.
Step 4: Get Your Bearings Straight
Out of everything you can learn from this instructable, this should be the one thing you learn. Finding these directions are the key to getting found.
1) Place a stick in the ground, sticking straight up.
2) The stick will cast a shadow on the ground. At the end of the shadow, place another stick in the ground, sticking straight up as well.
3) Wait a couple of hours.
4) When you come back to it, you will find that the shadow has moved. If you come back at noon, i.e. there's no shadow because the sun is directly overhead, come back an hour later.
At the end of this shadow, place another stick. (Technically, at noon you could use the original stick, but I'm trying not to confuse you).
5) Now between those two sticks you just placed on the shadows will form a line, more importantly, an East-West line. Perpendicular to this line is, you guessed it, North and South.
Step 5: Latitude
Likewise, if you were at the South Pole and looked straight up, you would be looking at the South Celestial Pole. Unfortunately for you, there are no readily visible stars that mark the South Celestial Pole, so you have to use the constellation, the Southern Cross, in order to find it. To find out how to use it, just google "using the Southern Cross." Just remember, if you're in the Northern Hemisphere, you use Polaris, and if you're in the Southern Hemisphere, you use the Southern Cross to find the South Celestial Pole.
Now latitude are the bands that run along the Earth. The Equator is a Latitude Line. Longitude are the ones that run through the Poles.
So for this example, pretend you're in the Northern Hemisphere. Your latitude is simply the angle between the North Star, and the Horizon. You can get a rough measure of this by using the techniques I showed with your hands.
Now unfortunately, this is the least accurate way to calculate, but sadly it's the only one I've found. The method for finding Longitude is much more accurate. If anyone knows a better method for finding Latitude, THAT WOULD WORK IN AN EMERGENCY SITUATION, please post it below.
Now also understand that if you do this on land, it could be flawed. Normally celestial navigators use a sextant at sea, using the horizon of the ocean to get the best measurement. The reason for this is that the ocean is, pretty much, flat. It's why we use 'sea level' as the standard for elevation. Unfortunately on land, you could have problems. Mountains, hills, valleys, all of these could interfere in this measurement. If you're in the desert, you shouldn't have a problem with this, just look at a flat stretch of land, and measure from the celestial pole. No matter how good your situation is though, you'll probably only get within two degrees or so. So you don't really need to be to concerned about this though.
Step 6: Longitude
Now to understand this, I'm going to have to teach you a little astronomy. As well all know, the Earth has a pretty standard rotation period, consisting of just over 23hr 56 min. However for simplicities sake, we say it is 24 hrs. The difference is where we get leap years. Those small minutes add up to (not quite) one extra day. In a century or so, we will have to have a Feb 30 to account for the even smaller differences we don't take into account.
Nevertheless, the day is 24 hrs long. This set time period means that (from our perspective), the sun moves across the sky at a set pace. It moves at a constant rate of 15 degrees and hour. Guess what, 24*15 is.... 360! So, we have a full circle, full rotation.
This constant rate is where we get our timezones from. The reason is, we define noon as the period when the sun is at a perfect right angle to the Earth, i.e. directly above us. However, what is noon for one side of the world isn't the same for the other side. So, in order to help account for this, the Earth was divided up into 24 time zones. So that there could be some standard by which everyone on Earth could say they lived under.
This system is also the one by which we get the origin for our longitude system, which I'll continue on in the next slide.
Now, if you'll take a look at the map below, you will see that whoever drew the timezones doesn't know how to draw a f@%&ing straight line. The reason for this is, politics. That, and because most of the land areas that are drawn in the wrong time zones do business primarily in those areas. It really is B.S. though. With the advent of the internet that connects all the continents, people do business all over the world, meaning that they have to deal with different time zones anyway. I feel sorry for the guys in the Alaskan Islands. Several of them are about 4 or 5 timezones off.
Also, this system was started by the brilliant men in Greenwich, England. If you take a look at the map, they are the origin of the map (as well as the only ones with a perfectly straight line). This is commonly referred to as Zulu time.
Step 7: Longitude Pt. 2
Now, as I said, noon is the point at which the sun is exactly at 90 degrees in the sky. The scientific term for this is zenith. Now with the timezones, we know that at different areas of the world, the sun will be at it's zenith at different time. For every hour that goes by, a different part of the world will be at noon. This allows us to predict the sun's path, or to find our location.
We know that the sun moves at a constant rate of 15 degrees per hr. So for instance, the first time zone after Greenwich, when it is at noon, we know it's longitude is 15 degrees west. A second example. I live close to Dallas, Tx. I am six time zones away from Greenwich. This means that at 15*6, I'm at 90 degrees west. Are you guys starting to see the pattern here?
Now here's the thing. Go back and take another look at the time zone map. What you'll notice about Greenwich is that it's actually situated equally between two other time zones. It's the same for all the others. The actual noon for that time zone, is on the line perfectly between the time zones.
This is also where the next part come in. If you're in a time zone, that means that the sun will only be at it's equinox, when a clock says it's noon, if you're on that line. Most of us are going to be somewhere either east or west of that line. This allows us to calculate where we're going to be.
Now for this trick, you're going to need a stick and your watch. You need to place the stick in the ground, either at an angle, straight up, it doesn't matter. What you need to look for is when the sun is at it's zenith, by whenever the shadow of the stick is directly underneath it. This is kind of tricky. You're going have to do you best at it, there's not really much else I can do for you.
Now when you see that the sun is at it's zenith, take a look at the time, and make some kind of note of it, either by writing it in the dirt, or remembering it in your head. I suggest writing it down, because we're about to get into the math area.
Now, going back to the path of the sun. Knowing that the sun moves at a constant rate, we can begin narrowing it down. Take a look at these
1 hr = 15 degrees
1 min = 0.25 degrees
1 sec = 0.0042 degrees
So, let's use an example. Say I'm someplace in Texas, and I do this trick. At the sun's zenith, I record the time as being 11:45 p.m. What I can deduce from this is that, because it is not 12:00, the sun has not passed the exact middle of the timezone I'm in, which, if you'll remember, is 90 degrees. So, I am east of the 90 degree mark, meaning it's less than 90 degrees. I know that I'm 15 minutes off, so, 15 * 0.25 = 3.75. 90-3.75 = 86.25 degrees West
If it had been greater than 12 o'clock, then I would have known I was west of the 90 degree mark, so I would have added to it. Now if you end up being either 30 minutes greater or lesser, then you'll know either you're in a different time zone, or in one of those effed up areas of the map (which is very likely). This shouldn't affect your calculations, but it's something you should bear in mind.
Step 8: Lunar Clock
Step 9: Finale
More than anything, I pray that none of you will ever find yourself in a situation where you have to use these. However, one should always hope for the best, but plan for the worst. So you need to be prepared. These are techniques that mankind has mastered over several thousand years, and that we should not forget.
Above all, if you want to get good at these, you should practice them. Remember, practice does not make perfect; perfect practice makes perfect. Get good at these things when the heat is off, so that when it comes on, you'll be able to handle it.
Anyone who has a technique they would like me to add, or if you think anything needs correcting, please feel free to contact me. If you send me a new technique, I will be happy to add it and mention you as the one who sent it in to me. Please remember, these are emergency techniques. Please only include them if they have roughly the same sort of resources I mentioned in these techniques. Of course, if they involve something you can make in the middle of nowhere, that would work as well. Just remember, EMERGENCY, so nothing to complicated.
God bless anyone who has to use these,