## 2011-06-29

### Survival Guide: Tell time using the stars

Whenever technology is not immediately available, I try to tell time using the stars. When I say stars I mean either the one closest to us (aka the Sun) or those further away. In today's survival guide, I'm going to show you how to estimate the time using only the stars and a bit of math.

(As I have mentioned in previous Survival Guides, if you are unable to use the techniques below due to weather conditions, I strongly suggest that you be less concerned with the current time and focus instead on quickly finding shelter nearby.)

NORTHERN HEMISPHERE
STEP 1: Find the star Polaris (North Star) and the constellation Ursa Major (Big Dipper). [help]
STEP 2: Imagine a straight line from Polaris drawn through the two stars of Ursa Major which are furthest away from its tail.
STEP 3: Imagine that the line is the hour hand of a clock with Polaris at its center. Estimate what time the hand falls on. For example:
If the line to the two stars is perfectly level to the right, that would be 3:00.
If the line is midway between the bottom and level at right, that would be roughly 4:30.
STEP 4: Add an hour for every month that has passed since March 7th and the current month's 7th. Or subtract an hour for each month between this month's 7th and the approaching Marth 7th.
(For additional accuracy you can add or subtract two minutes for each day before or after the seventh of each month.)
Some examples:
- At midnight on March 7th, our hour hand is also at midnight. So, this is our zero date (in the Northern Hemisphere).
- November 7th is eight months after March 7th, so 8 hours are added to our STEP 3 time.
- January 2nd is two months and five days before our zero date, so we subtract two hours and ten (5*2) minutes from our STEP 3 time.
- March 10th is three days after March 7th so we add six (3*2) minutes to the STEP 3 time.
STEP 5: Double the STEP 4 time. (e.g. 3:00 * 2 = 6:00, 4:30 * 2 = 9:00, 7:45 * 2 = 15:30)
STEP 6: Subtract the STEP 5 time from 24. (Subtract it from 48, if it is initially larger than 24.)
STEP 7: This is the estimated current time. You may choose to make local adjustments (e.g. AM/PM, daylight saving time, timezones, etc.)

SOUTHERN HEMISPHERE
STEP 1: Find the Southern Cross constellation and the pole (imaginary southern point). [help]
STEP 2: Imagine a straight line from the pole drawn through the two stars of the long bar of the Southern Cross.
STEP 3: Imagine that the line is the hour hand of a clock with the pole at its center. Estimate what time the hand falls on. For example:
If the line to the two stars is perfectly level to the right, that would be 3:00.
If the line is midway between the bottom and level at right, that would be roughly 4:30.
STEP 4: Add two hours for every month that has passed since March 29th and the current month's 29th. Or subtract two hours for each month between this month's 29th and the approaching Marth 29th.
(For additional accuracy you can add or subtract four minutes for each day before or after the twenty-ninth of each month.)
Some examples:
- At midnight on March 29th, our hour hand is also at midnight. So, this is our zero date (in the Southern Hemisphere).
- March 19th is ten days before March 29th, so we subtract forty (10*4) minutes from the STEP 3 time.
- June 29th is three months after March 29th, so we add six (3*2) hours to the STEP 3 time.
STEP 5: Double the STEP 4 time. (e.g. 3:00 * 2 = 6:00, 4:30 * 2 = 9:00, 7:45 * 2 = 15:30)
STEP 6: Subtract the STEP 5 time from 24. (Subtract it from 48, if it is initially larger than 24.)
STEP 7: This is the estimated current time. You may choose to make local adjustments (e.g. AM/PM, daylight saving time, timezones, etc.)
Discerning the time from the stars can be a useful skill in non-emergency situations, though it may not be of high importance in circumstances where your survival is threatened. However, it can be a welcomed distraction when needed to keep yourself calm while facing a mentally stressful situation while trying to survive in the wild.

## 2011-06-28

### Happy Tau Day

Three months and fourteen days ago, I wrote an article in celebration of "Half Tau Day" (better known to many as "Pi Day"). In that article I began to point out the benefits of using Tau (τ) or 2*pi (2π) in Mathematics.

Today, in full celebration of Tau Day, I would like to present more about the benefits of adjusting our established norms for a more comfortable digestion of Math. (A great deal of the information I will present here is processed from "The Tau Manifesto" website. I encourage you to take a more detailed look at the information there, if what I present here intrigues you.)

The constant of 2π is wide-spread in use throughout Mathematics, especially in Trigonometry and Calculus. This commonality occurs simply because of the relationship between circles and their radii.

Pi (π) exists because it is the ratio between a circle's diameter and its circumference. It has been stated (and sometimes argued) that "it is easier to measure a circle by its diameter than its radius". That may be so, but most formulas involving circles use its radius (e.g. area, angles, fractions, etc.); some charts and real world applications use radius as well, such as "pie graphs" and even slice the real-world application of slicing a piece of pie. Which means that the diameter would have to be divided after measurement anyway, especially if you want to measure more than circumference.

So, why not use a variable based on the ratio between a circle's radius and its circumference in the first place?

Circumference:
C = τ r
Area:
A = (τ/2) r²
Volume (of a sphere):
V = 2/3 τ r³

There may be some formulas which may seem more useful with π. Personally, I have no objection. Afterall, a meter is just 100 centimeters, yet we choose to use both "m" and "cm" everyday. I think π and τ should coexist in Mathematics in the common goal of providing a consistently easy and logical understanding of the concepts. (Meaning, let's make Math easy and fun for students.)

Keeping the students as the priority, certain "weird math" gets discarded. For example, did you know that a full pi radian angle is only 180°. If I were to use only pi to cut you a slice of pie that means you would only get half of what you asked for because a circle is really 2π. Using τ you would have access to the full 360°.

All-in-all, I want the focus in learning to be on the learner not the establishment. I encourage you to challenge yourself, question your logic, and most of all keep your eyes open and focused on new horizons.

Happy Tau Day! Now, go enjoy TWO pies!

## 2011-06-25

### Survival Guide: Find North

Regardless of whether your life is in immediate danger, it's important to always know where you are, at least in relation to where you came from or where you're going. One of the easiest ways to sense your relational location, is to know how to find North (and South and East and West).

There are a few ways we can find North, but environmental conditions will affect which ones you can use in any given situation. (As will also be true with future guides, if you can't use any of the methods listed below for whatever reason -- especially weather conditions. Find shelter nearby and stay there. Seriously.)

Once you're facing North, remember: South is behind you, East is on your right, and West is on your left.

["Cardinal direction" - Wikipedia]

STEP 1: Stab a stick into the ground so it's pointing straight up.
STEP 2: Mark the tip of its shadow with a small distinguishable object.
STEP 3: Wait a bit.
STEP 4: Mark the tip of the shadow with another small distinguishable object.
STEP 5: Stand with your left foot at the first object and your right foot at the second object. (Not enough room to do that with both feet? Repeat Steps 3 and 4.)
STEP 6: Look straight ahead. That's North.
NIGHT-TIME, SHADOWS CLEARLY VISIBLE FROM A BRIGHT MOON
(Use the same method as described above for the Sun.)
NIGHT-TIME, STARS CLEARLY VISIBLE
STEP 1: Find this constellation...
Northern Hemisphere: Ursa Minor (Little Dipper) [Wikipedia]
Equator: Orion [Wikipedia]
Southern Hemisphere: Southern Cross [Wikipedia]
STEP 2: Locate a specific area in the sky...
Northern Hemisphere: The tip of Ursa Minor's tail (the end of the Dipper handle) is Polaris (the North star).
Equator: Find Orion's raised arm, belt, and his legs.
Southern Hemisphere: Imagine a line from the long end of the cross about four times the long width. Imagine a point at the end of that line.
STEP 3: Position yourself.
Northern Hemisphere: Face Polaris.
Equator: Position yourself so Orion's feet are "behind" you and his raised arm is "forward".
Southern Hemisphere: Face directly away from that imaginary point.
STEP 4: Look straight ahead. That's North.
SUNRISE OR MOONRISE
STEP 1: Position yourself so that the rise is at your right.
STEP 2: Look straight ahead. That's mostly North.
SUNSET OR MOONSET
STEP 1: Position yourself so that the set is at your left.
STEP 2: Look straight ahead. That's mostly North.
COOL, MOIST CLIMATE
STEP 1: Find a tree or rock which is -- or usually is -- casting a large shadow.
STEP 2: Locate the side with the most moss, moisture, or snow.
STEP 3: Position yourself...
Northern Hemisphere: Face away from the located side.
Southern Hemisphere: Face the located side.
STEP 4: Look straight ahead. That's mostly North.
ANYTIME, CLOUDY WITH SOME WIND
STEP 1: Watch the cloud movement. Fronts generally move West to East.
STEP 2: Position yourself so that clouds are coming toward your left and away from your right.
STEP 3: Look straight ahead. That's probably North.
As I stated briefly before listing these techniques, it is very important that you find shelter in the immediate area and not wander. I will try to discuss this more in a future survival guide, so to keep it simple here: you risk injury and death, decrease the odds of rescue, and increase your panic when you are lost. So, if you don't know where you need to go, stay put until you do or until you're found.

## 2011-06-21

### Survival Guide: Tell time using the Sun or Moon

The June solstice occurred today (2011-06-21) at 17:16 UTC. A solstice is when "the Sun's apparent position in the sky reaches its northernmost or southernmost extremes" ["Solstice" - Wikipedia]. For the Northern Hemisphere of our planet, that means it is the middle of traditional Summer. For the Southern Hemisphere, the middle of traditional Winter. Knowledge of today's solstice will be useful in the first of the survival guide series when "telling time using only the Sun or Moon".

CAUTION: Daylight saving time can cause confusion in some of the calculations, so I recommend ignoring DST entirely until you have the final times you are seeking. Only then should you try to adjust it according to the strange daylight "saving" time system or make any adjustments based on your preferences or location.

ESTIMATE DAY LENGTH
The length of the day depends almost entirely on Latitude. (Your location North or South of the Equator.)
- At the Equator, the day is always twelve (12) hours and the night is also twelve.
- During the equinox (mid-Spring and mid-Autumn), the day is roughly twelve (12) hours, regardless of Latitude.
- During the solstice (mid-Summer and mid-Winter), the day is roughly fourteen (14) hours (Summer) or ten (10) hours (Winter) at the "midpoint" between the equator and a pole.
- During the solstice, the day is either all hours (Summer) or non-existent (Winter) at the poles.

I try to remember those as the "10, 12, 14 facts" - 10 in the Winter, 12 in the Spring, 14 in the Summer.

You can roughly guess how long the day is at your location using the "10, 12, 14 facts" I listed above and a rough guess at your Latitude. (Keep in mind the days are longer closer to the pole in Summer and shorter closer to the pole in Winter. Also, remember the "10, 12, 14 facts" apply best at the approximate "midpoint" between a pole and the equator.)
CALCULATE TIME OF SUNRISE AND SUNSET
STEP 1: Find your estimated day length.
STEP 2: Divide the STEP 1 result by 2.
STEP 3: Subtract the STEP 2 result from 12 to get the time of sunrise (in hours). Add the STEP 2 result to 12 to get the time of sunset.
STEP 4 (optional): Convert to AM/PM, if you must. Personally, I think the 24hr clock is cleaner.

(Do not adjust for daylight saving time, if you intend to use these times in other calculations.)
NOTE: Knowing how to roughly estimate the sunrise and sunset times can be helpful even if you have a clock. Sometimes it's just nice to know how much time you might have remaining in your day or night.

ESTIMATE THE TIME OF MOONRISE AND MOONSET USING EARTH'S SHADOW
(We use the Earth's shadow on the Moon to estimate the Moon's rise and set times based on sunset and sunrise. Since a full Moon has no shadow on it, it needs no adjustments; a full Moon rises at sunset and sets at sunrise.)
STEP 1: "Read" the Moon from its right edge to its left. The right edge is sunset, the left is sunrise.
STEP 2: Imagine that the moon is divided (from top to bottom) into a number of segments equal to the number of hours in the night.
STEP 3: Estimate how many of those segments are covered in the Earth's shadow.
STEP 4: Look at where the Earth's shadow falls on the Moon. Is the shadow to the left or the right of the light?
- If the shadow's on the right, add the STEP 3 result to the time of sunset to get the time of moonrise.
- If the shadow's on the left, subtract the STEP 3 result from the time of sunrise to get the time of moonset.
STEP 5: The moon transits the sky in approximately 12 hours.
- If you know the Moon's rise time, add 12 hours to estimate the set time.
- If you know the Moon's set time, subtract 12 hours to estimate the rise time.
ESTIMATE THE TIME USING THE SUN OR MOON
STEP 1: Pick an "orb" that you can see. Sun or Moon?
STEP 2: Imagine the path of the orb across the sky. (Remember, depending on your location and the season, the orb may not ever pass directly overhead; it may only arch in some portion of the sky.)
STEP 3: Divide the path of the orb into segments of the same number as the hours of its transit. (For the Sun, this is day length in hours. For the Moon, this is 12 hours.)
STEP 4: Note the segment which the orb is currently in, counting from left (rise) to right (set).
STEP 5: Add the STEP 4 result to the rise time of the orb.
STEP 6: This is the estimated current time.

Knowing how soon dawn or dusk will occur is something which I consider a necessary life-or-death survival skill. (We'll discuss this further in future guides.) Beyond that essential skill, knowing how to tell time using only the natural environment is, at the least, a trick which can entertain a few interested friends.

## 2011-06-20

### Survival Guide series

I am launching a new series of blog entries intended to guide readers in a variety of survival techniques. This, so called, "Survival Guide" series is my attempt at providing readers with the type of knowledge I think is fundamental to the survival of the independent human animal when facing "extreme" situations.

Beginning tomorrow (the day of the June solstice), I will publish a new "Survival Guide" on the INDY Blog every four days until July 31st, the day before the cross-quarter day of Northern Hemisphere Autumn (Southern Hemisphere Spring). The subjects covered will range from interesting "tricks" useful anywhere to skills necessary in obtaining basic needs in challenging situations.

My knowledge of these subjects has come from various sources. I credit the most impact to my lifelong involvement with the Boy Scouts of America (from Tiger Cub all the way through to Eagle Scout and Venture Scouts). I've also always been interested in testing the limits of the human body and mind; a study of the basic needs is essential to that understanding. I will be cross-checking my techniques in the various manuals I have and with some internet resources, if I find any that offer good visuals or more detail I'll be sure to link to them in the related article.

At the least, I hope you will tuck these tips away in the back of your mind, so that you can have them should you need them.

## 2011-06-09

### INDY Members attach OpenIDs

In a post in April, I encouraged all current INDY Members to attach OpenID logins (e.g. Google, Twitter, etc.) to their INDY accounts. By doing so, members would not have to remember an additional username/password for the INDY website and information would be better secured.

If you are a current INDY member, please consider attaching an OpenID to your INDY account as soon as possible. For assistance with this process, please revisit the original post on the subject of OpenID.

I intend to phase out the INDY password in favor of the more secure (and memorable) OpenID authentication by 1 July 2011, so attach an OpenID now to avoid any inconvenience or interruption of your access to the INDY website.