How can two persons orient themselves without a compass in an environment without sun, stars or remarkable landscape features?

Question

A character of my story is in the following situation: He is in the middle of a forest and has lost his way out. He wants to be sure to keep straight on and not to move in a circle.

• He has no compass
• The sun and stars do not exist, just diffuse light.
• A second person is with him, they have no special equipment (I could give them some things that they have in their pockets, but no large gadgets).
• He is a scientist and very clever.

Is there a way my characters can make sure that they walk straight on for several kilometers under this conditions?

EDIT: I asked this question yesterday and since then I got a lot of nice answers, thank you.

But I decided to describe the setting a little bit better since some answers do not quite fit and there are a few questions in the comments.

My story takes place in a fantasy world. In this world sun, moon and stars do not exist. The light comes uniformly from all directions (not from the underground), so one can not use it for orientation. Weather-phenomenons also are distributed isotropically. Furthermore there is no magnetic field so a compass would not work.

The forest itself is very homogeneous. There is only one sort of trees, they are about three meters high and not very close together. There is no underwood, only grassy forest floor. The underground is flat, there are no hills or troughs and no rivers. I described it in my story as 'like the sea, always the same but always different'.

I hope the setting and the reason why even my clever charakter got lost and has problems to find a way out is a bit clearer now.

Answer 1

This answer was in response to an earlier version of the question where it seemed possible that the story environment might resemble Earth on a cloudy or misty day.

Navigation in dense woodland without a compass is very hard. Here are some tactics:

1. If the wood has a distinctive underlying topography, then you can follow that. For example, you can follow a ridge (easier uphill), or a valley (easier downstream). You can follow a contour line by refusing to climb or descend.

2. If the region has strong prevailing winds, then the trees may show the direction: they may have stronger growth on the sheltered side, or bigger root systems on the windward side.

3. If sun often penetrates into the wood, then vegetation will distinguish the sunny and shady directions (south and north, respectively, in the northern hemisphere). Flowers prefer to point in the sunny direction; moss prefers the damp conditions on the shady side of trees; phototropic climbers prefer the sunny sides of trees.

4. If the trees are climbable, then you can climb them and sight distant landmarks.

I use tactic (1) all the time—but it relies on knowing the general topographic layout of the landscape, for example from looking at a map. The observations in (2) and (3) are from Tristan Gooley's The Walker's Guide to Outdoor Clues & Signs. But I find these techniques far from easy to apply in practice and I would hate to have to rely on them. Tactic (4) is pretty desperate—even if you're lucky enough to find a tree tall enough to give you a view over the canopy, it's very risky.

Answer 2

If he doesn't want to go in a particular direction but just wants to leave the forest without getting turned around, walking downhill is guaranteed to eventually work. Downhill is a better choice than uphill because in nature there is almost never a bowl shape without a downhill exit (due to the need for drainage), but peaks are common. In addition, civilization often clusters near water, which is found by going downhill.

Once water is found, this strategy becomes "follow the water", and there is little chance of getting turned around. Water never flows in a circle.

Here is a famous example of a girl who, after a plane crash, navigated out of the Amazon rain forest, travelling ten days to civilization, using this technique: https://en.wikipedia.org/wiki/LANSA_Flight_508

Answer 3

First person places stick where he is. Second person chooses the direction to go to and advances, they must both remain visible to each other.

The second person stops when he thinks he has advanced enougth and signals the first person.

The first person advances half of the way and place another stick in the middle.

The first person then advances beyond the second person until he can barely see the newly placed stick.

I think you can see where I'm going with this....

In short by using the sticks they can maintain a straight line.

Answer 4

I felt this would be better suited for a separate answer from my original, though it might be contrary to the criteria: have the characters make their own compass.

If you granted the characters a magnet and a small metallic object (such as a paper clip or needle) in their pockets, the latter could be magnetized and placed on top of a (very) small leaf or something else that would float in water. The object will then turn with the leaf and point north. The body of water would have to be still and possibly portable somehow (an uncovered thermos, perhaps?) unless you combined my other answer with this one- find north (or whatever way you wanted to go) and leave a trail.

Answer 5

A method that doesn't take any equipment:
Choose two trees where one is in front of the other by some amount, and walk so that they always line up. When you get to the closest of the two trees pick two more that line up past the second. Every time you get to one of your trees mark it by peeling off some bark, breaking a branch so it hangs down, or something so that by looking back you'll be able to see where you came from.
This will help in case you somehow get disoriented and lose your chosen trees.

You'll have to stop at night, so putting several stakes into the ground to mark the direction you want to go before dark will help you find the next two trees when it gets light again. You'd also be able to look back and get a pretty good idea of where you want to go.

This will not get you moving in any particular direction, but it will take you in a straight line so eventually you'll get to the edge of the forest.

Answer 6

I don't think there is a certain always works method. Trees obstruct your line of sight and make it impossible to actually walk straight over extended distances. That said people walk in forests without compass or other navigation aids all the time and mostly come back alive.

First advice would be not getting lost. This is not the same as knowing where you are, you just need to pay attention when walking in the forest so that you can walk back the same way you came if necessary. This basically amounts to recognizing things you passed when walking the other way. In practice people also recognize things they passed the other times they were in the same forest so that they can navigate familiar forests with ease.

So basically saying a very clever person got lost in the forest kind of assumes he thought the other guy was navigating for them. And the other guy obviously thought the opposite. In such case it is possible neither of them paid attention to their surroundings and cannot recognize anything.

Even so the goal should be going back the way you came in hopes you will recognize something. So it is generally a good idea to have some idea which direction you are going when you go to a forest otherwise trying to determine directions after you get lost is an exercise in futility since it won't really make a difference which way you go.

Assuming they know the original direction relative to either sun or wind they can try looking up. Even when the light is diffuse and the wind non-existent in the ground, the tops of the trees might have clear light and shadowed sides and so some wind. This is because the light and wind on the forest floor are being obstructed by the trees. This is probably the best bet for "something a clever guy would realize" as it hinges on realizing the reason the light is so diffuse and the wind non-existent.

If the wind is really almost non-existent it might still be possible to detect direction by using very light object. Similarly the direction of sun can be detected by using a sunstone. Although it is extremely unlikely they are carrying one. Still recognizing one you see and being able to use it would be pretty impressive. And many crystals have similar properties, remembering you carry one and that it can be used for detecting the direction of sun would also be pretty impressive.

There are also moss and lichen that grow better on specific sides of the tree trunk. If common in your forest this can be spotted and used to get a direction. Specifics vary, it can depend on either sunlight (north-south) or prevailing winds (east-west). EDIT: This is actually same but bit different than what Gareth Rees mentions in his answer. What I am talking about is only available in some forests, but is actually more practical to use if available since it is more consistent.

I said the tress make it impossible to walk straight. Still you can and should avoid walking in circles. Pick a tree. Walk toward it. Pick a tree behind the first tree. Walk toward it. And so on. This doesn't allow you to walk straight, but it helps avoid the natural tendency to walk in circles. If you are not sure which way to go anyway, this is good enough.

Answer 7

I believe the question is aimed at a scientific 'Macgyver' solution, in this regard, consider this:

The scientist has a key-chain flashlight, by filing down (hunk of glass/costume jewl/quartz from the earth) he is able to focus the light to a point.

He removes some bark from a tree (point A), focus' his light-source at another tree (Point B), and walks to it, removing some bark from the next tree, and pointing the source away from the first tree (A), he decides on the next point to travel to (Point C).

Or, given a laser-pointer.... But that's too easy.

None the less, it uses the play that light always travels in strait lines.

This type of mechanism is often used for maintaining alignment of tunnels during mining - though on a more accurate scale.

Answer 8

Your character could use a simple method that I myself have used to make safe landings on a rocky, cliffy coast at night. We used the steep and rocky foreshore at the landing site to place two light-sticks, one above the other, so placed that they and the safe entrance to the cove formed a straight line. No closing with the shore until the two are lined up!

Your heroes just take out that handy little folding saw you left in their pockets and cut enough wood to make two tall, skinny masts which they tie to separate trees using some paracord they just happened to have, or perhaps improvising rope from sliced and twisted bark. Now, they just need to keep glancing backward as they walk - if the two masts are in alignment, then they have not deviated.

Answer 9

Apocryphally, moss always grows on the northern side of the tree (well, in the northern hemisphere at least).

If you actually go out and try this, you'll find it works as poorly as you would expect. Surveying a large number of trees you might be able to establish a side on which moss grows best. But is that because that side is to leeward, northern-exposure, pointing-uphillest, or something else?

[Edit: thinking about it, that possibly doesn't matter, so long as it's not the last option. If the moss is consistently directional, then you can use it for making sure your path does not diverge, regardless of whether you know what direction you are traveling in. So I suppose this does answer the question as asked, even though there are far better responses in other answers. Sadly, things like leaf direction won't tell you the direction you expect the sun to be, since the light is diffuse. This fact may also affect the moss thing: direct sunlight would make the effect far stronger.]

Answer 10

If it isn't important which straight line you walk in, just that it's straight, then I can get you there with a fishing line and a stick.

Take your stick and draw a straight line. Have your companion hold one end of the fishing line while you hold the other. Walk to the end of the fishing line while your companion keeps the line parallel to the line you've drawn on the ground.

When you reach the limit, draw another line on the ground at your feet parallel to the fishing line. Have your companion come meet you.

Repeat as necessary.

Answer 11

Grass and trees, when not wet, burn... pull up grass, find those sticks, build a fire. always keep the rising column of smoke at your back, or better, have your friend point a long stick at the smoke, go to the end nearest the fire, look for the most distant object in line with the stick's far end. keep it in your gaze and walk to it, repeat. All the they need is a lighter and long stick and dry fuel..clear a burn barrier around your fire or you may burn the whole forest down...yes this method has been used before..but not always a safe option to use!

Answer 12

The Romans had a tool for ensuring roads went in a straight line. It was essentially a cross that could be mounted on a stick, in the middle, so that on each of the 4 points of the cross, a weight hung from a string.

Place a 1st stick in the ground at a point, then advance to a point where that stick is still visible, and place a 2nd stick in the ground, with your tool on top of the stick. Stand on the side of your tool, opposite to the first stick and rotate the cross, until both of the hanging strings line up, with the first stick and the centre stick of your tool (the 2nd stick), in a line.

Now have your colleague advance in what they believe to be a straight line away from the 1st stick and your tool. At some point, when they can still see you, they stop and place a 3rd stick. You look down the line of your tool, and the 2 strings, with the first stick behind you, and indicate to your colleague whether they need move the 3rd stick to the left or right to get into line with the string.

When they're lined up, you remove your tool from the 2nd stick, and go to place it on the 3rd stick. Your colleague can now go forth and line up a 4th stick. Eventually you'll have a line of sticks, in a perfectly straight line.

Clearly in the forest you may have issues, and want to vary the distance between sticks and vary your line a little to circumvent trees, but as long as you keep it as straight as possible, and if you have to deviate, alternate between left and right, you'll end up with a roughly straight path through the woods.

Answer 13

Try the breadcrumbs approach.

Have them take something from the forest (rocks, bark, flora, etc.) and leave it behind them in a trail. If they happen to walk in a circle back to where they started, the trail should be recognizable to them as their own creation.

Answer 14

Battery powered gyroscope. Here's one that's been MacGyvered. Method of use:

1. Suspend from string with axis approximately parallel to the ground.
2. Hold axis in direction you want to go.
3. Turn on, and wait for it to spin up, then let go.
4. Only walk (on average) in the direction of the axis. (You may have to go around trees and other obstacles.)
5. Except for torque similar to that experienced by a Foucault pendulum, the pointing should be stable to a few degrees until the battery runs down.

The torque in the last item will be very small because you aren't tall enough to have a long string and aren't intentionally rocking the gyroscope back and forth. That torque might not even exist in your setting if the "planet" doesn't rotate about some axis.

For substantially more information, read up on inertial navigation systems. Various implementations run quite a range of cost, size, and weight. However, single chip systems do exist, so the protagonist could already have one integrated into something in his pocket.

Answer 15

If he only needs to walk straight, all he needs is a straight rope that drags behind him. He should aim for the rope to always be as straight as possible and the longer it is the better.

Answer 16

The following method may not be super-precise because directional hearing is not as good as seeing, but could circumvent the line-of-sight problems of other solutions:

1. Person A walks away for certain distance (say, 100 m)
2. A calls repeatedly for B and B walks ahead following the source of the calls.
3. Once B believes to be somewhat closer but not too close (50 m, say) he calls A to move ahead away from his (B's) repeating calls
4. When A is at a distance of about 100 m again, return to step 2

Answer 17

Based upon the updates to the question:

Orientation

If your characters need to orient themselves in a particular direction before they start walking, it will be very difficult for them. You've removed all the things that might typically be used. None of the following are available:

• Sunrises/sunsets
• Moonrise/moonset
• Stars at night
• Magnetic fields
• Natural landmarks
• Artificial landmarks
• Water features
• Predictable/persistent weather patterns

Thus I'm not sure of any practical orientation technique that would allow them to set out on a specific heading. Though perhaps that's not required?

If it is, maybe at night they can see a faint glow on the horizon in the general direction of the nearest settlement. Or maybe there are auroras or some other aspect of the fantasy world that would be usable to get a ballpark directional fix. Otherwise...I don't see how your characters can orient on a specific heading with no visual references whatsoever, unless they have a sixth sense or a very keen sense of smell or similar contrivance.

Maintaining a Heading

This is easier based upon the scenario you've described. The trees in your forest aren't that large or that dense, they're just homogeneous and cover a large, flat area with no built-in visual references.

In that situation, all your characters need to keep a straight heading is a bit of wire, a knife or other sharp tool for making marks (optional), and some math. Your character should make a loop out of the wire, and attach it to their headgear so that it sits in front of one eye. They can then line their makeshift targeting reticle up with a distant tree and walk towards it. They'll travel in a straight line as long as they keep the tree centered in the reticle. And they should keep a count of the total number of steps taken to reach the tree.

When your character reaches the tree, they should mark their inbound trajectory with the knife (for instance, in the ground leading up to the tree, or the tree itself). Continuing on that trajectory they should proceed to the far side of the tree and look for a new tree in the distance to use as the new reference point. Before they go anywhere, they should mark the angle to the new reference point, and take note of the angle by which it deviates from their inbound course (I'm assuming that the trees won't always allow for a perfectly straight path to be followed).

Now all they have to do is proceed to the next tree, and repeat the process. By tracking the angle of each course deviation and the distance traveled between each tree, your scientist character should have no problems holding to a straight course by making minor corrections when choosing the next reference point (i.e. if you deviated to the right by 5 degrees for 500 steps, you'll want to compensate left 5 degrees relative to the original heading for 500 steps).

That should allow them to maintain a reasonably straight heading over a relatively long distance. Or if you give your characters very accurate tools for measuring distance and angles (a pedometer and a protractor, maybe?), it should keep a straight heading essentially indefinitely as long as there are trees to use as reference points. They could even execute turns and other maneuvers to detour around problematic bits of terrain if need be, just by keeping track of the angle and distance of travel. It's essentially a poor-man's inertial navigation system.

But won't work if, for instance, they get chased by something and lose track of either bit of information.

Answer 18

Use a couple of sticks!

You say the terrain is perfectly flat. All the trees are the same height, exactly. There is no sun, moon, stars. Ergo, you are not on a planet thus no horizon curvature, no rotational effects, no magnetic fields, no directionality of light. All of the traditional navigational tools are unavailable.

So use line-of-sight tracking!

Cut down one tree. Climb another, and put the cut-down tree on top. You now have an anomaly in the forest, one tree sticks out! Using just this, keeping the tree to your back, you will walk in a moderately straight line.

If you need a more precise line, just repeat with a second tree a couple hundred paces away. Now when you look, you see two trees behind you. Keep them aligned, and your direction is set to within less than one degree of compass.

You can repeat this process each time you get far enough that the tree 2 units behind you becomes hard to see, and make a new beacon.

P.S. This also works if the trees are unclimbable, you just need to reduce the distance to whatever you can manage at ground level. It would depend on the achievable line-of-sight. Your description of "not very close together" sounds promising though.