Will a sundial work at the equator?
A sundial with a vertical pointer (“gnomon”) will indicate noon correctly when its shadow points north or south. [North in northern middle latitudes, south in southern ones, while near the equator it can be either way, depending on season.]
Does a sundial have to point north?
Sundials need to point in the direction of True North, and the style (either a sharp straight edge or thin rod, often located at the edge or tip of the gnomon) must be aligned with the Earth’s rotational axis. You can also position your sundial so that there is no shadow shown at high noon.
What angle should my sundial be?
The gnomon of the vertical sundial makes an angle of 90°–L with the vertical (that is, an angle L with the horizontal), as shown in the side view in Figure 5. In the southern hemisphere, the vertical dial is north-facing. Unlike the equatorial dial, the hour angles are not equally spaced.
Is a sundial accurate all year?
A sundial is a horological device that tells the time of day (in modern usage referred to as civil time) when there is sunlight by the apparent position of the Sun in the sky. The style must be parallel to the axis of the Earth’s rotation for the sundial to be accurate throughout the year.
How does latitude affect sundial?
A sundial at a particular latitude in one hemisphere must be reversed for use at the opposite latitude in the other hemisphere. A vertical direct south sundial in the Northern Hemisphere becomes a vertical direct north sundial in the Southern Hemisphere.
Do Sundials move clockwise?
Why do the hands on clocks go “clockwise?” Seems like a circular definition, but if you looked closely at sundials in the northern hemisphere, you’d notice that the shadow of the sun moves around the sundial in a “clockwise” direction. This was adopted by clock-makers and became the standard we know today.
How do you find true north without a compass?
Ten ways to find true north (without a compass)
- Stick shadow: Place a stick in the ground vertically.
- North star: Look up.
- Southern Cross: If you’re in the southern hemisphere, find the Southern Cross.
- Orion’s Belt: Find Orion, and then the three bright stars of its belt.
Why does a sundial have to face north?
Since the gnomon’s style must be parallel to the Earth’s axis, it always “points” true North and its angle with the horizontal will equal the sundial’s geographical latitude; on a direct south dial, its angle with the vertical face of the dial will equal the colatitude, or 90° minus the latitude.
How do you position a vertical sundial?
Ideally, the ‘dial’ of a Vertical Sundial should be fixed to a South-facing wall or surface. In this situation the Gnomon is located in a plane at right angles to the ‘dial’ and will cast a vertical shadow at Noon. If placed on a wall which is not South-facing (e.g. S.E. or S.W.)