Dancing with the sun

Lets start from the very beginning…

We do not want to assume you know anything at all about stars, how the earth rotates around its own axis or how it moves around the sun in the centre of our solar system. Even if you are aware of the concepts presented in this section, be sure to read the ‘take away’ parts, so you do not miss out on important information that we will refer to later on again.

1. The earth rotates

The earth rotates on its own axis once every 24 hours. It would be more fair to say that ‘Each time the earth rotates on its axis, we call that length of time one day.’ Be clear that the length of our day depends on the rotation of the planet. The planet itself.. does not use hours or clocks. It simply rotates.

We know how to measure a day; a day is from one sunrise till the next sunrise. It is a repeating, complete cycle.

Take Away

The period between two dawns is called a day

2. The earth circles the sun

The earth cycles round the sun in 365 days each year. Again, it would be more fair to say that ‘Each time we complete a full cycle round the sun, we call that length of time one year‘.

You know how to measure a day; a day is from one sunrise till the next sunrise. But how does one know when the earth has travelled round the sun one full circle. What helps us decide what a year is?

The changing of seasons, in a continuous cycle, are a pattern that represents the year. Lets look at what creates this pattern of seasons.

Take Away

A year is the period between 2 days, where on both days, the sun exhibits the same behavior.

3. The earths rotates, but at an angle

If the axis of the earth was spinning perfectly on its north-to-south axis in the solar system, we would always have days of the same length. The sun would always rise at the same time, and set at the same time. The influence of the sun on earths biology would be fairly consistent and there would be no periods of hotter or colder weather.

But we do not have these conditions on earth. We shift between 2 types of days; the longest day of the year, and the shortest day of the year. This is due to the fact that the earth spins on an axis that is offset by 23.5 degrees.

Take Away

The earth rotates on its own axis, at an angle.

4. Titled Axis, Seasonal Changes

Because the axis of earth is titled, and the fact that earth rotates in its orbit around the sun, a wave like character is introduced to how the days change over the period of a year.

Depending on your position on the planet, you will experience that yesterday the sun rose earlier ór it rose later (and more to the right or left) than today. If it rose more to the left yesterday, the arc of the sun is declining and you are going towards mid-winter. If the sun rose more to the right yesterday, the arc is increasing and you are heading for the middle of the solar year.

You would experience the results of the suns impact on nature around you as its daily rising spot and maximum altitude change over time.

The blue line represents the amount of sunlight coming down on the northern hemisphere as the year unfolds. The red line is for the southern hemisphere.

Take Away

Seasons happen because the sunlights intensity varies from north the south during the period of a year.

Take Away

A day is the time period between two sunrises
A year spans the period between two sunrises in the same place on the horizon
Seasons are the result of the increasing of decreasing number of hours of sun each passing day

Next : Enter the moon