All this is happening above our heads
Does the Sun Rise in the East?
From our earliest childhood, in primary school or at home, we've heard our elders tell us time and again that the Sun rises in the East, that at noon it's in the South, and that it sets in the West.
Is all of this correct?
Throughout the year, the Sun follows a path called the ecliptic, inclined at 23° and 27' to the celestial equator.
Around March 20th or 21st, the two lines intersect, and this point is called the vernal equinox. This is springtime, and it's also the spring equinox, when the Sun is equidistant from the South and North Poles. Day and night are equal, each lasting 12 hours.
If you take out a compass to see precisely where the Sun will have risen above the horizon, it will indeed point to the East. That's 90°. Just like in the evening, it will touch the ground exactly in the West. 270°. So, what our ancestors told us is true? In this case, yes, but let's look further.
Starting today, March 20th, get up a little before sunrise, and armed with your cup of coffee or hot chocolate, as well as your trusty compass, watch for the appearance of our star. You will notice that day after day, it will cross the horizon line further to the left than the day before. And conversely, it will set further to the right of the West. This oscillation will continue until June 21st, the day of the Summer Solstice. It will then rise at 57° and set at 302°. Therefore, far from both East and West.
The movement will reverse until the winter solstice on December 22nd, when it will reach different azimuths: 122° for sunrise and 234° for sunset.
Of course, on September 22nd, it will cross the celestial equator again; there will be another equinox, this time the autumn equinox, and it will indeed cross the horizon to the east and west.
These are only two days of the year when this old adage is truly true.
The rest of the time, it's only an approximation. This tilt of the Earth relative to the Sun's equator creates the seasons. The closer the Sun rises to the north, the more extensive its path across the sky will appear, and the longer its presence will seem. The reverse is also true: the closer the sunrise is to the south, the shorter its path appears. On December 22nd, the Sun will only be visible for 8 hours in our sky, while it will shine for 16 hours on June 21st. These are the seasons.
The Earth is round, and the laws of astronomy aren't the same everywhere. While it's true that at noon the Sun appears to be moving south, be careful if you're in the Southern Hemisphere. At noon, the Sun will be moving north.
In the intertropical zone, the calculation is even more complex, as there are days that appear to be moving south and days that appear to be moving north.
Observing the Sun throughout the year is a constantly changing spectacle. When my terrace is bathed in sunlight, I know that our star has reached the furthest point of its path, and it's summer. But if I see the Sun illuminating the coffee table in the living room, the Sun is very low in its path. It's time to let it in to provide some warmth; it's winter.
The Sun has always dictated the rhythm of human life. It is a beacon that illuminates our daily lives. Knowing about its appearances can only strengthen the close bond of the inhabitants of Earth, our planet, who exist because our star, the Sun, allows us to.
The movement will reverse until the winter solstice on December 22nd, when it will reach different azimuths: 122° for sunrise and 234° for sunset.
Of course, on September 22nd, it will cross the celestial equator again; there will be another equinox, this time the autumn equinox, and it will indeed cross the horizon to the east and west.
These are only two days of the year when this old adage is truly true.
The rest of the time, it's only an approximation. This tilt of the Earth relative to the Sun's equator creates the seasons. The closer the Sun rises to the north, the more extensive its path across the sky will appear, and the longer its presence will seem. The reverse is also true: the closer the sunrise is to the south, the shorter its path appears. On December 22nd, the Sun will only be visible for 8 hours in our sky, while it will shine for 16 hours on June 21st. These are the seasons.
The Earth is round, and the laws of astronomy aren't the same everywhere. While it's true that at noon the Sun appears to be moving south, be careful if you're in the Southern Hemisphere. At noon, the Sun will be moving north.
In the intertropical zone, the calculation is even more complex, as there are days that appear to be moving south and days that appear to be moving north.
Observing the Sun throughout the year is a constantly changing spectacle. When my terrace is bathed in sunlight, I know that our star has reached the furthest point of its path, and it's summer. But if I see the Sun illuminating the coffee table in the living room, the Sun is very low in its path. It's time to let it in to provide some warmth; it's winter.
The Sun has always dictated the rhythm of human life. It is a beacon that illuminates our daily lives. Knowing about its appearances can only strengthen the close bond of the inhabitants of Earth, our planet, who exist because our star, the Sun, allows us to.