The dark side is "illuminated" by the Sun
Picture above demonstrates the basic principle of immobilization between two light bodies of a different element. For a full understanding of Moon phases get familiar with "mobilization and immobilization of light bodies" in the category "Scientific publications"
Contrary to the commonly held belief, it's not the bright side of the Moon that is lit by the Sun, but the dark. The bright side of the Moon radiates its own, high-frequency light and the dark side looks towards the Sun. The reason for that lies in the element of the Moon, which is Lightning. When the light bodies of Sun and Moon interact, the parts of the Moon's light body which intersect the Sun's light body are immobilized and do not vibrate. Consequently, the corresponding areas of the Moon appear dark since the “static” section of the Moon's light body does not transmit visual information, and, naturally, the corresponding sections are not visible.
On a new moon, the Sun aligns with the Moon, and the light body of the Moon is entirely covered by the light body of the Sun. Accordingly, the entire circumference of the Moon is not visible due to the static light body. However, as the distance between the Sun and the Moon increases, the Sun's light body releases areas of the Moon's light body, which we perceive as waxing of the Moon. This continues until the Moon is at its farthest point from the Sun, namely, twenty thousand kilometers. At this point, the Moon's light body is completely unobstructed by the Sun and radiates its own light. As the Sun approaches the Moon from the east and the distance between the two decreases, the Sun's light body increasingly obstructs and immobilizes the Moon's light body. We perceive this process as waning of the Moon. There are exactly fourteen days of waning, and fourteen days of waxing, since it takes fourteen days for the Sun to recede from the Moon due west, and fourteen days to approach the Moon from the east until they eventually align on the next new moon
A new moon. The Sun and the Moon are leaving the eastern portals. The light body of the Moon is almost entirely obstructed and immobilized by the light body of the Sun.
We're seven days into the new month, and the Moon already falls behind the Sun to one quarter of the whole cycle of 40 075 kilometers, which is approximately 10 000 kilometers. The Moon is waxing as more and more of its light body withdraws from the Sun. At this point, we observe a half moon. In picture above, we can see the outlines of the Moon's light body and of the Sun's light body, and areas marked 1-6. 1) - is the light body of the Moon. Provided that the sky is clear, the Moon is visible above the horizon anywhere within its light body, which is depicted blue. 2) - The Sun's light body.
The Sun is visible anywhere within its light body as outlines of the Sun's light body mark the daylight zone. 3) - is night zone. 5) - is the zone where both, the Sun and the Moon are below the horizon line since none of the light bodies covers that area. 4) - is a section in the night area in which the Moon is above the horizon. The Moon does not immediately rise after sunset, or sets immediately before sunrise; it can rise in the middle of the night; it can be already in the sky before sunset and set in the middle of the night. Some people have paid attention to the fact that the Moon can be seen during the day. This is illustrated in area number 6: The Moon is visible above the horizon during daytime because its light body is present in the daylight zone
Another seven days into the month, and the Moon is exactly half of the total circumference of the Earth behind the Sun. At this point, we observe a full moon since the major areas of the Moon's light body are not intersecting the Sun's light body. The Moon now unfolds all of its blueish, high-frequency radiance.
Another seven days later: The Sun approaches the Moon from the east and obstructs areas of the Moon's light body. This process is perceived as waning of the Moon. As the Sun's light obscures more and more of the Moon's light body, the Moon wanes. At this point it's half moon.
Another seven days later: It's new moon again. The Moon's light body is entirely obscured and immobilized by the Sun's light body -on this day, the Moon is not visible in the sky.
A little later, a crescent moon appears in the daytime and begins to wax. A small area of the Moon's light body covers the night area and the Moon can be seen a few hours after sunset before it eventually sets as well. Generally, the more the Moon is waxed, the longer it can be seen during the night. A full moon rises after sunset and sets before sunrise since its light body covers the entire night zone. A new moon or a waning moon, on the other hand, are never seen over the horizon throughout the entire night. On the contrary, most of the time that the crescent moon is visible in the sky is in the daytime. Picture above shows why.