Tag: the signature of time

Temperature decreases with an increase in altitude. The reason or this is:

The ground absorbs more radiation from the sun and during night time the ground emits this absorbed radiation to its surroundings. The molecules of air surrounding the land also absorb the emitted radiation from the ground. At locations near sea level where air is most dense the air is very warm at sunset and a few hours after sunset.

At higher altitudes, the air get very rarified i.e. less dense. The less-dense air can seldom absorb the heat emitted by the ground because they are very far apart. The net result is a drop in temperature at higher altitudes.

As a summary, the decrease in temperature is due to the very less heat energy absorbed by the air molecules and the very far distance of air molecules from each other.

C. The tilt of Earths Axis

Seasons happen because Earth's axis is tilted at an angle of about 23.4 degrees and different parts of Earth receive more solar energy than others. Because of Earth's axial tilt, different areas of Earth point toward or away from the Sun at different times of the year. Around the June solstice, the North Pole is tilted toward the Sun and the Northern Hemisphere gets more of the Sun's direct rays. This is why June, July and August are summer months in the Northern Hemisphere. At the same time, the Southern Hemisphere points away from the Sun, creating winter during the months of June, July and August. Summer in the Southern Hemisphere is in December, January, and February, when the South Pole is tilted toward the Sun and the Northern Hemisphere is tilted away.

The temperature depends on latitude because when you are closer to the equator it's hotter, but whenever closer to the arctic circles it will be colder.

 At the equator there are no seasons because each day the Sun strikes at about the same angle. Every day of the year the equator receives about 12 hours of sunlight.

A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the sun, Earth, and moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can occur only the night of a full moon. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes.

A total lunar eclipse has the direct sunlight completely blocked by the earth's shadow. The only light seen is refracted through the earth's shadow. This light looks red for the same reason that the sunset looks red. Because of its reddish color, a total lunar eclipse is sometimes called a blood moon.

D. The tilt of the earth's axis of rotation

Seasons happen because Earth's axis is tilted at an angle of about 23.4 degrees and different parts of Earth receive more solar energy than others. Because of Earth's axial tilt (obliquity), our planet orbits the Sun on a slant which means different areas of Earth point toward or away from the Sun at different times of the year. Around the June solstice, the North Pole is tilted toward the Sun and the Northern Hemisphere gets more of the Sun's direct rays. This is why June, July and August are summer months in the Northern Hemisphere. At the same time, the Southern Hemisphere points away from the Sun, creating winter during the months of June, July and August. Summer in the Southern Hemisphere is in December, January, and February, when the South Pole is tilted toward the Sun and the Northern Hemisphere is tilted away.