"Day and Night" PPT

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"Day and Night" PPT

Part One: Heliocentric Theory

The ancient Greek scholar Ptolemy believed that the earth is stationary at the center of the universe, while celestial bodies such as the sun and moon move around the earth, so there is an alternation of day and night on the earth. This is the "geocentric theory" proposed by Ptolemy

Copernicus' "heliocentric theory" pointed out that the earth is not the center of the universe, but the sun is the center of the universe. The moon revolves around the earth, the earth revolves around the sun, and the earth rotates every day.

The heliocentric theory is an important milestone in human understanding of the universe, promoting the revolution in astronomy and laying the foundation for establishing a complete concept of the universe.

(1) The distance between the flashlight and the globe should be appropriate, with the flashlight aperture reaching half of the globe.

(2) After adjusting the positions of the "sun" and "earth", do not move during the experiment.

(3) When rotating the globe, keep a constant speed.

(4) Group members should divide work and cooperate to complete the experiment together.

(5) Fill in the experiment record report form.

Simulation experiment conclusion:

The Earth is an opaque sphere, and sunlight hits the Earth. The side of the earth facing the sun is bright, which is daytime; the side facing away from the sun is dark, which is night. As the earth continues to rotate, day and night phenomena appear alternately.

Day and Night PPT, Part 2: Day and Night of Animals

Why is it difficult to see owls during the day? Why don't sparrows crow at night? And why do bats always appear in the evening? It turns out that they all have their own "day" and "night".

Most birds and mammals, such as swallows, sparrows, magpies, rabbits, and monkeys, are active during the day and are therefore diurnal animals. Birds are representatives of diurnal animals.

Most animals such as owls and house mice rest during the day and are active at night, so they are nocturnal animals.

Both diurnal and nocturnal animals arrange their activities, rest and reproduction time according to the duration of light. As the days get longer, nocturnal animals delay their activity, while diurnal animals wake up earlier. Therefore, scientists can change an animal's behavior by changing the hours of light and dark. When diurnal birds in a dark environment are exposed to bright lights, they become active in just 15 minutes. Nocturnal birds quickly fall asleep when bright lights are shined on them. Based on this principle, when the light gradually dims in autumn, chicken farms will turn on the electric lights in the chicken houses to create artificial daylight and increase the number of eggs laid by the chickens.

Day and Night PPT, Part 3: Human Biological Rhythms that Need to be Adjusted

Some jobs are performed continuously day and night, such as telephone operators, flight control station staff, nurses, doctors, railroad workers, police officers, firefighters, truck drivers, etc. All people who work at night have their sleeping and waking hours reversed. But according to the general circadian rhythm, the human body should rest at night.

When people adjust to a night shift schedule for a few weeks and then switch to a day shift, they feel obviously uncomfortable, which can also cause confusion.

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"Day and Night" PPT courseware download:

"Day and Night" PPT courseware download part one: people's understanding of the changes in day and night in history. The ancient Greek scholar Ptolemy believed that the earth is stationary at the center of the universe, while celestial bodies such as the sun and moon move around the earth, so there is Day and night...

"Day and Night" PPT download:

"Day and Night" PPT Download Part One: Geocentric Theory and Heliocentric Theory The ancient Greek scholar Ptolemy believed that the earth is stationary at the center of the universe, while celestial bodies such as the sun and moon move around the earth. Geocentric Theory People's understanding of the changes in day and night throughout history..

"Day and Night" PPT courseware:

"Day and Night" PPT courseware Part One: Problem Thinking Thinking: Which celestial bodies in the universe are related to the occurrence of the alternation of day and night? How do the sun and the earth move to produce the alternation of day and night? Activity tips: 1. One student in the group stands up...

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Update Time: 2024-06-07

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