What do you think of the night time on the sundial?

Question 1: What do you think of the sundial? The sundial measured by the sun shadow has any form of sundial. The angle between the sundial and the ground plane must be the same as the local geographical latitude, and it must point to the North Pole correctly, that is, there is a pointer parallel to the earth's rotation axis. By observing the projection of this pointer on the designated area, the time can be determined. At present, the common sundial has the following different forms: (1) The horizontal sundial is the most commonly used sundial, and the horizontal dial is used. The inclination of the sundial axis is set according to the latitude of the place of use, and the scale needs to be calculated by trigonometric function. Suitable for use in low latitudes. (2) The equatorial sundial is a device that fixes the axis (hour hand) toward the north pole according to the latitude of the place of use, and observes the scale of the axis projected on the disk perpendicular to the axis to judge the time. The scales on the disk are equally divided, and the shadows of the summer and winter axes projected on the disk will be divided into the north and south parts of the disk, which is suitable for middle and low latitudes. If the disc is changed into a ring, it is called the equatorial compass sundial. (3) The plane projected by the polar disk pointer is parallel to the pointer, that is, the angle with the ground plane is the same as the geographical latitude, and it faces due north. The depiction of time can be handled by a simple geometric diagram, and the time axis of projection is a parallel line. Suitable for all latitudes. (4) The dial of the vertical south dial faces south and is perpendicular to the ground. This kind of sundial is suitable for mid-latitude (30 ~ 60). (5) The vertical direct east or west dial faces the due east or west of the sundial and is perpendicular to the ground. This sundial can only be used in the first half (east) or the second half (west), but it is suitable for all latitudes in the world. (6) The dial with horizontal and vertical tilt scales adopts vertical sundial. This kind of sundial needs to be calibrated according to the direction of the building wall, so it is not easy to make. Depending on the season and time, sometimes there is no shadow. The sundials in the south and perpendicular to the east and west can be regarded as special cases of this shape. (7) The daily sundial does not have an hour hand, but only draws ellipses with different oblateness on the ground plane according to different geographical latitudes, and draws a time line on it. The long axis points to the positive east-west direction, while the short axis in the north-south direction needs to be engraved with a date to indicate the correct position of the vertical rod to measure the time. Calculation of sundial angle, etc. Besides the correct installation of the pointer, the description of the timeline can not be ignored. The timeline description of various sundials is related to the geographical position of sundials and the height of the hour hand. Suppose the geographical latitude is φ, the height of the hour hand is h, and the difference between the time to be marked and noon is t; The angle between the time axis and the hour hand is a, and the distance is d, then the calculation formula of each sundial is as follows: (1) horizontal sundial: TAN(A)=TAN(T)*SIN(φ) (2) equatorial sundial: equal to hourly 15 degrees, vertical. (3) Polar sundial: D=H*TAN( 15*T) (4) Southward vertical sundial: TAN(A)=TAN(T)*COS(φ) (5) East or west vertical type: d = h * tan ((6) Refers to the time line difference between an hour hand and an hour hand cot (r) = cot (θ) * sin (φ)TAN(φ) θ: the oblique angle of the sundial wall (7) Projected sundial: D= SIN(T* 15), and V = sin(φ) * Cot.

Question 2: What about the sundial at night? The sundial is a kind of time measuring instrument in ancient China. Its principle is to use the shadow cast by the sun to measure and divide time. Limited by the level of science and technology, the sundial itself can only provide vague time information, but it cannot accurately time.

The sundial will lose its function at night. In the city, there are night watchmans playing in the street to remind the time; In rural areas, under normal circumstances, farmers work at sunrise and rest at sunset, so there is not much demand for night timing. For families with chickens, it is enough to decide the time to get up by crowing the rooster. In addition, temples or some well-off families can use big incense burners to be punctual, and when conditions permit, they can buy timekeeping tools such as hourglass and copper pot drip, which is also the way for ancient China people to be punctual at night.

Question 3: How does the sundial show the time, month and season? From "watch" to sundial is a gradual transition process. If the "watch" is divided with appropriate scales on the ground, it can become a horizontal sundial. The calibration of horizontal sundial needs the knowledge of projection geometry, which was lacking in ancient China. Although the installation of equatorial sundial is complicated, its scale is relatively simple. Therefore, it is natural that the equatorial sundial was popular in ancient China.

Materials and tools:

Corrugated paper box, disc, ruler, scissors, pen.

Production method:

1. Unfold a corrugated box, draw an outline along the disc and cut it out.

Find the midpoint of the circle with a ruler and divide it into four equal parts. Put the ruler at 3 o'clock and 6 o'clock, divide this quarter into three equal parts, and then mark the positions at 4 o'clock and 5 o'clock. By analogy, mark the position of 12, which is the face.

3. Cut out a right triangle with cardboard. One of its right-angled sides is the distance from the midpoint of the dial to each number, and the other right-angled side is half of the longest side. This is a needle. Stick the pointer on the dial, and the end of the pointer points to VII.

Then, let's be pillars. Draw the shape of the column on the carton and cut it out. Pay attention to the symmetry on both sides. Two such pillars need to be manufactured.

5. Cut one pillar from top to bottom in the middle and the other from bottom to middle. The thickness of the incision is the same as that of the cardboard. Insert two pillars together and make a stable support.

6. Stick the sundial board on the post, and then put the sundial in the sunny garden. The shadow on the sundial will tell you the time now.

Tip: This sundial may not be accurate. What is provided here is only a relatively simple sundial making. In order to make the sundial go more accurately, many calculation formulas need to be used in the production process, and the relationship between latitude and longitude of the earth needs to be understood.

The timeline description of various sundials is related to the geographical position of sundials and the height of the hour hand. Suppose the geographical latitude is φ, the height of the hour hand is h, and the difference between the time to be marked and noon is t; The angle between the time axis and the hour hand is a, and the distance is d, del: the declination of the sun, and v: the value of the time point in the short axis direction.

D: the value of the time point in the long axis direction, then the calculation formula of each sundial is as follows:

Horizontal sundial: TAN(A)=TAN(T)*SIN(φ).

.. 2) equatorial sundial: the division of labor is equal to 15 degrees per hour, and the noon line is vertical downward.

Polar: D=H*TAN( 15*T)

.. 4) Southward vertical sundial: TAN(A)=TAN(T)*COS(φ)

... 5) East or west vertical type: D=H*TAN((6-T)* 15)

... =' a' = sin (o) * tan (r+15 * t).

... refers to the angle between the hour hand and the vertical of the wall, TAN(W)=SIN(θ)*COT(φ)

..... refers to the angle SIN(O)=COS(θ)*COS(φ) when the hour hand is higher than the wall.

..... refers to the time line difference between the hour hand and the noon line COT(R)=COT(θ)*SIN(φ).

..... the included angle between 6 o'clock and 12 o'clock timeline COT(S) =SIN(θ)*TAN(φ).

..... θ: the oblique angle of the sundial wall.

.. 7) projection sundial: D= SIN(T* 15), V= sin(φ)*COT(φ).

..... the ratio of the major axis to the minor axis of an ellipse: sin(φ)

..... the position of the vertical pole (where people stand): Z=TAN(del)*COS(φ)

I just gave you a general idea. You can try. I hope it helps you!

Question 4: What time does the sundial indicate? The sundial, also called "sundial", is a kind of time measuring instrument in ancient China. Its principle is to use the shadow cast by the sun to measure and divide time. A sundial usually consists of a copper pointer and a stone disk. This method of timing by the projection of sunlight is a great invention of human beings in the field of astronomical timing, which has been used for thousands of years.

The sundial, also called "sundial", is a kind of time measuring instrument in ancient China. It usually consists of a copper pointer and a stone disk. The pointer made of copper is called "Gong Pin", which passes through the center of the disk vertically and acts as a neutral rod in the standard watch. Therefore, Gong Pin is also called "table", and the disk made of stone is called "Gong Mian". On the stone platform, the stone platform is high in the south and low in the north, making Gong Mian parallel to the equatorial plane of the sky. In this way, 12 large squares are carved on the front and back sides of the brick surface, and each large square represents two hours. When the sun shines on the sundial, the shadow of the sundial needle will be cast on the surface of the sundial, and the sun will move from east to west, and the shadow cast by the sundial needle on the surface will slowly move from west to east. Therefore, the moving shadow of the coffin needle seems to be the pointer of modern clocks and watches, and the coffin surface is the surface of clocks and watches to show the time.

From the vernal equinox to the autumnal equinox, the sun always runs on the north side of the celestial equator, so the shadow of the ray needle is cast above the ray plane; From the autumnal equinox to the vernal equinox, the sun runs on the south side of the celestial equator, so the shadow of the needle is cast below the surface of vernal equinox. therefore

Copper pointer is called "pointer"

When observing the sundial, we must first know the projection position of the sundial needle in two different periods.

Haha, I can see that. I don't understand. Please be smart and give a definite answer as soon as possible.

Question 5: How to time the sundial. 5 minutes sundial, the original meaning refers to the shadow of the sun. Modern "sundial" refers to a kind of timing instrument used by ancient humans to measure time, also known as "sundial". Its principle is to use the projection direction of the sun to measure and divide time, which usually consists of a needle and a plane.

During the day, the shadows cast by objects illuminated by the sun are constantly changing:

Copper pointer is called "pointer"

First, the length of the shadow is changing. The shadow is the longest in the morning. As time goes on, the shadow becomes shorter and longer after noon.

The second is that the direction of the shadow is changing. North of the Tropic of Cancer, the shadow in the morning is in the west, the shadow at noon is in the north, and the shadow at night is in the east. In principle, it can be timed according to the length or direction of the shadow, but it is more convenient to time according to the direction of the shadow. Therefore, the timing is usually based on the position of the shadow. [1] As time goes by, the shadow on the needle moves slowly from west to east. The moving shadow of the hand seems to be the pointer of a modern clock, while the surface of the hand is the surface of the clock to show the time.

In the morning, the shadow is cast near Shi Mao at the western end of the disc; When the sun reaches the highest position due south (upper meridian), the needle shadow is located due north (lower), indicating the local noon time. In the afternoon, the sun moves west and the shadow leans east, pointing to each hour in turn.

Question 6: How does the sundial tell the time? Angle calculation, etc. Besides the correct installation of the pointer, the description of the timeline can not be ignored. The timeline description of various sundials is related to the geographical position of sundials and the height of the hour hand. Suppose the geographical latitude is φ, the height of the hour hand is h, and the difference between the time to be marked and noon is t; The angle between the time axis and the hour hand is a, and the distance is d, then the calculation formula of each sundial is as follows:

(1) horizontal sundial: TAN(A)=TAN(T)*SIN(φ)

(2) Equatorial sundial: bisecting the disk, which is equivalent to 15 degrees per hour, and the noon line is vertically downward.

(3) polar coordinates: D=H*TAN( 15*T)

(4) Southward vertical sundial: TAN(A)=TAN(T)*COS(φ)

(5) East or west vertical type: D=H*TAN((6-T)* 15)

(6) Horizontal and vertical formula: tan (a) = sin (o) * tan (r+15 * t)

Refers to the angle between the hour hand and the vertical line of the wall, TAN(W)=SIN(θ)*COT(φ)

Refers to the angle sin (o) between the height of the hour hand and the wall surface = cos (θ) * cos (φ).

Refers to the time line difference between the hour hand and the noon line COT(R)=COT(θ)*SIN(φ)

The included angle between 6 o'clock and 12 time line COT(S) =SIN(θ)*TAN(φ).

θ: the oblique angle of the sundial wall.

(7) Projection sundial: D= SIN(T* 15), V= sin(φ)*COT(φ).

The ratio of major axis to minor axis of ellipse: sin(φ)

The position of the vertical pole (where people stand): Z=TAN(del)*COS(φ)

Del: the declination of the sun, and v: the value of the time point in the short axis direction.

D: The sundial, also called "sundial", is an ancient time-measuring instrument in China. It usually consists of a copper pointer and a stone disk. The pointer made of copper is called "Gong Pin", which passes through the center of the disk vertically and acts as a neutral rod in the standard watch. Therefore, Gong Pin is also called "table", and the disk made of stone is called "Gong Mian". On the stone platform, the stone platform is high in the south and low in the north, making Gong Mian parallel to the equatorial plane of the sky. In this way, 12 large squares are carved on the front and back sides of the brick surface, and each large square represents two hours. When the sun shines on the sundial, the shadow of the sundial needle will be cast on the surface of the sundial, and the sun will move from east to west, and the shadow cast by the sundial needle on the surface will slowly move from west to east. Therefore, the moving shadow of the coffin needle seems to be the pointer of modern clocks and watches, and the coffin surface is the surface of clocks and watches to show the time.

From the vernal equinox to the autumnal equinox, the sun always runs on the north side of the celestial equator, so the shadow of the ray needle is cast above the ray plane; From the autumnal equinox to the vernal equinox, the sun runs on the south side of the celestial equator, so the shadow of the needle is cast below the surface of vernal equinox. Therefore, when observing the sundial, we must first understand the projection position of the sundial needle in two different periods. China ancient time measuring instrument. It consists of a grating needle and a grating disk. The grating needle is perpendicular to the disk surface, and the time can be measured by the direction of the sun shadow on the disk surface. Due to the different directions of the disks, sundials can be divided into horizontal sundials, equatorial sundials, vertical sundials and inclined sundials. The early history of the sundial is unclear, and the earliest reliable record is Sui Shu? The short shadow sundial invented by Yuan Chong in the 14th year of Sui Dynasty (594) mentioned in Tian Wenzhi. The clear record of the equatorial sundial was first seen in the shadow picture described in Volume II of Zeng Minxing's "Lonely Wake Magazine" in the Southern Song Dynasty, but the dial was made of wood. Later, it was changed to stone grate plate and metal grate needle. The Forbidden City in Beijing and other places have preserved the stone equatorial sundial made in Qing Dynasty. The surface of the equatorial sundial is parallel to the equatorial plane, and its pointer points to the north and south poles. After a long stalemate, the sundial gradually moved. -Ming? Ma, The Legend of the Wolf in Zhongshan

(2) sundial: a device that uses the shadow cast by the sun to determine the time. Also known as "solar gauge", it is an ancient time measuring instrument in China that used the sun shadow to measure time. It usually consists of a copper pointer and a stone disk. The pointer made of copper is called "Gong Pin", which passes through the center of the disk vertically and acts as a neutral rod in the standard watch. Therefore, Gong Pin is also called "table", and the disk made of stone is called "Gong Mian". On the stone platform, the stone platform is high in the south and low in the north, making Gong Mian parallel to the equatorial plane of the sky. In this way, 12 large squares are carved on the front and back sides of the brick surface, and each large square represents two hours. When >>

Question 7: How was the time of night determined in ancient times? On Time Units in Ancient China

Now the daily day and night is 24 hours, while in ancient times it was 12 hours. When western mechanical clocks and watches were introduced into China, people called the time points of China and the West "Da Shi" and "Shi Shi" respectively. With the popularity of clocks and watches, people forget "Da Shi", and "Shi" is still in use today.

In ancient times, time (big time) was not counted by 1234, but marked by ugly children and animals such as rats, cows, tigers and rabbits, which was easy to remember. The specific division is as follows: from eleven o'clock to one o'clock, twelve o'clock is the punctuality; Ugly (cattle) from one to three, with two points as the punctuality; Yin (tiger) is from three o'clock to five o'clock, with four o'clock as the punctuality; Mao (rabbit) is from five to seven, with six o'clock as the punctuality; Chen (Dragon) is from 7: 00 to 9: 00, with 8: 00 as the punctuality; It's 9 o'clock to 1 1, and 10 is the punctuality; At noon (horse), it is eleven o'clock to one o'clock, with twelve o'clock as the punctuality; When you are not (sheep), it is 1 until 3 o'clock, with 2 o'clock as the punctuality; When applying for (monkey), it is from three o'clock to five o'clock, with four o'clock as the punctuality; You (chicken) are from five to seven, with six o'clock as the punctuality; From 7: 00 to 9: 00, 8: 00 is the punctuality; Shanghai is now 9: 00 to 1 1 point (pig), and 10 is the punctuality.

The ancients said that time and day are different, saying "bell" during the day and "more" or "drum" at night. There is also the saying "the morning bell and the evening drum". In ancient times, there were many bell and drum towers in towns. Ring the bell in the morning (7 o'clock today), so say "what time" during the day; At dusk (today 19), drums are ringing, so the night is also called a few drum days. It is more useful to say time at night, because the night watchman beats the banger while patrolling and tells the time by counting. The whole night is divided into five classes, and the third class is midnight, so it is also called "midnight".

The unit of measurement below hours is "hours". One hour is divided into eight hours, and each hour is equal to fifteen minutes now. There is a saying in the old novel called "three cuts at noon", that is, at three minutes at noon (fifteen minutes from noon), at this time, the yang is full and the yin is instantly dissipated. This heinous crime should be "not even allowed to do ghosts" to show severe punishment. Yin and Yang experts say that Yang is the most abundant, which is different from modern astronomy. Not at noon, but at three o'clock. In ancient times, beheading was carried out in different periods, that is, beheading was important. Generally, beheading is to operate at noon and let it have a ghost to do; Repeater or heinous criminals must choose the operation at 3: 30 noon, and don't let it be a ghost. The meridian gate of the imperial city is also the most prosperous, regardless of time, so the emperor ordered the people who started the meridian gate to behead, and no ghosts did it.

The word "Zi" is engraved below. As for Zi, it is still used in Cantonese-speaking areas of Guangdong and Guangxi and Minnan-speaking areas of Fujian and Guangdong, such as "3: 10 pm", which means "15: 50". According to the analysis of linguists, there are a lot of "ancient Chinese" in Cantonese. The reason is that Gain lived in Lingnan for a long time, and his language was not synchronized with those who stayed in the Central Plains. The following points of Ci are unknown, according to Sui Shu

According to the calendar, the second is the ancient unit of time, and below the second is "sudden"; How to convert, the book did not make it clear, only said: "'two' is as thin as a mountain; "Suddenly" is like the best spider silk. "

In ancient times, there were two kinds of timing tools, one was "sundial" and the other was "leakage". The sundial is timed according to the movement of the shadow, which corresponds to the scale on the surface of the sundial. Needless to say, you should have seen the sundial in the Forbidden City and the Observatory in Beijing. The leaky pot method commonly used in poetry first appeared in the Western Han Dynasty, which divided a day and night into 100 equal parts, also known as the hundred-hour system. The ratio of day and night is 40: 60, and winter and summer are the opposite. Water leakage is timed by dripping water, and it is a combination of four copper pots filled with water stacked on top of each other from top to bottom. There are holes in the bottom of the first three, and an arrow-shaped buoy is vertically placed on the bottom one. The water level rises with the drop of water, and the pot body has scale timing. The original day and night was divided into 100 minutes, which was changed to 96, 108 and 120 minutes successively because it was not divisible with twelve o'clock, and it was officially set as 96 minutes in Qing Dynasty. In this way, one hour is equal to eight quarters. A moment is divided into three parts, and there are twenty-four parts in a day and night, as opposed to twenty-four solar terms. Note that this minute is not the current minute, but a word. Between two moments, two strange symbols are engraved, so it is called "word". The bottom of the word is divided by lines as thin as wheat awns, which is called "second"; The word "two" consists of "he" and "Shao", where he refers to wheat and Shao refers to tiny awns. You can't row below seconds, you can only say "as thin as spider silk", which is called "suddenly"; For example, the word "suddenly" means a short time, but it means change, which means change in a short time.

"Geng" is a kind of "Geng" at night. & gt