The Weapon Tycoon Who Traveled to Great Qin

Shangwen's speech in the final State of the Union address was quickly printed into newspapers and quickly spread to various places. The emergence of newspapers and other media is actually to make some affairs transparent and open. Of course, Shang Wen from the future society understands the role of the media. Before others even noticed this powerful weapon. Shangwen must give full play to its role. Obtain the support of the people by establishing an image of justice. Occupy a favorable position on the issue of popular sentiment.

Shangwen's proposal requires a reply from the other party before further action can be taken. But before waiting. Shangwen still has one important thing to do. Popularize a lot of astronomy and geography knowledge. Especially the map civilization that extends between the two.

"This is an astronomical telescope. He looks a little rough. But he can prove that what I saw is correct." Shang Wen faced the podium, crowded with all kinds of people. There are skilled craftsmen from six countries in this group, as well as representative figures from various families. In short, there are all kinds of people. Even those Confucians from Jixia Academy also participated.

In order to popularize this knowledge, Shangwen announced the news in the newspapers early and had to give lectures at Qin Guo University. As soon as the news came out, many people came here admiringly. Fan Zeng also quietly walked into a large lecture hall that can accommodate 300 people. There are too many people. Many people are sitting on the stairs listening to Shangwen's explanation.

"This astronomical telescope can see our satellites. The moon. In fact, the moon is a sphere. In the same way, the earth where we are. The earth is also a sphere. Just like this." Shang Wen said and pointed to the platform. Big iron ball. Shangwen was originally used to demonstrate the causes of lunar eclipses and solar eclipses. But obviously it can't be done. Because there are too many people. Shangwen's theory is too advanced. Some people haven't realized it yet.

"This question, put it aside for now. If you are interested, you can go and see when the night comes. I am very welcome." Shang Wen made a welcome gesture.

"My theoretical basis is to build on this theoretical basis. Our earth is a planet. And we live on the earth. How do we observe and know that." Shang Wen said loudly.

"We will use this." As he spoke, Shang Wen took out a sextant.

"This is a sextant. It is used to determine our latitude. I will explain the issue of latitude to you later. But first, I want to explain to you why we can use a sextant to determine our latitude. ."

"First of all, our earth does not rotate around the earth at a certain inclination. For example. Look at it." Shang Wen said as he held a big stick and went directly through the wooden star. That represents the earth.

"He has a certain inclination angle. It is because of this inclination angle that the direct sun's point rotates back and forth between the Tropic of Cancer." Shang Wen said while demonstrating. Many people stared intently. They see. It is this oblique angle that causes the difference in the direct shot point. Some of those who responded quickly suddenly realized. Can't speak with open mouth.

"The orbital plane of the earth's revolution we call it the ecliptic plane and the equatorial plane of the earth we call it the equatorial plane. The angle between these two surfaces is the yellow-red intersection angle. The preliminary settlement is obtained. This angle is 23 degrees 26 minutes. Also. It is this angle that appeared. Our spring, summer, autumn and winter." Shang Wen didn't know how to explain, he was a weapon expert, and made a temporary cameo as an astronomy and geographer.

Some students of Qin Guo University even picked up a pencil to quickly record. And more people are paying full attention to this new knowledge. This knowledge is not available before.

"We call the two returning latitudes as the sun shines directly on the Tropic of Cancer. If you are very interested. I hope you can check it out on the spot in Chu State." Shang Wen said.

"It's also the direct rays of the sun to different locations. Therefore, we have spring, summer, autumn and winter, and we have the vernal equinox, summer solstice, autumnal equinox, and east solstice." Shang Wen doesn't know if there are these spring and autumn equinoxes, winter and summer solstices at this time. Whether it is there or not, this knowledge must be popularized.

"At the spring and autumn equinox. The sun shines directly on the equator. At the solstice of winter and summer, he is on the Tropic of Cancer." Shang Wen said.

"Since we know the date and angle of the direct sun point. Then we can use this to measure the height of the sun and the angle between the horizontal line. Conversion through a certain formula." Shang Wen said and wrote the formula on the blackboard. The blackboard is all black at the bottom of the pot. Shang Wen didn't know it himself, so that his hands were all black.

cosz=sinφsinδ+cosφcosδcost

"This is the formula." Shang Wen wrote several mathematical symbols on the blackboard. People underneath are talking. They don't understand why Shangwen drew such a symbol. Is it to exorcise evil spirits? Shang Wen couldn't take care of that much. Half an hour has passed. The big bell behind has already rang.

"We can get the latitude φ of the place by calculation. In the formula, z is the celestial zenith distance of 90 degrees minus the horizon height, δ is the celestial declination, and t is the hour angle, which can be determined from the local sidereal time and the celestial right ascension. By subtracting it, the sidereal time can also be obtained by simple calculation. If the geographical latitude is calculated from the position of the sun, the simpler algorithm is "Shang Wen said, picking up the spherical chalk and writing δ=z+δ.

"Through this, we can calculate the latitude faster." Shang Wen finished writing and said.

"Then let's explain what latitude is." As Shang Wen said, he took out a ball made of iron wire.

"It's like these woven wires running horizontally. This is our latitude. He goes around the earth. It goes all the way to the apex." Shang Wen said.

"They follow the east-west direction and encircle the circle of the globe, called latitude. All the latitude lines are parallel to each other and perpendicular to the longitude lines. The latitude lines indicate the east-west direction. The size of the latitude loops varies, and the equator is the largest loop of latitude. The two-pole latitude loop gradually shrinks to the north and south poles. The longitude and latitude lines are drawn on the globe and maps in order to determine the position and direction on the earth. The longitude and latitude lines are not drawn on the ground. However, you It is not difficult to see the meridian of your place: stand a bamboo pole on the ground. When the sun rises at its highest at noon, the shadow of the bamboo pole is the meridian of your place. Because the meridian indicates the north-south direction, the meridian is also called Meridian. Warp and latitude are perpendicular to each other."

"Time is running out. There is one last time. Class is about to end. I can't delay the get out of class. The meaning of the latitude and longitude line is that we can determine our own position without relying on geographical things. By calculating the latitude coordinates, we can even more Determine your location accurately. If you use it on a map, then our civilization will take a big step forward." Shangwen finished. The bell for the end of get out of class rang.

"Oh. Okay. Let's end get out of class." Shang Wen said with a shrug.