When a new day arrived, Fang Nan, who was handling government affairs in the office, received an invitation from Guangzhou University, an invitation from a student from Guangzhou University, inviting Fang Nan to participate in a flight experiment.

Seeing that it was an invitation to the flight experiment, Fang Nan readily agreed, and wrote a reply letter to the students who sent the invitation letters, saying that he would participate on time.

Soon, Fang Nan's reply was sent to Guangzhou University, and after receiving the reply from the Metropolitan Governor, the only three members of the Flight Interest Group, Dong Yan, and the team members Gao Xiang and Sun Weimao cheered excitedly.

Fang Nan has some impressions of the flying interest group formed by several students in Guangzhou University, he often goes to Guangzhou University to inspect or give lectures, and often communicates with students, and some of them say that they want to fly into the sky.

Flying into the sky is a very interesting thing, Fang Nan and a few students who are interested in flying have a simple discussion.

Dong Yan, Gao Xiang, and Sun Weimao dreamed of being able to fly to the sky, and they also thought about how to fly to the sky, and the first idea of the three of them was to insert a pair of wings on a person like a bird, and with wings in both arms, people could fly into the sky.

Fang Nan pointed out the problem in the thinking of the three people, birds can fly into the sky by relying on wings, it does not mean that people can also make their own wings to fly into the sky, the wings are small and cannot provide enough lift, and the wings are large, and they can't fan with the strength of human arms.

In the end, Fang Nan provided Dong Yan, Gao Xiang, and Sun Weimao with a new idea - Kong Ming Lantern.

Legend has it that in the fifth dynasty (907~960 AD), there was a Xin Qi Niang, when she was fighting with her husband in Fujian, she had used bamboo strips to tie into a square frame, pasted paper, made a headlamp, placed on the chassis with burning pine resin, the lamp flew into the sky by hot air, used as a military liaison signal, this kind of pine resin lamp, called Kong Ming lantern in Sichuan, the main reason is that the shape of this lantern is like the hat worn by Zhuge Liang.

Another theory is that Kong Ming lantern was invented by Zhuge Liang during the Three Kingdoms, when Zhuge Liang was besieged by Sima Yi in Pingyang, the whole army was helpless, Zhuge Liang came up with a clever plan, calculated the direction of the wind, ordered people to bring thousands of blank papers, paste into countless lanterns, and then use the gravitational force of smoke to take them into the air.

One by one, small lanterns were raised, and the soldiers in the battalion shouted: "Mr. Zhuge is breaking through with a sky lantern!" Sima Yi actually believed it and led his troops to chase in the direction of the sky lantern, and Zhuge Liang was able to escape, so later generations called this lantern "Kong Ming lantern".

The origin of the Kong Ming lantern is no longer important, the most important thing is that the Kong Ming lantern can really fly to the sky, if you make a big Kong Ming lantern, is it possible for people to fly to the sky on the Kong Ming lantern?

Fang Nan told Dong Yan, Gao Xiang, and Sun Weimao about Kong Ming's lantern's ideas, and asked the three of them to study the principle that Kong Minglantern can fly, and they have already verified the feasibility of people flying into the sky on the big Kong Ming lantern.

After that discussion, Dong Yan, Gao Xiang, Sun Weimao and some people who were interested in flying all participated in the research, and not long after, Dong Yan, Gao Xiang, and Sun Weimao set up a flight interest group and applied to the school for research funds.

Interest groups are a kind of internal organization of Guangzhou University, students and teachers can create interest groups or participate in one or more interest groups, this interest group is a super simplified version of the People's Army Research Institute, you can write a plan, apply to the school for research funding.

In fact, the proposals submitted by the interest group are sent to Fang Nan, and only after Fang Nan's approval will funds be provided for students to conduct research.

The People's Army lacks researchers, and the students of Guangzhou University can barely use them as researchers, as long as they study something useful to the People's Army, Fang Nan will support it, and no matter how big the students' research projects are, the People's Army can easily support the required funds.

In the early days, the Flying Interest Group only conducted research on the Kong Ming Lantern and did not require much funding, but the Flying Interest Group spent a lot of time studying the flying principle of the Kong Ming Lantern.

If you were an old-time intellectual who was not in the KPA education system, it would be impossible to understand why Kong Minglan was able to fly, but the students of Guangzhou University could.

Gravity, buoyancy, fire, air, after understanding the relationship between these factors, everyone in the flight interest group understood the flying principle of Kong Ming lanterns.

To put it simply, in the case of ignoring the change in the volume of the Kong Ming lamp, the buoyancy of the Kong Ming lamp does not change, and the air in the lamp is heated to reduce the density of the air in the lamp, so that the gas gravity in the lamp is reduced, so that the total gravity of the lamp is less than the buoyancy force, so that the Kong Ming lamp will rise.

After understanding the principle of Kong Ming lanterns, the next flight interest group will go to research and manufacture a larger "Kong Ming lantern", the new Kong Ming lantern can carry a certain weight of items into the sky, the flight interest group began to apply for the next batch of research funds, which is more than ten times the first application for research rent, Fang Nan also approved.

In the new plan written by the Flying Interest Group to apply for research funds, Kong Ming Lantern has changed to develop towards a hot air balloon, and at that time, Fang Nan also spent a sketch of a hot air balloon in the document for the reference of the Flying Interest Group, and as for other things, it is better for students to study on their own.

Research is a necessary process, if it is all done by Fang Nan, without the process of research, when science and technology develop to the point that Fang Nan cannot guide, but researchers will not study, science and technology will stagnate.

Hot air balloons, airships, and airplanes, these three are all flying machines, hot air balloons are the first to appear, the flight altitude is low, the flight speed is slow, but the hot air balloon also has a lot of role for the People's Army.

Militarily, when the two armies are facing each other, people can fly into the sky in a hot air balloon and use binoculars to observe the enemy's arrangement, especially to guide the artillery units in the direction of attack.

For enemies who have never seen a hot air balloon, you can also use the heater to fly over the enemy and drop flyers or other items to intimidate.

Of course, what Fang Nan is looking forward to is the birth of airships and airplanes, the biggest role of airships is long-distance transportation, the speed is faster than horse-drawn carriages and trains, and it is not limited by terrain, and it can be used to transport supplies to places where there is no road construction and dangerous terrain through airships.

Even if an airplane is built, it cannot be compared with an airship in transporting cargo in a short period of time.

Airships and airplanes will not be born in a short period of time, and at present, only hot air balloons can be studied, which can be regarded as a relatively good development, if no one studies the aircraft, Fang Nan can only order someone to establish a flying machine research institute and select researchers to study it.

Interest in scientific research is a very important one, which can effectively improve the speed of research.