Chapter 242 To Take Off

This is a classic air pressure test.

The device with the highest technical content is probably this glass cup. It was specially made by Luo Qingqing with dragon scales commissioned by Xia Fan. Although it is dark green due to the problem of sea sand impurities, it does not hinder its excellent light transmittance.

Put four candles in a basin filled with water, then light the candles and put the glass cup upside down.

Under the watchful eyes of the crowd, the candles quickly ran out of oxygen and went out.

Then the water level inside the cup rose rapidly at a speed visible to the naked eye.

In less than a few breaths, the water pouring into the cup passed over the water basin outside and almost rose to one-third of the cup wall. From a distance, it looked like a new "hill" rose in the water basin.

Before that, the water surface inside and outside was at the same level!

"How did this water... move?"

"It feels like it was sucked up by something!"

The children's interest was immediately aroused.

"Everyone, why do you think about this phenomenon?" Xia Fan looked at the crowd again - in fact, he had arranged a shill from the Privy Council among the audience to prevent a dull moment caused by no one answering.

But this time someone gave the answer in advance.

"Could it be that you want to say that because the gas in the bottle was exhausted, the gas outside squeezed the water surface and pushed the water into the bottle?"

"Correct." Xia Fan looked in the direction of the voice with a little curiosity, and what he saw was actually a little girl. Judging from her position, she should be a guest invited by Fang Xiandao.

To be honest, this experiment is indeed classic, but it is not as shocking as the hemisphere experiment in terms of perception. It takes a circle to understand the principle. The other party seems to be young, but she can think of this layer quickly. Could it be that she is also a living dead?

"Can I ask a few more questions?" Qian Yan stood up from the chair, which made her suddenly shorter, "People in front, please make way."

Perhaps they have never seen such a girl with such an imposing manner, and everyone involuntarily left a passage.

"Master Qianyan..." Fang Yanni's face turned pale.

"Don't worry." Fang Xiandao spoke to comfort her, "The Xia Fan I know is not the kind of person who bullies others by taking advantage of his power."

On the other side, Xia Fan nodded with interest, "Of course, you say."

"Since there is pressure in the air, why don't we feel tired, and we won't be crushed even if we relax?"

"It's the same reason as this bottle, because there is air in our body, and the inside and outside are offset. If the air is taken out, the weight is enough to crush a person."

"Then what is air? Does it have a substance? Can it be touched directly?" Qianyan asked.

If it was the theory of reality and illusion in the past, it would definitely avoid answering this question directly and instead talk about some mysterious principles.

"Of course it does." However, Xia Fan did not force a change of subject. "You can think of gas as a thinner water, so when the temperature is low enough, it will freeze like water and become a 'lump of ice' visible to the naked eye - I think at that time you may be able to see more directly that you are touching a solid entity."

"Air - can be frozen?" Qian Yan was stunned. She never expected that she would get such an answer. "How low is the temperature?"

"It is much lower than the freezing point. This temperature may be difficult to achieve at present, but as long as you work in this direction, I think you should be able to see it one day - isn't the frost technique to condense the water vapor floating in the air into ice?"

Qian Yan showed a thoughtful look, and she looked up after a long time, "These are just your speculations, right?"

Xia Fan did not deny it.

She hesitated, "That is to say... whether the conclusion is correct is still in doubt."

"I know it is indeed hard to imagine. This is also a great pleasure of studying things: from the details that can be seen everywhere, deduce the principles behind things, and apply them to a wider range of fields, even if it is counterintuitive." Xia Fan turned to the excited students, "Everyone quiet! I have prepared another experiment, which will let you see that air is not only filled around like water, but people can also use it to do incredible things!"

This experiment is no longer limited to a glass bottle, but the world is the stage.

A simple air pressure experiment certainly cannot satisfy Xia Fan. He strives to make this open class the first shot to make the school famous, so he did not hold back at all.

And to show the charm of air, what can be more impressive than a representative machine that combines various aerodynamic studies and represents human conquest of the sky?

At his signal, two guards carried a biplane into the school.

Although its size can only be described as a model, it instantly attracted everyone's attention with its unique shape - at first glance it looks a bit like a kite, but everyone soon discovered that it is much thicker than a kite, with a size close to half a person's height and two wings that are longer than an arm. When it was placed on the ground, it did not move at all, and its weight was evident.

The next step was to build a runway about 100 meters long with smooth wooden boards.

Xia Fan originally thought that the key to the biplane model - the electric motor was difficult to polish by hand, but Mo Yun gave him a surprise. The slender iron rod that served as the rotor was precisely shaped by the latter's precise hands. In contrast, the copper wire and magnet surrounding the rotor were just the experience accumulated in the four-wheel drive era, and did not require much effort.

The two sets of home-made capacitors provide energy for the engine. They are made of layers of gold foil and lacquer paper. In order to prevent the insulation layer from being broken, the surface of these lacquer papers is also coated with sealing wax to ensure that the charge does not fly up and down.

The capacitor is charged by a layer of streamer technique. Even with thousands of shock techniques, Xia Fan burned several prototypes before mastering the intensity of charging the home-made capacitor.

Of course, he can also hold the wire in his hand and directly provide energy for the model machine, but this kind of "wired remote control" easily reminds people of kites, which inevitably lacks the feeling of freedom in the wind.

"What is this?" Qian Yan couldn't help asking.

"A vehicle that allows people to soar in the air, but it is just a model now."

"Soar... in the air? Do you mean, it can fly?"

This sentence is also everyone's question, after all, the model machine looks too heavy and clumsy.

"Because air flows like water, if used properly, it can also hold up things that are thousands of times heavier than itself, just like a ship weighing thousands of pounds can float on the sea." Xia Fan replied with a smile. Seeing that everything was ready, he turned off the switch that connected the circuit.

The propeller blades at the nose of the plane spun rapidly, making a huge buzzing sound!

The motor does not need power, as long as there is power supply, it will operate at maximum distortion.

Driven by the propeller, the biplane began to move forward slowly, and faster and faster. Until the pressure difference between the upper and lower wing surfaces exceeded the weight of the aircraft, it seemed to be lifted up by an invisible hand, and suddenly left the ground in the incredible eyes of more than 200 people, and soared into the sky with a roar!

The scene was silent for a while.

Xia Fan knew that the two sets of capacitors could only keep it running for a few dozen seconds, and then it would fall to the ground under the pull of gravity. But just these few dozen seconds were enough to leave an indelible impression in people's minds.