Chapter 248: To take off

This is a classic air pressure test.

The device with the highest technical content is probably this glass. It was

also made by Xia Fan commissioned by Luo to lightly fired it with dragon

scales. Although the sea sand has a deep green color, it does not hinder its

excellent light transmission.

Put the four candles in a basin filled with water, then light the candles and

buckle the glass upside down.

In full view, the candle quickly ran out of oxygen and went out.

Then the water surface 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 crossed the basin

outside and rose to almost one-third of the wall of the cup. From a distance,

it looked like a new "hill" had risen in the basin.

Before that, the inner and outer waters were still at the same level!

"How does this water... move?"

"It feels like being sucked up by something!"

The children's interest was immediately mobilized.

"You might as well think about why this phenomenon occurred." Xia Fan once

again looked at everyone-in fact, he arranged for the Privy Council among the

observers, just to prevent cold spots caused by no answer. .

But this time someone gave the answer in advance.

"What you want to say is that the gas in the bottle is exhausted, causing the

outside gas to squeeze the water surface and push the water into the bottle?"

"Correct." Xia Fan followed the prestige somewhat curiously, and it was a

little girl who caught his eye. Seeing her location, it should be a guest

invited by Fang Xiandao.

To be honest, although this experiment is a classic, it is not as shocking as

a hemispherical experiment. It takes a circle to understand the principle. The

other party seems to be young, but can think of this level quickly, is it \-

she is also a living dead?

"Then can I ask a few more questions?" Qian Yan got up from the chair, which

made her suddenly shorter. "The person in front, please let me."

Probably I have never seen such a magnificent little girl, everyone

involuntarily vacated a passage.

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

"Don't worry." Fang Xiandao comforted him, "The Xia Fan I know is not the kind

of person who bullies others."

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

"Since there is pressure in the air, why don't we feel tired, even if we

relax, we won't be crushed?"

"The same reason as this bottle, because we also have air in our body, which

is offset by the inside and outside. If the air is taken out, the weight is

enough to press a person."

"Then what is the air? Does it have a substance? Can it be directly touched?"

Qianyan asked.

If it's the imaginary and realism of the past, you will definitely avoid

answering such questions directly, and instead talk about profound and

profound principles.

"Of course it does." However, Xia Fan did not forcefully change the subject.

"You can understand gas as a thinner water, so when the temperature is low

enough, it will freeze like water and become visible to the naked eye. "Ice

bumps"-I think at that time maybe you could see more intuitively that you were

touching an entity."

"The air-can it be frozen?" Qianyan couldn't help but stunned, she did not

expect 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 hard in this direction, I think

you should be able to see one day-frost formation does not condense the water

vapor floating in the air into ice ?"

Qianyan showed a pensive look, and after a long time she looked up, "These are

all your speculations, right?"

Xia Fan did not deny it.

She hesitated, "That is to say... It is still doubtful whether the conclusion

is correct."

"I know it is really hard to imagine. This is also a great pleasure of

studying things: from the details that can be seen everywhere, the principles

behind things are deduced and applied to a wider range of fields, even if it

is counter-intuitive." Xia Fan turned to high interest. Students, "Everyone is

quiet! I have also prepared another experiment, which will let you see that

not only does the air fill the surroundings like water, but people can also

use it to do incredible things!"

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

stage.

A simple air pressure fun experiment certainly can't satisfy Xia Fan. He

strives to make this public class the first shot in the school's reputation,

so he didn't leave any hands.

And to show the charm of air, what can be more influential than the

representative machinery that integrates various aerodynamic studies and

represents the conquest of the sky by humans?

At his sign, two guards carried a biplane into the entrance hall.

Although its size can only be said to be at the level of a model, it instantly

attracted everyone's attention with its unique shape-it looks a bit like a

kite at first glance, but everyone quickly realized that it is much thicker

than a kite and its size is close to half human High, the wings are more than

an arm. This thing doesn't move when it is placed on the ground, and its

weight is evident.

The next step is to build a runway about 100 meters long with smooth wooden

boards.

Xia Fan originally thought that the key to the biplane model is that the

electric motor is difficult to polish by hand. As a result, Mo Yun gave him a

surprise. The slender iron rod used as the rotor was shaped by the latter with

precision hands. . In contrast, the copper wires and magnets surrounding the

rotor are only the experience accumulated in the four-wheel drive era, and it

does not require much effort.

To provide energy for the engine are two sets of soil capacitors. They are

made up of layers of gold foil and lacquer paper. In order to prevent the

insulation layer from being broken down, the surface of these lacquer papers

is also coated with sealing wax to ensure that the electric charge will not

fly up and down.

To charge the capacitor is a streamer technique. Even after thousands of

shocks, Xia Fan burned several prototypes before he mastered the strength of

charging the local capacitors.

Of course, he can also hold the wire in his hand to directly provide energy

for the model machine, but this kind of "wired remote control" is easily

reminiscent of a kite, and the feeling of freedom to chase the wind is

unavoidable.

"What is this?" Qianyan couldn't help asking.

"A vehicle that allows people to fly in the air, but it's just a model now."

"Soaring...in the air? You mean ~www.mtlnovel.com~ can it fly?"

This sentence is also everyone's question, after all, the model machine looks

too heavy and clumsy.

"It is precisely because the air flows like water, so as long as it is used

properly, it can hold things hundreds of times heavier than itself, just like

a ship that weighs a lot can only float on the sea." Xia Fan replied with a

smile. Seeing that everything was ready, he pulled down the switch that

connected the circuit.

The blades located in the nose of the aircraft spun quickly and made a huge

hum!

The motor does not need assistance, as long as there is power supply, it will

run with maximum distortion.

Driven by the propeller, the biplane began to advance slowly and faster and

faster. Until the pressure difference between the upper and lower wings

exceeded the weight of the airplane, it seemed to be lifted up by a pair of

invisible hands, and suddenly left the ground under the incredible eyes of

more than two hundred people, and soared into the air!

The scene was silent for a while.

Xia Fan knew that the two sets of capacitors could only run for tens of

seconds, after which it would fall to the ground under the pull of gravity.

But just these tens of seconds is enough to leave an indelible impression in

people's hearts.