North Xuantian, Crystal Palace.

After Lin Xuan returned with his baby daughters, it was already noon.

Lunch time is coming.

Lin Xuan, who just promised to cook a big meal for his daughters on the road, went directly into the kitchen.

While the little girls were waiting for dinner, they were playing in the garden.

Call~

At this time, a wind blew and rustled the branches and leaves.

"Eh? It's windy!"

"Wow, it hasn't been windy for a long time. It's really good today!"

"I want to become a gust of wind and take off with it!"

"You are the wind, so am I. We fly to the ends of the earth together!"

The little girls immediately danced with excitement.

Xuanxi's brain hole was wide open and said, "sisters, sisters, why don't we fold some thousand paper cranes and let them take off with the wind!"

When xuanzhu, Xuanhan and Xuanyou heard this, they immediately became interested: "OK!"

The four little girls rushed into the bedroom immediately.

Found out the origami that Lin Xuan had specially prepared for them, held several of them and ran out of the door.

Because Lin Xuan had taught them how to fold a thousand paper cranes before, the little girls easily folded four thousand paper cranes.

"Fly ~"

At the same time, they held the paper crane high and threw it forward along the wind.

Unfortunately, the paper crane couldn't fly in the wind and fell to the ground not far away.

"Eh? Why can't they fly with such big wings?"

"Are we not strong enough?"

The little girls thought about it, then came forward to pick up the thousand paper cranes, and then threw them out with all their strength.

This time, the thousand paper cranes still didn't fly, and soon they all fell to the ground.

"How could this happen?" xuanzhu reluctantly spread her hands.

"I thought they could fly!" xuanxi puffed up her mouth and looked tangled.

"Alas ~" Xuanhan sighed softly and shook her head.

"Why don't we make the thousand paper cranes bigger? Maybe they can fly!" Xuanyou suggested.

Xuanzhu shook her head: "if it's a little bigger, it's heavier, and it's even more impossible to fly!"

"But so many large monsters can fly, and they are also very heavy!" Xuanyou insisted.

Xuanxi and Xuanhan thought for a moment and said, "why don't we fold another thousand paper cranes according to the size of Linghua fairy goose!"

Linghua fairy goose is the most common bird in beixuantian.

The little girls thought that if they tried it according to its size, there might be a surprise.

Then, the four little cute divided their work and soon made a big thousand paper cranes.

In order to let the paper crane fly, xuanyoute took it to the top of the rockery and said proudly:

"Now it can fly!"

"Hoo ~ fly!"

The little girl threw the thousand paper cranes out.

Patter!

The plane crashed!

Xuanzhu, xuanxi, Xuanhan: "

"How could this happen?"

"The small ones can't, and the big ones can't. is it because the wind is too small?"

Xuan you looks very cute with a tangled face and squats on the top of the fake mountain with her chin in her hands.

Lin Xuan walked out of the bedroom and said with a smile:

"Babies, if you want something to fly with the wind, you can't just look at its size, but how much power it receives in the air."

"Does the air still have power?"

Hearing Lin Xuan's words, the little girls immediately looked surprised.

They had a hunch that their father would tell them a very novel and powerful knowledge.

Seeing the babies rushing over, Lin Xuan hugged them all in his arms and said:

"Of course air has power! And there's more than one!"

"Wow, that's great!"

Xuanzhu, they immediately exclaimed.

Lin Xuan looked at the four cute little faces and said:

"In fact, when you throw the paper crane out, it receives four forces."

"The first is the thrust that you throw out, the second is the resistance that the air hinders its progress, and then the buoyancy that the air below pushes it upward."

"The last... Is the gravity that all people and objects on this planet will receive."

"Only when these four forces reach a balance can they fly!"

With xuanjue Tianshu, Lin Xuan can tell his daughters this mechanical knowledge in the simplest way.

After hearing this knowledge, the little girls were stunned.

They didn't expect that there were so many forces in the air.

Even the servants on one side were shocked.

"I am also a person who has read books for more than ten years, but the knowledge that emperor Fu said is really unheard of!"

"I feel that after listening to him for a few years, I can become a bachelor in Hanlin academy!"

Some ambitious servants even thought so.

"Dad, isn't the thousand paper cranes unbalanced in the air, so they can't fly?" asked xuanzhu.

"Yes, xuanzhu baby is so smart!" Lin Xuan smiled and nodded. "So, dad taught you an origami that can fly at any time!"

"Can fly any time?"

"It feels great!"

The little girls are really stunned this time.

Lin Xuan smiled and immediately found a simple origami tutorial called "Taiyi flying pig" from the perfect dad tutorial.

Because the structure of "Taiyi flying pig" is very simple and balanced, it is very easy to fly, even if there is no wind.

Then he took a piece of origami and quickly made a Taiyi flying pig.

Xuanzhu they were captured by this novel little flying pig in an instant.

"Dad, what's the name of such a lovely origami?"

Lin Xuan said, "it's called Taiyi flying pig. You can call it Xiaofei pig."

"Little flying pig... What a lovely name!" the little babies twinkled with love in their eyes.

When Lin Xuan raised Taiyi flying pig and threw it out.

Seeing its flapping wings, the little girls screamed excitedly.

Then they rushed into Lin Xuan's arms and hugged him tightly:

"Daddy, teach us to be little flying pigs!"

"Good good!" seeing that the daughters were so enthusiastic, Lin Xuan was also very happy to teach them.

Because the production of taiyifei pig is very simple, and the little girls are very smart.

In a short time, they all learned this origami.

Then they lifted the origami together and threw them out.

"Fly!"

"Ha ha, it's really flying!"

"How can my father be so clever! I'm so happy!"

Seeing all the Taiyi flying pigs fly, the wings are very cute and interesting.

The little girls shouted excitedly, and the sound of happiness spread all over the garden.

Lin Xuan looked at it with a smile, his eyes full of the light of father's love.

Ding!

Just then, the system mechanical sound in the brain suddenly sounded.

"Your Dexterity taught your daughters a novel and interesting origami, reward: Taigu fire spirit!"