Dongfang Undefeated was stunned for a moment, and the disciples talked to her very sincerely and fearfully on weekdays, and they didn't even dare to raise their heads, but now they were actually given by Song Qingshu......

But soon the anger in her heart was diluted by the surprise of Edgeworth's flight, and her whole body hung on Song Qingshu's body, with a pair of Danfeng eyes wide, looking at the blue sky and white clouds like a newborn baby, as well as the rapidly regressing forest under her feet.

"If you could take me to touch that cloud, I wouldn't care what you just ...... That's the kind of behavior." Song Qingshu was trying to control the balance of the two, and suddenly the voice of Dongfang Undefeated suddenly came from her ears, and when she looked up, she was stretching out her slender and white fingers and pointing at a cloud not far away.

"What's there to touch with a cloud of saturated water vapor...... Song Qingshu muttered, still manipulating the wooden sword to fly over there.

"Did I actually touch the clouds?" When Song Qingshu rushed into the clouds with her, Dongfang Undefeated seemed to be a little undefeated, his eyes were white, he reached out to touch it, but he couldn't grasp anything substantial, he only felt wet, extremely illusory." I always thought that the clouds were soft to the touch, like marshmallows......" Thinking of the reverie that occasionally produced when looking up at the starry sky in the past, Dongfang Undefeated felt that he was so stupid at that time.

Suddenly, he only felt that his body was moving greatly, and Dongfang Undefeated was so frightened that he suddenly hooked his hands on Song Qingshu's neck again: "What's wrong?"

Song Qingshu was dripping in cold sweat, gritted his teeth and said, "I'm afraid we will ...... It's crashed."

As soon as the words fell, the two of them fell straight down, Song Qingshu only felt that the true qi in his body was intermittent, and his body was also hot and cold, and he was terrified in his heart: Could it be that he had gone mad?

Trying his best to control the speed of the descent, he tried his best to start gliding, and staggered down hundreds of meters, Song Qingshu couldn't control it anymore, and the two fell directly to the ground.

Fortunately, after this period of time, Dongfang Undefeated has recovered part of its internal force, and it is not too high from the ground at this time, she noticed that Song Qingshu's true qi was disordered, and quickly let go of the hands that hooked his neck, and held him in her arms with her backhand, noticing that there was a waterhole below, and she kept waving her palm to the water surface with the help of the internal force, and counter-shocked the momentum of the two of them falling.

However, the strength of the two of them fell more than a thousand catties, feeling the anti-shock force from the water, Dongfang Undefeated spit out a few mouthfuls of blood, and with a bang, the two of them just didn't enter the pool, and they fainted.

Song Qingshu woke up from a coma and found himself lying on the gravel stall, heard the sound of water nearby, followed the sound and walked over, only to see Dongfang Undefeated sitting on a stone on the shore, lifting the hem of his dress, a pair of crystal white calves soaked in the water, there was a narrow opening on it, blood was constantly oozing, Dongfang Undefeated was holding a handkerchief and gently wiping and cleaning the wound.

The water surface is sparkling, Song Qingshu can't really see it for a while, he only feels that the skin on Dongfang Undefeated calf is more dazzling than the lake, it is rare to see her gentle and quiet appearance now, for fear of alarming her for a while.

Dongfang Undefeated quickly noticed his arrival, naturally put down the hem of his skirt and stood up: "Are you awake?"

"I'm really sorry that you still suffered such skin injuries." Song Qingshu glanced at her calves and looked apologetic.

"What is this little injury," Dongfang Undefeated shook his head unconcernedly, "You've surprised me enough today, you might as well tell me how to achieve Edgeworth's flight." Thinking of the kind of leisurely walking against the wind when the two of them traveled in the sky, Dongfang was undefeated and had a surname for a while.

"It's okay to talk to you, but I'm afraid you won't understand." Song Qing hesitated.

Dongfang Undefeated's face turned cold when he heard this: "In the world, even if I don't call myself the first, I will be in the top three, do you think I won't understand?"

"Okay, listen carefully," Song Qingshu showed a hint of playfulness, and explained slowly: "When I fly on the wooden sword with you in my arms, the air flow in the air will bypass the lower surface of the wooden sword, as well as the upper surface of the movement, the lower surface of the wooden sword is a plane, and the upper surface of the wooden sword is me and you, just now I deliberately controlled our body and the sword body to maintain a streamlined angle, so that the speed of the air flow through our body is much greater than the speed through the lower surface of the wooden sword, according to aerodynamics and Bernoulli's theorem, The same fluid flowing through a certain surface has less pressure on this surface than the fast one, so when the air flows through the lower surface of the wooden sword, there is an upward support force on the wooden sword, and this force is greater than the downward pressure on the wooden sword when the air flows through the upper surface of the wooden sword, which just offsets our own weight, so we can fly with the sword."

It turned out that when Song Qingshu was on the Black Wood Cliff, when he flew over the lake, he realized that as long as the speed was enough, the stone could float on the water, so he had been thinking hard about how to use the power of the water to truly cross the river with a reed.

Originally, his thinking has been stuck in the category of martial arts, hoping that he can fully understand the power of water, but the more he thinks about it, the more his head hurts, until one day he has a flash of inspiration in his mind, thinking of the principle of aircraft flight in his previous life, it just happened that his company did an aircraft project in his previous life, when he studied relevant information, he had a certain amount of dabbling, and then he thought of using aerodynamics to solve the problem of Edgeworth's flight.

"Aerodynamics?Bernoulli's theorem?" Dongfang Undefeated frowned, and asked suspiciously, "Which sect's martial arts secret book is this, how can I never hear of it?"

"This?" Song Qingshu was also stumped all of a sudden, so he had to say, "This is the secret book of the physics sect in the extreme west, and naturally no one in the Central Plains has heard of it."

"Physical?" Dongfang Undefeated fell into deep thought, and suddenly raised his head and asked, "According to what you said, is it still related to speed that we can fly?"

"It's a pity that you don't study physics," Song Qingshu forgot in surprise. [,!] glanced at her and nodded, "Yes, you can simply understand that the greater the speed, the greater the lift the air gives you."

"Oh~" Dongfang Undefeated's eyes were full of excitement, and he looked up at the sky, "Isn't that as long as my speed is big enough, the lift force given by the air will be much greater than my own weight, and I can't keep rising and achieve the legendary feather and ascend to the immortal?"

"You're thinking too much," as a modern person who clearly knows that the outside of the sphere is a cold and silent universe, Song Qingshu doesn't quite understand why Dongfang Undefeated is so interested in such a thing as ascending to immortals, "When the speed of flight exceeds the speed of sound, the air will become sticky, and you must consider the Reynolds number, it's not as simple as I just said...... Of course, if your speed can reach the first cosmic velocity, it is not impossible to feather and ascend to the immortal, but you will be burned to ashes by air friction during the flight."

Dongfang Undefeated heard it in a fog, and said angrily: "Then you sue me directly, is it impossible to become an immortal?"

"It's unlikely." Song Qingshu nodded, making a regretful expression, "Well, I think you should care about your soaked clothes instead of caring about this kind of ethereal thing."