Hua Tuo, a science transfer student, opened his mouth and said, "Is it like fanning the fire when I burn medicinal soup?" ”

Yao Ran was surprised by Hua Tuo's reaction, but because of this problem, Hua Tuo's quick reaction was nothing. Pen @ fun @ pavilion wWw. ｂｉｑUｇE。 ｉｎｆｏ

After Yao Ran figured it out, he said to Xiaoping: "You're right! Yao Ran organized his words, looked at some basic physics knowledge in the retinal system, and the design principle of the blower and continued: "Do you know why you use a blower for flames? Do you know why you have to fan the wind in the stove when you cook medicinal soup, that is, when you boil medicine, or when you cook meat? ”

Hua Tuo still wanted to speak, but opened his mouth, stretched out his fingers, and didn't think about what he was going to say, then closed his mouth and shook his head.

Yao Huo and Xiaoping also didn't understand why. They all shook their heads one after another, staring at three pairs of eyes, eager for Yao Ran to give the right answer.

Yao Ran continued, "I'll tell you in principle. Saying that, Yao Ran took out a fire guide, a mud bowl, found some hay and small branches, and ignited them in a palm-sized place.

Yao Ran pointed to the small fire burning on the ground and said, "There are two necessary conditions for the generation of flames. Yao Ran picked up a small burning branch and held it up in front of the three apprentices.

"The first one is to have a combustible, and a combustible, as the name suggests, is an item that can be burned. It's like this twig in my hand. Yao Ran put down the branch in his hand. Still back in the small fire.

"So what's not to burn?" Yao Ran looked at his three beloved disciples with blazing eyes, looking forward to their answers.

Sure enough, none of the three of them disappointed Yao Ran, "The water can't be boiled." It's not combustible! Hua Tuo said first.

Yao Ran nodded, looked at Yao Huo who was squatting beside Hua Tuo, Yao Huo thought about it and said, "Mud is not combustible, we use mud to burn bricks to make him hard and use it to gather flames." ”

Yao Ran nodded and said, "That's right, that's right. ”

Yao Ran moved his gaze to the last apprentice, Xiao Ping.

Xiaoping bit his lip and said, "The stone can't burn." ”

Yao Ran nodded. Xiaoping's answer is actually not completely correct, and even what the first two apprentices, Hua Tuo and Yao Huo, said is not completely correct, because there is nothing in the answer given by the system that is really non-combustible, but under normal circumstances, such an answer is enough.

Yao Ran continued, "There are a lot of things that can be burned around us, and the non-combustible things are except water, sand, and stone. It's very little. ”

Yao Ran looked at his three apprentices and continued: "Then the last condition is oxygen. The three apprentices heard a new word and looked dazed. So Yao Ran didn't wait long to explain to his three apprentices what oxygen was.

Yao Ran took a breath and said, "Oxygen is a gas around us, it can't be seen or touched, but we can't live without it, it can be said that all living things need oxygen." Yao Ran's gaze swept over his three apprentices. Go on.

Plants wither without oxygen, and humans suffocate without oxygen. How do we know that a flame needs oxygen? How can I confirm that there is oxygen around us.

Yao Ran picked up the mud bowl next to him and buckled it on the small fire that was still burning just now, and after doing the action of buttoning the bowl, Yao Ran said, "We have this bowl on this fire now, so the purpose of I didn't do this is to isolate the contact between this fire and the surrounding air, and the flame of this fire will be extinguished after it is buckled." ”

At this time, Xiaoping interjected: "Then we also put a lid on the fire when we burn charcoal, why can we still get carbon?" ”

"It's because we put the lid on the wood inside and don't have enough oxygen for the wood to burn completely, and when we open the lid, we don't get a pile of wood ash." Yao Ran directly ended up with Xiaoping's problem, and asking questions is a good sign. Because everyone has learned and is thinking seriously.

Xiaoping, who got the answer, nodded. Yao Ran didn't care if he could fully understand it, and continued what he had just said, "We have isolated the air from this fire, so the oxygen contained in the air cannot continue to support the combustion of the combustibles, so the flame will be extinguished. Saying that, Yao Ran used a small wooden stick to pick up the mud bowl that was buckled on the ground, and sure enough, the flame that was still burning just now has now been extinguished, and after picking up the wooden bowl, a wisp of green smoke drifted out.

Yao Ran pointed to the small smoking fire on the ground and said, "Then we have a result now, that is, if we want to live, we need combustibles and sufficient oxygen, and these things are usually around us, but they don't burn by themselves." ”

The three apprentices also looked at Yao Ran with question marks on their heads, as if what Yao Ran said just now, the question raised was as if the three of them had just asked, waiting for Yao Ran to give a correct answer.

Yao Ran didn't talk nonsense and said directly, "The answer to the question is temperature, after we heat the wood to a certain temperature, that is, the heat, it will burn, after we heat the water to a certain temperature, it will become water vapor, and after we heat the iron ore to a certain temperature, it will become liquid." ”

The three apprentices thought thoughtfully about what Yao Ran had just said, and Yao Ran was not in a hurry to continue speaking, but just took the mud bowl that was still on the fire just now and fanned the flames on the ground.

The flame that had just been extinguished on the ground suddenly drilled a small spark, and in a moment it turned into a flame, and the wooden branches in the burning fire crackled.

After waiting for nearly a minute, Yao Ran continued to speak, "We have many ways to raise my temperature, such as friction. Yao Ran said and pulled one of Yao Huo's arms, who was sitting in the middle. Rub it quickly with the palm of your hand.

Seeing this scene, Xiaoping said, "I know that it's like we drill wood to make fire, and keep rubbing the wooden sticks to make the hay on the side of the sticks burn. ”

Yao Ran stretched out a finger and waved it and said, "It's not that the temperature of the hay increases, but that the temperature of the wooden stick itself increases, and then it reaches the ignition point of the hay." The ignition point of each burning object is different, and the ignition point is also related to their density. It also has something to do with the texture of the thing itself. ”

Yao Ran looked at the three apprentices in front of him, and at this time, Wolf Eye brought back the wood and dozens of slaves with the two dugs behind him. (To be continued.) )