1900: A physics genius wandering around Europe

Chapter 636 On-site Experiment! Hot Water Freezes First! Unbelievable! Shocking the Entire Audience! The Mpemba Phenomenon!
The question raised by Ridgeway shocked everyone.

It's not because it's too difficult, but because it's too easy.

It was so simple that even the junior high school students present knew the answer.

A few junior high school boys were chattering away happily.

"This is what the physics teacher talked about in class: changes of state."

"The transition of a liquid from a liquid state to a solid state is a process of gradual cooling."

"Hot water is hotter than cold water, so it takes longer to cool down to freeze."

"Therefore, the cold water must freeze first."

My friends all agreed.

"Brother Xuesen, you're amazing!"

Xuesen said to his friend next to him:
"Zhuxi is better than me."

Zhou Peiyuan, Wang Dezhao, and the others looked at the children's discussion with strange expressions.

That's what they thought too.

But now he just can't bring himself to say a word.

Just kidding, they are mature college students and graduate students, how could they have the same views as junior high school students?

There's definitely something fishy about this!

It's not as simple as it seems!

Zhou Peiyuan and Wang Dezhao exchanged a glance.

As seasoned veterans of the Physics Olympiad, they knew all too well the tricks of the trade.

The questions that seem simpler with fewer words are often the most difficult.

For example, the perfectly smooth rigid sphere in the first International Mathematical Olympiad was just like that.

In physics, many seemingly ordinary phenomena actually contain profound truths.

Wang Dezhao asked:
"Brother Zhou, what do you think the answer is?"

Zhou Peiyuan frowned slightly and said:

"Thinking in reverse, the hot water must freeze first."

"But I can't figure out why."

"That's unlikely!"

Wang Dezhao nodded.

He also felt that the question must involve the freezing of hot water, otherwise Professor Li would never have used it as an example.

But that doesn't make sense!

Xu Handong and Yan Renguang sat together.

He touched his head and asked:

"Old Yan, tell me, what's the principal up to?"

"It's obvious that the cold water freezes first."

"This doesn't even require scientific knowledge; you can feel it just from experience."

As the dean of the School of Physics, Yan Renguang's physics level is beyond question; he is definitely the best among those present except for Li Qiwei.

But at this moment he was also very puzzled.

He couldn't figure it out for a while.

The premise of this problem is very simple; the important part is "the cooling process".

Although Yan Renguang didn't know much about thermodynamics, he seemed to recall not having done much research in this area.

However, he was able to astutely point out Xu Handong's logical fallacies.

“Hey, Lao Xu, you’re the principal now, you can’t have such presumptuous ideas.”

"You said you can sense it from experience."

"Then think about it carefully, have you ever actually seen hot water and cold water freeze together?"

Forehead.
Xu Handong was speechless.

He really hadn't noticed.

Or rather, even if he saw it, he wouldn't observe it closely.

Because the brain has subconsciously assumed that cold water will freeze first.

This is the effect of habitual thinking.

"So, there really is something strange about this question?"

Could it be that the hot water really does freeze first?

"That kid Wu Dayou is probably going to get his comeuppance this time."

"He felt that there was no difficulty in his passion, but there was actually a whole new world to explore."

Yan Renguang smiled and said:
"I think the principal really admires him."

"See? He'll definitely be a physics genius in the future."

Xu Handong grinned and said sarcastically:
"Of course! My students will easily surpass you, Yan Renguang."

Yan Renguang laughed and cursed, "Get lost, you bastard."

At this moment, everyone was filled with intense curiosity about this question.

As the one being questioned, Wu Dayou is feeling very flustered.

He had just confidently declared that thermodynamics was no challenge for him, only to be proven wrong shortly afterward.

He really wanted to say the phrase "cold water freezes first".

But his intuition told him that the answer was definitely wrong.

Who is that imposing figure standing on the stage?

Science is number one in the world!
The strongest genius in Chinese history who single-handedly suppressed the Western scientific community!
How could the questions he set be childish?
But Wu Dayou suddenly had a change of heart.

"Is Professor Li deliberately testing me?"

"The answer is actually that cold water freezes first, but his powerful aura made me afraid to stick to my own opinion."

"If I answer that hot water freezes first, wouldn't that go against the core spirit of science?"

"Fear no authority!"

"Perhaps this is the message Professor Li wanted to convey to us."

Wu Dayou's eyes gradually brightened; he felt he had guessed Professor Li's intention.

Just to be on the safe side, he asked his four friends.

"Dayou, you know what, it's actually possible!"

"Anyway, I think it's obvious that the cold water will freeze first."

"Don't be afraid, speak your answer boldly, your brothers are backing you!"

However, Li Chengren noticed the faint smile on his father's face and sensed something was wrong.

Wang Ganchang even laughed and said:
"It's okay to be wrong."

"It's not unusual to make mistakes in front of Professor Li."

"What about the others who haven't had this opportunity yet?"

Encouraged by his brothers, Wu Dayou straightened his back and said firmly:

"Professor, I think the cold water freezes first!"

Wow!
Everyone started watching the show!
Li Qiwei smiled slightly and said:

"Oh?"

"Tell me your reasons."

Wu Dayou said:
"Freezing is a process of gradual cooling."

"Assume the hot water is 60℃ and the cold water is 20℃."

"So for hot water to freeze, it must first be cooled to 20°C and then go through the process of freezing cold water."

Therefore, hot water takes longer to freeze in total.

Everyone nodded.

The principle is that simple.

Li Qiwei, however, asked with a smile:

"Since this is your theory, have you conducted any experiments to verify it?"

Forehead.
Wu Dayou was completely dumbfounded.

How could he have done such an experiment?

Because there's absolutely no need to do it.

He answered honestly:

"I haven't done it."

Li Qiwei looked at the many students present and said:

"I believe that many students here, like Wu Dayou, have never done this experiment."

"But how do you know it's right without experimental verification?"

"Science walks on two legs: logic and experiment."

"Logic generates theory, and experiments generate verification."

"Two thousand years ago, the ancient Greek philosopher Aristotle believed that a large iron ball would definitely fall to the ground before a small iron ball."

"At the time, everyone agreed with his view because it was in line with common sense and experience."

"But Galileo later proved through the Leaning Tower experiment that both landed at the same time."

"Now we also know that in a vacuum, an iron ball and even a feather fall to the ground at the same time." "That's the magic of science!"

"It is independent of human will."

"Today, let's assume that Wu Dayou is Aristotle, and I am Galileo."

"Let's do an experiment to see which will freeze first, hot water or cold water."

Then, he looked at Xu Handong and said:
"In the dead of winter, prepare a refrigeration device, a cup of water at 60°C, and a cup of water at 20°C."

"Then I'll put them here and conduct the experiment on the spot."

boom!
The whole audience was shocked!

Xu Handong was too shocked to react; he quickly went out to prepare the equipment.

As the best secondary school in Southeast Asia, Huangpu Middle School naturally boasts top-tier educational resources.

All kinds of experimental instruments are available in science lab classes.

Not to mention such a simple experiment.

As soon as Xu Handong left, the venue erupted in chaos.

Students are still children after all, and their playful nature has been brought to the fore.

"Wow!"

"Professor Li is actually going to demonstrate the experiment for us right here!"

"This is so interesting!"

Zhou Peiyuan and others found it unbelievable.

"Principal Li is serious this time."

Even a small thermal problem required him to personally conduct experiments to verify it.

Everyone originally thought that Professor Li could explain it directly from a theoretical perspective.

Yan Renguang sighed:

"This is the principal's unique teaching methods and personal charisma."

"Although this experiment is small, it can leave students with an unforgettable impression for life!"

"In the future, no matter what cutting-edge scientific research these children pursue, they will remember everything that happened today."

Wu Dayou also looked incredulous.

At that moment, his love for science reached a level of pilgrimage and fanaticism.

Who is Professor Li?

However, when it comes to science, the two are equal.

The other party wants to use experiments to refute their theory.

Wu Dayou finally understood the essence of "not fearing authority".

That's not just a slogan, but a spirit ingrained in our blood!
At this moment, Li Qiwei's charisma was almost tangible, and he was worshipped by everyone!

The atmosphere in the venue grew increasingly enthusiastic.

Just ten minutes later, Xu Handong brought the equipment over.

At this moment, Li Qiwei deliberately said:

"Wu Dayou, and the student next to you, you two come up here together."

"To prevent individual influence, the three of us conducted this experiment together."

Li Chengren gave a wry smile, thinking to himself that his father was really something else; he must have done it on purpose.

At sixteen or seventeen, it's an age when people feel awkward being with their parents.

He had no choice but to bite the bullet and go up with Wu Dayou.

Wu Dayou was extremely excited, rubbing his little hands together non-stop.

Then, Li Qiwei said:

"To maintain a consistent variable, the hot and cold water are of the same quality and are stored in the same containers."

"The temperature of the refrigeration equipment is set at -10℃ and remains unchanged."

"Finally, put both cups of water into the refrigeration equipment at the same time to start cooling."

He explained and guided the two in conducting the experiment.

This experiment was indeed very simple, and Wu Dayou and Li Chengren, both physics whizzes, quickly got the hang of it.

After a brief simulation, the two began the experiment directly.

Xu Handong also thoughtfully prepared a watch to record the freezing time.

drop!
As the refrigeration equipment was switched on, the equipment began to cool, and the experiment officially commenced.

At that moment, the venue fell silent.

Everyone was afraid that their voices would affect the experimental results.

This also demonstrates the high overall quality of Huangpu Middle School students and their basic understanding of scientific experiments.

One minute
three minutes.
Five minutes.
Time passed by minute by minute.

Soon, condensation began to form around the edges of both glass containers.

This is a phenomenon caused by a significant drop in temperature.

Everyone's hearts suddenly began to clench.

Does hot water really freeze before cold water?

Wu Dayou was more nervous than anyone else.

Only after conducting the experiment himself did he realize how frivolous his words had been.

Behind every conclusion lies countless hours of hard work.

Without extensive research, a casual answer carries no weight.

He gained a deeper understanding of science.

Thirty minutes passed quickly.

Someone in the front row immediately exclaimed:
"Oh dear, it's starting to freeze!"

Wow!
Everyone's eyes widened immediately.

Which one froze first?

Wu Dayou and Li Chengren were right next to the instrument, so they had the clearest view.

I gasped in shock.

"My God!"

"The hot water froze first!"

"This is unbelievable!"

boom!
The crowd was utterly shocked!
Although many people have considered the possibility of this happening.

But when the experimental results were presented to everyone without any controversy, they couldn't help but be shocked!

Because it completely overturns people's experience!
Hot water freezes before cold water!

"It's so amazing!"

Not only junior and senior high school students, but even Zhou Peiyuan, Yan Renguang and others were shocked.

"As expected, the principal's speech is always unexpected."

"Such a simple experiment contains such a complex principle."

The reason they find it complicated is because they can't think of the answer yet.

Two minutes passed quickly.

The cold water only begins to freeze "slowly".

Faced with the undeniable facts, Wu Dayou could no longer hold back.

"Professor Li, why is that?"

Li Qiwei did not rush to answer, but instead asked the two to go down first, and then asked Xu Handong to take away the equipment.

"Strictly speaking, it is not enough to conduct an experiment only once."

"But I don't have that much time for my speech today. If you're interested, go home and try it out yourself."

"As you can see, physics has once again overturned your common sense."

"Cold water does not freeze before hot water."

"This is the scientific mindset I'm talking about!"

"Question everything that is irrational and not strictly logical, and verify the real world through experiments."

Wow!
Now all the students understood.

No amount of reasoning can be as impressive as today's experiment.

Li Qiwei planted a seed of science in the hearts of these young people.

In real history, this phenomenon has a specific name: the Mpemba phenomenon.

In 1963, a Tanzanian high school student named Mpemba learned how to make ice cream in class.

Strangely, when he put the freshly boiled hot milk into the refrigerator, an hour later, his milk had turned into solid ice cream.

However, the milk of the other students was still just a thick milky liquid.

So he asked his physics teacher, who told him he must have made a mistake.

By chance, Mpemba met a visiting physicist named Os at the school, and he asked him the same question again.

Os found it very interesting and conducted his own experiment to verify it, finding that the results were indeed as described.

So he and Mpemba studied the phenomenon and named it the "Mpemba phenomenon".

Now, this phenomenon probably needs to be renamed.

(End of this chapter)