In August 1900, the German mathematician Hilbert gave a famous lecture entitled "Mathematical Problems" at the International Congress of Mathematicians in Paris, putting forward 23 major problems that the mathematical community urgently needs to face in the new century, the fourth of which is: "A straight line is the shortest distance between two points." ”

Many people think that this question is too general, "the shortest line segment between two points", the first axiom of junior high school geometry is it, do you still need to doubt it? But then again, nowadays even "1+1=? This doubt can be understood.

But someone took out a piece of paper and randomly dotted two points on the two corners of symmetry, as if the shortest distance was the diagonal. However, when you roll a roll of paper and pinch the two corners together, the distance is infinitely close to 0.

By extension, there is the theory of "time and space tunnel".

Time tunnels?

When the flowery life is about to unfold in front of Sun Yuanqi, he is not willing to stay in the late Qing Dynasty and suffer crimes, not to mention the success of this Wuxu reform, after the Boxer Rebellion, the Xinhai Revolution, the Northern Expedition, the Eight-Year War of Resistance, the War of Liberation, after a short period of Yanchun, it is three anti-five anti-right, anti-right, three-year natural disasters, and special periods, so that it is the turn of reform and opening up.

I took out my mobile phone, but there was still no signal, and it was already 9:40.

"Hurry up and get in, maybe you can go back in time for the interview at ten o'clock!" Sun Yuanqi thought to himself. Ignoring the janitor's face, he went straight in, followed the way he had just come out, and walked back, thinking, "Maybe I can go back this way." ”

The shade of the trees in the courtyard is still cloudy, but the sound of cicadas is more noisy than when they came. The weather is getting hotter, and I am in a hurry, so I have taken off my suit jacket and put it on my arm. The neckline was also ripped open, and the tie was crooked to the side. Somewhat angry.

When he stood at the gate of the Horse Temple for the fifth time, it was already twelve o'clock at noon, and Sun Yuanqi confirmed a fact: he couldn't go back, and he couldn't catch up with the key interview.

Sun Yuanqi felt angry in his heart, feeling that he really had nothing to look for, why did he wander around the horse temple? How nice it would be to go straight to Five Cities Middle School! Seeing the stone lion next to the door, he stepped forward and kicked twice. After kicking, he only smoked the cold air by holding his feet: this is also nothing to look for!

The old man who guarded the door, from morning to now, had been watching him for a long time, and now he came up again: "You say, why did you Japanese come to our Great Qing Kingdom to teach?" ”

Sun Yuanqi was unhappy in his heart, and when he heard this, he jumped to his feet and scolded: "You are Japanese!" Your whole family is Japanese! ”

The old man shook his neck and said slowly, "Japanese? We're not uncommon! We are serious flag men. After saying that, he slowly paced back to the gatehouse to take a cool day.

At this shouting, Sun Yuanqi realized a big problem, he was wearing a suit. Standard Qing men now wear braids and long shirts. Rong Hong returned from Liumei, wearing a suit and dragging a fake braid. As for Dr. Sun, who dared to poke the big Qing basket, although he shaved his hair, the cat did not dare to return to China abroad. Nowadays, the yellow skin that dares to blatantly shave on the land of the Qing Dynasty is estimated to be Japanese.

Although the old man was the first person Sun Yuanqi knew in the Qing Dynasty, and he was his great-grandfather in terms of seniority, he was embarrassed to stay on the land after arguing with the old man. Moving forward step by step along the dirt road, there is a bit of a taste of resignation.

At noon, the early summer sun was also wicked, and after a morning of tossing, my stomach was so hungry that my heart was close to my back.

On the borders of the Qing Dynasty, there were no ATMs, no credit cards, and no RMB could be used, and now Sun Yuanqi was really penniless. Occasionally, a few dark Lifu walking by, you can hear them muttering in a low voice: "Little Japan!" ”

After listening to it a few times, Sun Yuanqi's thoughts became lively, since others say that I am a foreigner, then I will go to a foreign embassy or consulate for a meal! In Sun Yuanqi's heart, he thought like this: If you go to the restaurant of the Chinese people to eat, if you don't give money to arouse your anger, you will be in trouble, who knows if the Boxers have set up a branch altar in Beijing now, and the slogan of the people is "help the Qing and destroy the foreign", and the one who kills is the foreign devil, and he will inevitably suffer from the fish in the pond. Foreign embassies and consulates are more or less modern civilization, and they can still be on top of it.

As for the embassy of the country to go to, there is no doubt that it is naturally American. Although he is mistaken for Japanese, who does not know the feud between China and Japan? Besides, I don't know Japanese either, and I don't know anything other than "yameide" and "Sayonara", so it's easy to show my stuffing. CET-6 for graduate students comes in handy at this time. Why not go to the UK and go to the US? Quite simply, England, which had learned American English and was intoxicated by the afterglow of the empire on which the sun never set, had never been very interested in cousins who smelled of fresh cow dung. In the eyes of the British aristocracy, this country cowboy who is far away from the ocean is more like Grandma Liu who has just entered the Grand View Garden.

Now that you know you're going to the U.S. Embassy, the next step is to ask for directions. This is also very easy to do, grab a person on the street, who doesn't know that Dongjiaomin Lane, where ghosts live?

Fortunately, it's not far away.

Seeing the ghosts patrolling outside Dongjiaomin Alley from a distance, Sun Yuanqi buttoned up his neckline, straightened his tie, put on the suit resting on his arm, and took out a tissue to wipe the dust on his shoes. Originally, this outfit was rumored to support the scene, but now it is used at the right time, and then walks over with his head held high.

Looking at Sun Yuanqi's dress, the soldiers of the Qing Dynasty avoided it from a distance and did not come up for interrogation at all. However, the guard in front of the American Legation was more conscientious, raised the rifle in his hand, and asked:

"Stop! What for? ”

This sentence is said in Chinese, and I think it is "close to Zhu is red, close to ink is black", and I learned it temporarily after coming to China. Sun Yuanqi shrugged his shoulders in an American manner, spread out his hands, and said in English that he had practiced several times before: "Soldier, relax, I am not an enemy of the United States of America." I'm a friend of the ambassador and I just came to see him today. ”

Seeing that the person who came was well-dressed, unarmed, and not dressed in the appearance of the Qing Dynasty, and spoke American English, the guard slowly put down the gun in his hand and asked in English, "Then do you have an appointment with Mr. Conger?" ”

"I'm sorry, I didn't. In fact, I wanted to surprise him. Sun Yuanqi opened his mouth, "We haven't seen each other for a long time. In fact, he didn't know how long the U.S. ambassador had been in office, so he had to say vaguely that the flaws were smaller.

"The ambassador will have yellow-skinned friends?" The guard asked his comrades around him. No one knows about this. All they saw was that many Manchu officials with pigtails would come to visit, and in their eyes, Oriental people all looked the same, with yellow skin, black hair, and black eyes. One of them speculated: "Maybe it's a young boy from the Qing Kingdom who studied in the United States, and he has seen an ambassador in the United States before." As soon as the ambassador arrived, he hurried over to visit. ”

The current U.S. minister to China is Edin Hurd Conger (1843-1907), who was appointed by the U.S. government on January 19, 1898, and presented his credentials to the Qing government on July 8 of the same year—just a few days earlier. Saying this, the people around them nodded secretly, thinking that it was very reasonable. This fundamentally explains why an Oriental wears a suit, speaks fluent English, and is fair-skinned and tall...... None of this is like the citizens of the Qing Dynasty, in fact, more like black-haired Europeans and Americans.

Since they thought so, the soldiers relaxed a lot, put Sun Yuanqi in, and kindly told him: "The ambassador lives on the second floor of that building. ”

"Thank you. Good luck, soldier. "Sun Yuanqi passed the first hurdle.

When I walked into the courtyard, I saw Mr. Conger's house.

The door was opened by an old black woman with a puzzled face: "Sir, are you sure you didn't knock on the wrong door?" ”

Sun Yuanqi smiled: "I'm sure I didn't knock on the wrong door." Is Mr. Conger at home? ”

The old woman opened the door and muttered, "I've never seen an Asian boy come to Mr. Conger." ”

"Well, it's an honor that I'm the first." Entering the living room, it was like returning to the 21st century, and Sun Yuanqi suddenly felt much more relaxed.

"You wait in the drawing-room, I'll call Mr. Conger." The old lady, who was supposed to be a servant of the Conger family, turned around and walked upstairs, "Do you have tea or coffee?" ”

"A cappuccino, thank you."

Hearing Sun Yuanqi's answer, the old lady looked back from the stairs and looked at it again before continuing to go upstairs, "There are a lot of strange things today!" ”

Soon, Mr. Conger walked downstairs, and Sun Yuanqi quickly stood up and walked forward to shake hands with him: "It is a great honor to meet Mr. Conger today. ”

"Me too." Mr. Conger was about forty-five years of age, well-dressed in a suit, with a capable movement and a military temperament. In fact, Mr. Conger was a soldier by military background, serving as a Major in the U.S. Army.

After taking his seat, Conger looked at Sun Yuanqi carefully and asked, "Young man, if I'm not mistaken, this is the first time I've seen you." ”

Sun Yuanqi was a little embarrassed, but the pressure of survival overcame everything, and he plucked up the courage to say, "Yes, sir." I'm tempted to bother you because I need your help. ”

"Help?" Among the Orientals whom Conger knew, especially the bureaucrats, had always been known for their subtlety, which even the English, who were known for their gentlemanly manners, were ashamed of, and few of them were so straightforward. The first one who claimed to need help at the first meeting, this was the first one. He looked at Sun Yuanqi carefully, and felt that the well-dressed young man opposite really didn't look like a poor person, nor did he look like a bad person.

"Yes, sir." Sun Yuanqi also blushed a little, this is similar to begging, and with the addition of lies, the upright self-esteem was tied with countless bows at this moment, "If Mr. is free, you can let me state my predicament." ”

At this time, the old lady brought two cups of coffee, one of which was a cappuccino, Sun Yuanqi owed a slight debt and said "thank you".

"It's an honor." Conger smiled and said, "Maybe before you do that, you can introduce yourself." ”

"I'm really sorry, my Chinese name is Sun Yuanqi, and when I was in the United States, my friends usually called me YorkJohnson." The name was actually given to him by a foreign teacher when he took English classes, "My father was a naval officer who studied in England for a period of time, and he was very fascinated by Western technology and culture. When I was very young, I was sent to the United States as a young child in the United States. When I returned home the other day, I learned that my father had been killed in the Sino-Japanese War, a naval battle four years earlier, and I didn't know where my mother and brother had gone. The roof leak happened to rain overnight. Not long ago, my luggage was snatched away by a mob – they thought I was Japanese. Now I have no money, so I have to come to you for help. ”

"I'm sad to hear your story." Through the heat of the coffee, I couldn't see Conger's face clearly, "How can I help you?" ”

Sun Yuanqi lowered his head together, on the one hand, he was ashamed to cover up when he lied, and on the other hand, he was also a little sad, he had no parents, relatives, girlfriends, teachers and classmates in this world, and he was indeed helpless. After listening to Mr. Conger's words, I thought to myself, I can't just ask someone to borrow money if I can't meet each other, and it is better to find a job to earn a living. Suddenly, I remembered the words of the short old man today, Sun Jianai wanted to set up a Beijing Normal University Hall, and had an idea in his heart: "That's the case, sir." Originally, I heard that China was going to reform the law, so I rushed to Beijing to become a teacher in the hall of the soon-to-be-founded Beijing Normal University. Now I have lost my diploma and certificate, so I would like to ask you to write a letter of recommendation......"

"You mean, you got a degree in the U.S.?" Conger was surprised.

"Yes, a master's degree in physics from Yale University." Sun Yuanqi is very familiar with American universities, but it is not very clear which school admits Chinese students, so he has to close his eyes and choose one of his favorite Yale, MIT, and Princeton.

"It was amazing." Conger was indeed taken aback by the news, "I take the liberty of asking, how old are you?" ”

"Twenty-three years old, sir." Sun Yuanqi replied truthfully.

"You look very young, I thought you were only 18." Conger put down the coffee cup and stared at Sun Yuanqi for a while.

"Maybe it's because I drank milk and ate bread since I was a child." Sun Yuanqi also answered truthfully.

"Do you have a good understanding of physics? I mean, what part of physics are you interested in? After this period of dialogue, Conger is not very suspicious of Sun Yuanqi's background in the United States, but he has a lot of doubts about his "master of physics".

However, this is one of Sun Yuanqi's rare truths, so he calmly replied: "What I am most interested in is atomic physics, which is a brand new science. As you know, humans today know almost nothing about the microstructure of matter. Four years ago, physicist Michael Sun said in a lecture: "The vast majority of important fundamentals are firmly established. The famous physicist Kelvin also said: "The 19th century has built the whole edifice of physics, and in the future physicists will only embellish and perfect this edifice." But in the past few years, scholars have discovered X-rays, radiation, and cathode rays, which means that there are still many unknown things waiting to be explored, such as ......."

Sun Yuanqi talked on and on for nearly half an hour, during which time he tried to keep himself from mentioning any of the discoveries of the 20th century, and to describe some interesting phenomena of atomic physics to a diplomat who was a soldier in as plain language as possible. The result of this half-hour was to make Mr. Conger begin to believe that the other person was indeed engaged in physics research in the United States, and the others were still skeptical.

Looking up at the sun outside the window, it was about four o'clock in the afternoon. From the morning to now, running around, drinking only one cup of coffee, so hungry that I feel like my stomach is about to melt.

I'll have to work for dinner and lodging later! Thinking of this, Sun Yuanqi sighed.

;