All eyes were on the podium, and the big guys wanted to see what kind of results could make the always calm and calm Mr. Michael Faraday happy like this.

Faraday said with a smile: "I believe many of you here know that in fact, the world has been studying electricity and magnetism for many years.

But in the early days, researchers thought of them as two separate disciplines.

But the merchants disagreed with us.

Because in the 18th century, a London merchant made a shocking discovery that his box of iron spoons was amazingly magnetic after being struck by lightning.

This disagreement between scientific researchers and businessmen was not resolved until 1820, when the Danish scientist Hans Auster conducted an experiment.

He placed the wire parallel to a magnetic needle, and the moment he turned on the current, he was pleasantly surprised to find that the magnetic needle actually jumped.

After repeated experiments, Oster confirmed that this was not a coincidence. Soon after, he published a paper entitled "On the Experiment of Electric Current Impact of Magnetic Needles", a great discovery that the scientific community called 'the magnetic effect of electric currents'.

Since then, we shallow scientific researchers have finally realized that electricity can produce magnetism.

And when I was instructed by my mentor Humphrey Davy to move into the field of electricity, my first thought was that if electricity can produce magnetism, can magnetism produce electricity?

I have conducted countless experiments over the years for this conjecture, and finally, not long ago, I finally got an amazing answer.

Electricity and magnetism are not separate disciplines, but unified disciplines with strong relevance! ”

With that, Faraday uncovered the black cloth that had covered the experimental table.

What appeared in front of everyone was a six-inch round iron ring densely wound with white cloth, and the left and right halves of the ring were wrapped with two strands of insulated copper wire.

The copper wire on the left half connects a set of handmade batteries, forming a set of independent circuits.

On the other hand, the copper wire on the right side has only one ammeter connected.

Faraday enthusiastically introduced: "As you can see, these two sets of circuits are independent and not connected. We call the circuit with a battery on the left A, and the circuit without a battery on the right with an ammeter is called B.

Therefore, according to our common sense, even if circuit A is electrified, the ammeter pointer of circuit B will not be deflected.

But is that really the case? ”

Faraday stepped forward with a smile and gently turned on the switch on circuit A.

Under the gaze of everyone, everyone present noticed that the ammeter of circuit B actually deflected a little in a clockwise direction, but it quickly returned to its original position.

When Faraday turned off the switch, the ammeter was deflected counterclockwise.

"Oh my God!"

"What's going on?"

Someone exclaimed, "Mr. Faraday, isn't this really because you shook the table?" ”

Faraday humorously said, "Although the Royal Society has always lacked funds, we are not too poor to afford a suitable experimental table. If you don't believe it, try it yourself. From now on, my hands are off the table. ”

He invited the gentleman who had just raised the question to the stage, and the gentleman exclaimed after seven or eight attempts, and then carefully examined the table on which the experiment had been used.

"While I know every time your lectures are fantastic, this one was undoubtedly the best ever! On behalf of the audience, allow me to once again pay you the highest tribute. ”

With that, the gentleman took off his hat and bowed slightly with one hand to his chest.

The audience also erupted in long-lasting applause again.

At that moment, another man stood up in the lecture seat.

He questioned: "Mr. Faraday, although I have no intention of offending. But I wonder if it could be the one you used for your experiments?

After all, both circuits are connected to the hoop, and even though you insulated it with a white cloth, there may still be an electric current running down the hoop. ”

When Faraday heard this question, he didn't answer it directly, but smiled and said, "In that case, please look at the second experiment." ”

With that, he uncovered the black cloth on another experimental table.

This time, the experimental setup was much simpler, with only an ammeter, a hollow coil wrapped in copper wire, and two copper wires connecting the two.

Faraday pulled a magnet out of his trouser pocket and placed it into the hollow coil.

I saw the magnet flash through the coil and land on the table, and at the same time, the ammeter was also deflected.

Faraday smiled and said, "Sir, you see. This time, I didn't even use the battery. ”

The audience exclaimed, "Oh God! This could be the biggest discovery of the year! ”

"Mr. Faraday, by combining electricity and magnetism into one, you may be able to match Sir Isaac Newton with this achievement."

Faraday only nodded slightly in return to the audience's applause, his face filled with a big smile, and although he was happy that his academic achievements were recognized, he still did not forget his mission.

Conducting experiments is only the first step, the most important thing is to draw lessons from experiments and summarize them into a conclusion that can be verified repeatedly, and explain the causes and analysis process of this phenomenon.

Elder in the audience saw Faraday's experiment as if he was magical, and heard him start talking about terms like magnetic inductance lines, and he only felt dizzy and couldn't understand anything.

He elbowed Arthur beside him and whispered, "Do you understand?" ”

Arthur raised an eyebrow and winked at him, "Understand." Truth be told, I've actually heard this for the second time. ”

"Huh? Have you snuck to a lecture before? Why don't you tell me?

Forget it, then you tell me what messy magnetic inductance lines are, and how to distinguish the direction of the current from the direction of the magnetic field.

It's too difficult, and I finally came to the lecture to learn a little bit. Otherwise, I don't know what to say when I talk to those beautiful ladies who like science in the future. ”

Arthur said, "I'll teach you an easy way to memorize." ”

Elder wondered, "What's the easy way?" ”

Arthur spoke, "If you want to tell the direction of the current, stretch out your right hand." Keep the four fingers together and the thumb perpendicular to the other four fingers.

Yes, that's it, all five fingers are kept on a flat surface.

Next, align the palm of your hand with the direction of the N pole of the magnetic field, and align your thumb with the direction of the conductor's movement, which is the direction of the magnet falling.

So, the direction of your remaining four fingers is the direction in which the induced current is generated. ”

When Elder heard this, he was amazed: "Arthur! You're such a genius! How did you come up with this idea? ”

Arthur avoided answering this: "Do you want to learn how to judge the direction of the force on the conductor?" ”

"Learn, of course I want to learn!"

"Now, stretch out your left hand."

"Oh? Left-handed again this time? ”

"Don't talk so much nonsense, you listen to me......"

Before Arthur could finish his words, a gentle inquiry suddenly sounded in his ears.

"Excuse me, what are you talking about?"

Arthur turned his head to see that Faraday had actually walked to his and Elder side at some point, and the two ordinary boys suddenly became the focus of attention of the audience.

Faraday smiled kindly, "Mr. Officer, can you tell me about the right hand again?" The one in the right hand heard only half of it. As for the left-handed one, we'll talk about that later. ”