Chapter 741: The Art of Telecommunication
...
Roland wiped the fine sweat from Anna's forehead and held her in his arms.
In the dim light, one could still see an alluring blush on the girl's face.
Ever since their conversation about dreams, Roland felt that Anna had become more proactive in this regard, even diligently learning new techniques—however, unlike basic knowledge, her progress in this area was much slower. Watching Anna's clumsy yet earnest efforts was a completely new experience for him, the visual pleasure even surpassing the sensory experience, and a sense of superiority as an experienced driver arose spontaneously.
Of course, the storytelling time after pleasure was always unavoidable.
Smelling Anna's fragrant hair, Roland recounted the new information brought by the Taqila witches, as well as his own speculations about the Battle of Divine Will, in detail.
"Although I knew that where we are is just a corner of the continent, I didn't expect that under the mountains there were civilizations completely different from us... This world is really full of unknowns." Anna sighed, "Perhaps one day, we can set foot on that distant land and see what secrets are hidden across the sea."
"There will definitely be such a day, I promise," Roland replied with a smile.
Even if the sea route is impassable, they can still fly over—the land that can be seen with a telescope can't be too far away. Once there are internal combustion engines, large airships will have their use.
"However, do gods really exist in this world? Leaving relics and driving us to kill each other... Maybe it's watching us somewhere."
"Are you afraid?" Roland couldn't help but tighten his arms, holding her even closer.
"No, I should thank it."
"Why?" He was slightly stunned.
"Because it sent you to my side," Anna said softly, looking up.
Roland saw the blue lake light rippling in her eyes—that was her undisguised affection.
He felt a warm current surge in his heart.
"I will always be with you."
"But you can't always stay by my side."
"I—"
He was halfway through his sentence when Anna covered his mouth.
"You are the king, and also the commander of the army against the demons in the future, so how can you always stay in Neverwinter City? I can't occupy all of you because of my own selfishness. The soldiers fighting on the front lines need to see your figure, and the citizens of other cities also hope that you can be with them." She said softly, "Roland, I am already very satisfied to hear you tell me stories like this."
Roland was silent for a moment, "You're right, but no matter where I am in the future, you will be able to hear the stories I tell... I can guarantee that."
Anna blinked, as if she understood the meaning of his words, "Not relying on the Listening Magic Spell?"
"That's right," he nodded.
If even the sweet talk between the two of them had to be conveyed through the Listening Magic Spell, how could one bring themselves to say it?
"How to do it?"
"You'll know tomorrow," Roland turned over and pinned Anna under him, then kissed her neck... and then slid from her neck all the way to her collarbone, leaving a shallow mark on her fair and taut skin, "But now, it's my turn."
The two joined together again, and the sweet gasps of breath echoed and reverberated for a long time.
...
The next day after breakfast, Roland, full of energy, walked into the backyard of the North Slope Mountain with Anna.
"Good morning, Your Majesty." Lucia had arrived even earlier. She put down her work and bowed to him.
"Good morning, King! Good morning, Sister Anna! Good morning, Sister Nightingale!" Ling also imitated her sister's manner and shouted cheerfully, bending over.
Roland waved his hand with a smile, indicating that the two did not need to be so polite, and then walked to the workbench, took out a piece of white paper, and began to draw a design. He planned to take advantage of the time before the Taqila survivors migrated to the Western Territory to fulfill the promise he made last night—a communication tool that could communicate with Anna at any time without magic power.
That would be a wired telephone.
The principle of the telephone is very simple, it is just the most basic application of the electromagnetic induction phenomenon: sound waves cause the metal reed in the microphone to vibrate, which causes the magnetic flux to change in the magnetic field, and finally produces an induced current that varies in size. The earpiece, on the other hand, uses an electromagnetic coil to generate a magnetic force that varies in size, causing the diaphragm to vibrate and restoring the current to sound.
In other words, it is not essentially different from generators and motors, except that the latter converts vibration into rotation, and the power is much greater.
When he explained his ideas and design scheme, Anna immediately understood how this unprecedented communication tool worked.
"I'll call Mystery Moon and Soroya over!" Her eyes shone.
"Current... exchanged with sound?" Nightingale still looked blank after listening. She looked at Lucia, as if trying to find a sense of agreement, but found that the latter was lost in thought.
"Electricity and magnetism generate each other, and magnetism is then converted into force... I see."
Even the little girl Ling echoed, "Sister, are you talking about the content in Chapter Two of the book 'Elementary Physics'?"
Nightingale was immediately hit, picked up a piece of dried fish with heartache, and turned to escape into the mist.
Watching this scene, Roland couldn't help but laugh. That being said, it is not so simple to obtain a telephone with practical functions. The problem lies in signal transmission.
Electrical signals will attenuate.
This is also why the telephone was not put into large-scale use for a long time after it was first developed—once the distance was too long, it was difficult to hear clearly what the other side was saying. It was not until people invented electron tubes that could amplify electrical signals that it quickly became popular.
The electrical part is not Roland's forte. The books he wrote at the beginning hardly touched on this aspect. Now, even with the help of the dream world, he finds that manufacturing electron tubes is still a rather troublesome thing.
Since he doesn't plan to amplify the signal, he can only start by reducing attenuation.
For example, increasing the size of the wire and reducing route loss.
The former is very simple to achieve. Anna's black fire can accurately process the required copper wires. According to the memory data, using a wire with a diameter of four millimeters can maintain about fifty or sixty kilometers of non-relay communication, while ordinary telephone lines are only 0.4 to 0.6 millimeters. This is certainly a bit wasteful, but it can effectively avoid the trouble of signal amplifiers.
The latter can use coaxial cables to achieve the purpose—the so-called coaxial cable is to wrap another layer of metal around the outside of the wire, and separate the two with insulating material, so that the metal becomes a Faraday cage, which minimizes the divergence of the electrical signal. At the beginning of the popularization of telephones, the technology of wrapping metal layers was not yet mature, so at that time, loading coils were used, which were to put a spirally wound coil jacket around the wire to reduce signal loss. However, for Roland, there is naturally no need to follow this rule anymore. With Anna's processing ability and Soroya's special coating, he can completely make it one step at a time.