Chapter 195: The Extraterrestrial Civilization Responded

"Why would they reply to us?"

"That's because our original intention in sending out signals was to explore alien civilizations."

"For us Earthlings, we are in the initial stages of technology, the phase of outward exploration—a state of huddling together for warmth."

The audience and experts in the livestream room all understood.

Humans are social creatures; when a technology hits a bottleneck, it is natural to need a pointer or two from someone else.

If no one on Earth can provide that guidance, then one can only look toward alien civilizations in extraterrestrial star systems.

If the other party has a technological level similar to Earth's, they would surely have a high degree of common ground in technology.

"And those civilizations that reply to us must also be in the initial stages of technology, in their own phase of outward exploration. It's equivalent to saying: [I need something from you, you need something from me; let's satisfy each other and progress together.]"

"But here comes the problem!"

"The transmission methods of alien technological civilizations that are on par with our Earth's are identical to ours!"

"Because the technological levels are equivalent, they cannot give an immediate reply after we send a signal—"

"Because signal transmission requires time, often taking one, two, three, or even decades or centuries for light to travel."

"What does that mean?"

"If a technological civilization discovers our signal and then replies, considering the vastness of the universe, there is a high probability we won't see it in our lifetime; it's likely that hundreds of years later, our descendants' descendants will receive those returned signals."

"Look at Earth's history of astronomical development. Our human extraterrestrial exploration only began in earnest during the 60s, 70s, and 80s of the last century, with the United States and the former Russia leading the space race."

"So far, astronomy has only progressed for forty or fifty years. A signal traveling for forty or fifty years has barely flown out of the Solar System to reach the Milky Way Galaxy."

"The Milky Way Galaxy is a hundred thousand light-years in diameter, which means our signal needs a hundred thousand years to completely leave the Milky Way. A hundred thousand years is a terrifying figure of time. If Earth's civilization had started 100,000 years ago and sent a signal then, that signal would only just be leaving the Milky Way today. By the time an alien civilization outside the Milky Way receives the signal and replies to us, it would take humans another 100,000 years to receive it."

"By then, we humans might not even be living on Earth intact; we could very likely have entered an apocalyptic period or be at our last gasp."

As he spoke to this point, Jiang Zhe's expression showed a hint of emotion.

"So!"

"Current signals haven't even traveled one ten-thousandth of the Milky Way yet, let alone reached those alien civilizations on par with our technological level."

"When they will receive our signal is still a big question, let alone being able to reply to us!"

As this series of explanations concluded, the audience and experts fell into deep thought.

They arrived at a keyword: [Time].

That's right, it's exactly time that's needed. It's not that aliens aren't replying, but that alien civilizations on par with our Earth's haven't received the signal at all!!!

If they haven't received the signal, how could they possibly reply to us?

...

Meanwhile, inside the lecture hall.

A group of astronomers nodded in agreement one after another.

"This is a very common and widely accepted explanation."

"Exactly. The speed of light is the reason that limits communication between most civilizations in the universe."

"If we could open a wormhole outside the Milky Way and send signals directly through it, then we would surely receive a reply quickly, but that's only in science fiction movies."

"..."

On the podium, Professor Hua Yunfeng pondered and asked back: "But if you think about it, what about advanced civilizations?"

"They would surely receive Earth's signals much faster, so why don't they reply either?"

He sent this question into the bullet chat, prompting more and more comments to surge out.

"Yeah, what about advanced civilizations? Why don't advanced civilizations reply to us?"

"Low-level civilizations can't receive our signals, and civilizations on par with ours need a long time to receive them. Advanced civilizations surely have outpost detection bases, right? Maybe they have [Liaison Officers] in different parts of the Milky Way, just like how the Great Wall's beacon fires were used to transmit military information in ancient times."

"Could it be that the signals of advanced civilizations also cannot exceed the speed of light? So they are just like civilizations on par with Earth; it takes time to send signals back and forth?"

"That's possible. Referring to the 1994 Jupiter distress signal and the signals transmitted to the Inner-Earth people, it's very likely that aliens have already made contact with the Inner-Earth people but haven't contacted us surface dwellers yet."

"Argh, there are so many unexplainable questions. If I don't get an explanation today, I won't be able to sleep."

"..."

Listening to the bullet chat broadcast from the backstage director, Jiang Zhe noticed that most people in the livestream were curious about why advanced civilizations weren't replying to the signals.

Jiang Zhe looked thoughtful, trying to give as satisfying an answer as possible.

"Let's summarize the three levels of civilization in the universe."

"Low-level civilizations are in a feudal society, which results in them being unable to receive signals."

"Mid-level civilizations, meaning those on par with our Earth, need a long time to receive and propagate signals."

"Advanced civilizations—their signal transmission methods might be faster than the speed of light; there is a high probability they use Quantum Communication."

"I'm not talking nonsense. In the last century, we humans discovered the 'Bible' of the microscopic world: Quantum Mechanics; that is, the mystery of the microscopic world."

"As advanced civilizations, they must have discovered the microscopic laws of nature long ago. Their name for Quantum Entanglement might be different, but the essence of how the microscopic world operates is the same."

"If advanced civilizations all adopt Quantum Communication, then it means—"

"We humans are currently not on the same communication frequency as advanced alien civilizations. That is a much more powerful level of communication."

Having reached this point in his explanation, Jiang Zhe thought for a moment and gave a detailed clarification: "What does that mean?"

"Quantum Communication uses quantum states for information transmission. Any measurement of a quantum state will change its state, which means that if an eavesdropper or observer tries to obtain the information source, they will be detected by both communicating parties."

"This characteristic gives Quantum Communication extremely high security, but it also makes direct detection of its signals difficult."

"Currently, we humans on Earth cannot directly detect Quantum Communication signals."

"This means that for us humans to use current methods to detect quantum signals in the vast and brilliant starry sky is like trying to scoop the moon out of the water—a futile effort."

These words were not difficult to understand.

They directly indicated that human technological levels are not yet sufficient.

Not sufficient to detect the transmission methods of advanced civilizations' signals, which are as mysterious and unpredictable as quanta.

Quantum signals exceed the speed of light, traditional signals approach the speed of light, and the traditional signals used by humans = the speed of light.

Traditional detection methods cannot detect quantum signals; even their boundaries are difficult to grasp.

Soon, the audience's eyes lit up.

"Wait, does this mean that communication signals are likely flying all over the street in the universe right now, but because Earth's level is limited, we simply can't observe them?"

"Exactly, that's it. Advanced civilizations must have adopted Quantum Communication, and there might even be communication methods even more impressive than Quantum Communication that we just haven't discovered yet."

"My god, that makes sense. To put it in three sentences: low-level civilizations have no communication signals; mid-level Earth-like civilizations have signals that don't exceed the speed of light—receiving them back and forth is time-consuming and laborious, and they can't be caught; Quantum Communication—Earth's civilization can't detect it; and as for communication methods stronger than Quantum Communication—Earth's civilization hasn't even touched the threshold!"

"Oh My God, the solution to the fermi paradox is very likely what this host is saying!"

"..."

Meanwhile, inside a dormitory building at Tsinghua University.

Professor Zhuang's eyes lit up as he offered his evaluation:

"In this way, Jiang Zhe's answer perfectly resolves the lack of signs of alien civilizations in the universe."

"It's not that there aren't any, but that the universe is too vast and communication methods are too varied. Only when the human technology tree grows further can we join that higher tier."

"It's like the concepts of 'Thousand-Mile Eyes'—telescopes and microscopes—and 'Wind-Following Ears'—phones and walkie-talkies—to ancient people."

"If humans are at the technological level of 2024, then low-level civilizations are at the level of 1024, civilizations on par with Earth are at 2024, and advanced civilizations surpassing Earth are at 20240."

"This kind of epoch-making technological gap that transcends time is clearly not something that current technical gaps can bridge."