1900: A physics genius wandering around Europe

Chapter 591: Experiment Upgraded! Delayed Choice Experiment! Changing the Past Now! Dragon Chart! Everyone is Shocked!
In the conference room.

The atmosphere was very lively.

Two consecutive stunning interference experiments strongly proved the correctness of Bruce's interpretation.

Quantum mechanics gets even trickier.

Bohr even boasted:
"Quantum mechanics is already a complete theory."

In other words, today's quantum mechanics is comparable to the theory of relativity!
The two pillars of modern physics were officially established!

Heisenberg, Pauli, Born and other "Lee supporters" all looked delighted.

As supporters of quantum mechanics, they are excited about this.

Schrödinger was a little frustrated.

With the ironclad experimental facts before his eyes, he didn't even have the courage to question them.

“Is the world really probabilistic and unknowable?”

Schrödinger suddenly wanted to change his mind.

He was shocked and overwhelmed by Professor Bruce's amazing wisdom.

However, he suddenly looked at Einstein and smiled bitterly in his heart.

"If I betray Professor Einstein, I will be sorry for all the support he has given me."

For a moment, Schrödinger entered the state of Schrödinger's cat.

However, Einstein was unaware of Schrödinger's psychological activities.

He whispered:
"Don't worry, even if the principle of complementarity is fine, I still have other tricks up my sleeve."

"Quantum mechanics hasn't been tested at all yet."

Einstein might have been having a bad temper.

He believed that the theory of relativity he and Bruce created together was the most perfect theory.

Quantum mechanics, as a pillar, must also be one level lower.

However, the complementarity principle and the double-slit experiment completely convinced him.

Einstein would not continue to dwell on it.

Although he has opinions on quantum mechanics, he would never question it just for the sake of questioning. That is the mentality of a shrew quarreling.

The best thing about science is that there are absolute right and wrong.

As long as both sides are reasonable, then sitting down for a debate will definitely determine a winner.

The core of science is "because so", not "although but".

Just as everyone had different thoughts and were communicating with each other.

The host Lorenz asked with a smile:

"Bruce, are you done with your speech?"

"I don't think there's any need to ask any more questions."

"You're the only person I've ever met who came up with a theory and verified it right on the spot."

Everyone was moved.

Professor Bruce is always different.

Li Qiwei smiled slightly when he heard this.

has it ended?

of course not!

He will continue to challenge the limits of human cognition!

There are three even more incredible upgraded versions of the single-electron double-slit interference experiment.

They are: delayed choice experiment, quantum erasure experiment, and delayed choice quantum erasure experiment.

In real history, at the 1979th anniversary of Einstein’s birth in , Einstein’s colleague Wheeler proposed the idea of ​​the delayed choice experiment.

Wheeler thought deeply about the single-electron double-slit interference experiment and believed that the electron's decision could be "delayed".

What does that mean.

That is, let the electron pass through the double slits first, and then choose whether to pass through one slit or two slits.

The idea instantly shocked the physics community!

Because everyone thought Wheeler was mentally ill.

The electron has already passed through the double slit, so how can it choose whether to pass through or not?
Can things that have happened in the past be changed now?
That’s the idea of ​​a delayed choice experiment!
It is even more bizarre and incomprehensible than the single-electron double-slit interference experiment.

Five years later, physicists at the University of Maryland actually completed Wheeler's thought experiment using a single photon.

And the results are chilling!

Even if the photon has passed through the double slit, as long as additional measurements are made, the photon will pass through the single slit again.

It is equivalent to the current choice changing the past results!

Horror!
The entire physics community was shocked!

However, although the results of this experiment are terrible, it still satisfies the Copenhagen interpretation.

A few years later, another physicist proposed the "quantum eraser experiment."

This experiment requires the properties of quantum entanglement, which is extremely complex and precise.

Simply put, the key to the collapse of wave functions into particles lies in the "construction of information acquisition paths."

In the quantum eraser experiment, the photons are first observed using an instrument to cause them to collapse and the interference fringes to disappear.

Then, special means are used to erase the "instrument observation process" without affecting the photons.

The interference fringes reappeared unexpectedly.

The core of this experiment is that for photons, no matter how far they travel, the time is the same.

For example, the distance between points AB is four light years.

A photon is emitted from A and reaches B.

From our human perspective, it takes the photon four years to complete the journey.

But from the photon's perspective, it goes from A to B in an instant.

More extreme, if you could attach thoughts to photons.

Then you will see that the moment the photon is born, the universe has been destroyed.

Time has no meaning to light.

Therefore, the quantum eraser experiment still does not overturn the explanation of quantum mechanics.

The delayed-choice quantum eraser experiment, a combination of the delayed-choice experiment and the quantum eraser experiment, also did not overturn the result.

(The quantum eraser experiment is too complicated, and there is no point in explaining it. Just let everyone know.)
These experiments, together with the single-electron double-slit interference experiment, strongly prove quantum mechanics!

Although the Copenhagen interpretation is unreasonable and incredible, there is currently no evidence to find any errors.

Therefore, it is still the absolute orthodoxy of quantum mechanics!
Unless some genius emerges in the future and creates a more reasonable explanation of the wave-particle duality.

At this moment, Li Qiwei was thinking about these things in his mind and had made plans.

The quantum erase experiment cannot be done for the time being because it involves the phenomenon of quantum entanglement, which has not yet been proposed.

The delayed choice experiment was fine.

Although in real history the experiment was conducted with single photons, and beam splitters and mirrors were used instead of double slits.

Ridgwell could have improved the single-electron experiment to meet the requirements of delayed selection.

So he said to the crowd:
"My speech was almost over."

"But just now, another possibility suddenly occurred to me."

"My single-electron double-slit interference experiment may be able to be upgraded!"

Wow!
Everyone was shocked!
"Oh my god! The experiment can be upgraded?"

"Professor Bruce is horrible!"

Lorenz was also shocked!
He suddenly felt that three days might not be enough.

Bruce alone would need a day.

However, Lorenz was even happier.

This meeting was destined to become a legend for generations to come.

Under everyone's expectation, Li Qiwei said:
"In the observer effect experiment just now, I placed the detector in front of the double slits to observe which slit the electron went through."

"But what if I put the detector behind the double slit?"

"What happens if I wait until the electron is about to approach the display and then observe the electron?"

Ok?
Everyone was stunned when they heard this.

They didn't understand what this passage meant.

Because it seems like nonsense.

Even Bohr, Heisenberg and others were confused.

They didn't realize what Professor Bruce was trying to do.

At this time, someone asked:
"Professor Bruce, I'm sorry I don't understand what you mean."

"Since the electron has already passed through the double slits, is there any point in observing it?" "Interference fringes will definitely appear on the display screen eventually."

"Because after the electron passes through the double slit, the superposition of probability waves has been completed, and the interference process has been completed."

Everyone nodded.

Li Qiwei smiled mysteriously and said:

"It seems like everyone has the same idea."

"It is believed that if the electron is observed after it passes through the slit, the interference behavior will not be affected."

"But will it really be so?"

“I don’t think so!”

"I think the interference fringes will disappear!"

Wow!
Everyone was shocked!

"Does that mean the interference fringes of electrons will disappear?"

"Doesn't that mean that the current actions change the results of the past?"

"How can this be?"

“This is too unbelievable!”

“I absolutely do not believe this will happen!”

There was a heated discussion in the meeting hall immediately.

If that were true, it would mean that:
After the electrons are emitted, they pass through the double slits at the same time and interference occurs.

At this time, when the electrons that have interfered are observed, they no longer interfere, become particles, and fall onto the display screen.

At first glance, it seems nothing.

But if you think about it carefully, this result shows that the electron only passed through one slit!
How can this be?

The electron clearly passed through two slits at the same time, but after observation, it turned out to have passed through only one slit.

The past has been changed!

At this moment, everyone was shocked!

This completely subverts the law of causality in the macroscopic world!
Bohr, Heisenberg and others looked excited.

They wondered if this phenomenon could be explained by the blues interpretation?

“It seems that it is not impossible.”

Li Qiwei didn't care about everyone's surprise and began to prepare for the experiment.

He moved the electronic detector between the double slits and the display screen and carefully adjusted the angle.

Make sure that the detector can capture the electron after it passes through the double slit and before it reaches the display screen.

Following a snapping sound.

The venue suddenly became quiet!
Everyone widened their eyes, held their breath, and stared at the instrument.

Could such an incredible phenomenon really happen?

drop!
Electrons begin to emit.

The detector's sensor light also lights up at the same time.

This shows that the electron not only passed through the double slit, but was also detected.

The experiment went smoothly.

Next, it’s time to look at what’s on the display.

If interference fringes appear, it proves that Professor Bruce is wrong and the law of causality cannot be violated.

But if there are no interference fringes, it proves that Professor Bruce is right and current choices really do change past outcomes.

Time passed by minute by minute.

Everyone knew that the results would not be clear until ten minutes later.

But they still did not look away, staring at the display screen.

They were even more nervous than when they first watched the single-electron double-slit experiment.

The idea of ​​this upgrade experiment is really too outrageous.

Drop~~~
It seemed as if a century had passed.

At Pauli's exclamation, all expressions froze in an instant!
"The interference fringes are gone!"

boom!
At this moment, the whole venue was in an uproar!

Some people even couldn't believe it and went to see the stripes on the display in person.

The result is unquestionable, no interference fringes!
Everyone is confused!

"impossible!"

"Absolutely impossible!"

"The electron has clearly passed through the double slit, so how can there be no interference?"

"There are only two bright stripes, indicating that the electron randomly passes through one of the slits each time."

"It's incredible!"

In the macroscopic world, it is like you clearly eat an apple, but because of observation, the apple in your stomach turns into a pear.

Is there anything more outrageous than this?
At this moment, everyone's eyes changed when they looked at Professor Bruce.

Is this man in front of me really a human?
Could it be God?
Apart from God, is there anyone else who can manipulate cause and effect in this way?
The whole audience was shocked!

Lorenz rubbed his eyes and murmured:

"Is it because my eyes are blurry?"

However, everything is reality.

He couldn't help but ask:

"Bruce, what is going on?"

"I believe this is absolutely science, not metaphysics?"

Li Qiwei heard this and said with a smile:
"Professor Lorenz, this is certainly science."

"The delayed choice experiment still satisfies the principles of quantum mechanics."

“Any fundamental quantum phenomenon is only a phenomenon after it has been recorded.”

"Whether the decision is made before or after the electron passes through the double slit makes no difference in a quantum experiment."

“History is not certain and real unless it is written down.”

"To be more precise, between the time the electron passes through the double slit and the time it is detected by the detector, where exactly the electron is and what it is is a meaningless question."

"We have no right to talk about it because it is not an objective truth!"

"In other words, the electron travels all the way to the detector before it is seen."

Li Qiwei played a pre-prepared picture on the projector.

"Everyone, please take a look."

Everyone immediately became curious about the photo.

There is a head on the left side of the photo and a tail on the right side, but the body in the middle is blocked by fog and its shape cannot be seen.

And that head looks weird.

The head is shaped like an ox's head, the horns are like deer horns, and the eyes are like rabbit's eyes.
No one had ever seen this creature.

“Does it really exist?”

At this time, Li Qiwei said with a smile:

"This creature is a mythical beast in our Chinese legend: the dragon."

“This picture is the dragon picture.”

“The delayed-choice experiment is like this dragon.”

"The dragon's head and tail are certain, but the dragon's body is in the mist, and no one can tell for sure."

"Only when we really observe will the dragon reveal its true form!"

Snapped!
A clear picture of a dragon suddenly appeared!

Snake neck, fish scales, eagle claws, tiger paws.
A majestic and domineering dragon, so lifelike, seems to be flying in the sky!
Everyone was shocked!

"So this is the Chinese dragon."

Professor Bruce's use of the dragon diagram to illustrate quantum mechanics is so apt.

At this moment, Bohr and others understood instantly.

The delayed choice experiment is not about the present changing the past, but about there being no past without observation!
Before the electron is detected by the detector, "passing through the double slit" is not a fact that occurs.

When everyone was amazed at the principle of the delay experiment,
Wu Youxun and Yu Yin suddenly felt a surge of passion and enthusiasm!
That is the mark of the dragon in the blood of the descendants of Yan and Huang being awakened!
At this moment, in their eyes, Professor Li seemed to have transformed into a divine dragon patrolling the heavens!

A dragon can be big or small, and can ascend to the sky or descend into the earth.

The big ones can change the situation dramatically, while the small ones hide in the shadows.

When it rises, it soars into the sky; when it hides, it hides in the abyss.

This is the true portrayal of Professor Li!
(End of this chapter)