Chapter 11 Chapter 8 Controversy-2

Admittedly, isolating even such a small amount of uranium-235 is very difficult.The United States used 15,000 people and invested more than 2 billion US dollars to complete the entire Manhattan Project.In Germany, there are only more than 100 people engaged in this matter, and the total funds are only about one million marks. This is a joke.But this is not the point. The point is, does Heisenberg know the exact number?If he did have a notion of exact numbers, it would be difficult for Germany, but at least it would not be so unattainable and insurmountable.The British were equally difficult, but they knew the exact critical mass figures, so they still launched the atomic bomb program.

Heisenberg argued that he was well aware of this, citing numerous evidence that he did know the exact figure before meeting with Speer.It's a pity that his evidence is all vague and uncertain.German reports do say that a bomb may have required 10-100 kg, and Heisenberg also described a bomb the size of a "pineapple", which is seen by many as proof.However, these all refer to plutonium bombs, not uranium-235 bombs.These figures are not proved, but guesswork, Germany simply does not have reactors to produce plutonium in large quantities.German scientists have often expressed the impression that at least several tons of uranium-235 are needed for uranium bombs.

But of course, you can also understand it from the opposite side. Heisenberg deliberately concealed the number, and only God knows it.He has single-handedly created an exaggerated falsehood. As for the reactor, graphite can also be used as a good moderator, and Americans use graphite.But at that time, Heisenberg commissioned Porter to do experiments, and his results were several times wrong, showing that graphite was not suitable for use in reactors, so the Germans had to hang themselves on the tree of heavy water.This is another unsolved case, and Heisenberg blamed Porter, saying that the graphite he used was impure, which led to the failure of the entire plan.Porter is a very famous experimental physicist, and later won the Nobel Prize, how can he take this blame.He wrote to Heisenberg, implying that the graphite was pure, and it fit the theory!If the experiment is wrong, it is better to say that the theory is wrong, and Heisenberg is responsible for the theory.In the initial statement, Heisenberg was forced to withdraw the accusation against Porter, but in the following years, he, Weizack, Woz and others continued to bring Porter in to take the blame.It now appears that the Germans were wrong both theoretically and experimentally.

The debate on this koan gradually heated up, and the most influential works include: Robert Jungk's "Brighter Than a Thousand Suns" (Brighter Than a Thousand Suns, 1956), which praised the noble German scientist's Morality, not forgetting human morality during wartime, although insight into the mysteries of the atomic bomb, but did not open this Pandora's box. In 1967, David Irving published The German Atomic Bomb (The German Atomic Bomb). At this time, the German secret weapons report had already been seen, which brought a wealth of information to the work. Although Irving does not think that German scientists have such noble morals as they boast, he still believes that the Germans knew the atomic bomb technology back then.Then there was Margaret Gowing's History of Britain's Nuclear Program, which proved that the Germans were so wrong about some basic issues, much to the chagrin of Heisenberg himself.He said: "(This book) is completely wrong, every sentence is wrong, it is complete nonsense." He then published the famous autobiography "Physics and Beyond" (Physics and Beyond), naturally once again Emphasizes the moral and scientific level of the Germans.All the people who had something to do with this matter all made comments one after another, with different opinions, like a lawsuit, and no one could convince the other party.

In 1989, when Yang Zhenning gave a speech at Shanghai Jiaotong University, he also said: "...a good biography of Heisenberg has not been written yet, and the existing biographies are vague about this matter... This is a very complicated history. I am sure that in the future someone will write an important biography of Heisenberg." Fortunately, from then until today, things have finally changed as expected, and there have been fundamental changes. Four Einstein did not attend the 7th Solvay Conference in 1933. He was forced to leave his hometown by Nazi Germany and wandered in a foreign country, thinking melancholy about the tragic future of Europe.On the other hand, the topic of this Solvay conference has long been replaced by another exciting topic: the explosive development of atomic physics, instead of quantum theory itself.However, the achievements in this field are of course also achieved on the basis of quantum theory, and the basic form of quantum mechanics has been determined and has become the basis of physics.It seems that the dust has settled, and few people doubt its power and correctness anymore.

In the midst of people's optimism, a few people such as Einstein and Schrödinger seemed more and more lonely.Schrödinger and de Broglie attended the Solvay Conference in 1933, but neither made a speech, perhaps because they were not familiar with this field.New and new humans are excitedly discussing the creation and annihilation of matter, positrons, heavy water, neutrons... so many new discoveries make people dazzled, and they are simply too busy.And what else can Einstein and the others do now?Are their ideas really so outdated that they can't keep up with the flying pace of the new age?

On September 25, 1933, Ehrenfest shot and killed his mentally handicapped son in Leiden, the Netherlands, before committing suicide.He said in a letter to Einstein, Bohr and other friends: "In recent years, it has become more and more difficult for me to understand the rapid development of physics. I tried hard, but it was more desperate and heartbreaking. I finally decided to give up. EVERYTHING. My life is terribly tiresome... I feel guilty that I live just to support my children. I've tried other things with little success, so I'm thinking about suicide more and more All the details, other than that, I have no other way to go...forgive me."

In Einstein's view, the tragedy of Ehrenfest is undoubtedly the tragedy of an era.The ideas of two generations of physicists clashed and collided violently, in a world that was turned upside down and in turmoil, bringing intense pain to the whole physics.Although Ehrenfest supports Bohr intellectually, when a culture declines, those who once felt it must feel intense pain.The bleakness of the old golden age has been replaced by new trends of thought that have sprung up like mushrooms after rain. From quantum to quantum field theory, various new particles in atoms emerge in endlessly, and weird concepts rule the whole world.When did Einstein not have such indescribably great sadness in his heart as Ehrenfest?Einstein stood far away and alone on the other side of the gap, watching the young people marching into the distance without hesitation, everyone told him that he was standing in the wrong place.This feeling is so strange, it seems that the world seems hazy and unreal.No wonder some people once sighed that they would rather die a few years earlier than see such an unacceptable picture of modern physics.However, Einstein still did not fall down. Although he was in a foreign land, his second wife was seriously ill and would soon part with him, but none of this could make Einstein give up the strong belief in his heart. An obsessive belief in the firmness of causality, in a harmonious order in the universe.Einstein still chose to fight, and his figure stretched so long under the setting sun, as if he was a brave old soldier making his last tragic struggle for a lost kingdom.

This time he won two allies, they are his two colleagues Podolsky (Boris Podolsky) and Rosen (Nathan Rosen). In March 1935, the three jointly published in "Physical Review" (Physics Review) Review) published a paper called "Is Quantum Mechanics' Description of Physical Reality Complete?" , once again attacking the foundations of quantum theory.Of course they changed their tactics, no longer saying that quantum theory is self-contradictory, or wrong, but instead saying that it is "incomplete".Specifically, the trio argue that quantum theory's interpretation of observations and wave functions is wrong.

We describe their main argument with a slightly simplified experiment.We already know that quantum theory holds that the state of a particle is uncertain before we observe it, and its wave function is diffused to represent its probability.But when we detect, the wave function collapses, and the particle randomly takes a certain value and appears in front of us. Now let's imagine a large particle, which is unstable, and will soon decay into two smaller particles, flying off in two opposite directions.We assume that this particle has two possible spins, called "left" and "right", then if the spin of particle A is "left", the spin of particle B must be "right", so as to maintain the overall Conservation, and vice versa.

Well, now the big particle splits, and the two small particles fly out relative to each other.But remember that until we observe any of them, their states are indeterminate, and there is only one wave function that can describe them.As long as we do not detect, the spin of each particle is in a mixed state of left/right possibility superposition. For convenience, we assume that the two probabilities are divided in half, each 50%. Now we observe particle A, so its wave function collapses instantly, and a state is randomly selected, for example, "left" rotation.But because we know that the two particles should be conserved as a whole, then particle B must be "right" spin now.The problem is, before this, particle A and particle B may have been separated by a very long distance, say tens of thousands of light years.How can they communicate with each other in time, so that the moment particle A collapses to the left, particle B resolutely collapses to the right? The probability explanation of quantum theory tells us that particle A chooses "left", which is a completely random decision, and the two particles have not discussed in advance, saying that particle A will definitely choose left.In fact, this choice is made at the moment it is observed, without warning.The key point is that when A makes a random choice, B, which is far away in the sky, must make a corresponding collapse according to its decision, and become a different state from A in order to maintain the overall conservation.So, how did B learn of this distant information?Could there be a signal traveling back and forth between them faster than the speed of light? Suppose there are two observers waiting at opposite ends of the universe. At a certain time t, they observe at the same time.One observes A, and the other observes B at the same time. Then, will the two particles make a hasty choice because the distance is too far to match the aperture for a while, for example, two become "left" at the same time, Or "right"?Obviously it is impossible, otherwise it will violate the law of conservation, so what makes them maintain a tacit understanding, when you are "left", I must be "right"? Einstein and others believe that since it is impossible to propagate signals exceeding the speed of light, it is obviously difficult to justify particles A and B as "uncertain ghosts" before observation.The only possibility is that the state of the two particles has been determined from the moment of separation, and people's observations later only get the information of this state, just like the one depicted in the classical world.The idea that particles become real when they are observed clearly violates the principles of relativity, which involves instantaneously propagating signals.This challenge is named after the initials of the three initiators, and it is called "EPR paradox". Bohr was taken aback when he got the news, and he immediately put down his other work to concentrate on Einstein's challenge.This new formation, practiced with great concentration, looks menacing, majestic and impressive, but Bohr can be regarded as Einstein's old opponent.After he fell asleep, he immediately discovered the flaw in it. It turned out that this seemingly dazzling attack was a complete false move without real power.Bohr couldn't help singing a ditty triumphantly, making fun of Podolski. It turned out that Einstein and Bohr had no common ground at all.In Einstein's subconscious mind, there has always been a classic image of "reality".He self-evidently assumed that the two particles in the EPR experiment had an "objective" spin state before observation, even if it was a mixture of probabilities, but the particles existed there objectively.But what Bohr meant was that before the observation, there is no "spin" of any particle!At that time, the spin particle does not exist, and it is not a part of the objective reality. This cannot be expressed by the classical language, and only the wave function can describe it.So until observation, two particles - no matter how far apart - are still an interconnected whole!They still have to be regarded as a whole when the parent particle is split, and before observation, these two independent particles do not exist, let alone the objective spin state! This is a sharp conflict between Einstein and Bohr's thought foundation. Bohr believed that when there is no observation, there is no objective and independent world.The so-called "reality" is meaningful only in connection with the means of observation.Before observation, there are no "two particles", but only "one particle". Until we observe A or B, the two particles become real and become objective and independent existence.But until then, they remain an interconnected nothingness.There is no superluminal signal, and the two distant particles appear in the universe at the same time only when they are observed. They are originally a harmonious whole, and there is no need to transmit any signal between them.In fact, this system has no reality, not no locality. In fact, the EPR paradox is not a paradox at all. It shows at most that quantum theory is incomplete in the view of "classical reality view", which is simply nonsense.But in the view of Bohr's "quantum reality view", it is very complete and logically self-consistent. If there is love, how can there be glass?The debate of the century between the two came to an end.The difference on the basis of philosophy made the differences of opinion between the two people unable to reconcile until the end.Until his death, Bohr failed to convince Einstein that the explanation of quantum theory was complete.And Bohr himself has been fighting against Einstein's ideas. The day after his death in 1962, people still found sketches of Einstein's light box experiments on his blackboard.Both giants of science have fought for their beliefs all their lives, but other scientists have paid little attention to this dispute.Under the guidance of quantum theory, science appears to be so vigorous, and its various branches develop at a rocket-like speed, bringing a great technological revolution to human society.From semiconductors to nuclear energy, from lasers to electron microscopes, from integrated circuits to molecular biology, quantum theory has spread its brilliance to every corner of human society and has become the most successful physical theory in history.Many people think that arguing whether quantum theory is right or not is simply too ridiculous. Just turn your head, look at everything that is happening around you, and see the ever-changing society. Everything you see is the best proof of quantum theory. If there's one thing that's great about EPR, it's that it's different from other whimsy.As long as it is slightly modified, EPR can be tested by practice!We will talk about how the debate between Einstein and Bohr was decided by practice in the laboratory in the future. The concept of classic reality has nothing to do with it, leaving only a desolate back and a deep sigh. But quantum theory still haunts us.Its inner meaning is so confusing that there are still different opinions on its interpretation.The achievements of quantum theory are undoubted, but people have been unable to confirm its true face, and this debate continues to this day.It will bring into physics some concepts that have terrified physicists, and it will take a breath away to think about it.And there is Schrödinger in the opposition, who wants to release a terrible monster to bite people's reason and nerves. This is the "Schrödinger's cat" that has turned many people's faces. *********** Gossip after dinner: Heisenberg and the German atomic bomb program (4) Heisenberg himself died in 1976.Two years after his death, the British Jones published the book "Most Secret War: British Scientific Intelligence" (Most Secret War: British Scientific intelligence), which analyzed in detail the horrific crimes Heisenberg committed in calculations. Shocking error.But his analysis was not accepted by Mark Walker. In the detailed "German National Socialism and the Quest for Nubclear Power" (German National Socialism and the Quest for Nubclear Power, published in 1989), Walker still believed that Heisenberg In 1942 was clear headed and knew the correct facts. In 1992, David Cassidy of Hofstra University published the famous Heisenberg biography "Uncertainty: A Biography of Heisenberg", which is still considered the standard biography of Heisenberg.He analyzed the whole matter, and finally stood on the standpoint of Goldschmidt and others, thinking that Heisenberg did not have any subjective desire to "destroy" an atomic bomb program, and he did miscalculate back then. But soon in 1993, the dramatic situation happened again. Thomas Powers wrote the magnum opus Heisenberg's War. Powers is a journalist by training and knows how to make his work readable.Therefore, although this thick book has 607 pages, the writing is ingenious and fascinating to read, and it quickly became a bestseller. Powers said convincingly that Heisenberg not only "passively" treated the atomic bomb program, but also "actively" undermined the successful implementation of the program.He vividly described scenes of conspiracies, spies, and plans to people. Later, some people teased that the first half of the book was simply a spy novel.In any case, this book had a great response among the public, and the image of Heisenberg as a noble, witty and righteous scientist was also deeply rooted in the hearts of the people, which directly influenced the later drama "Copenhagen".It can be seen from what has been described above that almost uniquely in the annals of science has the number of extreme differences of opinion which have arisen in a few short years. In 1992, a very important historical material was disclosed, that is, Heisenberg and the others were imprisoned in the Farm Transcript of Hall's wiretapped recordings.This stuff has been kept secret for a long time, and can only be seen in the writings of a few well-informed people. The 1992 declassification of the document, known as the Farm Hall Transcript, published by the University of California, Berkeley, caused a stir. Powers used this new material to write his book. The book "Heisenberg's War" was read by British journalist and playwright Michael Frayn, who was deeply attracted by it and couldn't help but come up with an ingenious play idea.At the heart of the "Heisenberg Mystery", there is a very mysterious and long-disputed scene, that is, his visit to Bohr in 1941.At that time, Denmark had been occupied by Germany, and the Nazi offensive across Europe was in full swing.Heisenberg realized the possibility of making an atomic bomb at that time, and he and Weizak rushed to Copenhagen to meet Bohr, his teacher, under the guise of an academic conference.The purpose of this meeting and the content of the conversation have always been unknown, and Bohr himself kept a secret about it and never talked about it.The only thing that is certain is that the two had a very unpleasant quarrel at the time. The relationship between Bohr and Heisenberg was originally like father and son, but after this meeting, the friendship for many years was broken, and only superficial politeness remained.What happened? Some say that Heisenberg went to warn Bohr to draw his attention to German plans.Some say that Heisenberg went to try to bring Bohr into their plans.It was said that Heisenberg wanted to hear how the Allies were doing on this front.Some people say that Heisenberg felt guilty and wanted to ask Bohr, the "pope", for forgiveness... Michael Frayn was fascinated by Powers' statement that Heisenberg went to Copenhagen to ask Bohr to verify the progress of the Allied forces in this regard, and tried to reach an agreement that the two sides would "destroy" this terrible plan together.That is to say, scientists from either side should not actively invest in the field of the atomic bomb, so that everyone can be evened out and mankind can be saved.This is almost a dramatic scene that can be encountered but not sought after. Various complex environments and inner conflicts are intertwined, entangled with thousands of complexes, and form a wonderful climax.On the one hand, Heisenberg had strong patriotic enthusiasm and obedience, and he could not refuse the order to serve Germany.But Heisenberg struggled with the sense of responsibility of human beings and felt the moral feelings of scientists.Moreover, he was so afraid that the Allied forces would also create an atomic bomb, which would scar the motherland forever.Heisenberg faced Bohr, the great teacher Bohr, the Bohr he regarded as his father, the Bohr who once led the dreamy Copenhagen School, but also the "enemy" Bohr, the Bohr who regarded Germany as his enemy. Er, but it also teaches people how to speak and how to choose words... Memories of youth, physical thinking, respected teachers, real politics, feelings of the motherland, human moral responsibilities, war years... What will happen when these things come together? language and thoughts?Is there a more outstanding theatrical subject than this? The first act of "Copenhagen" has this line for Heisenberg: "Bohr, I must know (the Allied plans)! I am the one who can make the final decision! What choice am I making for my country if the Allies are also making bombs?  … If one thinks that if The motherland did wrong, he should not love her, that is wrong. Germany is the place where I was born and raised, where I grew up, she is the faces of my childhood, and it is the place where I fall The big hands I raised are the voices that summon up my courage to support me to move forward, and the souls that talk directly to my heart. Germany is my widowed mother and difficult brother, Germany is my wife, is My child, I must know what I am deciding for her! Another failure? Another nightmare, like the one I grew up with? Bohr, my childhood in Munich ended in In anarchy and civil war, are our children going to starve again, as we did? Are they going to be like me, crawling through enemy lines on hands and feet on cold winter nights, in the dark Crawling under cover in the snow just to get some food for the family? Are they going to be like when I was 17 years old, watching the terrified prisoners all night, talking to them non-stop all night because they woke up early in the morning? About to be executed?" Such a cruel dilemma caused a huge emotional impact on the audience and showed the entire complex human nature.The essence of drama is a series of conflicts. Such a wonderful theme is destined to be a great drama.But historically speaking, such a beautiful picture is not reliable. Michael Frayn later said that he thought Powers made sense, at least he had information that people didn't have before, that is, the Farm Hall Transcript, but unfortunately his bet seemed to be wrong. Fives Even without Einstein, quantum theory is not much easier.The difficult problem of measurement has always plagued most physicists, but they are usually happy not to think about it.No matter how weird it is, the sun still rises every day, doesn't it?There are still league games at the weekend, and that football is still rock solid.Your wages don't get fantastic increases because of uncertainty.There is still no chance of getting credits for a blank exam.You turned into a probability wave and went straight through the wall and walked outside the house. How to say, it is not completely impossible, but the chances are so low that you counted the sands of the Ganges River, reincarnated for billions of lives, and the universe entered After being destroyed and then nirvana countless times, it is still rare to see such a scene. That's right, the electron is a ghost and let it be.As long as the world we see every day is real, this will not add too much trouble to the optimistic world.But Schrödinger didn't think so. If the world is based on ghosts, who says the world itself is not a ghost?Don't try to escape his eyes by the deceitful tricks played by quantum theory. When EPR was introduced, Schrödinger was very happy and praised Einstein for "grasping the small pigtail of quantum theory." Inspired by this, he also published a paper in 1935 entitled "The Status Quo of Quantum Mechanics" (Die gegenwartige Situation in der Quantenmechanik), the tone of the text is very ironic.All in all, it is at odds with the Copenhagen faction. In Section 5 of the paper, Schrödinger describes the cat experiment that is often regarded as a nightmare.Well, the Copenhagen School said that before the measurement, the state of a particle is indistinct, and it is in the mixed superposition of various possibilities, right?Like a radioactive atom, when it decays is completely probabilistic.As long as there is no observation, it is in the superposition state of decay/non-decay, and only when it is really measured, it will randomly choose a state to appear. Great, so let's put this atom in an opaque box to keep it in this superposition.Now Schrödinger imagined an ingenious contraption that every time an atom decays and emits a neutron, it sets off a chain reaction that ends in breaking a poison gas bottle inside a box, while inside the box there is also a poor s cat.The thing is obvious: if the atom decays, the gas cylinder is broken and the cat is poisoned.If the atoms didn't decay, the cat would be fine. Natural corollary: when they're all locked in the box, since we're not observing, that atom is in a decay/non-decay superposition.Because the state of the atom is indeterminate, the state of the cat is indeterminate, and only when we open the box and look at it can the final conclusion: either the cat is lying dead in the box on all fours, or it is alive and kicking "meow" .The question is, what was the cat in before we opened the box?The only thing that seemed possible was that it was in a superposition like our atoms, and the cat was stuck in a dead/alive mix. Now it's not just a question of whether atoms are ghosts or not, now cats are ghosts too.Is a cat dead and alive at the same time?Is it in a superposition state of immortality?This conflicts too much with common sense, and it is also a strange theory from a biological point of view.If a live cat comes out of the box, if it can talk, will it describe the strange feeling of dead/alive superposition?I'm afraid it's unlikely. Schrödinger's experiment magnified quantum effects to our daily world, and now the strange properties of quantum are involved in our daily life, involving the question of whether our beloved pet cat is dead or alive.Although this experiment is simple, it is much more spicy than EPR. This time, the Copenhagen pie is painful enough.They had to take a step back to swallow the bitter drink: yes, the cat was alive and dead when we weren't watching. Not only cats, but everything, when we don't observe, is in an uncertain superposition state, because everything in the world is also composed of atoms that obey the uncertainty principle, so everything is inevitable.The quantum school later had a widely circulated argument: "When we don't observe, the moon does not exist."This is slightly off the point, precisely because the moon is also made of indeterminate particles, so if we turn our heads away from the moon, that mass of particles starts to spread out according to the wave function.Thus, the edge of the moon began to appear blurred and uncertain, and it gradually "melted" and became a probability wave that diffused into the surrounding space.Of course, the probability that such a large moon will completely melt into space will take a long, long time, but the essence of the problem is: if the moon is not observed, it will change from a definite state to countless uncertain superpositions.A definite, objective moon doesn't exist when you don't observe it.But as soon as he looked back, a round of bright moon hung high in the sky again, as if nothing had happened. It has to be admitted that this sounds very subjective and idealistic.Although it is actually somewhat different from the philosophical theory we usually understand, when it comes to this, many people will probably naturally think of the famous saying of Bishop Berkeley (George Berkeley): "To be is to be perceived" (Latin: Esse Est Percipi).If this sentence is slightly changed to "to be is to be measured", it will be indistinguishable from the meaning of the Copenhagen School.Berkeley's position in the history of philosophy is undoubtedly important, but people are usually happy to criticize him. Has our Copenhagen School gone further than him?Anyway, Berkeley also believed that things exist continuously and objectively, because there is always a "God" who is constantly watching everything.And quantum theory? "Your Majesty, I don't need the hypothesis of God". The representative of the East that complements Berkeley is probably Wang Yangming.He also said a famous saying in "Biography of Xilu? Part II": "When you haven't seen this flower, this flower will die with you; when you look at this flower, the color of this flower will suddenly become clear..." , he would probably say: "When you did not observe this flower, this flower did not really exist, and died according to the wave function; when you came to observe this flower, the wave function of this flower collapsed, and its color suddenly became a clear reality... ..."Measurement is reason, and there is no reason outside of measurement. Of course, we do not intend to turn this historical story into a purely boring philosophical discussion. Experience often shows that such empty arguments will eventually become meaningless and drowsy.Let's go back to the specific question. When we don't observe the situation in the box, is the cat really "alive and dead"? This is indeed an embarrassing and unimaginable question.Hawking once said: "When I heard about Schrödinger's cat, I ran to get a gun." Schrödinger himself described it in his paper as a "demonic device" (diabolische, English diabolical, people who play Diablo probably better understand what it means).We have already seen the amazing and even jaw-dropping weird properties of quantum theory, but that is only in the microscopic world that we are not familiar with or have much interest in understanding, but now it suddenly starts to affect everything around us?One might accept the fact that electrons are in superposition, but anyone would feel a little daunted when talking about macroscopic things like our cats being in some kind of "superposition".However, we now know a lot about this problem, especially in the past ten years, there have been many excellent experiments to confirm some of its strange properties.But let's follow the pace of our history and explore this interesting topic step by step, let's start with the Copenhagen interpretation. Cats in dead/alive superposition?People can't accept this, and the most critical point is that experience tells us that this strange dual state seems unlikely to be felt by a macroscopic creature, such as a cat or ourselves.Again: if a cat could talk, would it describe this sense of duality?If it survives, does it say, "Yeah, I became a probability wave and I felt like I was filling space, half dead and half alive. That's pretty blissful It feels like you want to try it too?" I'm afraid no one will believe it. Well, let's take a step back, cats can't talk, then we put a talking person into the box.Of course, this sounds a bit cruel, like a Nazi gas concentration camp, but we are only doing it in our imagination.Had this man survived, would he have said that?Obviously not, he must have declared extremely firmly that he lived a good life from the beginning to the end, and there was no such thing as a half-life or half-death state.However, this time is different, because he himself is already an observer!He keeps observing his own state in the box, thus constantly triggering the collapse of his own wave function, we put an observer into the box! But, curiously, why can't we say the same about cats?The cat is also constantly observing itself.What is the difference between cats and people?Is the difference just that one can come out and angrily refute the argument of quantum theory, and the other can only "meow"?To our surprise, this may indeed be the crucial difference!People can feel their own survival, but cats cannot. In other words, people have the ability to "measure" whether they are alive or not, but cats cannot!Humans have one thing that cats do not have, that is "consciousness"!Therefore, the human can measure its own wave function to make it collapse, but the cat can’t do anything, and can only stay in the wave function of the dead/alive superposition and let it develop. consciousness!It is unimaginable that this word appears in physics.Wouldn't it be dizzying if it came from a Nobel Prize winner in physics?Could it be that the world has really changed? 半死半活的“薛定谔的猫”是科学史上著名的怪异形象之一，和它同列名人堂的也许还有芝诺的那只永远追不上的乌龟，拉普拉斯的那位无所不知从而预言一切的老智者，麦克斯韦的那个机智地控制出入口，以致快慢分子逐渐分离，系统熵为之倒流的妖精，被相对论搞得头昏脑涨，分不清谁是哥哥谁是弟弟的那对双生子，等等等等。薛定谔的猫在大众中也十分受欢迎，常常出现在剧本，漫画和音乐中，虽然比不上同胞Garfield或者Tom，也算是有点人气。有意思的是，它常常和“巴甫洛夫的狗”作为搭档一唱一和出现。它最长脸的一次大概是被“恐惧之泪”(Tears for Fears)，这个在80年代红极一时的乐队作为一首歌的标题演唱，虽然歌词是“薛定谔的猫死在了这个世界”。 *********** 饭后闲话：海森堡和德国原子弹计划（五） 《哥本哈根》一剧于1998年5月21日于伦敦皇家剧院首演，随后进军法国和百老汇，引起轰动，囊括了包括英国标准晚报奖（Evening Standard），法国莫里哀戏剧奖和美国东尼奖等一系列殊荣。剧本描写玻尔和夫人玛格丽特，还有海森堡三人在死后重聚在某个时空，不断地回首前尘往世，追寻1941年会面的前因后果。时空维度的错乱，从各个角度对前生的探寻，简洁却富予深意的对话，平淡到极点的布景，把气氛塑造得迷离惝恍，如梦如幻，从戏剧角度说极其出色，得到好评如潮。后来PBS又把它改编成电视剧播出，获得的成功是巨大的。 但Thomas Powers《海森堡的战争》一书的命运却大相径庭。甚至早在《哥》剧大红大紫之前，它便开始被许多历史学家所批评，一时间在各种学术期刊上几乎成为众矢之的。因为对Farm Hall Transcript稍加深入的研究很快就表明事实完全和Powers说的不一样。海森堡的主要传记作者Cassidy在为Nature杂志写的书评里说：“……该作者在研究中过于肤浅，对材料的处理又过于带有偏见，以致于他的精心论证一点也不令人信服。（Nature V363）”而Science杂志的评论则说：“这本书，就像铀的临界质量一样，需要特别小心地对待。（Science V259）”纽约大学的Paul Forman在《美国历史评论》杂志上说：“（这本书）更适合做一本小说，而不是学术著作。”他统计说在英美的评论者中，大约3/5的人完全不相信Powers的话，1/5的人认为他不那么具有说服力，只有1/5倾向于赞同他的说法。 而在1998年出版的《海森堡与纳粹原子弹计划》一书中，历史学家Paul Rose大约是过于义愤填膺，用了许多在学者中少见的尖刻词语来评价Powers的这本书，诸如“彻头彻尾虚假的（entirely bogus）”、'幻想（fantasy）”、“学术上的灾难（scholarly disaster）”、“臃肿的（elephantine）”……等等。 OK，不管人们怎么说，我们还是回过头来看看海森堡宣称的一切。首先非常明显可以感受到的就是他对于德国物理学的一种极其的自负，这种态度是如此明显，以致后来一位德国教授评论时都说：“我真不敢相信他们竟能有如此傲慢的态度。”海森堡大约是死也不肯承认德国人在理论上“技不如人”的了，他说直到1942年双方的进展还“基本相当”，这本身就很奇怪。盟国方面在1942年已经对原子弹的制造有了非常清楚的概念，他们明确地知道正确的临界质量参数，他们已经做了大量的实验得到了充分的相关数据。到了1942年12月，费米已经在芝加哥大学的网球场房里建成了世界上第一个可控反应堆，而德国直到战争结束也只在这方面得到了有限的进展。一旦万事具备，曼哈顿计划启动，在盟国方面整个工程就可以顺利地上马进行，而德国方面显然不具备这样的能力。 海森堡的这种骄傲心理是明显的，当然这不是什么坏事，但似乎能够使我们更好地揣摩他的心理。当广岛的消息传来，众人都陷入震惊。没心计的哈恩对海森堡说：“你只是一个二流人物，不如卷铺盖回家吧。”而且……前后说了两次。海森堡要是可以容忍“二流”，那也不是海森堡了。 早在1938年，海森堡因为不肯放弃教授所谓“犹太物理学”而被党卫军报纸称为“白犹太人”，他马上通过私人关系找到希姆莱要求澄清，甚至做好了离国的准备。海森堡对索末菲说：“你知道离开德国对我来说是痛苦的事情，不是万不得已我不会这样做。但是，我也没有兴趣在这里做一个二等公民。”海森堡对个人荣誉还是很看重的。 但是，一流的海森堡却在计算中犯了一个末流，甚至不入流的错误，直接导致了德国对临界质量的夸大估计。这个低级错误实在令人吃惊，至今无法理解为何如此，或许，一些偶然的事件真的能够改变历史吧?