It would be accurate to call me a skeptic. There’s no intention in me to use this blog to debunk the overwhelming quantity of crap floating around the internet, but sometimes, I just need to open my mouth. Such an inspiration hit me while reading Respectful Insolence. In that post, Orac is talking about a reddit thread where a woman with an entrenched antivaccine view tries to drum up support for her unyielding stance of not vaccinating her unborn child, despite the father’s desire to vaccinate. While I have done my time in microbiology and immunology courses, I am certainly not a leading expert in medicine. For a medical professional’s opinion of vaccination, you’re not about to find it here. I am unquestionably pro-vaccine, but my interest in the blog post appears about midway through. The woman is trying to bolster her bonafides by outlining her education.
I am still finishing it up but it is a bachelors in holistic health sciences from the International Quantum University of Integrative Medicine (iquim.org). They are a relatively young establishment so not well known, but many of the faculty members are leading experts in quantum physics and many other areas (the school’s focus is a new perspective on medicine as based on modern quantum physics findings). It’s so fascinating whether you are interested in natural medicine or physics or both!
The word driving my interest should be clear. It’s the only word with a ‘Q’ in that entire paragraph.
You can’t just throw that word anywhere and expect it to mean what it means in its natural context. From what she has said here, I find it highly unlikely that she’s ever touched a Hamiltonian or worked a probability.
In curiosity, I went to the Quantum University website just to see what the education there entails. Is there even the vaguest possibility that the graduates learn any real quantum mechanics? I ended up centering on a blog post there titled “Quantum Physics: A New Scientific Foundation for Integrative Medicine” in some hopes that they would boil their teaching philosophy down to a bite-sized snippet. I was looking for some sign of physics provenance that might be traced to something real in their philosophy and I found the following.
A leading quantum physicist, Amit Goswami, PhD., has already laid the foundation for this in his book, The Quantum Doctor, a physicist’s guide to health and healing.
Apparently they attribute their ‘quantum physics’ to a guy named Amit Goswami. It isn’t hard to noticed that everybody on this website wears a PhD or a Doctorate behind their name and you have to wonder where these degrees came from–I don’t yet have a PhD and I am in a physics graduate program. Going for a PhD in physics was the hardest thing I’ve done in my life and it has given me real gray hair. I looked for publications by Amit Goswami on Web of Science and hoped for a list of ‘Physical Review Letters’ citations. Did I find them? Nope. But, he does have a couple citations in an Integrative Medicine journal. I’m trying to decide how this guy can be a leading quantum physicist when he has apparently never published under his name in a physics journal. Poor antivax lady, strike one for your capacity to discover the reality of anything. I am more broadly published in the primary literature than this guy and I don’t even have my PhD yet. I have no idea who Amit Goswami is beyond that, but I bet he’s making more money than me…
He is after all using quantum physics to justifying some pretty remarkable stuff:
Through the principles of quantum physics we can explain how ancient traditions of healing such as Oriental Medicine and Acupuncture, Ayurvedic Medicine, and modalities such as Homeopathy and Naturopathy, work with the body’s subtle energy systems such as ch’i, prana, and vital force energy.
The post really doesn’t say a huge amount more, but I saw absolutely no quantum mechanics. As I drifted down through the comments I eventually hit a guy making some statements that seems to be what I’m looking for.
Aiding us in our questioning, the tool of Quantum Physics provides much hope. Quantum theory holds the promise of helping us escape the ontological prison imposed by classical physics in which we objectify our observation experiences as events in a real world. In quantum theory, a single superposition state can give rise to multiple observation experiences, thereby, opening the door to confounding the classically determinate states that obtain in the world prior to and independent of our acts of observation.
Now, some of this sounds like stuff that might come out of a layman’s description of QM, but you’ve got to remember that whenever this guy says ‘observation’ he means ‘what a person sees in the world around them.’ Yes, indeed, a single state function can be a superposition of a number of eigenstates and an ‘observation’ can cause the superposition to collapse into a particular eigenstate. But, when a physicist uses the word ‘observation,’ he/she doesn’t literally mean ‘to look at with eyes.’ The world of the quantum is unfortunately divided from our world by a factor of Planck’s constant. This constant is in units of joule*seconds and has the value of 6.63×10^-34. This constant effectively puts a wall between classical reality and quantum reality so high that you can’t hope to cross it in your everyday life. Here’s why: quantization of state energies is discretized by increments of Planck’s constant, which is to say that this constant sets the energy difference between two eigenstates. That number is tiny –Homeopathy is often listed as aphysical because of a lack of comprehension of Avagadro’s number, here’s a number that’s even further out! For an object to behave in a quantum fashion, the energy of the difference between successive states in an energy spectrum must be about the same size as, or greater than, the ambient thermal energy (KbT, boltzman constant times the temperature). On the scale of human experience, the difference between two eigenstates is so tiny that you could not ever realize that there were different states, even if you witnessed a collapse. From our perspective, the discrete look continuous. This is why classical physics works at all: quantum physics reduces to classical physics when you start asking for observations on a level observable by human beings.
Consider yellow light, something we can witness in everyday life. Yellow light has a wavelength of approximately 550 nm. A back of the envelope calculation tells us that the frequency of this light is approximately 5.4×10^14 Hz. A quantum mechanical energy transition (the passage between two successive eigenstates) that produces yellow light is 3.6×10^-19 Joules. That’s the amount of energy contained in a single yellow light photon, a photon being the quantum scale package of light energy. To be quantum mechanical here, you have to be distinguishing on the scale of photons. Consider now the heat capacity of water (you are made mostly of water): it takes 4.2 joules of heat to raise one gram of water one degree Celsius in temperature. It would take 1.17×10^19 approximately yellow photons to raise one gram of water by a single degree. By physiological means alone, a human being cannot detect being hit by a single photon –can you tell the change in temperature by 1 part in 10^19th of a degree? That’s not one part per million, not one part per billion, not even one part per trillion… there are still seven zeroes to go to get to 1 in 10^19!
The back of your eye produces images from physiologic scales of yellow light interacting with cis-trans retinal in the Rhodopsin ion channels of cone cells in your retina (of which there are ~6 million). Rhodopsin is expressed en mass in these cells and they need bright light to operate, so you can figure some large number of Rhodopsin per cell, probably on the order of thousands, of which many need to fire simultaneously in order to cause the cell to transmit a signal to your brain. The color images you see are being produced by conservatively billions of interactions with light. Can you distinguish one strike? The limits of a human being work in a very obvious fashion: for something you see, perception transitions from discrete to continuous at about the frame rate of a TV, 32 frames per second, or 0.03 Hz, roughly 10^12 times slower than the frequency of yellow light and we need huge numbers of photons to build any visual images and billions and billions of photons to tell even the best we can for changes of temperature on our skin. The physiological human being is not fast enough or sensitive enough to witness ‘quantum events’ and understand them as ‘quantum.’ This is why Classical Physics is good enough to describe basically everything you encounter and observe in your day-to-day life. Ontological prison or not, we simply can’t see ‘quantum-ness’ directly.
Real physicists get around these huge gulfs of performance by conceding that a human being can’t witness a quantum thing directly. Doing experiments in quantum physics requires machines to intercede between human perception and quantum phenomena. One example is the MRI machine. To build an image by MRI, this huge machine is performing an experiment that causes the collapse of a quantum spin state ‘by observation.’ The MRI operator fires up a program in a computer that does the entire observation on the instrument whether the operator is standing there witnessing it or not. A computer is mediating the interaction. The person doing ‘the observing’ is not cognitively present for the quantum observation in question because the machine literally runs the state collapse experiment dozens to hundreds of times before spitting out a single result that the self-aware human mind begins to interact with. Everything quantum mechanical has been long since resolved when the human mind finally enters into the loop. Worse, in MRI, you basically don’t see the data about the quantum states; the computer performs a major mathematical operation in a split second to reconstruct where the signals of the quantum events are located into a tomogram that contains only the information about ‘density of signal.’ The person does not once directly interact with anything quantum… the keyboard, mouse and screen are all classically describable.
*sigh* Quantum theory is amazing. It is truly amazing. The math is neat and the results are mind bending. However, if there is no big machine between the thing being observed and the person doing the observing, what you’re talking about is probably not quantum mechanical. Empathy and emotional connection is a helpful thing in healthcare, frame of mind certainly helps to buoy distress, but none of these things is quantum mechanical in a way that human beings can directly understand, manipulate or control. Shoving the word ‘quantum’ into sympathetic magic and calling yourself a ‘quantum physicist’ insults generations of honest physicists who actually worked really hard to give us powerful medical tools like MRI, which don’t require an intimate understanding of their quantum mechanical underpinnings in order to operate. In that quote above, the speaker has stripped all the actual quantum mechanics out of the words and reduced them to a feel-good metaphor that has no more relation to quantum mechanics than a glass cuvette has to an elephant. I don’t care how well you articulate the words ‘ontological prison,’ if you can’t work a Hamiltonian or operate within the constraints of Planck’s constant, you’re not a quantum physicist and the place where you’re learning this metaphorical garbage is a diploma mill. The only ontological prison you’re interacting with is the one you set up for yourself when you started believing these comfort-food lies about quantum physics. That poor antivax woman in the reddit thread kind of deserves the bashing she received: she’s eroding the credibility of a real science.
There is a disingenuous quality to my argument here which has always bothered me. I hesitate in bringing it up because I think that without really understanding the physics the argument will seem to give credence to the cranks. There is some difficulty here in defining what an observation even means in terms of quantum mechanics and what physical interaction is required for the observation to occur.
I specified “observation” in the main body of the blog to be due to interactions between the human biological sensory apparatus and light. Our organism is limited to interacting with quantum mechanical phenomena by means of light. Question comes down to what quantum thing we’re observing.
If we’re looking for quantum mechanical behavior of the material universe around us, what we’re interested in is particle/wave duality of objects with mass, like the electrons and atoms that build up into the molecules and larger continuum of matter that composes our world. We can directly observe the outcome of quantum mechanics involving our material world in the light that comes to us from pretty much any source: you take a prism made of glass or plastic (or some material which has dispersity) and hold it into a beam of broad spectrum light from basically any source and that light can be split into its constituent colors. If you examine this sort of color spectrum, you’ll notice that it contains gaps. These gaps turn out to be a direct quantum mechanical phenomenon that you can see with your own eyes, but good luck describing how these gaps got there without actually invoking what quantum mechanics really says. Notice that even here, there is a tool being used to render the quantum mechanical behavior discernible. Without the prism, you can’t see this very well. By noticing that the light from an incandescent bulb is different from sunlight which is different from fluorescent light, you are directly seeing a quantum mechanical effect, but that you are unable to decompose the observation with precision to note exactly what it is that you’re seeing. What do the differences in color mean? Fact remains that most lightbulbs can be confirmed to be turned on whether you’re looking at them or not in the non-trivial effect they have on your power bill and that consciousness is not required for them to generate light (do you have to understand why the switch on the electrical generator must be flipped in order for it to make a bulb light up? Not really: you only need to know that it does.)
A second facet of this conversation is in the light itself. Because light has no mass, particle/wave duality permits it to be very wavelike. In fact, it is so wavelike that it was not initially understood to have particle-like properties. My arguments in the main body of this blog post center around the fact that the human apparatus is almost completely incapable of distinguishing the particle-ness of photons unaided. But, you can witness the wavelike properties directly: this is the reason shadows are always fuzzy along the edge (well, spot size is finite anyway… quite a bit of the shadow fuzziness arises from the light source being a particular size and shape). This is the reason images bend through water so that swimming fish appear to be in a different spot from where they actually are when viewed through the surface of a lake. This is the reason prisms split white light into all its colors. All of that is wavelike. It does not reduce to the ocean wave picture most people have in their heads of “waves” or the tangible vibrating guitar string, but all of that is wavelike. Further, it is all completely describable by classical electromagnetism, a form of classical physics. You really don’t need quantum mechanics to describe how waves of light work. In fact, EM is computationally easier to deal with, so it’s preferred wherever necessary because the quantum is much more difficult to manage. It is really quite stunning that classical models of light behavior lend themselves very readily to quantum mechanical models and it is no accident that you need to have a fairly good understanding of EM in order to really be able to manage quantum.
One thing that quantum does for physics is that it wraps distinct behaviors into the same explanation. Wavelike behaviors seen with material objects like electrons and atoms are the same sort of wavelike behaviors seen with light because of quantum mechanics. Particle-like behaviors of light are similar to those of material objects also because of quantum mechanics. Many people become fruity talking about quantum because they don’t even know what it’s intended to describe. Ayurveda? Prana Energy? How in the hell are these things even relevant to the discussion? People fixate on the indecisive language that is intrinsic to quantum mechanics –“Uncertainty,” “Wavelike,” “indeterminacy”– and they assume that this means there’s an open gap of nonspecific meaning where garbage can be crammed. If you note the “Ontological prison” quote I included above, this is exactly what the original author is intending with his comment; “because quantum supercedes classical physics and because quantum uses wiggedy language, I can use quantum to validate whatever I feel like validating despite the fact that classical physics would seem to claim that such things are impossible.”
I could go on like this all day, but it really doesn’t illuminate the conversation.
An experiment showed that the human eye can detect single photons. I admit that I was wrong about the sensitivity of the human eye above. Still, I don’t think this experiment qualifies as double blinded and the statistics in the paper are admittedly low. There are some weird gain effects present in that experiment which makes me wonder how true it is, but Nature Communications is at least a journal to pay attention to.
Trying to decide how it impacts my arguments above.
I guess the most major thing to note about how this does not validate crankery is that the human brain is known to operate at a finite speed. The photon detection event occurs some significant period of time prior to when the brain can have thought about what it saw. The quantum mechanics is resolved at the detection event. On the scale of nanoseconds, which is fast for quantum mechanical time scales (12-26-18: there’s a word botch here… nanoseconds… 10^-9 seconds, are actually somewhat slow by quantum mechanical standards… state-of-the-art probing techniques are at more like 10^-15 seconds or faster), this is a long time prior to when the brain can respond. That article on that link places a “60 bits per second” equivalent speed for the brain’s processing, which is kind of arbitrary since the brain doesn’t process in bits, but it shows how slow people are. The authors in the paper on the single photon detection do mention the “short-comings of the downstream processing in the human visual system.”
Your brain is fundamentally composed of quantum mechanical objects and it is tangled into the weird physics. But, this does not say that your action of thinking imposes some control over quantum weirdness. Better to say that your ability to think is a side effect of the quantum mechanics of the architecture of your anatomy, of which you had better be aware of the scale. The detection of light by your eye is a quantum mechanical event where single molecules of retinal switch their state of kinking when they absorb a photon of light. This detection is just the first event in a long cascade of events that take place significantly after the detection which translate into you ‘thinking’ about what it is that you saw.
Consider: your eye detects a single photon of light. The history of that photon is most likely that it was produced by a state transition of a single electron or ion somewhere in your visual field. I did not say ‘your eyes detect’ because a single photon detection is a single voltage gate opening in a single cell in only one of your two retinas. The event which produced that photon was a distance away that you cannot know because you can’t process typical distance cues with only a single cell; you cannot judge the shape of an image when there is no image and you have no stereoscopic depth on only one eye. Moreover, because we’re talking about shot noise, you do not know the color of that photon… the uncertainty principle assures that. Because of the delay between photon emission and detection, there is an entire sequence of things that could have occurred to the object which initially generated that photon which you cannot know about prior to when the emitted photon was absorbed and processed by your anatomy. Whether this means that the retinal in your eye is momentarily entangled on a quantum mechanical level with the source of that photon is not really a sure thing. The rest of your eye is mechanically and chemically pushing on that molecule, assuring decoherence of an entangled state before the signal even leaves your eye to be processed by the rest of your brain. And, as I’ve said in other posts, without statistical numbers of photons being detected, you can’t really know anything about the wave function. That’s the conundrum of quantum mechanics; the weirdness appears and is amplified in the shot noise and you must process many such events in order to build a picture of how many histories could have contributed to a detection.
My argument here is largely about the non-singular nature of an anatomical brain. Many quantum mechanical things are always occurring in your skull, granted, but they occur at a statistical norm. It does not follow at this level that the human brain is granted control over remote quantum weirdness. The structure of quantum mechanics imposes difficulty on understanding what scale the weirdness extends to and, as the authors in that paper note, it really kind of requires more testing.
A comment has lead me to believe that the august body of Quantum University is stung by my opinion as a professional physicist of their validity. Can you believe it? Right here on my little ol’ insignificant blog. Great! If I’m enough to rattle them, maybe I ought to keep writing articles about them.
If you want me to respect you, next time, bring physics, not pseudo-pop psychology. There is a right way to do quantum mechanics.
I do have some other thoughts about this comment. I will quote it here in its entirety so that you can see what the thinking looks like:
As someone who appears to be heavily indoctrinated in a “material-empirical” orientation with regards to science, it would be very hard for you to appreci- ate the type of education fostered at a place like Quantum University.
The material-empirical science oriented individual tends to live out of touch with Reality, for this to him/her is composed only of particles and myriad physical phenomena proven by math- matical formulas.
What does any of this have to do with your Life, your Consciousness, your Relationships… your own Soul. It’s only a Grand Illusion that you’ve been unable to perceive/discern the connect- ion between these and the brand of physics you’re pursuing.
If you’re ever fortunate enough to transition from the “ordinary mode consciousness,” dominated by obses- sive “left-brained,” rational/analytical thought, and shift toward the higher, more. transrational states for a break, you just may discover that indeed there is a connection to it all.
There is a lot in this little blurb. I think it may even have been written by the same fellow who wrote the “otological prison” quote I used above, though I couldn’t confirm that. He accuses me of being indoctrinated and claims that if only I escaped my rational analytical mind that maybe I would see the truth that we all live in the matrix or some such.
What is indoctrination?
According to the dictionary, it is “the process of teaching a person or group to accept a set of beliefs uncritically.” Direct quote from Google by my lazy ass.
The critical word here is “uncritically.” What does this mean?
Uncritically: “with a lack of criticism or consideration of whether something is right or wrong.” Another direct quote from Google by my even lazier and more tired ass.
So, indoctrination is an education where the student is not critical of the content of what they’ve been taught.
You have only my word to take for it, but I’ve walked all up and down physics. I’ve read 1920s articles on quantum mechanical spin translated from the original German trying to see what claims were being made about it. I’ve read Einstein. I’ve read Feynman. I’ve read Schrodinger… the real guys, their own words. I have worked probably thousands of hours rederiving math made famous by people dead sometimes hundreds of years ago just to be certain I understood how it worked (Do you really believe the Pythagorean theorem?) I’ve marched past the appendix of the textbook and gone to the original papers when I thought the author was lying to me or leaving something important out. And yes, I’ve found a few mistakes in the primary literature by noted physicists. Does that sound uncritical to you? In the 3 years since I originally wrote the Quantum U post above, I’ve earned a genuine physicist PhD from a major accredited university.
I would turn this analysis back on the fellow in the comments: have you done this kind of due diligence on what Quantum U taught you? Did you attack them to check if they were wrong? If not, you’ve been indoctrinated. Since they are about as wrong as it’s possible to be, my guess is that no, he didn’t and he isn’t about to… he’s a believer.
The next thought about this comment which pops up is a little claim about my dim-witted nature. I am clearly without a third eye and my life is definitely in the crapper because I am not seeing that other level beyond the workaday world where I could be mystically synergizing with some deeper aspect of reality in the hands of the Real truth. My dreadful left brain is clearly overwhelming my potential as a person. Do you actually believe that you know me?
By design I don’t speak often about my personal life on this blog. Fact is I’m not an unhappy or unfulfilled person. If you take the spine of that comment, the implication that if only I had a Soul, I’d see that Quantum U would have something to give me, truth is that I can say for certain that I need nothing from them in that regard. I came to a point in my life where I don’t need the training wheels… I, as a person, am enough. That has nothing to do with my scientist education, but everything to do with my complicated path through life. That path has lead me a long way and through a lot. Walk one mile in my shoes –I dare you!
Do not make assumptions about the soul of a person you know next to nothing about.
I have one piece of experience that I feel would inform a searcher who sees the allure of Quantum University and it’s “ability” to give students some deeper insight into consciousness, soul and self-actualization. The most difficult thing that people can ever grasp about themselves is the fact that we are all flawed in the sense that our very capacity to interact with reality is fundamentally confused about what’s real. Your brain, the generator of your reality, is not perfect and you can believe in a lie as if it were actually true. Did they find WMDs in Iraq?
I have to laugh at his “transrationalist” higher state of being nonsense because it seems that he’s bitten off the biggest lie imaginable. He believes that everything he thinks about the world is true! Why else would he sneer at material-empirical rationalist analytical mindsets? He wants to disconnect his mind from being connected to tangible reality… you can see that in every word he’s written, right down to the carefully chosen yet inappropriate caps.
The problem I have with that is a simple one: by decoupling your mind from everything else, you remove from yourself the ability to do an external error check based upon what is physically true in the world around you. This is pattern recognition with a broken compass. If you have no way of checking whether or not what you believe matches what is actually real, you have no way of confirming what, if anything, is false in what you see. Everybody can dream and imagine they have psychically contacted a dead relative or telepathically commanded a poodle to piss on a baby. There is no badge of honor to be gained by believing you can lie your hands on someone and heal them with the strength of your Chi because anybody can believe that. You can sit around, do deep breathing, and listen to the white noise in your own anatomy and ascribe all sorts of meanings to it. The hardest thing in a world is sorting out whether anything you imagine is actually true, particularly when you want something to be true. Your mind can dredge up some utter unreality that seems absolutely real in that instant. How can you ever be completely sure?
In my experience, the truth is true regardless of whether or not I believe in it.
That’s the thing about empirical reality. You have a chance to come back and interrogate something, or someone, external to yourself about whether or not you are seeing true things in the world around you. This is a timely subject, I think, because people have turned to filter silos –pocket realities where groups of people are telling you what you want to hear– to avoid having to do really painful self-checks. Empirical reality is imperfect because we never know everything about it, but at least it’s basically invariant and can serve as a good calibration point. That’s the thing about the truth: two contradictory things can’t be simultaneously true. Empiracism at least gives a stationary ground that every observer (literally every observer) can share. If we can all come back and agree that the sky is blue, we at least have something in common to work with, no matter what murmurings are pressing on the backs of our heads. You can’t show that “transrationalist” higher state of being is anything different from a schizophrenic fantasy because they have equal connectedness to the external world; there is no internal frame of reference by which to prove that the first isn’t actually the second. That somebody at Quantum U told you it’s so and you uncritically decided to believe them does not suddenly make it true… that’s almost like a filter bubble; you’re just using someone in particular as your authority whom you wish to believe. Never mind that the person you picked is, maliciously or not, lying their ass off to you.
I think the hardest thing in the world is facing when you’re really wrong about something you deeply want to believe. Sometimes people do get these things wrong. Are you among them? Clearly, the fellow in the comment understands that people can be wrong, or he wouldn’t accuse me of being wrong. Does he never turn his optics against himself?
Now, you may want to call me a hypocrite. Am I a believer? Surely I believe in physics, being a physicist. My answer here might surprise you. Only kind of. Quite a lot of it I don’t fully understand. I’m either agnostic or skeptical about the parts I don’t understand. And, I’ve gone to some pretty extreme ends to try to decide that I understand it well enough to believe certain things about it. This leads to two things, first, I know I don’t know everything and, second, I freely admit that I get things wrong. But that doesn’t mean that I have no idea what I’m talking about… what skill I have with Quantum Mechanics is well earned.
Let this serve as a warning: anybody else making comments about my soul or implying with heavy hand that there is a lack, I will delete what you say out of hand. That’s ad hominem, as far as I’m concerned. You don’t know me. That you make any such statement shows that you didn’t understand word one about human potential that anyone at any school tried to teach you. You have no idea who I am.
I have some more to say and I likely won’t be able to finish this section in the amount of time that is actually available. The very notion of Quantum University sets my heart on fire. I want to take away that funhouse mirror they use to admire themselves and put them in front of a real mirror so that they understand why people with actual comprehension laugh at them (or should be given the opportunity to laugh and point and maybe throw some rotten cabbage).
Still, the reality is that you can’t fix a believer. The one great problem with cranks of this sort is that a lot of them genuinely believe they’re onto something. Never really quite occurs to them that basically everything they ever do never achieves anything and that any achievements they come across only come from fellow travelers who also believe. A believer can only butt their uncomprehending head against the granite block that is reality and stop to wonder why there’s blood. They do not actually achieve, ever, they waste time running in circles doing everything they can to collect testimonials from dupes to mark their “achievements.” Oh, and utter curses about the vast conspiracies being leveled to keep what they believe down. Still, if they can get people to believe them, they can do one achievement that is meaningful in society: they can make money.
The fellow in the comments honestly believes that there’s a “brand” of quantum physics out there that doesn’t require you to know how to use calculus.
The profession of physics has a very distinct and simple structure. The entire purpose of a physicist is to translate a series of real world observations into numerical representations and then fit those values onto mathematical formulae. If the fitting is sufficiently good, the process can be reversed: the mathematical formulae discovered in the fitting process can be used to predict what real world conditions are required to reproduce certain observational outcomes. Note, this is flat-out crystal ball stuff; physicists predict what will happen observationally if conditions for a given formula are met and to what precision that outcome can be expected. I’m not saying “some brand of physicist” or “sometimes this is one thing we do”… this is what physicists do, end of story. If you cannot carry out this function, you are by definition not a physicist. Physics is completely inseparable from the math, so much so that the profession is divided down the middle into two classes: the people who wrangle the math, called the “Theorists,” and the people who wrangle the observations to plug into the math, called the “Experimentalists.” Theorists and Experimentalists work together to get physics to operate.
Any jackass bleating, “Well, you don’t know the Real(tm) science because you haven’t gotten around your evil, malicious logical right brain and circumvented the math to find the Real Reality,” has essentially shoved his own hand down the garbage disposal. By dumping the math, that person has admitted to not being a physicist –despite his/her claims to the contrary– without math, there is no physics. Period. End of story. This is totally non-negotiable. You cannot redefine reality and expect the rest of the universe to suddenly adhere to your declaration.
Since understanding this subtlety is a real challenge for those of Quantum University, I’m going to make an example here of just what it is that a physicist does and why physicists are deserving of the street cred that they’ve earned. These Quantum U jackasses crave the legitimacy of that word: “Physicist.” There is no other reason why anyone would accuse an actual physicist of being uncomprehending of the nature of physics. From what I intend to add here, anybody reading this blog post will be able to make an assessment of themselves as to whether they could ever be qualified to call themselves a physicist.
Quantum Physicist Self-Evaluation Quiz:
What I’m going to add is a quiz containing a series of questions that a genuine quantum physicist would have no difficulty at least attempting to answer –some will be very easy, but some may require more than transient thought. If you have any hope of completing it, you will have to do some math. I will write the problems in order of increasing difficulty, then detail what each problem gives to the overall puzzle of exploring quantum physics and try to add a real life outcome from the given type of calculation to show why physicists have credibility in society in the first place. Credibility is the point here; this is why Quantum U craves the word “Physicist” and is willing to rewrite reality for it. My point is that if you jettison the part of physics that allows it to attain credibility, you lose the right to claim credibility by association.
Problem 1) You suspend a 5 kg bowling ball on a 2 meter cable from the ceiling. With the cable taut, you pull the ball aside until the cable is at an angle 30 degrees from vertical. You release the ball and allow it to swing. What is the maximum speed of the ball as it swings and where is it achieved?
Why does this matter to Quantum Physics? This is a very basic classical physics problem that would be encountered midway through your first semester in introductory physics. The Quantum U jackass would immediately scoff, “Well, this is classical, quantum allows us to escape that!” Well, no, actually it doesn’t. This problem is the root from which quantum physics grows. This is one of the simplest Conservation of Energy problems imaginable and the layout of the calculation sets the root of Hamiltonian formalism, meaning that it is almost exactly the same as the layout of the time-independent Schrodinger equation. If you lose the Schrodinger equation, you’d better have something impressive ready to replace it because you can’t do quantum without this.
Why is this important to Physicist cred? Most introductory physics does not seem like it should be all that important. If you can solve this problem, does it mean you can load heavy things into your car without straining your back? Maybe, maybe not. This problem is important to society because it involves exchange of potential and kinetic energy in a conservative situation. With a tiny bit of tweaking, this particular problem can be rewritten to estimate how much hydroelectric power can be generated from a particular design of hydroelectric dam. What? You mean to say physics has real world implications? That sound you just heard was me driving a nail into the third eye of a quantum U jackass.
In this picture is an electronic circuit. I’ve labeled all the components. The switch connects the unlabeled wire to either wire 1) or wire 2). It starts connected at position 1). What happens when you turn it to position 2)… in other words, what’s the time varying behavior after the connection is closed? That’s the easy part of the question; to be a physicist, you have to answer this: what values of ‘L’ and ‘C’ could you pick to get a period of 2 milliseconds?
Why does this matter to Quantum Physics? I debated for a long time what sort of basic electromagnetism problems to add. I thought originally to keep it to one, but I decided instead on two because you really can never get away from electromagnetism while you’re doing quantum physics. There are four known fundamental forces and this is one; electromagnetism crops up in everything. This particular problem involves an oscillator and is therefore a forerunner to wave behavior. If you can’t do oscillators, you can’t do probability waves. If you know a thing about physics, this problem is actually extremely easy and is typically encountered in second semester basic electromagnetism and in whatever electronics classes you’re forced to take. The chemists, who do quantum physics of one sort, may have some difficulty with this problem, but the physicists really shouldn’t. If you call yourself a physicist, this should be as easy as wiping your ass.
Why is this important to Physicist cred? You have an evolved, heavily engineered offspring of this little doodad in every connected device carried on your person at this moment. The oscillators have all changed faces and the components to achieve them are probably almost unrecognizable at this point, but the physics is not. The thing in the picture above could be converted into the tank circuit of a radio. This was a gift to the 20th century by the hard work of 19th century physicists. Radio, electric power and the associated ability to instantaneously communicate long distances has built our world. If you stop to realize that William Thomson, the Lord Kelvin, made a mint off laying a telegraph cable across the Atlantic to connect England and North America for communications purposes, you will understand the power that all the offshoots of this technology had. The circuit above is two-fold; it relies on the electric conduction physics upon which Thomson’s telegraph infrastructure depended and also could be used to facilitate the generation of electromagnetic waves that could be transmitted through the air, as performed by Marconi (and Tesla… the real one, not the car maker). If you know what you’re doing, you can turn this device into a small EMP generator… you’re welcome. (As an aside, I always feel a little sorry for William Thomson: modern people mostly only ever call him Lord Kelvin and forget his actual name… the title of Lord Kelvin was created for him because of his success as a physicist, and so, his success deprived history of his actual name!)
Problem 3) You’re stranded on a deserted island. You go and hunt for food along the flood plain around the island when the tide comes in. You see a fish swimming along the sand beneath the flat surface of unperturbed water, by eye 60 degrees below the horizon line of the ocean. You stand 1.8 m tall and you have a 1.5 m spear. Measuring with your spear, you know the depth of the water is 2/3 the length of your spear. The index of refraction of water is about 1.333. You have a calculator for a brain. If you thrust the spear from your shoulder, what angle must you launch it at in order to hit the fish.
Why does this matter to Quantum Physics? Good question. This is the second EM question that I will add and it’s added because it deals directly with the physics of light. Snell’s law is a product of electromagnetism and it emerges from applying Maxwell’s equations to a boundary situation much like I’ve detailed in the problem above. Index of refraction is a direct ratio of speed of light in a vacuum over speed of that same light in a substance (like water). The phenomenon of light bending its path as it passes through the boundary between two translucent substances is a direct consequence of the wave-like properties of light. I have no doubt that the Quantum U jackasses love waves and vibrations. Can they handle this one? As I chose to add a problem about electromagnetic force, I needed to add a problem about the basics of light, which is directly connected to the EM force. Light is very pivotal to Quantum physics because most every observation people ever make involves some measurement of light.
Why is this important to Physicist cred? The lens maker equation is expanded from this foundation. Without this, there would be no glasses, no contact lenses and no corrective laser eye surgery. The work of physicists actually corrects vision in the two eyes that matter.
Problem 4) The half life of a muon is 2.2 microseconds. If it’s a cosmic ray traveling at 99.999% of the speed of light, on average how long does that muon appear to last if you happen to see it fly by while you’re standing on Earth?
Why does this matter to Quantum Physics? This is a token special relativity problem. A large portion of Quantum physics does not require relativity, but an equal amount does. As such, you can’t get away from relativity. You need to know at least some to be a quantum physicist. Quantum U jackasses clearly want to marginalize all those “particles and math-ematical equations” and beg that something exists beyond that, never mind that by removing the math, they have zero chance of ever defining what… I say fine, remove what you like, I’ll steamroll you flat anyway. I could as easily have said “You will live 79 years and 10 seconds, how long does that appear to be to somebody watching you run past at human foot speed for your entire life?” The relativity will probably say 79 years and 10.000001 seconds or something (I didn’t calculate it), but at least this is better than begging the limits of human potential and claiming the person ran by at 99.999% the speed of light. Somebody has to realistic about human potential. Relativity is pretty important because it’s the first time humans changed Newtonian physics. That precedent is important to understand in light of quantum physics (which was about the third time humans changed Newtonian physics, General Relativity being the second). Quantum physics didn’t emerge by immaculate conception… there was a huge background of math that lead to it. Discard it at your risk.
Why is this important to Physicist cred? Congratulations, you can now perform one of the clock calculations needed to make the Global Positioning System (GPS) work. You’re welcome; physicists just saved you from getting lost… again. Note, we’re also responsible for the military ability to drop a bomb down your chimney from a flying aircraft. I’d love to see you astral project out of that.
Problem 5) What do the ‘A’ and ‘B’ constants refer to in Einstein’s stimulated emission equations?
Problem context: To detail the situation for the mathematically illiterate, who are none-the-less following along because they are genuinely interested, Einstein’s set-up is a Bohr atom… a nucleus with electrons orbiting it at levels; he postulated that a passing electromagnetic wave causes a lower energy electron to hop up to a higher energy level orbit if the wave matches the energy difference between the two levels (absorbing a photon). The electron in this now excited state can either spontaneously hop back down to the lower state, giving off a photon, or it can be ‘jarred’ to give off the photon and hop back down to the lower state by being subjected to an electromagnetic wave that happens to match the energy difference between the two states –called stimulated emission.
Why does this matter to Quantum Physics? Einstein’s work on stimulated emission occurred in 1917, in the framework of what’s called the “Old Quantum.” This is my first genuine quantum physics question for you. Oh goody, right? Tired of the equations yet? Sorry, but if you can’t handle equations, you’re not a physicist. This work is the front runner of the Fermi Golden Rule. I’m skipping most of the other Old Quantum because it was still too incomplete.
Why is this important to Physicist cred? Without us, no lasers bio-tch! And, in the interest of full disclosure, the laser is one example of short-sightedness in physicists. Einstein had this realization in 1917, but failed to see the significance himself. Physicists then hurried on and found their focus on other shiny things while nobody thought more carefully about it. It took some 40 years until Maiman, Gould, Townes and Schawlow (physicists whose names you may not know, though Maiman was also an engineer) had the critical insights to finally make it work. I ended up including this problem on a lark mainly because it also helps to put guided missiles through windows militarily. Gotta put the p’chank of fear into somebody’s chakra. How many CD players do you suppose were built because of us?
Problem 6) A drunken hobo, who weighs 70 kg including his tattered blanket and a full bottle of peach schnapps, shambles along at about 0.5 m/s. If he were to stumble through a two-slit apparatus, how far apart would the slits need to be spaced for him to exhibit quantum mechanical interference? Can this setup be built?
Why does this matter to Quantum Physics? This question involves the de Broglie equation, the beating heart of modern quantum physics. This equation is one of several reasons why Quantum University craves the word “Quantum.” For those less versed, the de Broglie relation is the first equation written that explores the ‘wave’-ness of physical objects and is the source of particle-wave duality in matter waves. With the way that most quantum mechanical wave equations are written, the de Broglie relation is always hidden somewhere inside the argument (particularly in time-independent cases). In essence, because they do no math, quantum U gets it wrong because they fail to include Planck’s constant. Ask yourself what came first, an “institution” calling itself “Quantum U” or Planck’s constant?
Why is this important to Physicist cred? Do I really need to say it?
Problem 7) The hobo from the previous problem shambles along for a moment, then stumbles to a stop. He stands there wavering about, struggling to keep his balance, foot speed now reduced to 0 m/s. Because of the alcohol induced gaps in his memory, he may certainly think that this happens, but why doesn’t he ever just suddenly *pop* into existence in front of the hardware store or soup kitchen? Careful examination of the previous problem would suggest that if he stops moving, maybe he can!
Why does this matter to Quantum Physics? Are you kidding? This is the weird-ass core of quantum physics! I never did claim that weird stuff doesn’t happen. What I claimed was that there are specific expectations for how the weirdness can emerge. What is written in this problem should be analyzed with the Heisenberg Uncertainty Principle. The cranks typically use the Uncertainty principle as a get out of jail free card, “Well, there is uncertainty, so anything is possible, right?” The actuality is that the Uncertainty Principle acts like a governor, telling how much weird is possible depending on the set-up of a given situation. How exactly stopped must the bum be for his position to grow so uncertain that he can teleport around town? Note, the argument here would actually also work if he’s still walking, despite the hole in de Broglie’s relation, but his speed must be very perfectly uniform… the uncertainty of his momentum must be nil.
Why is this important to Physicist cred? This stuff is one of the fundamental reasons why quantum U jackasses covet the word “physicist.” Did the uncertainty principle come first, or the slack-jaws desperate to misunderstand it in order to promote their woo?
Problem 8) A lightning bolt strikes for about 30 microseconds, creating a radio frequency EMP. What is the frequency spread of the interference it causes in radio/microwave transmissions occurring around it?
Why does this matter to Quantum Physics? This is a second application of the Uncertainty Principle. In this form, it addresses a different pair of uncertainties, but it’s the same principle. I’ve included this problem to show the stark quantitative nature of the equation. There is nothing at all qualitative or indecisive about the Heisenberg Principle. It says something extremely specific and if you lose the math, it becomes a lie, period.
Why is this important to Physicist cred? We invented the Uncertainty Principle and we damn well have a say in how it works.
Problem 9) A tiny, effectively featureless quantum mechanical tiger of mass ‘m’ is caught in a prison of only one dimension. He runs back and forth trying to get out, but the walls on either end are infinitely high. The prison is large compared to the actual physical shape of the tiger and this tiger lives by feeding on heat energy. Further, the prison is sized so that it’s on about the same size-scale as the tiger’s de Broglie wavelength for the low temperature where this tiger lives –and in fact keeps the tiger alive under those circumstances where he’s starving. The zoo keeper must fire photons into the tiger’s cell one at a time to try to hit the tiger and see where he is. The frequency of the photon is very high and the zoo keeper can tell exactly where the photon went in and will be able to tell exactly where the photon comes back out, thus giving him an accurate understanding of the location of whatever the photon bounces off of. The photon will interact elastically with the tiger and the interaction is independent of the photon’s frequency. If the tiger has been allowed to starve and has the smallest energy a tiger of this impossible sort can, what is the probability of finding him at any particular place in this prison with a photon? After you hit him that first time with a photon, finding exactly where he is, how many of the prison’s eigenstates are needed to describe his location thereafter?
Why does this matter to Quantum Physics? This is the most basic Schrodinger equation problem, the particle-in-the-box. You should substitute ‘electron’ for ‘tiger’ in the interests of reality, but I can choose how I write the problem. A part of why I wrote this problem the way I did is to give a little bit of a feeling for what the quantum mechanics is like and how it works. In this kind of problem, you are outside the system looking in and the system is completely dark, you cannot see what’s going on. You could be a zoo keeper facing an angry tiger in a sealed crate; your only way to find this tiger is shove a prod through a breathing hole and see if you bump something. If he’s sleeping, you may discover a mass distributed somewhere in the middle of the crate. If he’s lunging back and forth, the prod may bounce off of something now and then, but it appears as if the tiger is distributed everywhere in the box. I added an embellishment too. In my version of the problem, I’ve included a prepared state and then a state collapse: I would recommend asking yourself what the difference is between the Hilbert space associated with the photon probe (designed around a position space representation) and the Hilbert space of the box (which would be the eigenspace solving the Hamiltonian of the tiger trapped in the box).
Why is this important to Physicist cred? The particle-in-the-box problem has actual physical applications. The 1D version can be used to approximate the absorbance spectra of aliphatic molecules containing stretches of conjugated bond. A 3D version of this problem can be invoked to describe the light absorption characteristics of quantum dots. Ever seen one of those beautiful Samsung quantum dot TVs? You’re welcome.
Problem 10) Suppose you did hit that tiger in the previous problem with a photon, momentarily finding his exact location in the box. What happens to the probability of finding him again at that location over time afterward?
Why does this matter to Quantum Physics? This is a time-dependent Schrodinger equation question. If you can’t understand why this is important to quantum mechanics, I feel truly sorry for you.
Why is this important to Physicist cred? The sort of logic in this problem is used in pump-probe experiments to see how excited states evolve, for instance. This is a real life example of Deepak Chopra’s “ceaselessly flowing quantum soup,” and I mean it in the sense that this is how it would actually be employed in reality by physicists that actually do quantum physics. In one sense only, Chopra is not wrong: the physics can be weird. But, for it to work in weird ways, you must match the circumstances where the effect is seen… the confinement must be on the size-scale of the matter wave. When you fail to invoke the appropriate scale, involving Planck’s constant and the size of the confinement relative to the size of matter wave of the object being considered, is where it becomes a lie. That’s why math is needed… it saves the reality from flowing over into becoming a lie.
Problem 11) In order to make a point about the nature of quantum mechanical tunneling, a physics professor lecturing a group of graduate students turns and runs across the classroom and crashes face-first into a wall. He has just insisted that one day he knows he’ll tunnel through and reach the other side. For a 0.25 m thick wall and a 70 kg physics professor, estimate the ratio of probability amplitude for the professor’s wave function on either side of the wall (or better, estimate the probability flux). Assume that the actual potential of the wall is constant over its width and can be approximated from the knowledge that the wall is just a little stronger than the normal force required to decelerate a 70 kg physics professor from human foot speed to stopped in a tenth of a second over the space of a hundredth of an inch. How many times would the professor need to try this experiment in order to achieve his dream of tunneling through?
Why does this matter to Quantum Physics? Quantum mechanical tunneling is a real thing. This is the effect where a physical object pops through a barrier, unimpeded. Think Kitty Pryde. To perform this, you need to do the particle in the box problem, but backward (a real physicist will understand my recommendation). This is prime weirdness, exactly why the cranks love quantum. I would recommend trying the same problem with an object the mass of an electron where the thickness of the barrier in question is about the same as the object’s de Broglie wavelength. This problem is based in part on a real-life anecdote, where the experiment in question was initiated by a real physics professor. When asked why he wouldn’t try it again since he knows that the probability is small and a large numbers of trials would improve his chances of success, he answered that the university only pays him enough to perform the experiment once a semester.
Why is this important to Physicist cred? Tunneling is responsible for radioactive decay –indeed, we just gave you nuclear power. Also, some of the best microscopes ever built, scanning tunneling microscopes (STM), rely on this physics.
Problem 12) You have a cubic (or rhombohedral) crystal of Ammonium Dihydrogen Phosphate whose optic axis is 52.4 degrees from normal to the crystal faces. You shine a 325 nm He-Cad laser through this crystal at some known angle to the optic axis. If the laser output is reduced so that you’re at the shot noise limit, hitting the crystal with one photon at a time, every so often, you see two photons coming out of the crystal. Many measurements show that the output photons lie in the same plane as the input photon, where both out-bound photons possess ordinary polarization and the same wavelength as each other and that they depart from the crystal along beam paths on the surface of a cone away from the incident beam –in other words, they leave at the same angle in opposite directions. Why are these new photons produced and what’s special about them? Suppose I tell you the output angle is 50 mradian, use physics to tell me the wavelengths of the output photons. Supposing the two photons are detected by detectors positioned equal distances from the crystal, what’s the time delay between detections?
Why does this matter to Quantum Physics? I spent some significant time thinking about this problem –this addresses a piece of quantum physics badly abused by everyone and their brother, but most intensely by the cranks. What’s written above is in basic structure an actual experiment dating from 1970. I avoided writing about this experiment in the typical pop-culture manner so that you can see what the reality actually looks like. I won’t name the quantum mechanical phenomenon that this demonstrates, but I will refer you to a paper by Einstein, Podolsky and Rosen from 1935. I’m hoping that it looks superficially boring because people want to see something really crazy here without thinking about what they’re actually seeing.
Why is this important to Physicist cred? I won’t be snarky this time. I want people to genuinely think about what’s written here for themselves. Preferably, you read the papers and really try to process it. Can you separate even the initial idea from the math? Believe me, it’s there in all its blazing, bizarre glory. What’s the point of this observation? Asking this question is the core of an education that is devoid of indoctrination. Don’t take my word for it, damn well do the work for yourself!
Problem 13) You have a proton and an electron interacting by electromagnetic force. Find the eigenstates of the electron. Impress me by finding the unbounded eigenstates of the electron (for electron energies greater than zero).
Why does this matter to Quantum Physics? This is at its heart a very basic problem that every physicist sees. If you haven’t seen it and you’re calling yourself a quantum physicist, you’re not from a place where they teach quantum physics and, no, you are not a quantum physicist. Tired of the math yet? Sorry, but you can’t be a physicist if you’re afraid of math. In all honesty, I’ve met physicists who claim to be afraid of the math, but these are people who do derivatives as well as they breathe and then get scared of what mathematicians do.
Why is this important to Physicist cred? The periodic table of the elements is largely understood based on the bound states found in this problem. The unbounded states are important for understanding how atoms collide in a low energy, non-relativistic collider. We’ll get to the relativistic ones soon enough…
Problem 14) You have a 4 Tesla magnet. You stick your hand into the bore and somebody across the room fires up a computer program to shoot radiowaves into the cavity of the magnet. What frequency and pulse duration must you fire into your arm in order to set your protons to clamoring most noisily? To what radio frequency must you listen to pick up that clamor? Should the input be polarized? Are you able to feel or hear this clamor? Why or why not?
Why does this matter to Quantum Physics? If you read my blog, you know that this problem can be approached in part classically. If you want to impress me as a quantum physicist, I expect the quantum version. This problem involves spin.
Why is this important to Physicist cred? This problem is about MRI. Yes, we’re responsible for MRI too. If I microwave somebody’s chi long enough, does a mystical turkey timer pop out to tell me it’s metaphysically done? I suggest we do an experiment and see; we can jam the safety on the door of a microwave oven and stick somebody’s face in there… any takers? (Oh, right, physicists also gave us microwave ovens and invented the safety screen in the window. Was it a mechanical engineer who suggested the door latch with the safety interlink? Actually, that was probably us too; we’ve been shooting holes through our own heads at particle accelerators for years.)
Problem 15) If I say a certain perturbative interaction involves spin-orbit coupling, write the term which would go into the Hamiltonian. From the symmetry of the term, are there any forbidden matrix elements? Use the eigenstates found in problem 13 to calculate the first order perturbation between the ground state and the first excited state.
Why does this matter to Quantum Physics? I am gradually turning up the heat here. State of the art modern quantum physics is still way up somewhere ahead. This problem is about a component of Fine structure.
Why is this important to Physicist cred? Fine structure and Hyperfine structure are basics necessary to explain spectroscopy. This tool is one of many that people use to engineer materials from medications to coatings for prescription glasses to the plastics used to built the chair you’re sitting in. Spectroscopy is how we know about the atmospheres of planets orbiting nearby stars (yes, this is a measurement that has been made in a few cases).
Problem 16) A certain transition involves the quadrupole moment operator. Determine selection rules for the operator and estimate the transition rate between levels connected by this operator. If you want to use the eigenstates from problem 13, go for it.
Why does this matter to Quantum Physics? I have a lot of these mechanistic problems floating around. These are middling level quantum physics. Wigner-Eckart theorem and Fermi Golden rule are both essentials; if you haven’t even heard of them, shame on you.
Why is this important to Physicist cred? These things are needed for modern laser engineering and are the product of physicists. I’m sorry, but this is what physicists do.
Problem 17) What is the set of matrices that can be used to represent the group of all proper rotations?
Why does this matter to Quantum Physics? I’ve asked a couple questions here that involve rotation in some form or another. Truth is that I just like this problem and have been thinking about adding it since I started writing these. This is hitting higher level quantum physics and it is actually peripherally a math problem rather than a physics problem.
Why is this important to Physicist cred? If you aren’t a physicist, you won’t understand why group theory is interesting. Your reaction to this problem should tell you something very strong about whether you should use the word “physicist” to describe yourself or not. Sorry, I can’t change the reality of what we are.
Problem 18) Write the character table for translational symmetry (Correction: discrete translations on a 1D lattice). Propose a viable candidate for the 1D representation and explain the associated eigenstates.
Why does this matter to Quantum Physics? Can’t mention group symmetry without spending a moment talking about Bloch theory. This is like taking the particle-in-a-box problem and putting it between mirrors.
Why is this important to Physicist cred? If you truly understand this, you can go tell Intel how to dope their semi-conductors. Yes, I just gave you microchips; without us, you wouldn’t be poring over this screed on your smartphone.
Problem 19) Is a Cooper pair a majorana fermion? How is the Fermi temperature associated with the disappearance of electrical resistivity in a cold solid?
Why does this matter to Quantum Physics? Can’t mention semi-conductors without going whole hog and mentioning superconductors. Majorana fermions are a concept that is still argued in many domains of quantum physics. This question is actually fairly qualitative… if you want to go the physicist route, I would suggest using the eigenstates from the particle-in-a-box problem and describing a fermion next to a boson. If you really want to impress me, pull a page out of a Feynman book and derive the partition function for fermions.
Why is this important to Physicist cred? Remember that 4 Tesla magnet in problem 14? Probably can’t build that without the super-conductivity mentioned here (full disclosure, we can do rare earth magnets that are that strength too, but again, real physicists are responsible for this). Maybe someday superconductors will give us floating trains.
Problem 20) Use the Roothaan equations to do a restricted self-consistent field calculation in order to determine what the ground state energy of propane is.
Why does this matter to Quantum Physics? I’ve recently done a version of this problem from scratch on my own time and I couldn’t rightly produce this quiz without adding it. This is starting to push against the limits of quantum physics. This problem matters because it is one of the few ways that we can determine wave functions of real systems more complicated than problem 13. If you legitimately try to do this problem from scratch by hand, you will discover that it is one of the most frighteningly difficult things you’ve ever done. As a supplement to this problem, when do relativistic corrections become necessary? What’s the Hartree-Fock limit and what do people do to try to get around it?
Why is this important to Physicist cred? This is one of the chief tools by which we understand the structure of atoms heavier than hydrogen. A Nobel prize was awarded for work automating the solution to this problem. For full disclosure, this prize was awarded in chemistry, but keep in mind that it is pure physics in the sense that modern chemistry is almost totally dependent on quantum physics. The automation for solving this problem is broadly disseminated in the hands of normal chemists so that they can design molecules without having to trudge through the nightmare of this physics problem for themselves.
Problem 21) Why does the Klein-Gordon equation imply antimatter?
Problem context: Buckle up sports fans, the ride gets bumpy from here. For mathematical context, Klein-Gordon equation is a low level relativistic analog to Schrodinger equation.
Why does this matter to Quantum Physics? Schrodinger equation is actually a manifestly classical construction. I’m sure this probably throws a wrench at the Quantum U worldview with me just somehow colliding the words “classical” and “quantum,” since Schrodinger’s equation is fundamentally the backbone of quantum physics as far as most people understand it. But, it’s actually true; Schrodinger’s equation has a pseudoclassical limit in that it assumes that information travels between particles without a speed limit –you derive Schrodinger’s equation by putting non-commuting operators into the equation I initially introduced you to all the way back in problem 1. Klein-Gordon is derived the same way, but from putting the non-commuting operators into the relativistic energy-momentum relation. In this sense, Schrodinger’s equation is a form of classical (in the sense of being non-relativistic) physics. One upshot from this is that you must be very careful about claims of simultaneity that hinge on non-relativistic quantum physics; like say, collapse of entanglement (you cannot tell the other guy that he should look at his particle, or what you saw when you looked at your particle at faster than the speed of light). Klein-Gordon implies antimatter, but this is actually understood in retrospect; Paul Dirac (another luminary you may not have heard of) suggested it from the Dirac equation, which is a fermionic analog to the bosonic Klein-Gordon. Disturbed by all this reference to math? Don’t be; this is what physicists do… they look at math used to represent reality and then make claims about reality based on that math. For the tenth time, a “physicist” who does no math is not a physicist.
Why is this important to Physicist cred? Physicists suggested antimatter to the world. Antimatter isn’t exactly sitting on every table or in every gas tank, but it does have at least one practical application. Have you ever gone to the hospital to get a PET scan? That’s positron emission tomography, which uses antimatter to make tomographic images of the human body. What, another real medical application that actually is known to work. Don’t believe me? That’s fine, go back to tending your cupping bruises and hope that nobody screwed up.
Problem 22) Show that non-relativistic path integral formalism is equivalent to Schrodinger’s equation.
Problem context: Yes, integrating along a path is mathematical. No, you can’t escape math if you’re in physics.
Why does this matter to Quantum Physics? Path integral formalism is a big part of everything that is used in high energy physics. Path integrals are introduced early in your quantum physics education, but they don’t become really important until gauge symmetry is introduced and you start working with functionals on fields. That’s right, no quantum field theory without path integrals. A more basic demonstration of path integral formalism is to show that in non-relativistic terms, it’s equal to the more basic Schrodinger’s equation. It’s a tricky conceptual proof that shows you really understand your quantum physics. And, no, I won’t do it for you.
Why is this important to Physicist cred? You want modern quantum physics, this is one route to it.
Problem 23) Two uncharged thin metal plates are placed in a vacuum such that they lie with surfaces parallel to one another. Explain why they spontaneously exert force on one another. How much force do they exert and how does it vary with distance between the plates?
Why does this matter to Quantum Physics? This is the set-up for Casimir effect. Welcome to the bizarre world of zero-point energy and vacuum fluctuations. Yes, this is a real thing.
Why is this important to Physicist cred? Someday, maybe this will form the basis of a science fictional star drive which requires no exhaust. Until then, it’s pretty curious and kind of cool. One thing to remember about the bleeding edge of physics is that many things we learn about do not always find technological application. Sometimes, the insight which leads to an application is years away. But, it requires having the real basis and not just the ability to spout nonsense technobabble. If you can apply Casimir effect to build something useful, be my guest… my hat will be off to you if you can actually prove you’re doing it.
Taken from INSPIRE high energy physics, these are Feyman diagrams for production of the Higgs Boson. Use these diagrams to write the Lagrangian for coupling to the Higgs field.
Why does this matter to Quantum Physics? Several somebodies won a Nobel prize for this. If you don’t get why and are claiming to be a physicist, shame on you.
Why is this important to Physicist cred? Good question. You tell me. Why?
Conclusion: This quiz could go a long way. I have to tie it off because I only know so much myself (words of wisdom: know thy limits!). There is so much real physics in quantum mechanics that specialists in the various subfields could add questions forever beyond my single class in QFT. Why does renormalization work? What is a topological insulator? Why do people try to build computers using atomic spins for bits? How is it that Chinese scientists are passing undecryptable messages to themselves? Why why why? A thousand questions with a thousand real answers. Anybody wasting time pretending they are learning anything about reality at Quantum University will never be able to answer any of them. They will continue to putz around and make believe that they know more than everybody else, calling themselves physicists, even though they do no math and therefore no physics.
There was a discouraged comment provoked by this post that I would like to try to respond to.
The comment was that this quiz was very good, but that it showed the speaker that he/she should leave physics to the professionals (essentially). This is paraphrasing.
Professional physicists have to deal with the feelings that have apparently been elicited by this quiz. Physics scales in difficulty to match your capacity for understanding it –it literally gets harder and harder until you can’t go any further. As a discipline, it was created by a collaborative effort among some of the smartest people who have ever lived. The physics written in books is one big act of genius, the sum total of all the eureka moments of these smartest people. It is every life’s work and piercing insight all at once! Nobody measures up to that. Nobody understands it all. Of physics as a whole, quantum physics is one of the hardest parts.
This is maybe one of the most difficult things that human beings have ever learned in the history of the world.
If it feels daunting to you, that’s the way the truth works. Coming to grips with that is necessary in order to move forward. Nobody understands it all. At the oceanside, it’s easy to walk on the beach and visit the shallows. But, if you swim out into it, at some point it gets deeper than you can handle. Not even Michael Phelps can swim from San Francisco to Tokyo.
There is a reward for coming to grips with that. Physics is built on the genius moments of some of the greatest geniuses that there ever was. If you study what they did and come to understand what their work actually means, you can have that spark of insight that the very best of us have had. If you want to understand what Einstein’s genius was, for instance, studying his work directly is a way to commune with him. Working really hard and finally breaking through and really seeing it is like nothing else.
Nobody gets it all, but most of us come to grips with the fact that nobody has to. See what you can see and enjoy the trip. There are gems even in the shallows.