Friday, November 4, 2016

I always feel Stupid and Confused

I often get emails asking me about physicist questions.  Sometimes I can't resist answering, especially if it's a simple problem on a fundamental principle.  Try answering the question without looking at my solution, and then check my work to see if I got it right.


Hello Professor -

My name is **** and I’m a WSU alum.  My daughter is taking honors science and we are a bit stumped on a question and I was wondering if you could help me.   

A 5 kg ball rolls at 4m/s and hits a fire hydrant.  The ball bounces off at 2 m/s. 

Which object has the greatest momentum.  The ball, hydrant, or is it the same? 

Ball - I chose ball because of the definition of momentum.  The fire hydrant is not moving – the ball is.    And the question is not about force and gives no other information about the hydrant.

If you have a second I’d love to know if I’m correct, or if there is a different answer and explain it to me. 


Hi ****,

I'm assuming that the question is asking for the momentum of the two objects just after the collision.  This problem is testing the concept of momentum conservation.  Momentum conservation ALWAYS holds even when mechanical energy is not conserved.  This is the principle to understand and apply.

Here is how I would solve the problem.  The initial moment of the ball is + 20 kg m/s and it's momentum just after the collision is - 10 kg m/s (assuming it bounced backwards).  Thus, the change of momentum is - 30 kg m/s.  But since momentum must be conserved, and it was initially 20 kg m/s, the ball must have imparted 30 kg m/s to the hydrant.  Now, momentum is conserved: 20 kg m/s (ball before collision) =  30 kg m/s (hydrant) - 10 kg m/s (ball after collision).  It seems strange because you can't see the hydrant moving but that is because it has so much mass.  So even though its velocity is near zero, the mass is so huge that the momentum is substantial.

The reason that I stipulate "just after the collision" is because the hydrant is attached to the earth, so while it might initially start to move one way, it will end up vibrating back and forth.  Probably more detail than you wanted to here, but just in case you were curious.  Another brain teaser: if the hydrant is oscillating after the collision, the momentum is oscillating too, so momentum seems not to be conserved.  The answer is that the hydrant is attached to the earth, so the earth and the hydrant will move in such a way that momentum is conserved.  It always needs to be conserved.

Don't let your daughter feel frustrated.  Applying physics concepts to problems is very difficult.  You only learn after making lots of mistakes, so have her learn from them.  When teaching any physics class, I give lots of problems of this sort, and some students get angry, accusing me of trying to trick them.  In attempting to do problems and then seeing the right way after struggling somehow results in it sinking in in a way that cannot be replicated by just giving the learner answers.

I don't want to undermine the teacher, who is probably giving the class a bunch of problems of this kind to train them to think, so I don't feel comfortable answering such questions in the future, because the struggle is an important part of learning and the teacher is, I hope, directing the struggles in a positive way.  Your daughter should attack problems by arguing with classmates, you, or whoever is up for a good fight.  My colleagues and I continue to do this even now as we learn new things.  Being able to thrive on being constantly confused in the quest to understand is the ticket for success.

I wish your daughter the best in her studies and tell her from a guy who is constantly confused and feeling stupid, this is the way it should be.  And don't give up!

(Pardon the typos, since I didn't have time to proof my email.)


Mark G. Kuzyk
Regents Professor of Physics
Meyer Distinguished Professor of Sciences
Washington State University
Pullman, WA 99164-2814

Phone: 509-335-4672
Fax: 509-335-7816

Web Page:

Monday, October 31, 2016

Letter to Trump

Dear Mr. Trump,

How can you call Hillary Clinton a liar when according to Politifact you lie over 70% of the time and she lies less than 30% of the time?   Don’t blame this inconvenient fact on the “liberal” media.  The world is not divided into only liberals and conservatives who buy the party line.  Unlike you, the geeks at fact-checking organizations are interested in the truth.

How can we not believe your female accusers when their charges portray the same man that you brag about being?  The respectable people that your victims confided in witnessed the anguish you caused, bolstering the likely veracity of their claims.  The fact that some other men behave deplorably does not absolve you.

Why do you call yourself a successful businessperson when you lost almost a billion dollars in a boom economy by making several unwise investments?  Through self-promotion, you gained celebrity status and used it lure investors into bad deals where you won and everyone else lost.  You routinely default on your financial obligations to small businesses and litigate against people that have offended you.  Ethical business people make deals that benefit all parties.  Will you be able as president to suppress your ego and represent the best interest of the United States?

How can you be trusted to make complex decisions when you do not solicit input from experts?  Solutions to modern-day problems require an informed leader who carefully weighs input from knowledgeable sources.  You treat your opinions as fact even when they contradict the evidence.  You state that climate change is a hoax perpetrated by the Chinese government.  Nonsense.  Even a well-seasoned PhD physicist such as myself is unqualified to judge science outside my field without input from the experts.  My conclusion that anthropomorphic climate change is happening draws on my knowledge of science and the consilience of evidence in the climate science literature.  Do you plan to continue to spew uninformed opinions that go against the evidence?  Doing so as the most powerful world leader could jeopardize the existence of humanity.

How could you not have known that Russia had invaded Ukraine and annexed Crimea?  When informed that Russia had already done so, you stated that it was your understanding that the people of Crimea rather be with Russia.  How would you react if Mexico annexed southern California because people there would rather be with Mexico?  Those with aspirations of being a world leader should be keenly aware of current events. 
Why do you bash the media?  The founding fathers so highly valued the need for a free and independent press that they elevated this principle to prominence by including it in the first amendment.  The media is an essential part of our democracy.  It informs our citizens and keeps politicians honest.  The media, which you so despise, has given you $3 billion dollars of free coverage, so do not complain when the facts investigators uncover are inconvenient.  Punishing the media would be an affront to the core principles of our democracy.

How can the elections be rigged?  A recent study showed only 30 cases of voter fraud out of a billion ballots cast.  You claimed, “People that have died 10 years ago are still voting,” and cited a report that found 1.8 million deceased people remain on voter registration rolls.  The fact that it takes time to remove people from the voting rolls does not mean that others are voting in their places.  In fact, studies show that such cases are extremely rare.  You also claim that “illegal immigrants are voting,” citing research from Old Dominion University.  The Harvard professor who manages the database says that this study misuses the data and that in fact very few undocumented residents are voting.  If such election fraud really existed, don’t you think that the offended party would be investigating?

How can we discount your behavior as indicative of an individual who is adept at self-promotion but shows contempt for the facts, takes pleasure in unsubstantiated conspiracy theories, refuses to accept criticism, acts impulsively, and lacks the nuanced thinking needed to make rational decisions?  Even if your ideology coincided with mine, a Trump presidency would terrify me.  Can you convince us that you have the temperament and wisdom to lead this country?  Your actions provide the strongest evidence that you do not.  Though you repeat how great things will be if elected, you have not outlined a plan to get us there, nor do you appear to have any new inspirational ideas.  Instead, you offer scapegoats and platitudes.

In my opinion, there is no evidence that you are fit to lead our nation.  Your inability to reason logically and your refusal to heed expert advice that contradicts your gut will be disastrous for our democracy and civilization.  However, if the people elect you, I will go along with the results and work towards proving me wrong in these assertions.

Mark G. Kuzyk

Saturday, September 24, 2016

A Journal Reviewer who gets the point

Even as a senior professor, I still cringe at negative reviews of my work.  It's nice to occasionally get a good one, as I did for a recent paper.  Below is the review:

Review of “A path to ultralarge nonlinear‐optical susceptibilities” by Mark G. Kuzyk

This paper is essentially a quantitative ‘stream of consciousness’ of its author as he ruminates about the origins of the nonlinear polarization in molecular‐scale objects.  Not every author could get away with this type of discourse, but this author is the pioneer of explorations of the fundamental limits of nonlinear optical phenomena and also the founder of the fundamental understanding of scaling phenomena in nonlinear optical molecules.  Those two achievements enable the author to precisely reveal the essential elements of what constitutes a good nonlinear optical structure in this most original of works.

The present paper brings together the two concepts of limits and scaling to attempt to understand how to build a quantum unit (a molecule, in the author’s nomenclature) whose absolute nonlinearity gets large with size when its intrinsic nonlinearity is constant with molecule size.  Many of the scaling concepts are familiar to readers of his papers, but this paper appears to be the first to step back and take a close look at the origin of nonlinearities as a function of the number of participating electrons.  The author carefully examines the quantum to classical transition and shows that the ideal system is made of microscopic units whose size falls just below the classical limit, provided they are properly arranged in the bulk form.  The author examines scaling in 1D and 3D, showing that the existence of transverse modes in 3D essentially removes electrons from participating in the nonlinear response, whereas in 1D, all electrons are longitudinal and can participate, provided they aren't otherwise tied up keeping the molecule bound together or living in shells close to the nucleus.  The emphasis on ‘participating’ electrons isn't new, but their use in scaling arguments appears to be original.

The author emphasizes the need to optimize the so‐called figure of merit (FOM) of a material, a macroscopic quantity related to the physics of a device or phenomena exploited in a device.  Recent work by Mossman et al. has shown how this works using resonant enhancement in a nonlinear material.  The fact that the present paper raises the issue of FOM optimization indicates an attempt by the author to shift the collective discussion of how to make better molecules from a focus on better nonlinearities to a focus on better materials.  The reviewer believes this paper may be referenced in future years as a turning point for the field of nonlinear optics materials research, much as the author’s 2000 Phys. Rev. Letter on the fundamental limits led to discoveries of the origins of large intrinsic nonlinearities, delineation of the required spectral properties of good molecules, and the invention of new materials.

In brief, it is an excellent, original piece of work and should be published.

My original pleasure induced by these strokes to my ego dissipated quickly.  I detest authority and would not want to become one.  Everyone should make judgments based on the strength of the evidence, not on the source.  I don't want to be given a free pass, nor do I want to impose my will on others.

Accepting the title of "authority" admits to stagnation.  I would rather be exploring new territories, filled with confusion but fueled by a drive to seek an understanding of the mysterious novelties that are just out of reach.  Answers always lead to more questions, like a series of stepping stones that stretch out in all directions with new branches emanating from each one.  The stepping stones in the distance are an alluring draw from the familiar ones that I have visited.  I yearn for them.

My many years as an academic have brought me great fulfillment in making discoveries and learning new things in the companionship of students and colleagues.  It keeps me young.  On the flip side, I am burdened by responsibilities that are neither intellectually stimulating, nor produce any tangible benefits to my constituents.  I stand at a crossroads where I am bursting with ideas that are squelched by inane responsibilities.  Should I abrogate my duties and dive into my research, whose benefits I know will surpass my selfish desire to learn, or should I continue to be a loyal soldier, obeying orders that restrain intellectual creativity?  It is a decision that I alone need to make, and nobody can lesson this burden.  The sense of responsibility yanks me away from my passions.

I dream of becoming a recluse for a summer or a semester, surrounded by my books and doing calculations on  huge sheets of paper, without interruption.  I would have to ignore funding agency reporting requirements that ask the same questions in 14 different ways, as if to excise every bit of creative energy.  I would have to ignore annual reviews that force me to waste a day filling in boxes in a form that neither makes the provided information clearer or more assessable.  I would have to ignore calls for proposals, which require researchers to come up with ideas that are not so novel as to not be appreciated, but beyond trivial so that reviewers can be impressed.  I would have to ignore nagging emails that incessantly interrupt my train of thought. Ignoring these activities would surely result in a loss of funding, something that the university expects, but that I wouldn't need.  Is it ethical to use the security of my tenure to ignore expectations that come from above even though I believe the university would potentially benefit more in the long run?

The guilt strings pull at my gut as I spend time writing this post, even though I'm at the keyboard at 9:00pm on a Saturday night -- a time that should be my own. Airing out these frustrations, I hope, will be an exercise that will help me sleep, which has not come easily these days. The obligations that are pulling me in multiple directions prevent me from making any meaningful progress in my most important activities, and I lay in bed in panic that I will miss important deadline.

The check list on my desk has many items that need attention.  I just finished grading and need to prepare for lectures, make up homework problems, and solve them -- a process that I find deeply fulfilling.  Next I need to reply to the reviewers' comments and revise my manuscript.  Rereading my manuscript, which is necessary when making revisions, is like visiting with old friends and rehashing the past, a pleasant pastime where ideas are batted around and reformed.  Since my colleagues were kind enough to review my manuscripts, I am ethically bound to act as a reviewer when asked.  Obligations of this sort are made many times each day, so I must accept the fact that I will never be able to withdraw fully.

Now it's time to get back to responding to the reviewers and revising my paper.  The details in the reviews suggest that both reviewers took the time to critically read manuscript and understood the nuances of my paper. For this I am grateful and excuse them for implying that I am an authority.  Since it's almost 10:00pm, it's time for me to complete this post.  No time to proof it.  No apologies.

Saturday, May 28, 2016

We Deserve the Lies

This election season is the most bizarre that I have ever seen.  The electorate seems to care more about the message (jobs won't be leaving the US anymore, free tuition for all, there is no drought in California, ...) than on sound policy that will get us to where we want to be.  The few details that are given by the populist candidates show a gross misunderstanding of how things work, and is proof that they will be ineffective leaders with potentially disastrous consequences.  Yet the moths continue to be attracted to the flame as untruths fill the airwaves and internet.

I blame the stupidity of the electorate as the source of the problem, and part of me feels that the people deserve the candidate that they elect.  This reaction comes form the gut, which we know is not the ideal source of sane information.  I therefore decided to write an op-ed piece that spells out the facts without emotion.  It appeared in print 12 hours after I submitted it to the Moscow-Pullman Daily News.

For those of you who don't get the Moscow-Pullman Daily News, the opinion piece is reproduced below.

The presidential candidates are being unduly criticized for lying. The fault is not in our politicians, but within us.  We want to hear lies that confirm our dearly-held ideologies.  The pleasure centers of our brains burn brightly when our ideologies are reinforced, and turn cold in response to nasty facts that contradict what we wish to believe.  As a result, we reward candidates who lie to us with our votes.

Lies uttered by ideological adversaries are easily discerned as such, but objectivity is lost in proclamations from ideological bedfellows, fortifying the ideologue’s certainty.  No wonder that the electorate is so polarized and government deadlocked.

The overwhelming evidence for human-caused climate change is extinguished in the deniers’ minds when Sarah Palin smugly asserts that she doesn’t believe it.  Hell with them 97% of climate scientists who are convinced by the data.  Hell with consilience.  The deniers know better, delightfully wringing their hands as they cherry-pick for scraps of data that validate their faith.

Those who believe that vaccines cause autism don’t want to hear about the lack of evidence for their convictions.  They prefer testimonials to facts, confuse correlation with causation, and scour the internet in search of “evidence” that supports their ideology rather than the medical research.  Protesters against genetically modified foods are not dissuaded by the dearth of supporting facts.  Instead, they write it off as a corporate conspiracy.  Alien abduction zealots, on the other hand, point to a government cover-up.  The list goes on.   This pathology cuts across party affiliations.

The defense against self-deception is the scientific method; but, even science has come under attack when it conflicts with the ideologue’s cherished beliefs.  Science is implicitly humble, admitting that truth is difficult to come by.  This tiny perceived flaw is attacked by the ideologue who equates his or her gaping ignorance with the small uncertainty of science -- no matter how tiny -- proclaiming that “science is uncertain, so my belief in biblical creation, denial of evolution, and conviction in a 6,000-year-old earth is as valid as the science that conflicts with this view.”  The fact that we can never be 100% certain does not make all beliefs equal.

Reality, rather than wishful thinking, drives complex technologies and social institutions on which we depend.  Solutions to problems require a deep understanding of how things work, which guides a nuanced course of action that is not amenable to soundbites and campaign slogans.  Often, the optimum response is counterintuitive and defies common sense.  Ideology coopts reason and leads to actions that run counter to our priorities.  If we are truly interested in solving societal ills, we should set aside subjective passions and act upon objective evidence.

The next time you become irate by the lies, take a look in the mirror.  The politicians will continue to lie to us as long as we continue to lie to ourselves.  It’s time for us to make an effort to be honest with ourselves and to apply some scientific thinking in our lives.  Only then can we come together and begin to solve the horrendous problems that lie ahead.