The Hunt For Axions

Axions, which in some circles is a Dark Matter candidate different from WIMPs, is the focus of this news story.

This is kind of a Cinderella story – the story of a favorite and an underdog, in what may be the world’s most esoteric sport. The leading candidate for what might make up dark matter is called a weakly interacting massive particle, or WIMP. It gets most of the research money and most of the ink.

But there’s another candidate, a bit of an also-ran, called the axion. Its profile is lower, but for Rosenberg, it just seems to fit in with how the universe works.

Of course, as with WIMPs, the search for axions has also been fruitless so far, as I've mentioned at least a couple of times earlier. We just have to sit back and wait to see how this develops in the next few years.

Zz.

The Awesomest Physics Cake Ever?

I don't know if it is, but it certainly takes the cake (pun intended) for being quite creative! I wouldn't mind getting a cake that looks like that, or some variation of it with some condensed matter theme or accelerator physics theme......

Hum... I think I've come up with an idea for something. Wonder if my local bakery can make it?

Zz.

Don't Miss Looking At The Trees Due To The Forest

This is a report on a proposal to enable us to view a "movie" of a Rydberg atom:

In addition to having a large electron cloud, an unusual feature of a Rydberg atom is that its highly excited electron can exist as a coherent superposition of several different atomic orbitals. These orbitals interfere with each other, which means that the electron cloud changes shape with time. These fluctuations are much slower than the movement of electrons nearer the atomic nucleus, which is why Kirrander and Suominen argue that the fluctuations could be tracked by firing intense and coherent pulses of X-rays at the atoms.

Such pulses can be produced at accelerator-based free-electron lasers such as the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory in California or the X-ray Free Electron Laser (XFEL), which is set to come online at DESY in Hamburg, Germany in 2016. Kirrander and Suominen have also calculated that the motion of the corresponding "electron hole" in the atom – the superposition of inner orbitals that the electron has left behind – can be visualized as well. As the inner electrons are involved in chemical reactions, the new technique could therefore be a powerful tool for chemists.

When I said not to miss looking at the trees, most people reading the article will be enamored by the proposal that we can actually view such a thing in real time, that we can see the evolution of such an atom, and the potential that we can view the dynamics of a lot more system having such short time-scale. These are the "forest".

The trees here, which *I* am more interested in, and what most people will have missed, is the advancement made in accelerator physics that allows the ability to make such a measurement. The instrument being used is within the realm of accelerator physics, and specifically, the study of beam physics and engineering. This field of physics is often the unsung hero that enables the advancement in many other fields of physics. Think of what the LHC and the Tevatron could do without advanced knowledge of accelerator physics.

And this brings us to a very important point here. Many areas of science can only advance in knowledge when they have the ability to perform the experiments that they want. Inevitably, this means that that they have the equipment and tools to be able to do these experiments. This ranges from high-spatial-resolution instrument to high-temporal resolution detectors. In other words, they depend on others to provide them with the instruments to advance their knowledge.

It also means that if you kill research in these grass-roots areas, you are killing more than just one area. When a lion killed the nursing mother of deer, for example, that lion took not one, but two lives with that kill. When funding for many of these areas of physics is severely reduced, the chain reaction and impact can trickle very quickly down stream. It affects the advancements in many other fields that would have gotten the benefit from it. Think of how many different usage of facilities such as a synchrotron light source or a free-electron laser.

So when you read an article such as this, don't miss paying attention to the fact that these proposed abilities to do such-and-such are benefiting from the advancement and investment in another field that you might have not realized. The interconnectedness of science is never more apparent than in an example such as this.

Zz.

"A physicist examines the Kennedy assassination film"

With the anniversary of the Kennedy assassination recently, a slew of TV shows and articles on that tragic event came into being. One of the more fascinating documentary was on NOVA. One of the biggest source of controversy, and the source for many conspiratorial theory that there was more than one shot at the President on that day was the examination of the way the President's head moved upon impact of the bullet. Many believe that the fact that the video showed the head moving backwards, i.e in the opposite direction that the Oswald bullet entered, showed that there must be another bullet that entered from the front.

The NOVA documentary appeared to have ignored a physics explanation that had been put forward to explain this many years ago. David Jackson, the editor of AJP, expressed his surprise that a well-respected documentary such as NOVA let this observation stood unanswered. He wrote his commentary on this in the Jan 2014 issue of AJP.

But not only that. Due to the anniversary, and wanting to make sure the public knows that there's a perfectly valid explanation to account for what was observed using just a single bullet from the back picture, AJP is making Luis Alvarez paper from 1976 freely available.

Maybe someone from NOVA might get to read it!

Zz.

Ingenious Quantum Physics Essay?

I don't think so.

Sometime people are impressed by the wrong thing. A toddler can sometime be more fascinated by the box  rather than the toy itself. This time, it is almost the same thing.

A physics student (didn't say at what level) wrote an essay on "quantum physics" and did something that is called "Rickroll", whereby he included the lyrics of Rick Astley's "Never Gonna Give You Up" in the essay. You are welcome to read the tedious essay at the link.

And for that, he gets notoriety, not for the poorly-written essay, but for his ability to stick such nonsense into it. And let's say it for what it is, this is an awfully-written essay. It is devoid of paragraphs, and the "story" here is extremely disjointed. The history of quantum physics and Bohr's contribution was chopped up, there never really a clear description on what Bohr's major accomplishment was. But then, he was focusing more on trying to match up on the lyrics rather than paying attention to the material. I wonder if his teacher gave him a D- for something like this? I would, but then I'm a curmudgeon.

So yeah, I was more interested in the toy rather than the box. Unfortunately, in this case, people are so enamored by the box, they didn't realize how awful the toy was.

Zz.

The Ghost Particle

No, not the often-used "god particle" that was designated to the Higgs, but rather the "ghostly" particle being used to describe neutrinos.

This NPR review of Ray Jayawardhana's book "Neutrino Hunters" has some basic intro to the history and mysteries of neutrinos if you are not familiar with it. And it is certainly true that, unlike the Higgs, the study of neutrinos has not received the same amount of publicity that it should have.

Neutrinos rarely get the press they deserve. Writers love to wax breathless about Higgs Bosons, antimatter, hypothetical thingies like tachyons (faster-than-light particles) and, of course, whatever makes up Dark Matter. But the ghostly neutrino turns out to be essential to everything from the physics of the early universe to the fusion reactions that keep the sun burning to the supernovas that light up the cosmos.

But as important, while the US has completely closed down all high energy collider physics, neutrino physics is the one area in which it still has a lot of involvement, both within the US and outside. Current projects within the US such as MINOS, NOvA, etc. are pushing our knowledge in neutrino physics, and future projects such as LBNE should ensure, if it gets continued funding, that the US will have a strong involvement in neutrino physics study.

BTW, if there's any crackpot out there who thinks that by calling neutrinos as "ghost particle" allows them the poetic license of justifying the existence of "ghosts", then they'd better read an earlier blog entry I made on this. Don't laugh! You'd be surprised at the extent these crackpots will go to simply to justify their incoherent and faulty logic.

Zz.

No Evidence of Time Travelers From Scouring the Internet

I mean, really!

As my first candidate of the year for the Ig Nobel prize, we have a couple of physicists who went looking for evidence of time travelers by examining the internet. Their work, which I think is still unpublished yet, was covered here.

Robert Nemiroff and Teresa Wilson from Michigan Technological University’s physics department developed a strategy for tracking down time travellers by trawling the internet for references to prescient information posted before it should be possible.

For instance, they searched for mentions of “Comet ISON” prior to its discovery in September 2012, theorising that it was a large enough event that it would be known to those even far in the future and possibly mentioned online by accident after they travelled back in time.

Similarly, they looked for mentions of “Pope Francis” proper to March 2013, as the current pontiff is the first to have ever had the name.

The researchers scoured popular search engines such as Google, but also turned to Twitter and Facebook.

To cut an amusingly long story short, they found none.

Unfortunately, they were forced to conclude that no time traveller has ever come back from the future and left visible clues online.

“Although the negative results reported here may indicate that time travellers from the future are not among us and cannot communicate with us over the modern day internet, they are by no means proof,” they said.

“There are many reasons for this. First, it may be physically impossible for time travellers to leave any lasting remnants of their stay in the past, including even non-corporeal informational remnants on the internet. Next, it may be physically impossible for us to find such information as that would violate some yet-unknown law of physics.

“Furthermore, time travellers may not want to be found, and may be good at covering their tracks.”

They forgot one other reason. These time travelers knew that these two will be trying to trace them via such means and thus, made sure they did not make any such comments as to give themselves away.

:)

Zz.

Where To "Apply"?

Last last year, the American Physical Society (the publisher of Phys. Rev. family of journals) announced that they are soliciting submission for a newly-created journal under their wing. Called Physical Review Applied, the call for papers reads:

The editors are encouraging scientists to submit their theoretical or experimental work on materials science, surface and interface physics, device physics, condensed matter physics, optics and any intersection of physics and engineering. The journal will publish both short letters as well as longer journal articles.

Now, of course, those of us who are familiar with the various physics journals will wonder, is this new APS journal competing directly with the American Institute of Physics's family of Applied physics journals? The AIP already has a couple of established applied physics journals, namely Applied Physics Letters, and Journal of Applied Physics. From the description of Physical Review Applied, it looks like they are looking for the same type of papers as APL and JAP.

For those of us (including me) who do work in the applied fields, we certainly won't complain that another journal, especially from the well-established organization such as the APS, providing another avenue for us to consider for publication. We just have to figure out the level of standards that they will adhere to for publication in the new journals.

Zz.

Particle Fever

It looks like there is a documentary film about the search for the Higgs making its way around film festivals. Other than the uninspiring title, Particle Fever seems to be getting a rather good review. I am more impressed that the people responsible for the production of the movie are really physicists themselves.

It’s crucial for starters that the subject is second nature to the filmmakers: director Mark Levinson earned a doctoral degree in particle physics from Berkeley before veering into film, and producer David Kaplan, a professor of theoretical particle physics at Johns Hopkins, has also been active on History Channel and National Geographic science programs. They’re able to simplify and synthesize without dumbing down the material and put non-science-oriented viewers at ease by drawing a smart parallel between science and art: Both endeavors ultimately represent attempts to explain our existence and our place in the universe.

I'll have to check and see if and when they'll show that in my neck of the woods. Have you seen it? If you have, what did you think of the movie?

Zz.

Starting Fire In Water

The ISS might be useful after all, in addition to having the AMS. From this video, you get to at least learn about some of the properties of supercritical water.



Zz.

"Telling You the Answer Isn't The Answer"

I made a blog post earlier on why it is not advisable to help anyone who simply claimed that he/she doesn't know where to start, at least not in the sense of giving the person the starting point without first figuring out where the problem lies.

In a related blog post, Dr. Allain Rhett wrote about why Telling You the Answer Isn’t the Answer. Here, he clearly described the process of learning, at least in science, and why simply giving you a set of information does not make you understand anything. In fact, the process and the struggle of trying to learn something IS, in fact, the necessary part of learning and understanding. Note also that the exercise he gave was quite similar to how I want to revamp the undergraduate intro physics lab, whereby the students are really not told on how to do things, but rather simply given a task to find out about certain behavior and relationships.

I've always emphasize this notion that being aware of the learning process in science has benefits that extends beyond science itself. I see this way too often in our world where people simply accept things being told to them, without even making evaluations of the validity of these things. Even less, they can't even make the logical connection from one to the other (see Rhett's example on why it is warmer in the summer and how students can't explain why even when it is told to them!). This is an extremely clear example where one has all the facts that one needs, but one simply is unable to make a logical and sequential connection of cause-and-effect. It is an extremely clear example where just because one has the information, it doesn't mean that one knows what to do with it!

We only need to look around us at stuff happening in the news, and the things being uttered by talking heads on TV. Try it some time. Figure out, if you are able to, how many of the numerous statements that you see being uttered in the media actually (i) have  verified, supporting evidence and (ii) have  logical connection in which A causes B.

Proper science education is needed not to turn people into scientists, but to teach people to think and analyze!

Zz.

Highlights Of The Year

APS Physics lists the highlights of the year from papers published in the APS family of journals. I'm glad to say that I mentioned many of them on this blog when they first appeared.

Zz.

Q&A With John Pendry

This is a quick question and answer with John Pendry, the person responsible for many of the physics behind metamaterials. I can totally understand why he gets tired of having being repeatedly asked about the "invisibility cloak".

Valerie Jamieson: Invisibility cloaks can guide light around objects as if they weren't there. It is awe-inspiring physics. So why the frustration?

John Pendry: It's when I give talks, particularly popular ones. Of all the things I am interested in, I am always asked about invisibility cloaks. I think, "Oh God, not another invisibility cloak lecture." I still enjoy giving them, but there are many other things I'm working on that are more profound; they just don't have that fertile soil which J. K. Rowling prepared for us.

Zz.

More Update On Feynman Lectures Online

I've been posting updates on the availability of the infamous Feynman Lectures online. Mike Gottlieb has posted a new update on Vol. 2 at Physics Forums.

I have just posted FLP Volume II at The Feynman Lectures Website and at it's speedy Caltech mirror. This more or less completes the online edition of the book, though there are still some improvements to be made that I will be working on as time allows. For example: in Volume II you will notice under the title of many chapters (linked) recommendations for review of chapters or sections in Volumes I or II, references to other books and papers, and helpful reminders such as, "In this chapter c=1." Though this kind of supplementary information was never present in Volume I, it is present in (the printed and PDF editions of) Volume III but is currently missing from the HTML edition, and I intend to add it. I also plan to improve the tables, and the typography of the text and mathematics in Volume I, and to improve figure and table placements throughout all volumes.

In addition to posting Volume II, I have made some systemic style changes. Previously the pages had margins 70 pixels wide on each side. I have reduced that to 10 pixels (max) on the left, and 65 on the right to make room for the floating menu, which is slightly narrower and now also includes a "style changer," implemented mostly for the sake of iOS users who wrote to inform us that our text was un-readable on their devices: too small. The default font sizes are the same as before (12 pt body text), but now you have a choice: you can scale the size of all fonts up by 125% or 150%, and when you do so the left margin becomes narrower and the text is no-longer justified, which saves screen space. You're style preference is remembered between pages and between sessions, so you should only have to choose once on each device you use to read FLP. (There was another problem too on tablets: our pages were sometimes not opening zoomed to fit the device width: now they should.)

I would also like to inform you that Dr. Rudi Pfeiffer and I have (finally!) completed the manuscript for our edition of "Exercises for The Feynman Lectures on Physics," which was started in 2008. It's 306 8.5"x11" pages include approximately 1000 exercises covering the main sequence material in all three volumes of FLP, with 28 pages of answers/solutions in the back. According to our Executive Editor at Basic Books, the exercise book will be available in paperback online and in stores in the summer of 2014. We will also offer a PDF edition in our "Desktop" format (the same as the printed book, but with margins all on the right). My next project will be to produce a "Tablet" edition of the new exercise book to go with our recently released Tablet Edition of FLP.

In closing, I would like to thank all those people who have written to us. You're appreciation and interest in FLP is very rewarding and encouraging. I wish to particularly thank those who informed us of _problems_ with our web interface, or errors in the text or equations of the online edition of FLP; you're input helps make FLP more accessible, and more comprehensible. So, please keep those emails coming!

Best regards,
Mike Gottlieb
Editor, The Feynman Lectures on Physics New Millennium Edition
---
www.feynmanlectures.info
www.feynmanlectures.caltech.edu

There ya go!

Zz.

Phil Anderson 90th Birthday Symposium

A symposium in honor of Nobel Laureate Phil Anderson's 90th birthday was held at Princeton this week.

The workshop to honor Anderson, the Joseph Henry Professor of Physics, Emeritus, and a senior physicist, was held Dec. 14 and 15 at the Frick Chemistry Laboratory on campus. About 150 colleagues and former students from as far away as India and Japan attended, as well as five fellow Nobel Prize winners and one Fields Medal recipient. The gathering was organized by N. Phuan Ong, the Eugene Higgins Professor of Physics at Princeton, and Piers Coleman, professor of physics at Rutgers University.

Anyone who has followed this blog for a while would have seen me mentioned Anderson's name a few times. He, of course, had a huge role to play in the formulation of the Higgs mechanism. And the discovery that bears his name, the Anderson Localization, has been a ubiquitous presence in condensed matter physics. But of course, he also championed the notion that More Is Different, an influential essay that started other physicists to question the reductionism philosophy.

The general public may not know him, but he has inserted his influence into our modern world.

Zz.

Making Better Fog With Dry Ice

In case you are ever in a school play that requires a lot of fog.....



Zz.

The Physics, And Metaphysics, Of Santa

We get this kind of articles popping up at this time of the year. So why not another one. This one has a bit more detailed description of what Santa has to do to accomplish what is said that he does (for a living). For example:

• How long would it take Santa to deliver presents to every child in the world?

Considering the 3.5 billion children on Earth (without regard to religion) and 500 million square kilometers of the Earth’s surface, Santa would need 14 years if he traveled at the speed of our fastest jets (Mach 10). Santa could finish the job in about 80 minutes assuming he travels at light speed — a timeline that even Amazon’s Jeff Bezos with his experimental army of delivery drones would find difficult to match.

Now, the more important message in this article is not really about Santa, or his reindeer, or even the problem being tackled. Rather, it is one aspect of science that is often neglected and what many in the general public aren't able to do. It was described as the "Fermi problem".

For non-geeks: Enrico Fermi was the landmark Italian-American physicist of the 20th century who discovered nuclear fission. “Fermi problems” are (in the succinct words of Wikipedia) “justified guesses about quantities that seem impossible to compute given limited available information.”

In other words, this is the wacky trivia that physicists love to debate after a couple of glasses of spiked eggnog. Santos calls them “back-of-the-envelope questions” and scratches out a typical solution within 5 or 10 minutes. He loves “the idea of being able to come up with something using as little information as possible.”

“It doesn’t tell you what the answer is,” he clarified of this more stringent estimation game. “But it tells you what the answer can’t be.”

This is often a crucial step whenever we think of something, especially when it is new. We make gross estimate of what the result should be, so that we know that at the very least, it can't be either bigger, or smaller, than such-and-such a number. But this requires, as you can see, a QUANTITATIVE understanding of it. You make an estimate and produce a value, rather than just a qualitative idea. It tells you of the SCALE of things.

For many people, this is what they do not have a feel for.

Zz.

"I Don't Know Where/How To Start!"

I get that type of plea often on physics forums and when students used to come and see me for help with homework-type problems. Often, the person asking the question simply typed in the problem, and showed nothing else other than the claim that he/she just simply didn't know how to tackle the problem. This was despite my explicit requirement that required students to show their attempts.

Not only that, this policy of forcing the person asking the question to actually show attempts, or at least, what they know, has also been criticized. Somehow, this requirement was deemed to be unusually harsh by some people

There are three separate issues here that will require a bit of explanation on why this policy is in place. And this policy is especially applicable homework problem in physics/engineering/chemistry/biology, etc.

1. In order to assist, help, and teach you how to solve a problem, we must know (i) what you know and (ii) what you don't know. We need to know what you have already understood, and then build from that. It is useless to simply tell you something that has no connection to what you've already understood, because if we do that, you will end up MEMORIZING it without understanding it, which is a recipe for disaster and failure in physics. When we can connect it to something you already know, then you can see a connection and a logical progression of your knowledge. The information isn't just hanging there in mid air. It has some logical connection with what you've learned and already know.

This is why we always need to know what you have attempted. It is not because we want to force you to do it, but a good teacher will be able to figure out what you already know and where you got stuck! We can point it out to you where you made the wrong turn. You, in turn, should also find this highly useful, because you learn more from your errors than from what you did right. You can do your own self-diagnosis on why you did something wrong, and why such-and-such is correct. This is the essence of learning!

If you simply say "I don't know where to start!", it tells us absolutely nothing. You simply must know SOMETHING in order to be given homework problems. Did you sleep through the class? Did you not even read the chapter in the book? You must know something! Can you even make a sketch of the problem? If it is a simple kinematic problem, can't you even show us a free-body diagram? At the very least, we can tell if you know what the relevant forces are! You must know something!

2. There is a misunderstanding of what a "starting" point is. When we ask you to show what you have attempted, we don't just mean "equations" or "calculations". In fact, in my personal approach, when you tell me that you don't know where to start, I will quiz you if you even know the relevant physics concepts that are applicable in the problem. Let me give you an example.

Say that I give you this problem: After a completely inelastic collision between two objects of equal mass, each having initial speed v, the two move off together with speed v/3.  What was the angle between their initial directions?

If you come to me and tell me you don't know where or how to start, I will ask you what is the relevant concept here.

If you tell me that it is the conservation of momentum, then I will at least know that you are aware of the physics being tested here. That is a big plus! And that, by itself, IS THE STARTING POINT! If I'm grading this problem, if the student simply did nothing else but indicated that this a conservation of momentum problem, he/she would have already received partial credit from me.

So now that I've already determined that the student is aware of the relevant concept, I want to see if the student can actually APPLY the concept. I will then ask "So if this is the conservation of momentum problem, what can you tell me about the momentum before and after the collision?"

If the student says that the momentum before the collision from both objects must be the same as the momentum of the two objects sticking together after the collision, then there is another indication that the student simply just didn't memorize the concept, but has some understanding of how that concept works.

Next, I will ask the student to sketch out the problem. Often, for this question, this is where the student gets stuck. The question doesn't say how they collided. Did they hit each other head on? At an angle? Via simple physics, we can rule out the former, because head on collision of identical objects with equal and opposite velocity will not result in a net velocity of a final object AFTER the collision. Furthermore, making them collide at an angle is a more "general" problem that we can solve. So if this is where the student got stuck, then we have found the source of the problem. As an instructor, I can make a mental note to make sure I emphasize on this aspect of problem solving. As a student, you learn where you got stuck, and how to get unstuck.

Note that the ability to make this sketch is crucial! By making use of the symmetry of the problem, the student will simplify this problem because the final velocity will only occur along the x-direction. This means that the momentum before and after along the y-direction will be zero! This ability requires insight, understanding, and repeated practice.

Next, I will ask the student to proceed to actually write down the mathematical form of the conservation of momentum. This will tell me if the student has the ability to translate "word concepts" into "mathematical equation", which is necessary to solve this problem. If the student gets stuck here, then I know where the problem is. This is also another common issue with many students, trying to translate conceptual ideas into mathematics. If the student realizes that this is where he/she often gets stuck, he/she can make a conscious effort to pay closer attention to when the instructor makes such a connection. I, on the other hand, as the instructor, will try to make a clearer emphasis during lecture, or when helping a student, that this is where we formulate our understanding into mathematics.

For this problem, we can write the momentum before and the momentum after, based on the sketch that we had drawn:

p1_x + p2_x = pf_x = pf

p1_y + p2_y = 0.

Notice the simple form for the y-component of the momentum as mentioned before.

From now on, it is just a matter of solving the math by substituting what we know and given from the problem. There is no more physics involved here.

2mv*cosθ = 2mv/3

cosθ = 1/3

θ = 70.5 deg.

So the angle between their initial directions is

2θ = 141 deg.

This demonstration and example is an illustration where there is a step-by-step progression in solving the problem. Every step is distinct, and as someone who wants to help the student trying to solve this problem, it must be clear if the student either understands, or is able to make each of the step. When he/she can't, then we have diagnosed the problem, and that is extremely important. One has to figure out where the source of the problem is, where the student got stuck. This is because it is a symptom of a bigger problem where there is a lack of understanding or knowledge in that particular area. Knowing where the problem is is beneficial not just to the instructor, but also to the student! He/she at least will know where to pay closer attention to and try to overcome that hurdle.

I've lost count how many times I hear students complaining that they find physics very difficult, and they can't solve physics problems. Upon undergoing a similar diagnosis such as this, more often than not, the most common problem that the students have was their lack of mathematical skills! In other words, I could have set up the problem for them and ask them to write down the vector components of the momenta, and they can't because of their lack of ability to do algebra and trigonometry. So here, we have also diagnosed the problem, and hopefully, the students realize that they have issues, not with physics, but rather with mathematics. Again, knowing this, the student has the ability to take the necessary actions to correct this.

The important thing here is that when a student is stuck, one has to figure out WHERE the sticking point is. Simply saying that "I can't do a problem" or "I don't know how to start" provides ZERO information to diagnose this.

3. If you look at the above example that I've given, you'll notice that the physics part actually comes in at the beginning. Being aware that (i) this is a conservation of momentum issue and (ii) being able to write down the mathematical form of the conservation of momentum that is relevant to this problem ARE THE PHYSICS PART! Once those are known and written down, the rest is mathematics. To put it bluntly, any monkey that knows math can, from that point on, solve this problem without knowing any physics!

This is important to realize for those who complain that we must help the student who don't know where to start. By telling them how to start, we are doing the physics for them! This is the most important part of the problem and it is why they are in the class studying it! As an instructor, I am keenly more interested in seeing how the student start and approach the problem. I have very little interest in seeing if they can deal with grinding out the math and spitting out the final answer. The physics here occurs at the very beginning!

So giving a student the starting point is not helping. It is depriving him/her of using the physics to set up the problem. The start IS the physics. You might as well tell the readers who did it at the beginning of a mystery novel. If I tell you how to start, I've practically done the physics part of the problem for you. I then have no clue if you didn't know what physics concepts were applicable, or if you've never heard of the concept, or if you didn't understand how to use it, etc. This deprive both of us in diagnosing the source of your problems, and because of that, there's a good chance that your lack of understanding will continue to perpetuate beyond this problem.

It is why I have such a policy.

Zz.

Note: The example I took here came from a terrific set of example problems from Prof. Marianne Breinig at U. of Tennessee.

http://electron9.phys.utk.edu/phys513/Modules/module2/problems2.htm

Her examples of worked problems in that link are exactly how I would teach and approach problem solving in physics, where there is a systematic identification of each step. It clearly shows where the "starting point" or how to start tackling a problem is the identification of the relevant physics concepts involved in that problem. This is what I want to see from a student.

Stephen Hawking's Snapshots of the Universe

Just saw this app on Apple's App Store. It's produced by Random House Digital. The description is rather long. The general description is that it teaches "... both adults and students the basic theories that govern our lives on earth as well as the movement of the stars and planets"

It costs $4.99. So far the review has either been good, or it has been complaints that it crashed or can't access certain levels.

Not sure if it is also available on Android.

If anyone has this, or has intention to get this, I'd like to hear what you think.

Zz.

Would You Hire Peter Higgs Today?

This is a rather thought-provoking piece on how competitive it is now in the physics job market, especially for academic position. Peter Higgs was asked if he thinks that he could get a job in today's environment. His answer was "No".

Low productivity, Higgs believes, would sink his chances for an academic post in today's job market. In the 49 years since he wrote the papers laying out what physicists now call the Higgs model, he has "published fewer than 10 papers," The Guardian notes.

Fortunately for his career, at the time Higgs did his groundbreaking work he had a faculty post at the University of Edinburgh, where he is now a professor emeritus. His scanty publication record made him "an embarrassment to the department when they did research assessment exercises," he says, as quoted in The Guardian. Only a 1980 nomination for the Nobel Prize kept him from being let go, he told the paper.

We need to keep in mind that times have changed. Things that used to work, or things that one can get away with a couple of decades ago, may no longer work now. I cringe every time I hear advices being given to people by using the examples of Einstein and Galileo and Dyson, etc. as indicating that something can be done that way. This totally ignored the reality of today and how things no longer work the way they did back then.

Zz.