Tuesday, December 28, 2004

So You Want To Be A Physicist - Part 8

We are still discussing the final year of your undergraduate education. So far, we have covered what you need to consider if you want to go on to graduate school and prepare yourself as best as you can for that part of your journey. However, this isn't the only path one can take with an undergraduate physics degree. Many physics degree holder do not continue to pursue a graduate degree in physics. So in this part of our series, I will discuss this aspect of an education or career beyond the traditional physics path.

If you have followed the series so far, you would have noticed that very early on, I emphasized one very important thing: the acquiring of a range of skills during your undergraduate years. This includes everything from computer programming skills to experimental skills. This is extremely important for any students, but especially if you end your physics education at your upon completion of your undergraduate degree. If you decide to pursue employment, your employability depends very much of what you can do. Let's face it, not many employers are looking for someone who can "do physics". There are, however, employers who would like someone who can analyze numerical models and maybe write codes, or maybe someone who can work in an electronics industry doing thin film fabrication, etc. You will be surprised that some of the things you accidentally picked up in an advanced physics lab might be the very thing that gets you the job.

One of the most popular path that physics graduates take at this point is to go into teaching at the high schools. Most who intend to pursue this line of work usually were enrolled in a simultaneous education program while they were pursuing their undergraduate degree. That way, but the time one obtain one's physics degree, one is also qualified to teach high schools. However, there are many graduates who obtain their teaching certificates after the fact. So it is never too late to decide that this is the profession you want. Keep in mind that different states in the US may have their own requirements with regards to teaching credentials. Some may even allow you to start teaching while you are in the process of getting your certification. So this advice comes with plenty of caveat.

One of the growing options for physics degree holders is to go into a graduate program in a different field of studies. There is now a clear, growing need for physics degree holders to go into law. With the high demand for patent lawyers (not to mention very high salary), there are many physics graduates who are pursuing their law degrees.

Another popular career change is to go into medical schools. This is very common to many students especially if they intend to go into medical physics research (note that one doesn't need to go into medical school to major in medical physics). Again, there is a growing number of physics degree holders who are making use of their physics degree in this field.

One of the other "untraditional" avenue being adopted by physics graduates is to go into either journalism, or writing. There are schools now offering cross-displinary programs in which students majoring in an areas of science or engineering can also augment their education with either a minor or even a double major in such untraditional subjects. Most are training either to go into mass media (science reporter), or even politics as assistants to various representatives in Congress. There clearly is a demand for scientists who can write and speak very well to the public, and programs such as these aim to produce such people.

There are many other avenues one can pursue with a physics degree. I have only listed just a few. However, in every single one of these, the preparation is still the same. One must have as wide as an experience as possible as an undergraduate. This will allow for the possibility that something one did might end up being the useful skill that one needs for a certain line of career.

In the next installment of this series, we will finally graduate out of our undergraduate years and go into the dreaded first year as a graduate student and the nightmare of facing with the qualifying exam!

Zz.

Monday, November 15, 2004

Misconception of the Heisenberg Uncertainty Principle

One of the common misconception about the Heisenberg Uncertainty Principle (HUP) is that it is the fault of our measurement accuracy. A descripton that is often used is the fact that to observe the position of an electron, for example, one needs a probe, such as a photon, with very short wavelength to get any reliable accuracy. But a very short wavelength photon has a very high energy, and thus, the act of position measurement will simply destroy the accurate information of that electron's momentum. Hence, this is an example of the HUP.

While this is true, it isn't really a manifestation of the HUP. The HUP isn't about a single measurement and what can be obtained out of that single measurement. It is about how well we can predict subsequent measurements given the identical conditions. In classical mechanics, if you are given a set of identical conditions, the dynamics of a particle will be well defined. The more you know the initial position, the better you will be able to predict it's momentum, and vice versa.

The most direct way to illustrate this is using a single-slit measurement. Let's first consider the classical case so that we know what we normally expect to happen. I suggest you sketch the setup along (since I'm unable to show sketches on here, but will try to make an effort to clearly explain the orientation of things).

Let's say you have a source of classical particle that emits this particle one at a time on demand, and emits it with a constant velocity and kinetic energy. At some distance from this source is a single slit. For clarity sake let's say the slit is alligned along the x-direction, so that the width of the slit is along the y-direction. The orientation of the x and y coordinate axes is in such a way that (using the right-handed coordinate system) the z-axis is along the direction of propagation of the particles. So the direction of the z-axis is from the source to the slit, and beyond.

Beyond the slit is a screen of detectors (could be a photographic plate, a CCD, etc.) This detector records where the particle hits after it passes through the slit. Let's say this screen is a distance L after the slit.

Now, let's get some basics out of the way:

1.If a particle gets through the slit, then I can say that my knowledge of the position of the particle at the slit has an uncertainty equal to the width of the slit. Thus, the width of the slit Delta(y) is the uncertainty in the postion of the particle when it passes through the slit.

2. The y-component of the momentum of the particle can be found by looking at how far the particle drifts along the y-direction when it hits the screen. This makes the explicit assumption that no external forces acts on the particle at and after it passes through the slit, so that it's momentum remains constant from the slit to the screen (which is a reasonable assumption). Let's say the particle drifts from the center, straight-through line and hits the screen at a distance Y. If it takes the particle a time T to reach the screen (which we can assume to be a constant if screen distance from the slit is much larger than the width of the slit (i.e. L >> Delta(y)), then the y-component of the momentum is p_y prop. Y/T. Now, there is a measurement uncertainty here in determining where exactly the particle hits the detector. This measurement uncertainty depends on the resolution of the detector, how fine is the "mesh", etc. But this is NOT the "uncertainty" that is meant in the HUP. We haven't gotten to the uncertainty of the momentum YET. All we have is a measurement of the y-component of the momentum of the particle.

Now, let's do the experiment with the classical particles. You shoot the particles one at a time and record where it hits on the screen. Ideally, what you will end up on the screen is only one spot where the particles that pass through the slit hit. However, closer to reality is that you end up with a gaussian distribution at the slit, where the peak lies directly along the straight-through direction that has zero y-component of momentum. The uncertainty in the momentum then corresponds to the width of the gaussian distribution (full width at half maximum). Now THIS is Delta(p_x) as refered to in the HUP!

Let's make the width of the slit smaller. This means Delta(y) is smaller. You are now letting a smaller possible angle of incidence of the particle from the source to get through the slit. This means that there will be a smaller spread that is detected on the screen. The gaussian distribution will be thinner. So classically, what we expect is that as Delta(y) gets smaller, Delta(p_y) also correspondingly becomes smaller.

This is what we expect in classical mechanics. If all the initial conditions remans identical (I have the same source), then the more I know where the object is at any given instant, the more I can predict its subsequent properties. I can say what its y-momentum will be with increasing accuracy as I increase my certainty of its position by decreasing the width of the slit. I can easily predict where the next particle is going to hit since I will know what its momentum is going to be after it passes through a very narrow slit. My ability to predict such things increases with decreasing slit width.

Fine, but what happens with a quantum particle such as a photon, electron, neutron, etc.?

We need to consider two different cases. If the slit width is considerably larger than the deBroglie wavelength (or in the case of a photon, its wavelength) of the particle, then what you have is simply the image of the slit itself. The ideal situation would give you simply a "square" or gaussian distribution at the screen of the intensity of particles hitting the detector. This is no different than the classical case.

It gets interesting as you decrease the slit. By the time the width of the slit is comparable to the deBroglie wavelength, something strange happens. On the screen, the spread of the particles being detected start expanding! In fact, the smaller you make the slit width, the larger the range of values for Y that you detect. The "gaussian spread" now is becoming fatter and fatter. This is the single-slit diffraction pattern that everyone is familiar with.

Now THIS is the uncertainty principle at work. The slit width, and thus Delta(y) is getting smaller. This implies that Delta(p_y) is getting larger. Take note that the measurement uncertainty in a single is still the same as in the classical case. If I shoot the particle one at a time, I still see a distinct, accurate "dot" on the screen to tell me that this is where the particle hits the detector. However, unlike the classical case, my ability to predict where the NEXT one is going to hit becomes worse as I make the slit smaller. As the slit and Delta(y) becomes smaller and smaller, I know less and less where the particle is going to hit the screen. Thus, my knowledge of its y-component of the momentum correspondingly becomes more uncertain.

What I am trying to get across is that the HUP isn't about the knowledge of the conjugate observables of a single particle in a single measurement. I have shown that there's nothing to prevent anyone from knowing both the position and momentum of a particle in a single mesurement with arbitrary accuracy that is limited only by our technology. However, physics involves the ability to make a dynamical model that allows us to predict when and where things are going to occur in the future. While classical mechanics does not prohibit us from making as accurate of a prediction as we want, QM does! It is this predictive ability that is contained in the HUP. It is an intrinsic part of the QM formulation and not just simply a "measurement" uncertainty, as often misunderstood by many.

Zz.

Tuesday, November 09, 2004

So You Want To Be A Physicist - Part 7

We are still stuck in the discussion of your fourth and final year of college. This time, I feel that a clearly explanation of the US graduate school system is warranted, especially to others from the rest of the world who intend to continue their graduate education in the US. This is because there is often a great deal of confusion, from the conversation that I've had, regarding what is required to apply for a Ph.D program in physics in the US.

The broad dichotomy of higher education in physics in US institutions can be lumped into (i) undergraduate education and (ii) graduate education. When you have completed your physics undergraduate education, you typically earn a degree of Bachelor of Science (B.Sc). (There are some schools that actually award a Bachelor of Arts in physics, but that's a different path that we won't discuss here.) This is what we refer to as your undergraduate degree. If you do decide to go on to graduate school, then the two different physics degrees available to you are the Masters of Science (M.Sc) and Doctor of Philosophy (Ph.D).

Now the next step is where US institutions differ from many educational system throughout the world. If you intend to pursue a Doctorate degree in physics, you do NOT need to first obtain a M.Sc. degree. Practically all of the universities in the US that I'm aware of require that you have an undergraduate degree to apply to a Ph.D program. Your undergraduate degree and transcripts of your undergraduate class grades are the ones being used to evaluate your candidacy. This is different from, let's say, the UK system, where you first pursue your M.Sc, and then after completing that, go on with your Ph.D. In US institutions, if you are pursuing your Ph.D, you can get your M.Sc "along the way", since at some point, you would have fulfill the requirements for a M.Sc degree. In fact, I know of a few people who didn't even bother declaring for their M.Sc degrees. So you will see some people with academic credentials as "B.Sc in physics from so-and-so; Ph.D in physics from so-and-so", with the M.Sc degree missing.

These differences have created a sometime confusing discussion from people intending to enroll in the graduate program in the US. The first confusion comes in when they check the average length of time to complete a physics Ph.D. Most are shock that the average length of time to complete a Ph.D in the US is 5 1/2 to 6 years. I was told that it takes an average of 3 years in the UK. However, if you consider what I have mentioned earlier, the length of time for a Ph.D is taken from the enrollment into the program by someone with a B.Sc degree, whereas the UK number is taken from the start of the program after someone has obtained a M.Sc. or equivalent. It takes an average of about 2 years to complete a physics M.Sc in the UK, I think. So now there is a explanation of the apparent discrepancy between the length of time. The total length of time to obtain a Ph.D after someone has a B.Sc degree is still roughly similar in both educational systems.

The second, of course, is the idea that one must have a M.Sc degree before applying for a Ph.D degree. Again, if one were to browse through the requirement for acceptance into a Ph.D program at a US institution, one will see that the major requirement is an undergraduate degree. I know of many international students who either (i) stayed in their home countries to get their M.Sc and then apply for a Ph.D program in the US, or (ii) apply explicitly for a M.Sc program in the US even though their goals are to obtain a Ph.D, because they assume that one must obtain a M.Sc first, before going on to a Ph.D program. This can actually create additional annoying problems, because one sometime has to REAPPLY for enrollment into the Ph.D program (this means you may have to pay again the application fee, fill in application forms, etc...) They also must apply for a change of status on their visas, because they are now pursuing a different degree.... In other words, these are all messes and annoyances that could have been avoided had one understands the graduate school system.

So remember: check the requirements for admission into a Ph.D program for a US institution. A B.Sc degree is required, not a M.Sc. So if you intend to pursue a Ph.D, apply directly for a Ph.D program, using your B.Sc. degree.

Zz.

Thursday, October 21, 2004

You Need to be Shallow, Perky, and Superficial

It would be nice if we all could just work on things that we like, maybe even important, without having to justify or keep reporting on why we need to do these things. But we do not live in such an environment. Doing science is still a large, public endeavor that sometime requires huge amount of public funds. In tough times of restricted budget, scientists need to learn to sell their program, not only to funding agencies, but also to the politicians and the general public.

Unfortunately, the communicaton between scientists and the rest of the general public isn't as smooth and easy as it might appear. While scientists in general tend to emphasize on facts and details, the public on the other hand tends to be more persuaded by what I could call "fluff". It is not the substance that is important here, but rather style! Pat Dehmer, who at the time that I heard her spoke, was the US Dept. of Energy's Research Grant Manager (or something to that effect), once said that whenever she has to meet the politicians in Washington DC to talk around scientific research fundings, she has to be "shallow, perky, and superficial" to be able to get through to them and sell these research proposals. It isn't how important or what that research is about that is crucial, but rather how well one can sell it that may determine its fate.

So why is this happening?

Many recent surveys in the US of the public's opinion of science and technology reveal an interesting schizophrenia.[1] When asked about the importance and interest in science and technology, an overwhelming majority of the people surveyed indicated that they believe science and technology are important. However, this is where it gets interesting. A survey on the scientific literacy of the american public also reveals that the level of such literacy is quote low! For example, only HALF of the respondents to the survey knew that:

(i) the earliest humans did not live at the same time as dinosaurs;
(ii) It takes Earth one year to go around the Sun;
(iii) Electrons are smaller than atoms;
(iv) Antibiotics do not kill viruses;
(v) Lasers do not work by focusing sound waves.

So on one hand, they show an overwhelming support for science. However, on the other, more than 25 percent believe in astrolgy, at least half of them believe in ESP, 1/4 believe in haunted houses and ghosts , and faith healing, etc. As one science reported noted:

"Without a grasp of scientific ways of thinking, the average person cannot tell the difference between science based on real data and something that resembles science—at least in their eyes—but is based on uncontrolled experiments, anecdotal evidence, and passionate assertions…[W]hat makes science special is that evidence has to meet certain standards"

Now, what this means is that, while the public in general supports science, and scientific endeavors, they are doing it NOT because they are aware of what science is and what it does, but rather based on the PERCEIVED importance of science and technology. This is extremely important to keep in mind, because this implies that the support for science is built on an extremely shaky foundation. Such foundation can be easily eroded either via a mishap, or simply good "Public Relations" done by people against science.

A case in point happened recently at the Brookhaven National Laboratory that was in the major news. A radioactive leak from a storage area connected to a research reactor into the monitoring well caused major public upheaveal in the surrounding communities on Long Island. One would think that a major disaster occured. However, if one were to look at it carefully, one noticed that (i) the monitoring wells were doing what they were supposed to do and (ii) the amount of radioactive material that leaked was so low, it was less than the radiation one would get from an EXIT sign at a movie theater!

Unfortunately, those two facts were buried in the massive campaign by several organizations that included a few well-known movie stars. While the scientists at Brookhaven repeatedly reported on the facts, famous celebrities went on TV and various other public media with scare tactics that were devoid of valid facts. Guess who won?

Most of the scientists made the error into thinking that if we just tell the public these facts, they'll realize that there's nothing to be worried about. This failed miserably. They over-estimated the public's ability to analyze and comprehend the facts of the matter. As a result, the Brookhaven's High Flux Beam Reactor, the site of two works that resulted in Nobel Prizes, is now decomissioned and closed for good. This shows that the apparent public support for science can turn in a blink of an eye, because it is not based on a solid understanding of what science is, but rather on something more superficial.

If you are lucky enough to be in this profession, you cannot assume that others know, understand, or even appreciate what you are doing, and why it is important. You can play a small part in erradicating this ignorance by continuously "selling" your work. Add bells and whistles to your presentation to the public. They are more effective than the content in most cases. Do not assume the facts will always win.

Zz.

[1] See http://www.nsf.gov/sbe/srs/seind02/c7/c7s1.htm#c7s1l4a

Monday, October 18, 2004

Photoemission Spectroscopy

Sometime, when a phenomenon is so well-known and well-understood, we often use it to study other things. X-ray diffraction is one example. Another is photoemission/photoelectric effect.

Photoemission is the extension of our understanding of the photon picture of light. Ever since Hertz's discovery of the photoelectric effect phenomena, Einstein's theoretical photon model, and Millikan's subsequent verification of the Einstein's photon model, this effect has been so well-tested and understood that today, we use it to study other things. In particular, photoemission, in its various forms, is used to study the electronic properties of solids, such as metals, semiconductors, superconductors, etc. In fact, the clearest verification of the validity of the band structure of solids came from photoemission spectroscopy.

The progress in this experimental technique evolved rather spectacularly after the discovery of the high-Tc superconductors. Having the 2D layers of copper-oxide planes where most of the superconducting effects are thought to occur, made them a natural candidate to be studied by photoemission, especially using a technique called angle-resolved photoemission.

It is imperative to point out that ALL of the theory of photoemission, including those applied in the study of materials that we are now using in modern electronics, make use of ONLY the photon picture of light. There have been NO other alternative formulation of light to account for the experimental observations of photoemission spectroscopies. NONE.

There are two very good reviews of the usage of the photoemission technique on superconductors. The identical technique is also used on other materials.

http://arxiv.org/abs/cond-mat/0209476
http://arxiv.org/abs/cond-mat/0208504

Zz.

Friday, October 15, 2004

So You Want To Be A Physicist - Part 6

We are still discussing the final year of your undergraduate program where you are in the midst of applying to graduate schools. In Part 5, I mentioned the word "assistantship" several times, and it is important you understand what this is, and why you should apply for it. So this part of the series will focus solely on the issue of assistantship. Take note that the kind of assistantship that I will be discussing applies only to US universities. However, ALL incoming graduate students, irregardless of whether they are US citizens or not, qualify for these assistantships. So a qualified student from another country can certainly apply for one of these.

There are two forms of assistantships: (i) teaching assistantships (TA) and (ii) research assistantships (RA). No matter which form of assistantships that is being offered, typically what is involved is a complete tuition/fees waver, and a stipend. What this means is that your schooling tuition and fees are being paid for by your department, and you will also receive a paycheck (stipend) for your services. The amount of your stipend depends entirely on your school. So this award is certainly significant especially since top tier schools can have outrageously high tuition and fees. So now, what are the differences between the two types of assistantships?

In practically all physics departments, and especially so at large schools, they need the manpower from the physics graduate students to either conduct tutorial/discussion sections, run physics laboratories, and/or do homework/exam grading of lower-level physics courses. Therefore, they award a number of TA each year or semester. So you become part of the department's manpower to help the various faculty members in various physics courses.

As an incoming physics students, TA'ship is the one you most likely have a chance to get. However, your chances of getting one depends on the number applying for it. Each school tends to already reserve TA'ships for they graduate students who have already earned one the previous year. So whatever is left to fulfill their needs/budget is the one being offered to the new incoming pool of applicants. So certainly, competition for this award can be intense. Take note also that in many schools, especially the ones that care about the quality of their instructions, you may need to prove your ability to communicate clearly in English, both written and verbal. Since you will be dealing, often directly, with undergraduate students taking those various physics classes, it is important that you are able to communicate with them. So if you are from a non-English speaking background, you will need a good TOEFL scores, and other supporting evidence, to bolster your chances.

The RA'ship, on the other hand, isn't usually available for new, incoming graduate students. An RA is a research position, and it is awarded by individual faculty members based on the research grant that he/she has obtained. Most faculty members do not award RA'ships to a graduate student until he/she has at least passed the department's qualifying exam (more on what this exam is in a future installment of this series). For most graduate students, the RA'ship is a way to do one's doctoral research work while being paid for it. So your RA work also becomes your doctoral dessertation, meaning that you'd better be working in the area of physics that you want to specialize in.

Depending on what field of physics you want to go into, and whether it is theoretical or experimental, you may end up receiving a TA'ship throughout your graduate career, especially if your supervisor has no research grants to hire you. Experimentalists tend to have higher chances of getting an RA'ship, simply due to the nature of the work.

The point that I'm trying to get across is that depending on your ability and your GPA, graduate school may not cost you an arm and a leg. It's true that many US universities are extremly costly. However, a physics graduate student has a lot more options in finding ways to reduce such cost. Schools such as Stanford, for instance, automatically assumes that you will require some form of assistantship when you apply to the physics graduate program. In fact, practically all of their graduate students are on some form of assistantships/scholarships. However, due to intense competition for the limited funds, you need to do all you can to make yourself stand out. Hopefully, you have done that during your undergraduate program, and have sent in your applications early.

Zz

Wednesday, October 13, 2004

So You Want To Be A Physicist - Part 5

We have now reached the final year of your undergraduate program. By now, you would have gone through courses in the fundamental pillars of physics (Classical mechanics, Quantum mechanics, and E&M), and even courses in Thermodynamics/Statistical Physics. Academically, this is where you start taking more advanced courses, even some graduate level courses. There are plenty of options, depending on where you go to school, how large your physics department is, etc. The choices can range from a class in Solid State Physics, Particle Physics, advanced laboratory work, etc. If you already have a clear set of interest and know what area of physics you would like to end up in, then this is where you want to try to enroll in a class in that area. But even if you don't know for sure yet (and this tends to be the case for most students), it is still valuable to enroll in one of these "specialized" area of physics, even if you may not eventually go into that field.

The start of your senior year requires that you do some serious thought on what you wish to do upon graduation. Most physics majors will go on to graduate school with the hope of obtaining their doctorate. So in this part of the series, we will concentrate on the application process of going to graduate school. If this is the path you intend to take, then you need to prepare yourself in a number of ways:

1. Prepare to take your Graduate Record Examination (GRE). This should include both the GRE General and GRE Subject Test. While the GRE scores may not be required for admission application in my schools, they are usually required if you are seeking any form of assistantship. So it is best if you already have the test scores.

2. Apply to graduate schools EARLY! If you intend to enroll in the Fall, you should have ALL your applications in by December of the previous year, especially if you are seeking assistantship. In many highly competitive schools, your applications may need to be in even earlier. It is NEVER too early.

3. Unless you have a 4.0 GPA, have outstanding letters of recommendation, and the son of the President of the United States, you have some uncertainty if your first choice of schools will accept you. It is ALWAYS recommended that you group the schools you are applying to into 3 categories: (i) Top Tier schools that you know are very difficult to get in (ii) Middle tier schools that you may have a chance to get in and (iii) lower tier schools that you think you can definitely get in. Note that these does not have any reflection on the QUALITY of instructions/programs at each school. In may instances, it is only the "perceived" prestigue that makes one school more "desirable" than the other.

4. Do as much research on each school that you are applying. If you know of some program or research area that a school is good in that you are also interested in, then look it up and try to find the latest publications in physics journals. Your admission application usually requires that you write an essay regarding your aims, ambitions, and why you would want to study there. So it is always good to be specific, and not just give some generic description. Mention things specific to that school and that physics program and why you want to be involved in that. It is extremely important if you can also show a previous interest or work in a similar area. This will tell the admission officer that you are a candidate that can be beneficial to them.

5. This last part is a bit dicey, since the situation can either turn out very positive, or very bad. If you feel confident enough in your ability, you may want to contact directly a faculty member of school that you would like to attend. Obviously, this would be a school that is highly competitive. You want to do this in cases where you think a direct communicaton may enhance your chances - so don't do this if you think your contact may backfire. The best way to do this is to see if any of the faculty member of your undergraduate institution know of anyone there personally. It is always best to have such recommendation. If you do decide on such contact, tell the person on why, your interest, and that you would be interested in working in his/her research group, etc.

In the next installment, I will try to describe what you can expect graduate school to be BEFORE you get there.

Zz.

Tuesday, October 05, 2004

Things you MUST do at the Walt Disney World Resort

What does a tired, overworked, and sometime stressed-out physicist do for a vacation? Why, he goes to DisneyWorld, of course!

I've been to DisneyWorld in Orlando, FL under two very different circumstances. The first time was when I went there blindly, without knowing anything, just went to the parks and randomly tried what I came across. It was an enjoyable experience, but I never had the urge to go back. The second time was with a larger group of people, and with someone who knew the entire resort like the back of his hand. I tell you, the difference was like night and day. I had SO, SO, SO much fun that second time around (Thanks, Brian!). It was an eye-opening experience that simply by knowing what to do, when is the best time to do it, what to see, where to see it, and all the amenities that came with it, most for FREE... It truly was a magical moment.

Ever since then, I have become a regular at DisneyWorld (I now have an Annual Pass) and have myself become, I think, quite an expert on what to do (I've also become quite a collector of Disney pins, but that's another story). If you are planning on visiting DisneyWorld, I would suggest going over the list of things you should do and other useful info that you should know by the time you get there. Remember, DisneyWorld may look like it is for kids, but they actively aim everything within the park to include adults (the Dumbo ride, for example, has seatings for TWO adults).

Magic Kingdom

1. Space Mountain (rollercoaster)
2. Thunder Mountain Railroad – the best place to ride this is towards the rear. You can ask to ride it on the last row or two.
3. Splash Mountain
4. Teacups
5. Haunted Mansion
6. Mickey’s Philharmagic – this has become the #1 attraction at Magic Kingdom. Do this early, or get Fast Passes. If not, try getting in while there is a show or a parade going on.
7. Jungle Cruise – A good ride when your feet are tired, as long as you don’t mind your tour guide spewing out a lot of bad puns.
8. Spectra Magic Light Parade – Check the parade route and try to move away from Main Street where it WILL be crowded. Some place in Frontier Land will be good.
9. Wishes – Even though you can see the fireworks from a large area of Magic Kingdom, the show involves more than just that. So to get the full effect, the best place to view it is still right in front of Cinderella’s castle. Unfortunately, this is also the most crowded and popular area.
10. A good quick place to eat – Columbia Harbor House. Take note that there are additional seatings upstairs with a condiment/utensils/etc. kiosk that are seldom packed. There are also additional washrooms at this level.

Epcot

1. Test Track (be there when Epcot opens and head directly to Test Track – get in line immediately or take Fast Pass. Test track is extremely popular and will have long lines later in the morning/day).
2. Mission Space – same warning as in Test Track. However, if you are susceptible to motion sickness, you may not want to ride this. [Hint: if there are people not riding Mission Space, it might be a good idea for those waiting to get Fast Pass tickets for Test Track. That way, by the time the Mission Space people get off that ride, it will be close to the Fast Pass time for Test Track].
3. Maelstorm at the Norway pavilion (World Showcase pavilion around the lagoon opens at 11:00 am). Note: there is a small bakery at the front of the Norway pavilion and they have (if they haven’t sold out) this sweet almond pretzel. It is to DIE for!
4. Also at the Norway pavilion – Restaurant Akershus. This is an EXCELLENT place to eat. Unlimited food from their cold buffet bar, and all-you-care-to-eat from their entrée menu. Reservations are strongly recommended during peak season/hours.
5. Honey I Shrunk the Audience
6. Illumination at 9:00 pm around the lagoon (if it doesn’t rain, people usually start staking out the best spots around the lagoon ½ to one hour before the show). As with Wishes at Magic Kingdom, you can view the fireworks and light show from all around the lagoon, but the best place to view it in its full “symmetry” is still right at the pavilion by the entrance to the World Showcase lagoon.
7. Spaceship Earth. It’s cheesy and tame, but it’s inside that big “golf ball” and the show may not last that much longer if the rumor of it being renovated to hold a rollercoaster ends up being true. Do this ride late in the afternoon or early evening – the lines are not as long then.
8. Restaurant Marrakesh at the Morroco pavilion – If you come at the right time, you might get to see live musicians and belly dancers. The food is excellent too! Reservations are strongly recommended for dinner during peak seasons.

Disney-MGM Studios

1. Tower of Terror – ride this as many times as you can. It is different each time since they have a random program of “drops”.
2. Rock ‘N Roller Coaster
3. Muppets 3D
4. Star Tours
5. Fantasmic Light Show - 3 different restaurants offer a “Fantasmic” dinner package. They are the Brown Derby, Mama Melrose, and Hollywood and Vine (this list may be outdated). You get a separate entrance and reserved seating for Fantasmic with this package. Reservation is strongly recommended or even required (you need to mention the Fantasmic dinner package). Plan on having dinner at around 5 pm to 6 pm to have enough time to catch the show afterwards.
6. A fun place to eat – Sci-Fi Dine-In Theater. You get to sit in your own car and watch old sci-fi movies on a large screen while you munch on your food.

Animal Kingdom

1. Kilimanjaro Safari – do this as early or as soon as the park opens. It is very popular.
2. Kali River Rapids – assume that you WILL get drenched (bring ziplock plastic bags for your wallet, cellphone, etc.).
3. Primeval Whirl – don’t do this immediately after you eat, it will not be pretty. Also avoid if you are susceptible to motion sickness.
4. Dinosaur – be warned that this ride can be quite intense for young children.
5. It’s Tough To Be A Bug.
6. Best places to eat: Tusker House and Flame Tree BBQ. Take note that Flame Tree BBQ has a lot more seating than it appears. Try walking down further into the greenery and you’ll find a wonderful seating area by the lake that is seldom crowded.


Other Locations

1. Breakfast with Chef Mickey at the Contemporary Resort – Plan this waaaay ahead, even weeks (or months) before you get to Orlando. It is fun, if you have kids, or just a kid at heart.
2. Downtown Disney – 4 words to describe it: shop, eat, shop, eat. However, kids may prefer the Lego store.
3. Cirque Du Soleil’s La Nuba at Downtown Disney Westside – Even if you have seen other Cirque Du Soleil shows, see this one! It will be an experience you will never forget.
4. Pleasure Island – 8-Tracks is a fun retro dance club.
5. Boma at Animal Kingdom Lodge – this is the BEST buffet dinner anywhere in Disney World, in my opinion. It is African-themed, but also has the regular, familiar food for those who do not want to venture out of their comfort level. Don’t miss the crispy flatbreads with the three wonderful and exotic spreads.


Things to Keep in Mind

1. If you’re staying at a Disney resort, you can have all your purchases anywhere in Disney World sent to your hotel. This saves you from having to lug everything you bought with you.
2. If you are staying at a Disney resort, take note also that if you decide to drive to the Disney parks instead of taking their free busses/monorail, parking is FREE. Just show your room key/card as you enter the parks.
3. More shopping tip: If you end up buying a large number of items at a single store (such as at the World of Disney in Downtown Disney), you may want to consider having them ship all of them directly to your home. You pay only ONE shipping flat rate no matter how many items you want to ship, AND, the sales tax is not included. Depending on how much you are spending, the money you save on sales tax alone might pay for the shipping. Keep in mind that I think they will only ship (using that one flat rate) the items you are paying for at that moment, not the items you have already purchased, even from the same store.
4. While you are there, you can make dinner reservations, buy park tickets, etc. throughout the Walt Disney World at any Guest Services office (Guest Services can be found at all parks, resorts, Downtown Disney). If there is a special occasion for making the reservation (such as a birthday or anniversary, etc.), be sure to mention it to the Guest Services cast member – you might get some special treatment then, or later.
5. As soon as you walk through the turnstile at any of the Disney parks, look for a slip of paper (usually at a kiosk or on racks by the wall) that lists all the parades, show times, character greetings, and special events for that day. This list changes everyday, so pick one up each time you walk into a park.
6. For parents who want to get on a ride, but an accompanying child is either too scared, or too small to be on that ride, most rides at Disney World has a “parent exchange” area. This allows one parent to get on the ride while the other stays in a holding area with the child. When the riding parent is done, the next parent can go on that ride without having to go back to the end of the line. Ask a cast member if a particular ride has this.
7. When you go to Magic Kingdom via the “regular” Disney busses or by driving your own vehicle, you will arrive at the Transportation center, and then you can either board the Magic Kingdom monorail, or a boat to get to Magic Kingdom itself. There are three monorail lines here: one is the express monorail to and from Magic Kingdom, one for the Magic Kingdom resort hotels, and one going to Epcot. (So you could, if you prefer, park here and go to Epcot. This is a good idea if you intend to be jumping around between Epcot to Magic Kingdom on the same day. That way, your vehicle is always in the middle of the two parks.) Take note that BOTH the Magic Kingdom express monorail, and the Magic Kingdom resorts monorail go to and from the Magic Kingdom and the Transportation center. The only difference being that the resort monorail will make stops in between for the Magic Kingdom resort hotels. So keep this in mind if the Magic Kingdom express monorail is very busy with people. Most of them do not know that the Resort monorail also goes to the same place. This also applies when you are coming back from Magic Kingdom to go to the Transportation center.
8. Remember that Disney Theme Park tickets do not expire (except for the Ultimate Park Hopper). So if you bought a regular 5-Day Park Hopper or Park Hopper Plus, and you used only 3 days, the remaining 2 days (and any “Plusses”) do not expire! You can come back at any time to use the remaining days. The Ultimate Park Hopper, on the other hand, is only valid during the days that you are a guest at one of their resorts. So if you checked into a Disney hotel on the 8th and checked out on the 12th of the month, your Ultimate Park Hopper will only be valid for entrance to the Disney parks from the 8th up to and including the 12th.

Have a Magical time!

Zz.

Wednesday, September 22, 2004

Communications of legitimate physics ideas

In physics, there are principly two means of communicating one's ideas to others in the field. The first and most common means is via publishing one's work in a peer-reviewed journal. The other is via a presentation at one of the many conferences/workshops held throughout the world. I will discuss the former.

For a physicist, there are three most prestigous journals for one's work to be published: Nature, Science, and Physical Review Letters. These journals not only require that the work submitted to be of significant importance and quality, but also have wide-ranging impact beyond just a small, specialized area. This is especially true for Nature and Science where both journals tend to only publish papers that will have a high impact value.

It means that getting one's work to be published in one of these three journals is not that easy. Nature and Science have editors that are actively involved in weeding out all the submitted papers. My guess is that between 50% to 60% of all papers submitted to these two journals never made it past the editors. These editors sometime consult ranking physicists in the appropriate fields to see if a submitted paper has enough of an impact for it to continue to the next stage. Of the remaining papers that did get through and went on to be reviewed by selected referees (typically 2 or 3 referees for each paper), only about less than half that actually got approved for publication. This process is similar for Physical Review Letters, except the editors tend to be more liberal in letting the papers go to the refereeing stage (they still weed out the obvious quackeries, which from what I gather, they receive almost everyday). However, the referees are as strict and demanding as those for Nature and Science.

Why are these three journals that prestigous? First of all, because everyone in the field knows how difficult it is to have a paper published in those journals, it means that having one is a sign of accomplishments. Many funding agencies look favorably if someone has work appearing in these high-impact journals. Secondly, these journals have their own public relations people that advertize and produce press releases of select papers in their journals. This makes some work widely known and cited both within the field and in the public media. Having one's work published in one of these journals is a sign of very high achievement.

If those three are what I consider to be the top tier journals, the next in line would be the Physical Review series of journals (i.e. Physical Review A,B,C,D, and E), the Journal of Applied Physics series and Applied Physics Letters. It needs to be emphasized here that just because these journals are of a lower tier than the first three, it doesn't mean they are of any less importance or less impact. Often, the Physical Review journals serve to expand the work published in the Physical Review Letters (PRL), since PRL has a limit of 4 typeset pages for each paper. Other than certain specialized sections, the Physical Review journals have no length limitations. The papers published here also tend to be more specialized for people working in a particular field, i.e. it doesn't have that "wide-ranging" impact that Nature, Science, and PRL require.

The next tier of journals would include European Physical Review, Journal of Physics series, Europhysics Letters, and Physica journal series. Again, there have been very important papers being published in these journals, even though in terms of prestige, they are not typically considered as high-impact journals.

The level of refereeing also tends to be commensurate with the prestige of the journals. One tends to see a more liberal refereeing for a lower tier journal, and maybe each submitted paper might have only one referee, as opposed to 2,3, and up to 5 referees for papers submitted to Science, Nature, or PRL.

To end this, here's a very sobering fact. Since the establishement of peer-reviewed journals in the scientific field (let's say since 1900), there have been NO instances of any work or ideas making a significant contribution fo the body of knowledge in physics that have not appeared in a peer-reviewed publication. Now think about this for a second. If you have a discovery, theory, ideas, etc., and you have not or unable to have it accepted and published in a peer-reviewed journal, you have an ABSOLUTE ZERO chance of having any impact or contributing to the body of knowledge in physics. PERIOD! This is what the history of science has shown. It means that if one only has one's theory appearing on some website and/or discussion areas, and these are the ONLY avenue for such an idea to see the light of day, there is a 100% chance that such an idea will go nowhere, do nothing, and will disappear into obscure-land. Having one's work appearing in a peer-reviewed journal is a NECESSARY criteria, although not a necessary AND sufficient criteria, for having any impact and making a contribution to physics.

Zz.

Monday, September 20, 2004

Imagination without knowledge is Ignorance waiting to happen - Part 3

This is more of ignorance of the workings of physics. Most quacks and crackpots like to imagine that physicists are determined to save the status quo of physics ideas, and that they are stuck with what they know and were taught, and very unwilling to work "outside the box". Their biggest "evidence" that they like to point out is that each time they try to come up with their brilliant ideas, some physicists will always try to shoot them down and show why they will not work, etc. This, they argue, stifle creativity, something physicists do not have and unwilling to envoke.

It is unfortunately that such effort in "creativity" is not accompanied by knowledge and, more importantely, logical thinking. There are two major points that can easily trump over such criticism against physicists:

1. If the argument is true, then there is no explanation for the accumulation and the expanding of the horizon of knowledge that we have observed. There are NUMEROUS things that we know of now that we did not know of before. There are many new phenomena that we have either discovered, or can now be accurately described. The fact that the boundaries of our knowledge of the physical world continues to expand is a clear contradiction to the false argument that physicists are only interested in upholding current ideas.

2. Practicing physicists, by definition, study things that either are new, have no current explanation/description, are not completely understood, or beyond the realm of validity of current ideas. This fact is always a surprise to most quacks. We do not study things that are already well-verified! Try getting a research funding to verify Newton's Law under terrestrial condition! Physicists study things that are simply beyond what is known and understood! This is where creativity and imagination come into play. Physicists have to call upon those qualities almost every day in studying complex and difficult ideas and phenomena. However, to know what is new and unexplained, one has to first make sure one knows what is known and understood! Without that, one would not know what is new even if it comes up and bites on one's rear end.

This naturally brings us to an often-used argument made by quacks, that "revolutionary" ideas such as those by Einstein would have been rejected and opposed, very much like the opposition their "theories" are facing. This argument reveals the ignorance and fallacy of how things run in physics and science in general.

While new ideas by Einstein and Planck were initially challenged (as well they should for anyone proposing wildly different and new ideas), it should be pointed out that both of them were proposing ideas not based on ignorance of the subject matter, a fact that is often ignored by quacks. Both Einstein and Planck were masters of the subject. In fact one has to know intimately classical physics to be able to know what was wrong with it. Einstein had to know classical electrodynamics very well (not just from reading a pop-science book) to know how and why it isn't invariant under a galilean transformation. Planck had to know classical statistics very well to know why the Blackbody radiation just simply didn't fit the theoretical description. These are not something one can comprehend simply based on a superficial knowledge of physics.

While physicists at that time were skeptical and critical of both ideas, no one ever argued that Einstein and Planck were putting out their theories based on ignorance of the physics at that time. The same cannot be said with a lot of quackeries found all over the internet.

Zz.

Monday, September 13, 2004

Imagination without knowledge is Ignorance waiting to happen - Part 2

In this part, it is certainly ignorance gone wild.

One of my pet peeve is people who barely know enough physics, but then do not feel the slightest bit of hesitation in using it for their own agenda. They see no problem at all in extending their ignorance into other areas without realizing the hysterical and illogical consequences. Of course, some people give them credit for having a wonderful imagination and cite that often-bastardized Einstein's quote.

One such example is the ongoing assault on The Theory of Evolution. Now keep in mind that this is NOT an essay on the validity of either the Theory of Evolution or Creationism/Intelligent Design (ID) (that would require a completely separate diatribe on my part). What I will do is look at two particular arguments that have often been used against Evolution by advocates of ID. These two arguments have a direct connection to physics. This is clearly a strong reason why the Evolution versus ID affects all of science and not just biological sciences.

1. Evolution is only a THEORY.

This stems from the pedestrian usage of the word "theory", meaning to nothing more than an educated guess, if that. It implies that a scientific "theory" is nothing better, not verified, or still not accepted. Again, nothing more than an educated guess.

This argument reveals the ignorance of how the word "theory" is used in science, and especially in physics. There are two broad dichotomy of the nature of scientific studies - experimental and theoretical. Experimental involves experiment! This includes data collection, analysis, phenomenological models, etc. Theoretical, on the other hand, involves either phenomenalogical models of experiments (same as experimental), or theoretical extension of preexisting ideas via ab initio derivation. So a theory is a mathematical/logical description of an idea.

Furthermore, saying something is just a theory somehow implies that a theory can "graduate" into a law or a principle. This of course is absurd. Laws, theories, principles, etc., are all the same. Each may have varying degree of certainty or varification, but it doesn't mean one is better than the other, or that they evolve into one another.

To attack Evolution by saying it is "just a theory" is also an attack on BCS Theory of Superconductivity, Quantum Field Theory, Band Theory of Solids, etc, etc. If one is aware of how successful those physics theories are, one would never make such an idiotic argument. So this is an example of an argument made based on ignorance.

2. Evolution violates the Second Law of Thermodynamics

Already, this is something that affects physicists, because inadvertently, our area is being dragged directly into this battle.

The argument comes from the apparent understanding of two things: (i) life beings are "ordered" structure and (ii) 2nd Law of Thermodynamics reflects an increase in entropy or, to put it crudely, disorder.

Now, I will not go into detail why to equate entropy with disorder is inaccurate (that will be saved for another time). So let's assume that both (i) and (ii) are correct. ID advocates point to the fact that if Evolution did happen, it implies a trend towards order of our Earth system. Random distribution of atoms and molecules in primovial Earth somehow form ordered and more sophisticated congrlomeration that eventually form life forms. Thus, the earth went from disorder to order. This clearly violates the 2nd Law of Thermodynamics and thus, is not very likely. So evolution cannot be the explanation for life.

Again, such an argument is being made without an understanding of the 2nd Law, or even basic thermodynamics in the first place. The 2nd Law clearly states that in an ISOLATED SYSTEM (no energy or any kind going in and out), entropy cannot decrease. The earth is certainly NOT an isolated system. In fact, the earth DEPENDS predominantely on one source of external energy - the sun! So even if we consider the most simplified system, we have to consider the sun and the earth as the complete isolated system, not just the earth alone. Within this system, there is nothing to prevent one part of the system to have a lower entropy with time (example: carnot cycle). Thus, even if the earth does really have a lowering of entropy, this certainly does not violate Thermodynamics' 2nd Law.

One would be surprised that, even when this is already explained in several articles and books, that there are still numerous websites supporting creationism/ID that still carry this argument (do a google search if you don't believe me). Either the authors are not aware of how ridiculous such an argument is, or they are hoping that the reader are not aware of it, or not good in simply thermodynamics. This isn't a stretch of imagination because the general public do not have any significant understanding of basic thermodynamics principles and thus, can easily be fooled into thinking that physics has made evolution impossible! It costs nothing to perpetuate the lie.


These two examples, unfortunately, are just the few that illustrates how ignorance can lead to often serious consequences, either socially, politically, or otherwise. If one is going to use something as the foundation for an argument or an idea, it is illogical and irrational to not properly determine that one has something beyond just a superficial idea of it.

Zz.

Monday, September 06, 2004

Imagination without knowledge is ignorance waiting to happen - Part 1

Having been on the 'net for a very long time, I get asked often to look at some rather outrageous claims being made by a lot people, many of them in need of serious psychiatric help. This one is a doozy from quite a few years ago.

A guy had a coil of wire stuffed into a cylinder (I think a brass cylinder). The two ends of the wire stuck out on the opposite ends of the cylinder. The cylinder was suspended from the ceiling by some cables. He then connected a heating element to the end of the wire at the bottom of the cylinder. The moment he turned on the heating element, he started time. He has a thermocouple of some kind monitoring the temperature at the other end of the wire. As soon as the temperature had risen by 50 C (I don't quite remember the exact number so I made this up), he stopped time. Call this Time A.

Next, he connected the heating element to the top end of the wire. He repeated the experiment, this time monitoring the temperature of the bottom end of the wire till the temperature has changed by 50 C also. Call this Time B.

He noticed that Time A is shorter than Time B. He said that this means that the heat in the conductor can travel faster upwards than downwards. His conclusion was that he has discovered an anti-gravity effect, and that there was an anti-gravity component to heat. [Honest! This is what was said! You can't make up idiotic statements like this!]

This is where having just a little knowledge can result in something hysterical. Anyone who has studied physics can immediately see two very obvious problems (there may be more) with this interpretation:

1. Convection. The inside of the cylinder is at atmospheric pressure and not in some level of a decent vacuum. So by heating from below, a heat convention can easily carry some of the heat upwards, thus heating the top end faster.

2. Cooling gradient. This is the more important aspect. I asked this person (yeah, I actually made contact with him) if he waiting for the wire to cool down back to room temperature before he did the 2nd part of the experiment. He said, no, he continued right on. This means that he had no clue that the rate of heat loss depends on the temperature gradient of an object with its surrounding. Heating an object in air from 20 C to 70 C is not the same as heating it from 50C to 100 C, even though the temperature change is identical. As the temperature of the object increases, the temperature difference between it and the surrounding also increases, and so will the rate of heat loss. This is straight-forward law of cooling. So of course he would take longer to heat the 2nd part since he is starting off at a higher temperature!

We teach physics majors all the things that are known and can already be explained, NOT because we want them to be able to mimic and repeat all of them when they become physicists. We teach them those things so that they will KNOW when they encounter something new and unexplained. You cannot know what you are observing or discovering is new if you don't already have a clear idea of what are known and can already be explained! This person that I just described lacked the knowledge to know that what he thought was "new" can, in fact, be explained quite simply based on existing ideas. He certainly had a vivid imagination, but it is nothing more than mere ignorance of the knowledge he did not have.

Zz.

Wednesday, September 01, 2004

The most influential physicist.

If you ask a bunch of people on who is the most influential physicist of, let's say, since the beginning of 1900, you would get the usual answers: Einstein, Feynman, Bohr, Heisenberg, Dirac, etc... all the big names. However, consider this: there is only ONE person who has won the Nobel Prize for Physics twice; this person is a co-inventor of the most important device that is now the foundation of our modern society that we use everyday; and this person is not on that list above.

Ladies and Gentlemen, let me introduce you to John Bardeen!

(Who? WHO?)

In my book, John Bardeen is the physicist that has the MOST direct influence on all of our lives. His first Nobel Prize was awarded for the invention of the transistor along with William Shockley and Walter Brattain. To say that the transistor has revolutionized our world would be almost an understatement, unless one has no clue what a transistor is and why it is useful.

That invention alone would have been sufficient to put him at the top of this list, but nooooo.... His second Nobel Prize in Physics pushed him way over the top. He is the "B" in the BCS Theory of Superconductivity, along with Leon Cooper and Robert Shrieffer. The BCS theory is considered to be one of the most successful and highly verified theories in all of physics. Till 1986, it was thought that the BCS theory has explained everything there is to know about all of superconductivity. However, the significance of the BCS theory goes way beyond just explaining a single phenomena. It marked one of the earliest sucesses of the application of quantum field theory in the emerging field that is now known as condensed matter physics. This sparked further refinement of the field theoretic methods in the study of materials, something that we now are reaping the rewards from. So the impact of this theory transcends beyond just what it describes.

But why isn't he more well known?

He is one of those rare breed of physicist that isn't eccentric, is not loud, profoundly understated, and intensely private. While the general public may not even know of his existence, those of us in physics, and especially in condensed matter physics, have nothing but the utmost respect and admiration for him as a person, and his body of work.

I highly recommend the biography of Bardeen written by Lillian Hoddeson, Daitch Vicki, Vicki Daitch titled "True Genius: The Life and Science of John Bardeen" (National Academies Press, 2002). This could be the most fascinating and important person that you have never known.

Zz.

Friday, August 27, 2004

So You Want To Be A Physicist - Part 4

So far, I have covered what I believe a student needs all the way to the end of the 2nd year of studies. In most schools in the US, an undergraduate must have a declared major by the end of the 2nd year (if not sooner). So by now, you should already be officially a physics major. Hopefully, you would have made acquaintences with other physics majors and know who are in the same year group as you. This is important because chances are, you may want to find someone to discuss homework problems, etc. This is where having a local chapter of the Society of Physics Students (SPS) at your school can be useful. You get to meet other physics majors, and also talk to the more senior students who can give you a better idea of what to expect (or which professor to avoid in certain classes). You should also keep in mind that there is a good chance that these are probably the same people who might continue on in this profession, and that the friendship you are establishing might someday turn into a valuable point of contact in your professional career. Never underestimate the value of personal contacts.

The transition from the 2nd year into the 3rd year of college can mean smaller classes and more advanced subjects. This is where you start studying the "meat" of a physics program - what I would call the 3 foundations of physics: classical mechanics, electromagnetic fields, and quantum mechanics. These are taught in separate courses, typically over 2 semesters each. Typical textbooks for each course are: classical mechanics - Marion or Symon; E&M: Griffith, Reitz/Milford/Christy; QM: Griffith, Liboff. Now pay attention to this: ALL other physics subjects BUILD on the foundation laid by these three courses. The importance of these subjects cannot be overemphasized. In fact, if you are able to do it, you may even want to consider lowering your class load for 1 or 2 semesters while you're taking one or more of these classes just so you can devote extra time to them. An E&M class, for example, can easily suck in a lot of time to understand and the homework problem can take a long time to finish. If you can afford it, do not hesitate to buy one of those books that have sample questions and worked out answers (Schaum and Rhea have a series of those). Now don't cheat! Use them as guides and extra practice exercizes to make sure you understand the material.

If you are in a school with a small student population, chances are that the faculty would already know you either by sight or by name. If not, this is where you have to start distinguishing yourself. Talk to your instructors if you do not understand something, that is why they have office hours. Introduce yourself so that they know your name. By the middle of your 3rd year, you should have enough physics knowledge that you might be somewhat useful to do some work. Ask around if there are any research projects or groups that you can work in, or find a professor that might be interested in giving you a simple project for you to work on. This is especially relevant in your 4th and final year where most schools have a senior research class available. Start attending your department's weekly seminar/colloquium. Most of these may be way over your head, but they tend to cover a lot of research front areas of physics. You might also get some flavor if some of these research work are either done, or of some interest, at your school. The point here is that you need to start distinguishing yourself slowly by this time. The faculty in your department should not just see you during class time.

The next part of this essay applies only to US universities and to US citizens/permanent residents. If your school lacks the research work that are of any interest to you, or if you want additional experience over the summer holidays, then you may want to consider applying for the summer internship programs provided by the US Dept. of Energy. This provides an excellent opportunity for you to work at a world-renowned facility with practicing physicists. You may find the necessary information at the DOE website below:

http://www.scied.science.doe.gov/scied/sci_ed.htm

Keep in mind that competition for the internship is very intense. So, apply early!

In the next installment of this series, we address the final year of your undergraduate life, and the looming reality of either joining the rat race, or continuing on to graduate school.

Zz

Thursday, August 26, 2004

So You Want To Be A Physicist - Part 3

In most universities in the US, a student must have a declared major by the end of his or her second year. So this is an important transition - making the commitment in a particular area of study. By now, if you have followed the first two chapters of this series, you would have been aware of the necessary background to pursue your academic life in the physical sciences or engineering. All the discussion that we have had so far has been "generic" to a large variety of field of studies. However, at this point, this discussion will be more specific towards being a physics major.

The end of your second year marks the beginning of a more advanced undergraduate physics courses. You will probably no longer be in the same classroom as other majors, and most of your classes will comprise of only physics majors. This part of the series will focus on additional preparation you should have to be able to sail through your advanced undergraduate physics courses.

It was alluded to in a previous posting on here of having sufficient mathematical background. It has often been said that a physics major sometime needs more mathematics than even a mathematics major. Mathematics is viewed as a "tool" that physicists use in describing and analyzing physical phenomena. So one just never know what tools are needed for which job. This means that a physics major must have a wide ranging knowledge of different areas of mathematics, from differential equations, linear algebra, integral transforms, vector calculus, special functions, etc. These are the mathematics a physics major will encounter in courses in classical mechanics, electromagnetic fields, and quantum mechanics. Unfortunately, most physics majors do not have the inclination, nor the time, to be able to take all the necessary mathematics classes. What typically happens is that they learn the mathematics at the same time they are learning the physics. This is an unfortunate way to learn the material, because more often than not, the mathematics gets in the way of understanding the physics. It is hard enough to learn the physics, but having to also learn the mathematics simultaneously makes the problem rather daunting.

Many physics departments are aware of such problems, and one of the remedies is to offer a course in mathematical physics. This is typically a 1 year, 2 semester course covering a wide range of mathematics that a physics major will need. The purpose of such a course is to give a brief introduction to various areas of mathematics, not from the point of view of rigorous proofs and derivations, but from the point of view of how to use them effectively and correctly, especially when applied to actual physics problems. If there is such a course at your school, I highly recommend that you enroll for it as soon as you can, especially before you need them in your physics classes.

That last part, however, can be a problem. I have observed that in many schools, a mathematical physics course tends to be offered late in undergraduate program, or even as a graduate course. This, of course, does no good for someone wanting to learn the mathematics before one needs it. If this is the case, I would strongly suggest that you purchase this text: "Mathematical Methods in the Physical Science" by Mary Boas (Wiley). If you are a regular to our IRC channel, you would have seen me recommending (threatening?) this text to several people. This book is meant for someone to start using at the end of the 2nd year, and can be used as a self-study. It doesn't require the mathematical sophistication that other similar books require, such as Arfken. Furthermore, the Students Solution Manual that suppliments the text is a valuable book to have since it shows the details of solving a few of the problems. I would recommend getting both books without the slightest hesitation.

Knowledge of computers is almost a "given" nowadays. However, in physics, this goes a step further. No matter which area of physics you intend to go into, you MUST know (i) how to program and (ii) how to do numerical analysis/computaton. The first part is automatic. Most schools require at least a class in computer programming, using a favorite computer language. Most areas in the field of physics, FORTRAN is still in wide usage, C is a language that is gaining in popularity, and C++ is beginning to take hold. I suggest that the minimum number of programming language you should at least have a working knowledge of is 2: Fortran and C.

The 2nd part of programming, numerical analysis, isn't as automatic. This is the part most computer science majors do not do, but where most physics, mathematics, and engineering majors, have to do. In many instances, the mathematics that describe a physical system is not solvable analytically. This may be in the form of large matrices, non-linear differential equations, etc. In those cases, one can only find values out of the mathematics by solving them numerically. Learning the mathematics of numerical analysis is an extremely valuable skill for your academic knowledge, and even for your "marketability" to be employed. Do not be surprised if a few of your courses require a class project involving numerical computing of physical systems. Whether you intend to be an experimentalist or a theorist, you will need to know how to perform numerical computation.

To give students such skill, most schools offer a specific course in computational physics (in some cases, this is a specific area of study in itself at the graduate level). However, sometime such a course is not offered by the physics department, but rather by either the mathematics department (as a numerical analysis course) or the engineering department. Either way, you need to make sure you get a formal education in one of these, especially if it isn't part of a required set of classes that you have to take.

In the next installment of this series, we will discuss on the most important people in your life as a physics major: your adviser, your instructors, and your teaching/laboratory assistants.

Zz.

Wednesday, August 25, 2004

So You Want To Be A Physicist - Part 2

So now you're in college, and you have every intention to be a physics major (actually, what I'm about to describe applies to anyone who is taking a physics class, not just for physics majors). In most US universities, as a freshman, you do not have a major-specific academic advisor, mainly because most freshmen do not have an officially-declared major. What you would probably get during your first week is a "generic" advising based on what you INTEND to go into. In all likelyhood, assuming that you have all the necessary background, it is a safe bet that you would need the complete sequence of Calculus (typically a year, or 3 semesters worth). This would cover all the basic calculus and analytical geometry (level of Thomas-Finney), and towards the end of the sequence, may superficially cover more advanced topics such as vector calculus and partial differential equations. As a physics major, you will need more mathematics than this, and that includes a separate mathematics course in the two advanced topics that I have mentioned, and maybe even a course an complex analysis. These are the courses that you may have to take after you complete the calculus sequence (more discussion on mathematics in the next installment of this series).

The introductory physics courses can vary from school to school. Typically, the broad dichotomy would be Intro Physics with or without calculus. As a physics major, you would take the former. This means that, if you do not have any calculus background, you may have to delay your first physics class after you have at least completed the first semester of your calculus class (high-school students, take note of this!). The typical intro physics courses in US universities would be at the level of Halliday-Resnick. It is typically covered in 2 or 3 semesters and is intended to be a general survey of many different aspects of physics. These courses tend to be accompanied by laboratory work, which is intended to be an introduction to a systematic experimental study of various physics concepts.

I would like to expand on the importance of such laboratory work, mainly because for many students, this is looked upon as a waste of time, especially if the experiments and laboratory conditions are less than ideal. There are certain things that cannot be taught, but can only be acquired. These are what we call skills. The reason why one has to physically DO something during a laboratory session is to acquire such skills. This does not just mean physical skill, such as the ability to read an ammeter, to be able to perform a task with the least amount of errors, etc., but also mental skills, such as the analytical ability to look at the object of the experiment and figuring out why certain things are done certain ways. This includes the ability to critically analyze the experimental data and how to extract relevant information. Upon completion of such exercise, one must then be able to clearly explain in words and pictures (graphs) what one did, and the results. Again, such ability is important for obvious reasons and it is a skill that can't be taught. It can only be acquired through practice!

Note that what I have described above is not just applicable to physics majors. Such skills that can be acquired are important to anyone, regardless of one's major. In fact, I would make the assertion that acquiring such skills is MORE important for most students in a physics class than knowing the material. It is a fact that the majority of students in a physics class are not physics majors. Although the knowledge of physics is important as a foundation for other classes, for most of the students, the skills that can be acquired through physics classes and laboratories are the more valuable traits that they will carry with them throughout their academic life and beyond. The ability for critical analysis and knowing the reliability of data and results are important skills that are useful in all everyday life.

If you are an undergraduate in a US university, there is no excuse for not enrolling yourself in The Society of Physics Students (SPS). This organization is open to all students, not just physics majors. As part of your membership dues, you get a year's subscription to Physics Today, a journal that practically all physicists read and contains timely information on the world of physics and physicists. You will also get a newsletter and information specifically targeted for undergraduates like you, and also entitles you later on for significant discounts and even free registrations to attend various physics conferences. In other words, if you have even half a brain, enroll in this! The benefits are just too great to not to. Go to the physics department at your school and ask if they have a chapter of the SPS there. You can enroll via your school's chapter. If there isn't any, go to the SPS website at

http://www.aip.org/education/sps/index.html

and you may enroll there as an individual member. It is NEVER too early to be a member, so do it as soon as you are settled. If you are not in a US university, you may still subscribe to Physics Today by going to their website at

http://www.aip.org/pt/

Throughout your first 2 years, the BEST thing you can do for yourself is to get excellent grades. This, I'm sure, goes without saying, but you have to realize that typically, these are the easiest and the most important courses you will see in your undergraduate years. They are the foundation that you will build upon for your other courses, and they are the ones you have a better chance of achieving the highest grades. Do not be discouraged if you feel that at this stage, you are one of the many anonymous "numbers" in a large class. Most classes at this level tend to be huge and it isn't easy to distinguish oneself from the crowd (you will have plenty of opportunities to distinguish yourself later on). But do not let this stop you from seeing the instructor during his/her office hours, or using the Teaching Assistants if you need help. They have been PAID to do just that!

In the next installment, we will discuss the transition between the intro classes and the more advanced undergraduate classes, and your first tentative steps towards distinguishing yourself from other students.

Zz.

Tuesday, August 24, 2004

So You Want To Be A Physicist - Part 1

Most of us have various reasons or impetus for wanting to go into this profession. I sometime liken it to wanting to be a priest (I have a bad joke to accompany that, but I won't say it) - the calling towards it that somehow can't be ignored. We all know that being a physicist would not make us filthy rich, but there is somehow an intrinsic satisfaction working in this field.

In this part of the series, I'd like to start at the beginning. No, not during conception, or while one is still in the womb (although it isn't too late to read to a fetus about Newton's Laws of motion). The preparation one makes while still in high school before proceeding to college can be important. The most important of which, in my opinion, is one's mastery of basic mathematics. Typically, by the time someone enters college, there should already be a good command of algebra, trigonometry and geometry. Taking intro physics without a good command of these three is a recipe for disaster. In many cases, one also needs at least a semester's worth of calculus if the intro physics class includes calculus.

Although this appears to be obvious, it isn't. In my brief teaching experience at the freshman level (1st year students in a university in the US), I often found that many students struggled with their physics homework not because they did not understand the physics, but they could not do the mathematics. Of course, they then blamed the difficulty of physics for this without realizing that the physics course itself was not to be blamed. Interestingly enough, we often encounter similar situation on our IRC channel. Students coming in with physics problems are often stuck more with the mathematics.

So, adequate preparations in mathematics at the high school level is crucial. In the US, one can still catch up on the necessary basic mathematics even after enrolling in a university by taking which ever mathematics courses that one needs. However, this will mean delaying other physics courses till one has the necessary mathematics skill.

Are high school physics classes necessary? Definitely. It is always advantageous to have a flavor of the simple ideas of physics before hand. In the US, there is such a thing as AP Physics, where high school students get advanced physics lessons almost at the college level of intro physics. This can do nothing but add to one's advantage.

Unfortunately, sometime these high school physics classes can backfire. It is a sad reality that in many high school in the US, the physics classes are often taught badly, and often by someone without a physics degree. This has the negative effect of turning many students off this subject. Ask anyone who hates physics and chances are, they had a bad introduction to it in high school.

In Part 2, surviving the first year of college.

Zz.

So You Want To Be A Physicist

One of the most frequent questions we get (besides the annoying "can anything travel faster than c?" or "shouldn't light have mass since E=mc^2?") is the process and background of being a physics major. Often, we have students asking what are the requirements of obtaining a physics degree, and what can one do with such accomplishments.

I am hoping that, in a series of postings on this topic, we get to go over and demystefied the whole process of what one can expect as a physics major in college, all the way to going through a Ph.D program, and even beyond that in the land of postdoctoral work and employment. This is not as easy as it sounds, especially considering the wide-ranging educational systems we have throughout the world. So in most cases, the perspective I will tend to have the most understanding with is the US educational system. This is where someone from another country can come in and contribute their experiences and wisdom.

What I hope to impart is not only what is known, as described in various brochures and guidelines from many schools, but also what is never told to the students. Most of these come from personal experience, things that I found myself saying "Boy, I wish someone would have told me that earlier!".

As usual, feedback and questions are welcomed as this series progresses. Who knows, maybe after this, I may finally be inclined to compile all this into the book that I've always wanted to write! :)

Zz.

Tuesday, July 27, 2004

Are You A Quack?

This is the best ammunition against physics quackeries:

http://insti.physics.sunysb.edu/~siegel/quack.html

Zz.

Thursday, July 22, 2004

Welcome to my Blog

There's no particular reason to start this, since it's not as if I lack the means to expression my opinion. So at this early stage, I am creating this Blog simply because I can. Eventually, I'm sure this will evolve into a more meaningful exercise.

Till then, if you are keen in participating and learning more about physics and physicists, try visiting the Yahoo e-Group that I run at

http://groups.yahoo.com/group/undernetphysics/

Thanks for reading.

Zz.