Entries by ZapperZ

“Classical Physics Is Wrong” Fallacy

One of the common questions or comments we get on PF is the claim that classical physics or classical mechanics (i.e. Newton’s laws, etc.) is wrong because it has been superseded by Special Relativity (SR) and General Relativity (GR), and/or Quantum Mechanics (QM). Such claims are typically made by either a student who barely learned…

Very Little Excuse To Ask A Question Cold

We frequently get questions such as these: “What is energy?” “What are Cooper Pairs?” “What is conservation of momentum?” etc…etc. And the persons who asked such questions didn’t bother to explain the context of the question, what exactly did he/she wanted to know, and didn’t reveal the level of education that he/she could understand. While…

Fake News and Science Reporting

During and even after the recent US election campaign, there were numerous reports of fake news, made-up news, and other kinds of news that were deemed either outright fabrication, or inaccurate or incomplete reporting of something to skewer it into one point of view or another. While the outright-fabricated news can easily be spotted eventually,…

Why Is Quantum Mechanics So Difficult?

Strangely enough, QM’s formalism isn’t any more difficult than other areas of physics. The mathematics of the “standard” QM isn’t any worse than, let’s say, electromagnetism. Yet, to many people, especially non-physicists, QM presents a very daunting effort to understand. I strongly believe that it all comes down to how we understand things and how…

So I Am Your Intro Physics Instructor

I posted this elsewhere (on my personal blog), and someone mentioned that maybe it might also be useful here on PF. So I’m reproducing the entire entry here in case it might make a difference. This is essentially a “sequel” to my earlier essay on “So I am Your Academic Advisor“. My aim in writing…

See an Electron Lately?

This is not about seeing an electron, but rather, the notion that seeing something with our eyes is the end-all requirement for the validity of anything. I will show that our human eye, as a light detector, is NOT a very good detector at all in many aspects, and thus, using it as the standard…

Do Photons Move Slower in a Solid Medium?

This question appears often because it has been shown that in a normal, dispersive solid such as glass, the speed of light is slower than it is in vacuum. This FAQ will strictly deal with that scenario only and will not address light transport in anomolous medium, atomic vapor, metals, etc., and will only consider…

Why Is Acceleration Due to Gravity a Constant?

This question has popped up many times. So here is an attempt to address it. To answer this question at the elementary level, a number of assumption will be made, which will become obvious later on. Still, at this point, we will simply deal with objects with spherical symmetry and no complicated mass distribution. In…

Imagination Without Knowledge Is Ignorance Waiting to Happen

Introduction My feelings on people who think that imagination is more important than knowledge is well-known. These people simply are parroting Einstein’s phrase without understanding the context and implications.To prove that, I will cite two specific examples that I’ve encountered personally. These either came to me via direct contact with the person who made such…

Do Photons have Mass?

Do photons have mass? The quick answer: NO. However, this is where it gets a bit confusing for most people. This is because in physics, there are several ways to define and measure a quantity that we call “mass”. Now, it doesn’t create any confusion among physicists because we tend to know in what context…

You Will Not Tunnel Through a Wall

We periodically get questions on PF about people wanting to know of a tennis ball, a ping pong ball, a person, a cow, etc. can tunnel through a wall, or fall through the ground. This is due to an aspect or a consequence of quantum mechanics in which quantum particles have the probability of tunneling…

Your Curriculum Vitae As a Physics Graduate

    I am going to backtrack a little bit and talk about writing your Curriculum Vitae (CV) and what you should focus on in search for a job in physics. This includes looking for a Postdoctoral position, a research position, and possibly a faculty position at a university. I am going to base this…

How to Get a Postdoctoral Physics Position

    If you intend to pursue an academic/research career, chances are, you will need postdoctoral experience. This is typically a 2 to 3-year appointment either at a university, national laboratories, or industrial laboratories such as Bell Lab. It is not uncommon for someone to do 2 postdoctoral positions before finding a suitable employment. So…

How to Get a Physics Job!

    In the previous chapter, we have reached the point where you have finished with your thesis defense, and also thesis submission to the graduate school. You are all set to go into the nasty physics world and look for a job. If that is your case, then you are SCREWED! You do NOT…

Your Physics Thesis Defense Guide

    At this point, you have completed writing your thesis, your adviser has approved of it, and you have distributed it to all the members in your thesis committee. It is now time for you to do your thesis defense. Officially, this is the final obstacle standing in your way between you and your…

Oral Presentations – Addendum | Physics Career

I’ll try not to make a habit out of this, but I believe there’s something to add to this chapter of the series. In Part XIV, I mentioned the APS Meetings – March and April – which typically tend to be the largest yearly gathering of physicists. They both covered different areas of physics, i.e….

Publishing in a Physics Journal (Addendum)

  When I first wrote this part of the series, I wasn’t quite sure if I should include this. for most people submitting to most of the physics journals, this isn’t an issue. But considering the number of very bright students we have on here, inevitably some of you might consider submitting a manuscript to…

Oral Presentations As a Physics Major

    I mentioned earlier that there are two ways for physicists to communicate their work. The first is via publications in peer-reviewed journals. I have covered this in the last chapter of this series. The second, which we will cover here, is through oral presentations at various scientific conferences. Each year, there are scientfic…

Initiating Research Work As a Physics Major

    It has been a while since the last installment of this series, so let’s recap on where you are right now. You should already made a choice on the physics subject area that you want to work in, and you have picked an advisor who will be (i) supervising your Ph.D research work…

Entering Physics Graduate School From Another Major

    I have decided to tackle this issue because it became a very common question in many physics forums. Can someone, without a degree in physics, get accepted and succeed in physics graduate school all the way to obtaining a Ph.D? Obviously, this question cannot be answered easily, because it depends on (i) your…

Alternative Careers for a Physics Graduate

    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. This is the “traditional” path that many physics students…

Applying for Physics Graduate School

  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…

The Life of a Physics Major

  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…

Mathematical Preparations For a Physics Major

  Part III: Mathematical Preparations 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…