Questions that ask about some aspect of physics research or study which doesn't involve the actual physics. In general, soft questions can be answered without using physical reasoning.

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31 views

Order of magnitude

When finding out the order of magnitude of quantities, as said in my textbook, we compare the numerical part with $3.2$ (approximately $\sqrt{10}$ or rounded off version of $3.162$) Thus, $9.12 ...
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2answers
148 views

What is the gist of the equations on Alejandro Guijarro's “2/14” “Momentum” blackboard?

The artist Alejandro Guijarro has an exhibit of photographs of a variety of blackboards with physics equations, drawings and text on them, as covered at Quantum Chaos on Display in Top Physicists’ ...
1
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1answer
69 views

How far do atoms move in a wire when whirling it horizontally?

so the question is: I whirl a mass m attached to a wire with length L and diameter d around my head in the horizontal plane. The mass takes t seconds to move around a circle. How far do the ...
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1answer
59 views

How big was the first transistor?

The first working point-contact transistor made in 1947 by Bell Labs. I'm looking for specific dimensions, all I've been able to find is "Fits in the palm of your hand".
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1answer
63 views

How quickly does air return to a vacuum chamber?

I know there are a lot of variables that affect how quickly this would occur. Any information on the topic would be highly appreciated. For sake of argument, lets say 1 square foot chamber, lets say ...
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0answers
23 views

An easy source to understand classical dynamics — Rigid body Rotation [duplicate]

I've been having an extremely hard time at understanding rigid body rotation. The source that I'm currently studying from has been suggested by 't Hooft on his webpage. It's by Richard Fitzpatrick. ...
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0answers
29 views

Good First year physics lecture notes [duplicate]

My course textbook is Halliday fundamental of physics, this book is huge and since each week, they cover a lot of material in lectures (something about 6 chapters of the textbook), I find it hard to ...
3
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0answers
125 views

Comparison between Cadabra and other Symbolic Computer Algebra software [closed]

Does anyone has some experience about working with Cadabra and it's (dis)advantage in comparison to other Symbolic Computer Algebra software such as Maple and Mathematica (physics package) in the ...
3
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1answer
221 views

Why have $n$, $\ell$, $m_\ell$, $m_s$ been picked as quantum number symbols $\mathbf{\text{in this order}}$?

I’m learning about electron configurations and don’t quite understand why $n$, $\ell$, $m_\ell$, $m_s$ have been picked as symbols for the quantum numbers. As far as I understand it, the principal ...
2
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2answers
155 views

Expectation Value of a Dynamical Variable

In quantum mechanics, we generally take about "expectation values of dynamical variables". However, by the postulates of quantum mechanics, every dynamical variable in quantum theory is represented by ...
2
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0answers
137 views

How did the scientific community receive Einstein's theories when he published them? [closed]

By now, we have had multiple indications through observations and experiments that Einstein's theories on general and special relativity are correct. We recently had our second observation of ...
2
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3answers
90 views

Can a theory be proven by an experiment (or series of) that sustains it?

This is a question that I've always had but it wasn't until the recent news regarding the BICEP2 experiment that I really gave thought about it (please note that the question is general and not ...
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1answer
64 views

Looking for a projectile motion experiment tool

Is there a name for the device used in physics experiments when one wants to show that (under certain conditions) if two balls are initially at the same height and one is dropped while the other is ...
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2answers
74 views

Motorbike with parachute vs normal skydive

Had a strange discussion in the coffeeroom today. The background was a story about a guy that took his motorcycle to transport himself to the airstrip to do a skydive. Since there is no place to put ...
0
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1answer
46 views

All matter made up of energy? [closed]

I keep on hearing that behind all matter is just waves of energy. I even hear that it is made up of small energy tornado-like waves. This is theoretical physics right? If so, how strong is the theory. ...
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2answers
66 views

Studying Physics [closed]

I'm preparing for entry into a Physics degree course, and was planning on a double major in Physics (with a specialization in Quantum Information later) but am now considering a minor in ...
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1answer
99 views

What is the role of the speed of light in mass-energy equivalency? [duplicate]

Where does $c$ squared come into play in the equation $E=mc^2$. Multiplication obviously but how does energy equal mass times the speed of light?
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2answers
71 views

Should theory be the appropriate term? [duplicate]

Should theory be the appropriate term? I mean, for example, because of the quantum field theory we have been able to find the subatomic particles that it theorized and make the Standard Model. Why ...
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5answers
425 views

What does periodicity of $e^{-iHt/\hbar}$ mean in physical terms?

The unitary time evolution operator $U(t)=e^{-iHt/\hbar}$ has some distinct flavour of periodicity to it because of $e^{x+2\pi i}=e^x$. Is this periodicity reflected in any way in physical systems? ...
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2answers
145 views

Quantum Philosophy a la John Bell

I recently discovered this website http://www.quantumphil.org/ and wondering whether Quantum Philosophy is an actual field, or just an aspect of QM? Apologies if this is in the wrong place.
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2answers
181 views

What does library number 539 mean in physics books? [closed]

Every book I borrow have have this number in them. Even my library categorizes them with this number. Is it a universal particle physics book number?
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1answer
66 views

Info request on studying QIT/QIS or QM with a Computer Science background [closed]

I've been considering a career change for a long time and recently discovered the Two-Slit Experiment, which, to put it frankly, blew my mind. I then started some hefty reading and investigation into ...
0
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1answer
77 views

Pathria's “Statistical Mechanics” first edition [closed]

Does anyone know where I could find and purchase the book "Statistical Mechanics" by R. Pathria, in 1st edition (the 2nd and the 3rd are readily available, but I really need the first). I believe the ...
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2answers
177 views

Good ways for learning and cramming formulas? [duplicate]

I got an exam coming up and its numerical based (its pre-university level exam) but really tough. I want to know about various ways and methods to learn formulas. I know how can I derive them but its ...
2
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0answers
52 views

Prerequsites for Zee's QFT [duplicate]

What would be a good book or books for a sufficient prerequisite for Zee's book QFT in a nutshell? I have had a course in QM and relativistic QM, but I think there are some gaps that needs to be ...
5
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2answers
212 views

What is an effective and efficient way to read research papers? [duplicate]

I will be a grad student in condensed matter theory starting this fall. As an undergrad, I did the basic physics and math courses as well as a few grad classes (qft, analysis, solid state physics ...
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0answers
50 views

To all experienced theoretical physicists out there, what is the step by step process in your math education? [duplicate]

I am not doing a physics degree but an engineering degree but i am planning using my free time to self study all the math in preparing myself to self study subjects in theoretical physics. (I've ...
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0answers
27 views

Textbook on Diffusion and Diffusion NMR Spectroscopy

I am looking for textbooks ( Mathematical / Theoretical Physics ) that cover diffusion in general. Although it is not necessary that your recommendation covers it, I am also particularly interested ...
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0answers
27 views

Relationship between phase space volume and dynamical entropy

I would like to know if there is any analytical proof or relationship which can show that for a dynamical system in presence of chaos signal, if the phase space volume (PSV) minimization leads to the ...
2
votes
1answer
343 views

Can someone be too late for being a great physicist? [duplicate]

I am a first year physics student, but I am 20 years old (pretty old for my country, average starting age is 18), because I started after leaving med school, which I find extremely jailed in ...
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0answers
57 views

How to study physics as a first year student? [duplicate]

I firstly apologise if this question is off the topic. I am a first year undergraduate student and the required textbook for the course Advanced Physics is Fundemental of physics by Halliday. This ...
4
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0answers
81 views

Humour: Noble Gases, Music, Feynman diagrams [closed]

Google found these lyrics: I love the morn, to see the first Radon, When the stars Argon, As the night Krypton, And, if it’s cloudy, you won’t Xenon. Years ago, ...
2
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0answers
35 views

Kolmogorov entropy and noise

There are various ways of calculating the Kolmogorov entropy (KE)of dynamical system. According to Pesin's theorum, it is the summation of the lyapunov exponents; frominformation theoretic concet, it ...
6
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1answer
176 views

Physical intuition for deformation quantization of Poisson manifolds

First of all, I know almost nothing about physics. I was reading Kontsevich´s paper on Deformation quantization of Poisson manifolds, however I could not figure out what´s the intuition for such ...
2
votes
2answers
115 views

What might be a satisfying criterion to qualify something as having physical existence?

I'm a philosophy undergraduate student who has an interest in, and respect for (as most people do) what physicists know about the world. In philosophy, the traditional criterion of physical ...
2
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0answers
62 views

Quantum Field Theory and Lie Theory [duplicate]

I am reading Vol.1 of "The Quantum Theory Of Fields" by S. Weinberg. However I have come to a halt when connected Lie groups were introduced. I have solid knowledge in elementary group theory and ...
10
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3answers
178 views

$1.7\cdot 10^{-24}$ mole apples a day

As the title suggests I was wondering why the International Bureau of Weights and Measures decided a mole to be a standard (SI-)unit. After some research I found I was not alone with this problem. ...
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2answers
228 views

Does Newton's third law of motion fail anywhere?

Does Newton's third law of motion fail anywhere, including particle physics and other advanced topics?
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2answers
103 views

Everyday physics book reference

A few years ago I remember browsing a pair of books that had a list of challenge-like questions about everyday physics, such as why do we deep fry hamburgers, how air conditioning works, etc. They ...
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0answers
63 views

How to move from Special to General Relativity

I have understood special relativity nicely, and right now I am trying to learn general relativity from D'Inverno's book. I an finding it rather difficult to understand the pre-requisite math (i.e. ...
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1answer
30 views

Could each non-dependent physical contant represent dimentions, and our universe be a point on this n-dimentional structure?

For example say the gravitation constant instead of equaling G, was actually a range bounded between 0 and infinity. Our Universe would be at a point on this range (equal to our G value) where ...
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3answers
114 views

Meaning of invariable

Invariable means which is not variable i.e. can't be changed. Recently I have seen a sentence when reading a chapter based on measurement: The accepted standards must be accessible to those who ...
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2answers
150 views

Mnemonic for creation and anhiliation operators [closed]

I am not sure if this is question is withing the scope of this page. I have an exam in quantum mechanics in a few weeks and I always confuse anhilation and creation operator. $$ a^\dagger |n\rangle = ...
5
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1answer
89 views

Why are “quadratures” called this way?

In quantum optics (and hence also cv quantum information), given the annihilation and creation operators of the electromagnetic fields $a$ and $a^{\dagger}$, the "position" and "momentum" operators ...
1
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1answer
154 views

Who popularized $E=mc^2$?

When asking a layman for a mathematical or physical equation you will almost certainly get the answer "$E$ equals $m$ $c$ squared". In fact, $E=mc^2$ is something like a symbol of physics in popular ...
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1answer
53 views

Earthing or nothing

Sometimes, mostly in winter, when somebody touches the tap it passes current (especially when the hands are soaked in water or soap water). I read 3-4 years back in physics book that the tap circuit ...
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0answers
67 views

How can I answer the critical questions of mechanics? [duplicate]

I have passed my 1st year of undergraduate study life somehow I could have managed. But recently I have decided to fill up the emptiness of knowledge over mechanics. Besides I have my studies of 2nd ...
0
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1answer
180 views

Should I learn Classical Physics if I want to learn Quantum Physics? [duplicate]

I don't remember anything from school, so please what do you say about the title?
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1answer
134 views

Are there correct physical predictions made only from thought experiments other than in General Relativity? [closed]

When Einstein started to think about gravitation, he completely created a new theory that no experiment supported. He based his reasoning, as he explained it later, on small thought experiments ...
4
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1answer
146 views

Roadmap to the Renormalization Group Approach

I am an undergrad interested in HEP-Th. I have studied canonical quantization, and path integral approach for quantizing fields, and the EM field quantization, classical yang-mills theory. I want to ...