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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2
votes
5answers
559 views

Why mathematical equations can describe this world? [closed]

Since I want to understand the world, I learn physics from textbooks. But I feel there is a gap between the textbook and the world. I do not know why the equations in the textbook can control the ...
0
votes
0answers
76 views

What kind of physics topics exist? [duplicate]

The question says everything I want to know, but for more details: I enjoy studying physics but the problem is that I can't find any information with a summary of all physics topics, collected ...
1
vote
1answer
73 views

Eddington-Weinberg relation

The numerical coincidence that triggered Dirac to postulate his Large Number Hypothesis can be summarized by expressing the proton-electron gravitational angular momentum in units $\hbar c$: ...
2
votes
2answers
560 views

What does one need to learn to become a experimental particles physicist? [closed]

I know one needs E&M, classical, quantum, statmech at the graduate level. But what more does one need? Are quantum field theory, relativistic QM, advanced math needed? or just an advanced course ...
2
votes
1answer
109 views

Are there examples of online physics collaboration similar to polymath for mathematicians?

When it comes to maths collaboration online, the mathematicians seem to be very well organised. A recent example is Polymath8 from Terence Tao's blog: The main objectives of the polymath8 project, ...
1
vote
2answers
374 views

Why are diffraction gratings not called interference gratings?

It seems to me that diffraction gratings are completely described by the double slit experiment-why then is it called a diffraction grating?
3
votes
3answers
410 views

Physical significance of getting an non-integrable function in an equation

I just found out during my Calculus course in High School, that there exist functions which cannot be integrated. Then I thought that I come across a lot of integrals while solving Physics ...
0
votes
0answers
50 views

Helping/explanatory notes for Landau&Lifschitz Physics Course [duplicate]

I've recently restored my interest on theoretical physics (I have a master degree in Electrical Engineering) and began my study with first volume of the Physics Course by Landau and Lifshitz. This is ...
1
vote
2answers
89 views

Any projects to build a telescope in space?

Like in the title. With E-ELT we are pushing the limit of what we can build on the ground. With JWST we are pushing the limit of what can we launch into space. So instead, why don't we launch tools ...
0
votes
0answers
63 views

Books for learning Mathematics in Physics? [duplicate]

Currently I'm doing Advanced Classical Mechanics courses. I'm finding it hard to understand due to the lack of knowledge in linear algebra, multi variable calculus and other chapters. Can anyone ...
0
votes
0answers
43 views

A set of problems for “The Theoretical Minimum” Stanford course [duplicate]

I'm really excited by an opportunity to watch Leonard Susskind's course "The Theoretical Minimum". However, I couldn't find any physics problems on the website, and I'm a little bit wary of just ...
1
vote
2answers
301 views

How much physics a mathematician needs to know to study GR? [duplicate]

I'm intending to study General Relativity on my own. The thing is, my physics background is not very strong. I know classical mechanics and I know some electromagnetism. I'm familiar with Gauss' law, ...
4
votes
1answer
253 views

What do you call the period after sunrise when the sky is bright?

At sunrise, the sky isn't actually up in the sky yet. Twilight occurs before sunrise, then at sunrise the leading part of the sun crosses the horizon. But, the sky isn't bright yet. It takes some time ...
7
votes
4answers
741 views

Church-Turing hypothesis as a fundamental law of physics

The Church-Turing hypothesis says one can not build a computing device which has more computing power (in terms of computability) than the abstract model of Turing machine. So, there is something in ...
1
vote
0answers
232 views

Good place/supervisor for PhD in Theory of Condensed matter [closed]

I am currently finishing my undegraduate degree in physics and would like to do PhD in Theory of Condensed Matter field. Could you give advice on which are good groups/supervisors in the field. ...
5
votes
2answers
191 views

Celestial Time-Keeping and Navigation

Say, for sake of argument, someone was randomly transported in time and space. Would it be possible for them to determine their location on Earth and the current time using just observations of the ...
1
vote
2answers
314 views

Should we necessarily express the dimensions of a physical quantity within square brackets? [duplicate]

For example, should we write the dimension of mass, e.g. $\mathrm{kg}$ as $[M]$ or is it enough to write it as $M$?
0
votes
3answers
614 views

Measuring speed of a vehicle

I'm very primitive with my thought. So please help if you can in layman terms with an answer to this question. Here we go- by using a street power pole as the source responder, is it possible to read ...
21
votes
8answers
2k views

Why is there a size limitation on animals?

Why is there a size limitation on human/animal growth? Assuming the technology exists for man to grow to 200 feet high, it's pretty much a given that the stress on the skeletal structure and joints ...
3
votes
1answer
144 views

Does magnetism affect corrosion?

Supposing there is an iron nail that is left to rust, if we compare the time it takes to rust with that of a magnetized iron nail, will there be any difference in the time of corrosion (assuming other ...
1
vote
1answer
159 views

What cause scientists to study Black Body Radiation?

After spending hours understanding what exactly Black Body radiation and Ultraviolet catastrophe is, I cannot help myself asking what was the reason that make scientists such as Wilhelm Wien and Max ...
7
votes
2answers
331 views

Etymology of “Renormalisation”

Just out of curiosity, does anyone know why "renormalisation" is so named? Who first came up with the term, and why was it used? I did a mathematics undergraduate so to me "normalisation" means ...
3
votes
3answers
364 views

Would a sea level rise (on the other side of the Earth) if you would dip your finger into the ocean?

(I'm not a physicist & I hope this question isn't too basic/lame) The question says it all & assuming: No atmosphere No Earth rotation Not a single object in the ocean(s) Ignore all other ...
1
vote
0answers
37 views

Material to read before taking College Physics 1? [duplicate]

I'm transferring to a 4-year university from a 2-year college. I earned a Computer Science A.S., but must now combine Computer Science with Advanced Physics for my B.S. I'm actually very excited for ...
4
votes
2answers
140 views

Education : Students devising and solving their own problems [closed]

I apologize in advance for the nature of this question. I have been thinking lately of methods to increase the quality of my self-study. I have been meaning, but never actually got to, in addition ...
6
votes
1answer
956 views

Educational physics stories with a funny punchline [closed]

As a physicist, when I'm giving lectures or during colloquiums, I usually find it necessary to have some appropriate and related jokes in hand. All of the best teachers have some, and they use them ...
0
votes
2answers
230 views

What is the required prerequisite knowledge of QM, for starting QFT?

As a physics bsc student, I have a very limited knowledge of QM: Dirac formalism, Schrodinger equation and simple solutions (oscillators, particle in a given potential, hydrogen-like atom etc). There ...
26
votes
6answers
3k views

Canonical everyday-life example of a technology that could not work without humans mastering QM in analogy to the application of GR in GPS?

The GPS is a very handy example in explaining to a broad audience why it is useful for humanity to know the laws of general relativity. It nicely bridges the abstract theory with daily life ...
2
votes
4answers
492 views

Are Lagrangians and Hamiltonians used by Engineers?

Analytical Mechanics (Lagrangian and Hamiltonian) are useful in Physics (e.g. in Quantum Mechanics) but are they also used in application, by engineers? For example, are they used in designing bridges ...
2
votes
4answers
172 views

Suggestions of a non-linear example for a small research project on numerical solution of ODEs?

I'm a first year undergrad and I'm doing a small research extension on numerically solving ODEs. I have done the main ODE course at my university, as well as physics. The second part of the project ...
7
votes
1answer
121 views

An approachable example of a field with a “mass gap”

Preamble: I have come to believe that alot of difficulties in explaining physics to people of all levels comes from the relatively mundane idea of a wave equation with a mass gap $$\left(-\partial^2_t ...
0
votes
3answers
160 views

Clarity in Electric field Definition?

The electric field at a point is defined as q/$r^2$. How does this definition take the nature of source and test charge into consideration. If I bring any positive/negative charge around the source ...
3
votes
2answers
610 views

Is Hubble's constant really constant? [duplicate]

How does Hubble's constant resembles age of universe? Isn't universe getting old each day? How can a constant be a reciprocal of age of universe? Hubble's value must be variable, isn't it?
2
votes
1answer
307 views

Online physics diagram tool

What is a suitable tool for drawing physics diagrams online? I would love to know if there is a program like the excellent schematic drawing tool that is integrated into the electrical engineering ...
3
votes
1answer
183 views

Where did the concept of energy come from?

Energy seems to me to be a very abstract thing, and while it clearly works out very nicely, I don't understand how anyone would have thought to come up with it. Where does the concept of energy find ...
3
votes
2answers
113 views

Do I think or listen - physics talks [closed]

I am just a student, still I have already listened to a few talks on physics. In my study program everyone has to give a talk of about 45 minutes what he did in his about 1-2 month reach project ...
1
vote
2answers
170 views

Correct terminology for combined kinematic and dynamic state

The kinematic state is defined as the position and orientation in space. The dynamic state is defined as the associated velocities. What is the correct terminology for the combined kinematic and ...
0
votes
3answers
188 views

What is the name of the equation which led to the Schrödinger one?

What is the name of this equation: $$\frac {d^2\psi}{dr^2}+k^2\psi=0?$$ (I want a Wikipedia link for this equation, but I don't know what its name is.) Point: In this equation, the wave function ...
2
votes
2answers
155 views

How is everything a field

I've heard before that everything in physics can be thought of as either a field, or its excitation. Is there some intuitive explanation of how I can look at gravity, light, electromagnetism, etc as a ...
-2
votes
1answer
234 views

Superposition and the Winning Jackpot Numbers

Let's say I buy myself a lottery ticket (Mega-Millions). I have $\frac{1}{175,711,536}$ chance of winning. Before I tune on the tv/radio and listen to the winning numbers (i.e. make an observation), ...
-4
votes
1answer
155 views

why no derivation in scientific papers? [closed]

Is there a reason why scientific papers rarely show derivation of an equation? I fail to see the any advantages ( besides savings latex hours for the authors) of this approach which is the standard ...
6
votes
2answers
2k views

Application of Calculus in Physics

Why do we apply Calculus in Physics when most of the quantities are not continuous and are not symmetrical at all levels of magnification? Aren't most, if not all, forms of Matter and Energy discrete? ...
1
vote
0answers
57 views

Why are polymer representations called “polymer representations”?

Why are polymer representations called "polymer representations"? Polymer representations deal with non-continuous unitary representations of groups acting on nonseparable Hilbert spaces (see e.g. ...
2
votes
2answers
524 views

Human power on treadmill

On an elliptical treadmill a regular person can easily burn 1000 calories in one hour (treadmill reports calories burnt). This translates into: $$(1\times 10^3\mathrm{cal/hr}\times ...
0
votes
1answer
115 views

Is everything in the physical world composite?

In philosophy there is a principle that anything composite cannot have existed eternally, since it is preceded by its parts and whatever forces assembled it. Is everything in the physical world ...
0
votes
0answers
219 views

Does a point exist in the real world [duplicate]

In mathematics we can have an infinite number of points between two integers. This is really circular logic since a point is defined as infinitely small. Does a point exist anywhere in the physical ...
2
votes
1answer
143 views

English/German translation of Latin scientific texts in general, “Principia Generalia Theoriae Figurae Fluidorum in Statu Aequilibrii” in particular

I am trying to get my hands on an English or German translation of the seminal work by Gauss on fluid shapes in equilibrium: "Principia generalia Theoriae Figurae Fluidorum in statu Aequilibrii ...
11
votes
3answers
2k views

Why are they called “cyclic” coordinates?

In Lagrangian formalism, when $\frac{\partial L}{\partial q} = 0$, the coordinate $q$ is called cyclic and a corresponding conserved quantity exists. But why is it called cyclic?
-2
votes
2answers
162 views

Do physics laws really apply to anything? [closed]

My professor said that a law was stated and announced as a law because it happens in our everyday life. He gave us an example of Newton's 3 laws. He said that walking possess 3 laws of Newton's. Is ...
1
vote
1answer
103 views

Incompatibility of GR and QM [duplicate]

I am told that the theories of General Relativity and Quantum Mechanics are fundamentally incompatible... Why is that? Someone explained that it had to do with the fact that quantum particles such As ...