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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5
votes
6answers
280 views

Explain the notion of light/electromagnetic waves/photons to a non-physicist

A non-physicist asked me about special relativity. My explanations naturally were based on gedankenexperiments involving light. This forced the question: "What is light? It is particles, isn't? Or is ...
33
votes
8answers
6k views

Will we ever be able to view the past?

By analogy with the sun, whose light is apparently reaching us in 8 minutes, it means that we are only viewing the sun 8 minutes ago when we look up at it. However, what if we were eventually able to ...
2
votes
6answers
232 views

Is $∣1 \rangle$ an abuse of notation?

In introductory quantum mechanics it is always said that $∣ \rangle$ is nothing but a notation. For example, we can denote the state $\vec \psi$ as $∣\psi \rangle$. In other words, the little arrow ...
1
vote
4answers
132 views

Why does the mathematical constant $e$ enter into quantum mechanics so much?

In A. Zee's book Quantum Field Theory in a Nutshell, he mentions on pages 11-12 the following formula which he assumes reader had encountered before: \begin{equation} \langle q | p \rangle ~=~ ...
1
vote
0answers
99 views

What's the best GR book for recreational study? [closed]

I currently have four books. Hartle Schutz Cheng Carroll (lecture notes) Which one is best for me to read easily? (especially, for foreigners) Or Do you guys can give good recommendations that ...
0
votes
0answers
67 views

Intuitive model to show difference between photon energy and light intensity?

What would be a good (intuitive, easily comprehensible) model to explain the quantum nature of light insofar as there is a fundamental difference between intensity and photon energy? One example (not ...
0
votes
4answers
131 views

What is the 'normal/standard' formulation of quantum mechanics called?

I know of at least three equivalent formulations of QM: The "normal/standard" one, dealing with Hilbert spaces and state vectors. The Feynman path-integral formulation. The Wigner-Weyl phase space ...
0
votes
1answer
47 views

Semantics: alternative word for long-ranged interaction? [closed]

I am working on wording for a report. I need to a word to describe long ranged interaction that is constant in strength. But I am aware that people sometimes use 'long-ranged' to mean decaying ...
4
votes
0answers
54 views

Why is an Ampere an SI unit? [duplicate]

It has always annoyed me that an Ampere is an SI unit, rather than a Coulomb. Why is this the case? Was current discovered first historically? I believe that the standards were published in the 1960s, ...
2
votes
2answers
202 views

Why doesn't a glass french press shatter when boiling water is poured in?

When I was little, I accidentally shattered a glass cooking instrument due to applying far too drastic a temperature change to it. Since then, I've been a bit afraid of doing it again. Of late, I've ...
1
vote
3answers
628 views

Prerequisites for classical mechanics by Susskind

So I am an undergraduate in Electrical Engineering. We had a course on Physics in our freshman year which is equivalent to Classical Mechanics I as taught in MIT. I am interested in studying advanced ...
43
votes
5answers
5k views

Why is the harmonic oscillator so important?

I've been wondering what makes the harmonic oscillator such an important model. What I came up with: It is a (relatively) simple system, making it a perfect example for physics students to learn ...
6
votes
4answers
204 views

Is differential geometry used in solid state?

I'm an undergraduate in physics interested in a career in solid state. While I know that any additional math is helpful--I am on time constraints, and can only take a few supplemental classes. That ...
1
vote
2answers
121 views

Newton's Principia: Astronomical prerequisites?

I am planning to read the Principia but I currently have no knowledge about Astronomy. What astronomy prerequisites do I need to understand the Principia? I would prefer older books (or "treatises"), ...
18
votes
4answers
4k views

Why are grams usually only expressed as milligrams, grams or kilograms?

I'm a physics (and electronics and astronomy, etc.) enthusiast. As I learn and research topics, I notice that many SI units are often expressed using a variety of prefixes, such as in electronics ...
1
vote
1answer
94 views

Realistic Potential Wells

What is meant by the term "realistic" potential wells? I got stuck into the term as I don't know what are the limitations of the word realistic in this case. For example mentioned in line We ...
0
votes
0answers
26 views

Using theater lamp for heating [duplicate]

I'm asking myself a question about how to warm my house up, and the efficiency of such a thing : I live in a theater, and we got plenty of 1000W lighting fixture, mostly Tungsten incandescence ...
3
votes
0answers
80 views

When did people start to regard “time” as a physical quantity? [closed]

I was trying to figure out how people came to know about time then I realized that people started keeping track of time to know about sunset and sunrise. But I can't figure out how did time came into ...
2
votes
2answers
187 views

Is Physics being formally documented somewhere?

Physics is an extremely diverse subject, with new phenomenon being mapped by the second. So, is it all being formally documented somewhere? I'm specifically looking for a centralized, formal ...
1
vote
2answers
294 views

Examples of applications of real-valued closed 1-forms in physics [closed]

Closed 1-forms are well-studied in foliation topology, algebraic geometry, and theory of manifolds. What are examples of their most typical or most interesting applications in physics? I do not mean ...
1
vote
0answers
48 views

GRE subject exam advice [duplicate]

So, I would like to ask those of you who have had this experience for some advice. What book is best for GRE subject exam? I have noticed that some books online have mistakes, so I would like if you ...
2
votes
1answer
80 views

Advice on Major Selection [closed]

I need a bit of an advice in deciding my major. My university allows only one major (along with minors) and I'm having a little bit of trouble in deciding what to do. Here's the thing. I want to go ...
5
votes
1answer
222 views

Model Selection in Physics [closed]

My high-level understanding of the scientific method is that it can be summarized in the following steps, in no particular order: Make conjectures & hypotheses (theory) Make predictions ...
1
vote
0answers
66 views

Good Resource for Classifying Statistical Mechanics Problems [closed]

I've grown very interested in statistical mechanics ever since I took my first course in it. However, it feels like it is just overflowing with many types of problems and plenty of categories to ...
2
votes
0answers
119 views

If tachyons were real, where would they originate from? [closed]

If the hypothetical tachyon existed, where would it possibly originate from? or is this question off the realms within the current state of physics. Also what are some ways physicist have tried to ...
3
votes
1answer
2k views

“And God said…and there was light.” What does these equations mean? [duplicate]

Today while I was on the Internet I came across an interesting picture, that caught my eye. It's : I don't have to explain why this picture seems interesting to someone who knows the meaning and ...
4
votes
1answer
600 views

Maths behind gravity assist

What kind of maths is behind gravity assists and in general the theory of orbits, and how deep does it go? I am just wondering if I know enough prerequisites!
2
votes
0answers
203 views

What is the difference between a philosopher of science and a theoretical physicist? [closed]

What is the characteristic objective difference in objectively observable attitudes and research styles between a philosopher of physics and a theoretical physicist? Was Ernst Mach more of a ...
3
votes
1answer
106 views

What topics do I need to study electromagnetism on the quantum scale? [closed]

What topics do I need to study (in order) so that I can study electromagnetics on the quantum scale? What is the name of the discipline studying electromagnetism on the quantum scale? Do I need to ...
2
votes
0answers
43 views

What are some good physics websites for learning in general? [duplicate]

As a 17-year-old who is interested in physics and especially in the laws of the universe, what are some good websites that are clear explanations and straight to the point?
0
votes
3answers
113 views

Is it acceptable to base a physical theory on a philosophical idea?

Are theories that are based on the philosophy acceptable in Physics? If the theory is based on the philosophy that obtained from laboratory experiments, can it be accepted?
0
votes
0answers
31 views

Relativistic non-linear Walecka model

What is meant by a relativistic non-linear Walecka model? What are some various sources to study it? [And why cannot Google show a satisfactory result to such a simple question?]
3
votes
3answers
900 views

What's the difference between “numerical methods” & “mathematical analysis” as said by Feynman in his lectures?

While reading his lectures, I came to these lines: On the basis of Newton's second law of motion,which gives the relation between the acceleration of any body & the force acting on it,any ...
1
vote
1answer
105 views

Practical Book on Hamiltonian and Lagrangians? [duplicate]

Are there any terse, accessible books that are geared specifically at learning these two formalisms and how to effectively use them? So far I've only see either topic introduced as a part of another ...
1
vote
0answers
64 views

Why Penrose's conjecture that consciousness is affected by quantum phenomenon too much of a stretch for Hawking [closed]

Why did Stephen Hawking feels that Penrose's statement on quantum consciousness is too much of a stretch? This is a classical reductionist argument. Humans are made by atoms, atoms are made by ...
1
vote
2answers
289 views

How “fundamental” is quantum information/computation?

I am wondering how fundamental the study of quantum information theory and computation is, in the sense of contributing to our understanding of the basic laws of nature. Will quantum information ...
1
vote
1answer
94 views

Research papers readable by first years? [closed]

This coming Spring I'll be running a Mechanics I lab for freshman (as a teaching assistant) and I'll have some say as to the way I do it. So I was thinking it would be nice if I could find some ...
0
votes
1answer
847 views

Where did the Word 'Physics' Come From? [closed]

As the title suggests, where did the name for the discipline 'Physics' come from? - does it mean something in Greek?
1
vote
0answers
116 views

Is multiverse generally accepted among cosmologists? [closed]

Is it consensus among cosmologist that there is probably at least one type of multiverse? Is there any renowned physicist who rejects the idea of multiverse? I'm not talking about those who claim it's ...
3
votes
1answer
193 views

Greiner or Landau for Math major student? [closed]

For textbook series by Greiner or Landau, is it recommended to start reading for math major students, who have no serious physics background, but comfortable with maths ? It seems that both Greiner ...
0
votes
0answers
57 views

Confusion about the use of the term “Phase Space” in Strogatz text

I've just started learning about Hamiltonian mechanics, and from the definition given in Taylor's classical mechanics, phase space must always have an even dimension. However, I recall from reading ...
0
votes
3answers
140 views

Proof in physics

Is 100% proof of a theory possible in physics, or all we can do is to see how well it stacks up against observations and then decide if we accept it or not? If so, isn't there a danger ,however ...
0
votes
1answer
163 views

What is this simple mechanism called? [closed]

I often build with Lego and use this mechanism: It converts the rotational movement to linear by making the stick between the two blocks go back and forth. What is this mechanism called?
0
votes
3answers
63 views

Image angle illusion [closed]

I am not sure whether this question on-topic here. (please suggest to migrate if this is off-topic) What is the phenomenon/illusion (or something else?) known as where in a photo of a person, the ...
0
votes
2answers
149 views

Why is a thought experiment a valid way to prove anything?

Isn't a thought experiment as subjective as you could make science be? Is it that since it is impossible with our current methods, we are simply skipping too many hurdles that would have to first be ...
1
vote
3answers
147 views

What really is “inertial force”?

In Fluid Mechanics we often see the term inertial force when discussing Reynolds number. The problem is, I didn't really get what's this inertial force. Basically, the notion of inertia I have is that ...
1
vote
1answer
42 views

Specific scenario involving rotation and inertial frames of reference?

We recently went over some rotational motion in my freshman physics class, I had a question for the professor on your frame of reference, and how that would effect the rotation of the object. Say you ...
3
votes
1answer
133 views

The spin and weight of a primary field in CFT

A primary field in Conformal Field Theory transforms as $$\phi (z,\bar{z}) =\left(\frac{dz}{dz'} \right)^h \left(\frac{d\bar{z}}{d\bar{z}'} \right)^\bar{h}\phi (z',\bar{z}') $$ under a conformal ...
1
vote
0answers
269 views

Which field of theoretical physics is most promising? [closed]

I'm about to choose university and I really love physics, but I don't know about use of it. What field is most promising to study? Where could I work with subatomic particles PhD? Or maybe nuclear ...
1
vote
0answers
45 views

Will the usage of Exo-Skeleton Gear actually weaken the human body over time? [closed]

As we all know, Exo Skeletons as they exist now are just a series of Force multiplying apparatuses working together, also the human body changes to accommodate environment specific factors in order to ...