-3
votes
1answer
74 views

Why do we believe in a “force” driven universe? [on hold]

Why do we not believe in the potential for a "unified force field" universe, to the exclusion of the belief in the potential for a mechanical, gear driven universe, if the correct shape for the gear ...
4
votes
4answers
488 views

Quantum mechanics threshold

First of all I beg your forgiveness as I am not a physicist and the question I am going to ask may sound silly. I am aware that beyond a certain threshold in the hierarchy of building blocks of ...
0
votes
2answers
76 views

Are there two aspects of Born's rule?

I am having some problem understanding Born's rule. I am getting a little bit confused. Here it goes; Let $f(x,t)$ be a solution of Schrodinger equation. Then Born's rule says that the square modulus ...
0
votes
4answers
217 views

Does Newton's law and Quantum mechanics also apply for the matter which is not dead?

The following quote is extracted from the book "The Field-The quest for the secret force": ...There was other, quite practical, unfinished business with quantum theory. Bohr and his colleagues ...
6
votes
6answers
505 views

Electron shells in atoms: What causes them to exist as they do?

I have seen similar posts, but I haven't seen what seems to be a clear and direct answer. Why do only a certain number of electrons occupy each shell? Why are the shells arranged in certain distances ...
4
votes
3answers
334 views

Quantum Mechanics or Classical Mechanics? [closed]

I'm just a student of grade 11 but, I was interested in knowing about Physics much deeper. In order to start my interest in Physics, I watched this video of Quantum Physics NOVA : Quantum ...
1
vote
0answers
44 views

about MS in Theorectial Physics [closed]

I am an undergraduate student (Bachelors of engineering) about to complete my 1st year in the field of Information science and engineering or information technology. I am interested in pure physics ...
2
votes
2answers
453 views

Question regarding Schrödinger's equation

Here is my understanding of Schrödinger's equation and wave functions: (I'm considering the time independent equation.) The equation takes in values of energy as an input and, being a differential ...
4
votes
0answers
47 views

What does it mean 'the observer' in Quantum Physics? [duplicate]

Is it only necessary a human consciousness? A measurement device? Can it be said that any of them cause the wave function collapse?
2
votes
0answers
46 views

Trouble understanding quantum mechanical picture of atom [closed]

This year in college we"ve had a lot of quantum stuff thrown at us, and we"ve only been doing classical mechanics till last year. We"ve been introduced to Schrodinger"s equation, electron waves, what ...
0
votes
1answer
52 views

Stern Gerlach Experiment

Since l=0 for a valence electron in 5s state of silver, L=0 and therefore magnetic dipole moment is also 0 which means that the beam should not have deflected at all. So, we introduced the property of ...
0
votes
2answers
76 views

Measurement of Mass and Momentum of a particle simultaneously

In quantum mechanics can the mass and the linear momentum of a particle be measured precisely or do they commute ?
1
vote
0answers
65 views

Physical Meaning of Linear dependence of vectors in quantum mechanics

I have got some questions regarding the mathematical concepts in Quantum Mechanics that I have listed below- 1) What is the physical meaning of linear dependence of vectors in Quantum Mechanics ? 2) ...
1
vote
0answers
39 views

Spin with Stern gerlach Experiment [closed]

Within a week, I am trying to conduct a seminar on the topic " Spin with Stern gerlach Experiment" at my University. It would be great if you guys could provide me some inputs regarding the things I ...
1
vote
0answers
121 views

Partition Function of a three state particle system

I've just finished studying the partition function of a two-state particle system, where particles can have a 0 energy value or E energy value . That is: Where $t_j$ is a variable of value ...
0
votes
1answer
119 views

Quantum explanation of Newton's Third Law of Motion

Newton's law states that for every action there is equal and opposite reaction. This law explains how rockets fly in space and accounts for the the majority of the lift action generated by a ...
4
votes
2answers
253 views

Does Galileo's Tower of Pisa argument contradict quantum mechanics?

(My questions are at the end, but they may not mean much without explanation below.) Galileo argued that because the mass of a falling object can always be redistributed in ways that asymptotically ...
0
votes
0answers
43 views

Collapse of wave function

Can the collapse of a quantum mechanical state in general into one the eigenstates of an observable whenever its measurement is made written mathematically? If yes, how?
0
votes
2answers
245 views

Does light have mass/weight?

If I plug in my memory stick/USB into my laptop and load it up with documents etc. will its mass/weight increase?
1
vote
1answer
110 views

Infinitely many soft photons from pushing an electron?

I have been looking at some of the archives here and seen it quoted by Ron Maimon , that pushing an electron with a classical field means the electron will produce infinitely many soft photons should ...
2
votes
2answers
214 views

Higher moments of the kinetic energy operator in QM

I have set myself the task of studying the kinetic energy $T$ in a quantum mechanical system. For the latter, I use the simple case of the Hydrogen atom in the $n=1$ state. Then the wave function is ...
1
vote
1answer
46 views

How can enzyme/substrate reactions that adhere (largely) to quantum theory also require 'Newtonian' consideration of gravity?

I'd just like to ask for a little clarification here due to confusion from interdisciplinary studies. I'm currently reading the 1976 paper related to the recent 2013 Nobel Prize for Chemistry, by 2 ...
1
vote
1answer
98 views

Shifting the energy reference level [duplicate]

In non-relativistic QM, does it make a difference if an energy shift is applied to the systems's Lagrangian or Hamiltonian?
0
votes
1answer
164 views

Classically, how can an electron orbiting a proton radiate given its relativistic energy

In classical relativistic Electrodynamics, we are often told that any accelerating point charge inherently radiates (Bremstrallung). (This is the basis for the need for a QM conception of electrons.) ...
0
votes
0answers
50 views

The electron and classical dynamics

Can I use Newtonian laws of dynamics and kinematics applied to electrons (like $F = ma$ and $s = s_0 + v_0 t + at^2/2$)? If not, why not? I know that everything in principle behaves in a quantum ...
1
vote
0answers
46 views

How to prove Newton's second law with quantum mechanics? [duplicate]

Newton's second law claims that $F=ma$. In terms of quantum mechanics, the equality can be written as $ \frac{d\langle p \rangle}{dt} = -\langle \nabla V(x) \rangle$. How can I prove this with ...
1
vote
2answers
121 views

Are there problems solvable with Newtonian physics, GR and QM?

First I must let you know that I don't have much understanding of neither GR nor quantum mechanics, and therefore this question. I've mentally pictured Newtonian physics, GR and quantum mechanics all ...
0
votes
2answers
2k views

Newtonian Mechanics and Quantum mechanics

Why isn't Newtonian mechanics valid in Quantum world? Suppose you isolate an alpha particle and accelerate it in absolute vacuum. Why it doesn't follow the equation $F=ma$? If Newtonian mechanics is ...
9
votes
3answers
4k views

What exactly are Hamiltonian Mechanics (and Lagrangian mechanics)

What exactly are Hamiltonian Mechanics (and Lagrangian mechanics)? I want to self-study QM, and I've heard from most people that Hamiltonian mechanics is a prereq. So I wikipedia'd it and the entry ...