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comment How do I calculate momentum for a particle in a box, using the momentum quantum operator?
Equation 2 can only be true for $0 \le x \le L$ since the probability for finding the particle elsewhere is zero. One might write: $\psi_n(x) = \sqrt{\frac{2}{L}}\sin\left(\frac{n\pi x}{L} \right)\left[\theta(x) - \theta(x - L) \right]$
2d
comment Has New Horizons' visit to Pluto taught us anything deeper than mere… facts?
"I believe there's something to be said for exploring beautiful places — it's good for the spirit.”
Jul
25
answered Inductor - cause and effect
Jul
25
comment Relativistic flashlight and mirror
"How does relativity account for the 'paradox' I seem to have run into when thinking relativisticly?" According to Bob, Alice's clocks are not synchronized. According to Alice, Bob's clocks are not synchronized.
Jul
24
comment What is induced current?
This question does not show any research effort; it is unclear or not useful.
Jul
22
comment Why is space black?
possible duplicate of Why is the sky of the moon always dark?
Jul
21
comment understanding time: Is time simply the rate change?
FWIW: amazon.com/Time-Reborn-Crisis-Physics-Universe/dp/0544245598
Jul
20
comment Why electron can not be found at some node locations in the infinite potential well?
@atom, John's statements aren't contradictory; a quantum particle does not, in general, have a definite position until a position measurement is made. The energy eigenstates of the infinite well are not states of definite position. Further, when a position measurement is made, the particle is no longer in an energy eigenstate, i.e., the measurement process results in the state changing from one of definite energy to one of definite position.
Jul
20
comment Why electron can not be found at some node locations in the infinite potential well?
"The electron moves from left to right & right to left between the walls of the well." Not true according to quantum mechanics.
Jul
19
comment If traveling at the speed of lights stops time, why does it take light 8 minutes to reach Earth?
@PhyCSx, there are no inertial reference frames with relative speed $c$.
Jul
19
comment If traveling at the speed of lights stops time, why does it take light 8 minutes to reach Earth?
Consider an observer moving, relative to the Earth, arbitrarily close to the speed of light. According to that observer, the elapsed time in travelling between the Sun and Earth is arbitrarily small. According to clocks on Earth, it is about 8 minutes. According to other relatively moving observers, the elapsed time is something else. There is no universal time in relativity.
Jul
19
awarded  Necromancer
Jul
19
comment How does connecting different solar panels in parallel affect total current?
Would the EE stack exchange site be a more fitting home for this question?
Jul
18
comment Time and gravity relation
@SahilChadha, hover your cursor over the downvote button.
Jul
18
comment Time and gravity relation
This question does not show any research effort; it is unclear or not useful.
Jul
16
comment What is the wave in an electron?
kushy, fundamental stuff is what it is. As far as we know, the entity for which (what we identify as) electrons are the quanta is fundamental, i.e., indescribable in terms of 'more fundamental' stuff. In other words, the question of what a fundamental entity is composed off ignores the premise that the entity is fundamental.
Jul
13
comment How does the idea of a scalar potential for a 3-vector field generalize to Minkowski space?
Hint: a (Lorentz) scalar potential couples to a Lorentz scalar, e.g., a particle's invariant mass-energy. But the EM four-potential couples to a four-current.
Jul
11
comment What happens to half of the energy in a circuit with a capacitor?
The first sentence is correct but the rest of the answer is not. In the ideal case, the voltage across the capacitor is a step function and the current through is a delta 'function'.
Jul
11
reviewed Reject Why do electricity generators have to work harder for higher loads?
Jul
10
comment Why was general relativity needed to explain gravity?
@HarryJohnston, unless I'm mistaken, in the example I linked to in MTWs "Gravitation", the (vector) gravitational waves transport negative energy only.