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This is what I have:
but it turns out that the image is too close to the eyes (duh :D) and it hurts trying to focus on it. Usually, VR and AR headsets use some type of lens system. My only idea right now would be to put a convex lens between the eyes and reflective glass (what VR does) but that would make the outside ... |
When watching Seans Carrol's "A Brief History of Quantum Mechanics", he mentioned around the 50th minute (the video I linked to starts at that point) that
[about quantum fields in vacuum] ... and guess what! The closer they are to each other, the more entangled they are.
Why is it so? I was under the impression that ... |
I'm trying to understand the law of current induction in closed loops.
I just saw this example, of a non-moving circuit in a constant magnetic field $B$. On it, a sliding (conducting metal bar) which moves with a velocity $v$.
In this case, I saw that the EMF generated is $BLv$, since this is the flux change in either... |
I have read this question:
What is the reason that Quantum Mechanics is random?
where Puk says in a comment:
I see. I would call both "random", with the degree of "randomness" defined by ψ. But yes, just a matter of semantics.
On a measurement level, is quantum mechanics a deterministic theory or a probability theory... |
I'm a bit confused with the idea of EMT from the Polyakov action. The EMT is derived by variation of the action with respect to the metric which provide the constraint to the theory, $T_{ab}=0$. Clearly, the energy and momentum of the string is no need to be zero. Is the EMT here related to the physical energy/momentum... |
I am studying tensor algebra for an introductory course on General Relativity and I have stumbled upon an ambiguity in tensor notation that I truly dislike. But I am not sure if I am understanding the situation properly. Suppose I find myself facing the following tensor:
$$g_{ij}$$
This is surely a rank 2 tensor; usual... |
You can think about a paramagnetic material as being comprised of a bunch of quantum mechanical spins aligned in random directions. When an external magnetic field is applied, a fraction of the spins will align with the magnetic field. The stronger the external magnetic field, the larger the number of spins which will ... |
Referring to a situation like shown in this basic diagram of electrostatic induction:
Does electrostatic induction occur if you have charged objects on both sides of a grounded conductive sphere like shown? For the sake of the purpose of this question, lets say the two charged rods have larger cross sectional areas t... |
As you know, the electrostatic potential for a point charge in free space (at the position $\vec {r_0}=x_0\hat {x}+y_0\hat{y}+z_0\hat{z}$) is given by the relation:
$$V(\vec r)=\frac{1}{4\pi\epsilon_0}\frac{q}{\left|\vec r-\vec {r_0}\right|}$$
(I have assumed to assign zero volt to infinite distance from the source).
I... |
So, in Laser theory I learned that a two-level laser is not possible, because it would violate Einsteins equations and the Boltzmann distribution, which in a nutshell say that I cannot cause population inversion with electromagnetic radiation. Yet, a 180 degree NMR pulse is doing just that: we have a two-level system o... |
(Source:- JEE 2000).
What I did was prove that the electric fields in K1 and K2 are having the same E fields inside them(as shown in the image ). I then concluded that since the fields are uniform, constant and the distance which the dielectrics k1 and k2 occupies are the same, the potential drop across them should... |
I wish to study curved spacetime with torsion, however, the trouble is how do I go about with the variational principle? Should I assume the connection $\Gamma^{\alpha}_{\beta\gamma}$ and the metric $g_{\mu\nu}$ as independent variables? Maybe this is fine when metricity is relaxed but what if metricity is imposed i.e.... |
In a region of space which has no massive object light rays travel parallel to each other or ,simply, in a straight line. However, in a positively curved region of space (like near a planet or a star), like in this image light rays "bend" if that body is in there path.
Supposedly, rays of light are traveling from some ... |
In Schwartz book sec 10.3, Schwartz says following:
The Lorentz generators when acting on Dirac spinors can be written as $$S^{\mu \nu}=\frac{i}{4}[\gamma^{\mu},\gamma^{\nu}]$$
But what I am able to understand from reading chapter $10$ (Spinors) is that generator of Lorentz group when acted on $4$-vectors are the the... |
So, I'm trying to calculate the electric field at a point $r$ distance away on the perpendicular bisector of a finite line charge having uniform charge density $\lambda$
I arrive at the following expression for electric field:
$\dfrac{\lambda}{4\pi\epsilon_0 r} \left[\sin{\theta}\ \right]$
What I cannot understand howe... |
I am just starting to learn Electromagnetism and I am a bit confused about the idea that we need to attach a surface when evaluating the equation for Ampère's Law.
I am not talking about the 'why' in Math. I am talking in principal (Physics), why do we need that surface at all and what does it represent?
|
A free particle Lagrangian in a 3D curvilinear coordinate system can be written as an inner product with the metric $g$:
$$
L = \frac{1}{2}m\sum_{i,j=1}^3v^ig_{ij}v^j.
$$
This equation was taught to me in the context of curved coordinate systems that can be transformed to be flat, for example polar coordinates. Howeve... |
The 3 most common devices in electric circuits are inductors, resistors and capacitors. The relation between current and (terminal) voltage across these elements is often used in circuit analysis, namely:
\begin{align}
U = RI \\
U = L \frac{d}{dt} I \\
\frac{d}{dt} U = \frac{I}{C}
\end{align}
When the assumptions of ... |
Considering the following decay:
$$\Delta^{++}\rightarrow n\space + \pi^{+}$$
We know that for $\Delta^{++}$, $J^{P}=\frac{3}{2}^{+} \rightarrow$ the only possible value for the orbital angular momentum is $L=0$ (Correct me if I'm wrong here) What would that imply for the $L$ values on the R.H.S. ? Considering the fac... |
I'm watching this minutephysics video on Lorentz transformations (part starting from 2:13 and ending at 4:10). In my spacetime diagram, my worldline will be along the $ct$ axis and the worldline of an observer moving relative to me will be at some angle w.r.t. the $y$ axis.
When we switch to the other observer's spacet... |
I'm trying to understand for which constants $c_{ijkl}$ the two operators $\sum_{n\in\mathbb{Z}}a^\dagger_na_n$ and $\sum_{ijkl\in\mathbb{Z}}c_{ijkl}(a^\dagger_ia_ja_ka_l + a^\dagger_ja^\dagger_ka^\dagger_la_i)\delta_{i,j+k+l}$ commute. An obvious option is $c_{ijkl}=1$, but can we be more general? I would guess that t... |
There were some answer comments at Is it possible to make the Sun spin a coin in space? that could be a question in their own right, so here it is.
Posit that we have a coin in space, on both faces half reflective and half absorptive, as described in the answer. It is in a circular orbit in the invariable plane, 1AU f... |
Our professor in condensed matter physics derived a differential equation for the zero temperature Greens functions. In the derivation he makes use of the Heisenberg equation of motion to find the derivative of the particle field operator, i.e.
$i\partial _t \Psi(x, t) = [\Psi, H].$
Here $H = H_{s} - \mu N$, with the "... |
Anomaly means that: the system has a symmetry at classical level (both discrete and continous), but when we quantize the theory, the system no longer holds the symmetry.
I'm wondering for every anomaly, if we can design a experiment to check? For example, the global chiral anomaly, we can measure the life time of photo... |
Does it make sense to write the following expression:
$$F_{\alpha\beta}(x) :=\partial_\alpha\ \left( \partial^{-1} \right)_\beta f(x), \tag{1}$$
with $\partial_\mu := \partial/\partial x^\mu$, $\partial^{-1}$ the inverse operator of $\partial$ and $f$ some function of $x$? I am not sure how to define $\partial^{-1}$, h... |
I am considering the calculation of the black hole entropy, given the MTZ solutions for the mass and temperature (https://arxiv.org/abs/hep-th/0406111):
$$M=\frac{\sigma r_+}{4\pi G}\left(\frac{r_+}{\ell}-1\right)$$
$$T=\frac{1}{\pi \ell}\left(\frac{r_+}{\ell}-\frac{1}{2}\right)$$
where $\ell$ is the AdS length, $\sigm... |
The "Anti" heat engine is a misnomer what I mean is can you get mechanical work by removing heat from say atmospheric air via liquid nitrogen injection instead of adding heat via combustion or similar
|
I have a closed box with a hole in the wall. A IR beam is directed at the front of the box.
Due to a small 6mm borehole in the wall only a certain part of the beam can pass trough.
The left small pieces are IR sensors. I'm wondering now if I need an additional tube for focusing the beam like depicted?
Application is a ... |
We know that as the speed of an object increases, so does its relativistic mass.
But can it be said that dark matter may be due to the increasing relativistic mass of nebulae, stars, galaxies, etc. caused by their high speeds?
|
I read about a experiment conducted in 1933 by W.Meissner that follows:
Metal was put in constant magnetic field then been cooled down in order to enter superconductivity state. Then researchers discovered there is no Magnetic induction line inside the metal. Does this mean that stable magnetic field can induce current... |
We know that this density results in a flat universe.
$$\rho_c=\frac{3 H^2}{8 \pi G}$$
And we know that if the universe isn't flat, the density as a proportion of critical density can be expressed as this:
$$\frac{\rho}{\rho_c}=\frac{8 \pi G\rho}{3 H^2}$$
The FRW metric tells us that that spacetime is shaped like this ... |
What is the elastic limit of tempered steel?
I have to calculate the maximum charge that can be applied to a tempered steel wire of $0.08\ m$ of diameter without it exceeding its elastic limit
I am given the formula $EL=\dfrac{F_m} {A} $ where $EL$ is the elastic limit, $F_m$ is the maximum charge and $A$ is the area
I... |
like particles are vibrations in their quantum fields
are their corresponding anti particle a anti vibration of some sort?
and if so does this diagram accurately represent it?
(If I'm wrong please explain with diagrams and in layman's terms)
|
Imagine massive object such as 2 non spinning blackholes accelerate towards each other, just before they collides I wonder what would the region of space in between them would look like? Will it be interference pattern of gravitational wave or a smooth gradient of spacetime curvature?
|
What does it mean by conformal group act projectively, unitarily, and projective unitarily?
|
I am reading David Tong's introductory mechanics course and he says the following (pages 14-15): suppose you have 1D movement given by the potential $V(x)=m(x^3-3x)$. What can you say about the path of a particle that is initially stationary at $x_0$? He says that if $x_0=\pm 1$ then the particle will stay there for al... |
Energy define as (wiki page minimum energy of system in last section)
$E=ST -PV+\mu N$
$P$ is pressure and $V$ is volume, $Ν$ is the number of particles in the gas.
Entropy $S$ measure as the log of possible microstates of system*Boltzmann constant. I always stick at this point. What can be relation of possible micros... |
Equation (6) of Lagrangian and Eulerian Representations of Fluid Flow:Kinematics and the Equations of Motion [PDF], by James F. Price is this:
A convenient measure of the stiffness or inverse compressibility of the material is
$$B=\frac{S_{zz}}{\delta h/h}=-V_{0}\frac{\delta P}{\delta V}=\rho_{0}\frac{\delta P}{\delta... |
Here is the full document link
https://www.lapasserelle.com/cosmology/
Click on lecture 1 notes for the document
Now my question is why the acceleration with galaxies is receding is taken equal to gravitational acceleration? Is it just die to the fact that because stay fixed in fictious moving grid?
|
I have observed at my home that when there is a small puddle of water on a glass table and an inverted steel glass is kept on that puddle of water, the glass starts moving on its own after some time.
I was wondering how that was happening . I think it is due to the fluidity of water due to which the water flows and th... |
I was recently trying to attempt this question which was on 2019 JEE Advanced Physics Paper 2.
The question is as follows-
A small particle of mass m moving inside a heavy, hollow and straight tube along the tube axis undergoes elastic collision at two ends. The tube has no friction and it is closed at one end by a f... |
From my understanding, QFT combines QM and special relativity. So doesn't QFT in curved spacetime combine QFT and general relativity? I realize that we need to quantize gravity to have the more accurate theory, but I want to know if GR and QFT are combined by QFT in curved spacetime. If it does, why do people say it's ... |
I was recently reading up some literature on gravitational waves in curved spaces and came across the following confusion. Basically starting from the Einstein Field Equation (EFE),
$$G_{\mu\nu} = 8\pi T_{\mu\nu}$$
we can expand it in powers of $h_{\mu\nu}$ (where $g_{\mu\nu} = \eta_{\mu\nu} + h_{\mu\nu}$) as,
$$G^{(1)... |
Cold or slow neutrinos have non-relativistic velocities and hence very low energies. That makes them very difficult to detect. Answers to Where are all the slow neutrinos? make it clear that they are vastly abundant. Do we have any significant model of how they are distributed and what proportion of the Universal mass/... |
Can anyone please give me a clue on what the question wants? Based on the question, I am clueless if it asks for primitive translation vector of simple cubic or reciprocal lattice?
Because the form of the given $\mathbf k_1$, $\mathbf k_2$, $\mathbf k_3$ is very different from simple cubic one.
|
I'm reading the chapter about the renormalization group in Yeoman's book "Statistical mechanics of phase transitions" and I'm puzzled about how the author relates the scaling of the RG with the critical exponents. We have some RG map on the Hamiltonian $H\rightarrow R(H)$. We suppose that we are close to the fixed poin... |
Here I am considering the following cycle;
I know that the coefficient of performance for a heat pump can be calculated by;
$$COP=\frac{Q_h}{W}$$
Where $Q_h$ is the heat exhausted into the hot reservoir. I am running into a problem with this... From here I know that the work $W$ for this cycle is given by;
$$W=nkT_h\l... |
Wikipedia says that two identical fermions cannot occupy the same quantum state. My question is what does this quantum state means? In classical mechanics, this means that the two particles cannot have the same position and velocity.
Orbitals are places where an electron has a 90% chance of being there. Is that the sam... |
Consider a simple circuit: A battery and a resistor, where the resistor is connected between points A and B. We then have:
$$\int_{a}^{b}-\vec{E}.\vec{dl}= iR$$
Will the same expression hold if $\vec{E}$ is an "induced electric field"? For instance, Consider a stationary loop , containing a resistor enclosing an area A... |
What happens to water if you put into space while the water is spinning around like an empty circle? Or a round tube shape if you like.
|
Suppose we are using a pendulum.
From one extremity we just leave it, it reaches the other extremity and again reaches us at a certain time period. We will be able to apply the next force to it when it reaches us after a certain time period and hence we will be able to account for the damping force which it experiences... |
I am searching for a book about the measurement energy of hamiltonian in adiabatic quantum computing. Have you ever seen good resources?
I need good references for my work.
|
What is wrong with the following? (Note that the question is not about galactic dark matter, but about cosmological dark matter.)
Neutrinos are dark matter.
A neutrino condensate would be cold. (Often, neutrinos are dismissed
as being automatically hot dark matter.)
Cold neutrinos could be generated continuously by ... |
I had this doubt about what would happen when a capacitor of capacitance $C_1$ with a charge Q was connected to an uncharged capacitor of capacitance $C_2$.
I took to researching this question in Google and found answers in several places.
However every answer talked about Kirchoff Voltage Law, which I could not unders... |
My guess is that, in an ideal case and considering a single particle, it must be the case. With my current (lack of) knowledge, I imagine the opposite would imply some kind of delay between the reception of the original wave and the oscillation generating the new wave, which would imply the scattering is not fully elas... |
I was watching this (rather old) episode of The Making, where they show how a telescope is built in a factory. At 7:34, the cylindrical body of the telescope is shown to have a dark coating on the inside and the video explains that this prevents internal reflection of the light received from whatever you're observing.
... |
I wanted to start learning particle physics and I have studied all classical Field theories. I found out that I should read Introduction to particle physics by Griffiths. But when I started reading I did not understand it. It said
For example, in relativity, energy and momentum are always conserved, but (rest) mass is... |
I am a recent undergraduate from India and currently studying quantum mechanics.
I came across a result that quantum mechanics doesn't allow the cloning of even the smallest atoms because that would break the uncertainty principle.
I have a doubt that if we believe that nature is quantum mechanical and follows the post... |
I was trying to obtain the brachistochrone as a function of time, and I failed several times because I wrongly assumed that the $v=\sqrt{2gy}$ vector points downwards (vertical vector). However, in order to get the solution, the correct assumption was that this vector was the tangential velocity vector, the one pointin... |
In Chapter 6 of Spacetime and Geometry by S. Carroll, he says
‘‘Because the event horizon is a global concept, it might be difficult to actually locate one when you are handed a metric in an arbitrary set of coordinates.’’.
I understand what local and global variables are, and I have a rough understanding of the prev... |
Imposing local gauge-invariance naturally couples e.g. a charged fermion-field to the electromagnetic field.
To my understanding local gauge-invariance is imposed because a gauge in one system should not affect or fix the gauge outside its light cone. Is there a physical mechanism explaining why a gauge boson "generate... |
In the Schrödinger picture the state vectors evolve in time, but the operators (observables and others) are constant with respect to time.
In the Heisenberg picture the states are constant while the observables evolve in time.
In the interaction picture both the states and the observables evolve in time.
I'm fine... |
Consider the example shown above. Here we have connected an active inductor, in which the initial current is "I", to a resistance, with the help of a switch and close the switch at t=0. We know and it is given in almost all the textbooks that the current and magnetic flux through the inductor will slowly decay in this... |
Newton's First Law of Motion states:
"A stationary object remains at rest until you apply a force to it. Once you set it in motion, the object continues to move at a constant speed until it strikes another object."
However, the observable universe is described as expanding at a faster rate the farther away from Earth... |
Atoms have a specific absorption spectrum that determines what frequencies of EM radiation they are most likely to absorb. This is why visible light cannot pass through a wall, but radio waves can. However, if you make the wall thick enough, the radio waves will eventually be attenuated. Since the radio frequencies are... |
I have noticed that when you throw a bucket of water (or any other liquid), it spreads out. Why does it not stay clumped together like a ball or the shape of the container it was thrown from?
|
"From the Goldhaber experiment we can deduce that there are only left handed neutrinos."
I don't understand this. Can't we find an experiment that only produces overwhelmingly right handed neutrinos?
|
If superposition is just uncertainty due to a particle changing on observation and not literally 2 things at once, how come quantum computers work while having qubits that are literally 1 and 0 at the same time?
(sorry if this is a dumb question)
|
I was doing problems on the application of differential equations. This question popped out there.
It is a simple Separable Equation with initial and end condition given. I found out the temperature profile and plotted it.
Then, when the ambient temperature is changed, obviously the constant of integration has to be ... |
I'm contradicting my premise again and again and I have no idea what I'm doing wrong. Say there is a given current density in a charged infinite cylinder, $J$ in the $\hat{z}$ direction. It follows charges are moving in the $\hat{z}$ direction. If we look at Ohm microscopic law, we have:
$\vec{J}=\sigma \frac{\vec{F}}{... |
If that is the case would it be possible for those bosons to interact with other particles directly? Meaning the field associated with those bosons, interact with the field associated with other observables of other particles? (say, position, momentum, spin, etc.). Of course , this interactions should be limited, since... |
What will happen to a ice cube in space vacuum if you wrap it in aluminium and make it orbit the sun like Earth?
|
I was wondering if macroscopic objects can be influenced by QM in this thought experiment.
A die is launched on a perfectly flat surface. The interaction between surface and die is elastic (no loss of energy between each bounce), therefore the die will keep bouncing indefinitely.
This die is launced several times, ever... |
Given a finite dimensional multiplet of the Lorentz group $(A,B)$, let's use the notation $|A,a,B,b\rangle$ to denote the vector, how does time reversal $T$ act on this?
I know that $T$ acts on $\vec{A}=(\vec{J}+i\vec{K})/2$ and $\vec{B}=(\vec{J}-i\vec{K})/2$ the following way
$$T\vec{A}T^{-1}=-\vec{A}, \quad T\vec{B}T... |
I was reading on the the implementation of Hubbard 'U' in Density Functional Theory. The Hubbard 'U' can be thought of as a parameter that accounts for the on-site electron-electron interactions in correlated materials.
Meanwhile, the Hund's J, I'm given to believe is an exchange effect. Many texts mention the 'J' like... |
I understand that the pressure can be 50 atmospheres: https://en.wikipedia.org/wiki/Deep_diving.
Okay, I understand also that the pressure is equal all around but if someone was put between two metal plates the pressure of 50 atmospheres would I guess certainly crush him mechanically, like the flesh on his bones would ... |
So why does it happen that the speed does not change in non-uniform magnetic fields?
I read this post Speed of a charge in a magnetic field but the answer seems a little inconvenient.
My question is that if the magnetic field is changing then it should apply an induced electric field, right? For example - if it is a ti... |
When light shines on a metal, electrons are ejected from the surface of the metal provided the energy of the photons are greater than the work function of the metal.
My question is:
Where do the ejected electrons go? Are they running freely within the metal (ie ejected from the atom they were bound to) or are they phy... |
A punch collides (inelastically) with some object so how would one calculate the energy of the impact? How would one define the mass since "punch" isn't an object and how would one also define the velocity since, again, a "punch" isn't an object?
|
If I consider the last equation of Maxwell,
$$\oint_\gamma \mathbf{B}\cdot d\boldsymbol{\ell}=\mu_0\left(I_C+\epsilon_0\frac{d\Phi(\mathbf{E})}{dt}\right) \tag 1$$
where $I_C$ indicates the conduction current generated by a potential difference, and $I_S$ it is the displacement current
$$I_S=\epsilon_0\frac{d\Phi(\math... |
The geodesic equation describes the motion of a particle moving in a straight line embedded in a curved geometry.
$$\frac{d^2 x^\mu}{d\tau^2}+\Gamma^\mu_{\alpha\beta} \frac{dx^\alpha}{d\tau}\frac{dx^\beta}{d\tau}=0$$
Solving for the proper acceleration we find that
$$\frac{d^2x^\mu}{d\tau^2}=-\Gamma^\mu_{\alpha\beta} \... |
Is there a physical (intuitive) explanation for why most systems are not ergodic? As my book states, it is a natural assumption that a system is at least quasi-ergodic; it then proceeds to state that this hypothesis is, in fact, false, and that we need a different basis for statistical mechanics. I don't understand why... |
On p. 141 in chapter 2 of the second edition of Sakurai's Modern Quantum Mechanics, the authors write the following:
Consider some function of position at $\mathbf{x}$, $F(\mathbf{x})$. At a neighboring point we obviously have $$F(\mathbf{x}+d\mathbf{x})\approx F(\mathbf{x})+(\nabla F)\cdot d\mathbf{x}.$$ But suppose ... |
Some stupid meme my sister showed me went along the lines of "will my laptop get heavier if I put more files in it?", but it was sufficient to get me thinking--is there an energy change & associated mass change when a file is written to a solid state drive?
I don't know enough about how a solid state drive works to kno... |
I am wondering if the Navier-Stokes equations can predict the density jump (First Order phase transitions) within a liquid-vapor transitions? Or this discontinuity is only coming from the microscopic/molecular scale (determined by experiments).
Thanks
|
I learned that a Hermitian matrix $A$ is defined as a matrix that satisfies
$$A^\dagger=(A^*)^\intercal=A,$$
i.e. its Hermitian conjugate $A^\dagger$ is the same as the original matrix $A$.
I also learned that in QM, a Hermitian operator $H$ is defined as an operator that satisfies
$$ \langle f|Hg\rangle=\langle Hf|g\r... |
I've been trying to build a gravitational simulation using a newtonian law of gravitation and have just been going over what the initial conditions should be. Then I remembered the virial theorem and purely gravitationally bound systems in which,
$$ 0 = 2K_{tot} + U_{tot} = \sum_i m_{i} |\vec{v}_{i}|^{2} -\frac{1}{2} ... |
Recall that
the electron carries U(1) gauge charge -1.
the U(1) is gauged and mediated by the U(1) gauge boson which is the photon with zero U(1) gauge charge, thus $0$.
Now let us take this problem in the grand unified theory:
https://en.wikipedia.org/wiki/X_and_Y_bosons
https://en.wikipedia.org/wiki/X_(charge)
ht... |
I don't know why this equation cannot be used in flatspace, Who can help me?
|
I'm solving the following problem in Weinberg's QFT textbook: an observer sees a particle of spin 1 and mass $M$ move with momentum $\mathbf{p}$ in the $y$-direction, and spin $z$-component $\sigma$. A second observer moves relative to the first with velocity $\mathbf{v}$ in the z-direction. How does this second observ... |
It is know that
$$\epsilon{^\mu} {^\nu} {^\rho} {^\sigma} \partial_{\nu} F_{\rho} {_\sigma} = 0$$
How can one deduce from this equation that
$$ \partial_{\mu}F_{\nu} {_\lambda} + \partial_{\lambda}F_{\mu} {_\nu} + \partial_{\nu}F_{\lambda} {_\mu} = 0$$
How many terms does this equation have? My professor told me that ... |
For a center fed dipole antenna when operated at resonance, the AC electric potential applied at the feed point results in traveling waves of AC current which emanate from the feed point out towards the two ends of the antenna. When the traveling waves reach the ends of the antenna they are reflected back towards the f... |
A steel rod of some length rests on a SMOOTH horizontal base. If it is heated for a considerable temperature difference, say $0^\circ C$ to $100^\circ C$, what is the strain produced?
Strain is difference length/original length. New length is $L(1+\alpha \Delta T)$ and original length is L. Therefore strain comes out t... |
A Hermitian operator $H$ is defined as $$\int f^*(Hg) d^3\vec{r} =\int (Hf)^*gd^3\vec{r}$$
where $f$, $g$ are 3D square integrable functions and the integrals are taken over all coordinates.
I am trying to prove that the Hamiltonian operator is Hermitian.
The Hamiltonian operator is given by $$H=\frac{-\hbar^2}{2m}\nab... |
We all have seen the official release of the image of the black hole.
scientists took the image of a supermassive black hole at the center of M87, which is very supermassive but 55 M light year away.
why they don't take the image of the black hole at some nearby galaxy's black hole. There is obviously Andromeda.
In th... |
We know from Hubble law that the galaxy is receding from each other.
Also, the general theory of relativity predicts the metric expansion of space ( voids are increasing).
Then why Andromeda is approaching the Milky Way,
I think it should be going away?
Where I am getting wrong?
|
A person standing in a huge lift which is free falling.
Observation: for that person gravity will be relatively zero.
As we know the weaker the gravity is the faster time flows and stronger the gravity is slower the time flows( eg case of black hole)
So is it case of time travel? As for the person gravity is relativel... |
In low-temperature superconductor the formation of Cooper pairs results with zero resistivity. The transition to the normal state is second-order phase transition. In Ehrenfest classification it means that the entropy is continuous.
Simultaneously the entropy of superconducting state is much lower due to the Cooper pai... |
I have implemented a genetic algorithm to solve a problem. In the process of genetic algorithm, instead of random numbers, I have used the chaotic numbers generated by the logistics map. The genetic algorithm that uses chaotic numbers is more efficient than the genetic algorithm that uses random numbers. Why the use of... |
My teacher told me that an air bubble has 2 surfaces and a liquid drop has only 1 which is the reason for the air bubble having twice the pressure difference as a liquid drop with same surface tension. But I couldn't get it how an air bubble has 2 surfaces isn't it just 1 spherical surface ? Please help
|
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