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Integral-Solving

I know this is a very naive question but during my quantum optics study, I often come across the following kind of integrals. Sometimes there is an identity to get it solved but other times there is ...
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27 views

Measure small mass change on heavy item [closed]

I need to measure the change in mass on a large number of components we are developing with a size of a large orange and weighing between 0.3 and 1 kg to an accuracy of sub 10x10-6 kg. The mass will ...
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56 views

The Universe is a brain? [closed]

This research paper here shows extraordinary qualitative and quantitative physical similarities of the brain with the structure of the Universe Cosmic Web which it proves cannot be a coincidence. Why ...
• 3,186
32 views

Lord Kelvin's vortex theory of atoms may prove today to be more relative to particle physics? [closed]

Lord Kelvin's attempt to explain the atom's of different elements of the periodic table, inner structure as energy vortices of different types (i.e. knot theory) may today be more applicable for sub ...
• 3,186
24 views

I tried to do it by solve in both dir. of acc. then get confused where i did it wrong why we can only do thus question by song work energy theorem [closed]

Chapter :magnetic effect of current magnetic force on charge or current
32 views

Query regarding motion of a cylinder [closed]

I need help understanding the motion of this cylinder... Cylinder A of mass M is resting on two smooth edges, one fixed and other is that of a block B. At an instant block B is pulled toward left with ...
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1 vote
46 views

Scalar curvature from Riemannian metric

I want to compute the scalar curvature for points on an empirical manifold (sampled data). I have already an algorithm that learns the Riemannian metric and computes geodesics, so from the metric I ...
59 views

Is there an experiment that shows the strong force grows with distance?

Is there an experiment that shows the strong interaction increases with distance?
24 views

I am currently working on an physics engine to simulate collisions of balls. I have one blue and one red ball, the red ball moves forward in time, while the blue one moves backwards in time. Basically ...
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6 views

How to quantify the one-way flow of information in Markovian dynamics

It is said that in the Born-Markovian dynamics (Master equation), the information flow is one way, i.e. from the system to the environment. How to understand this sentence? Is there a quantity of the ...
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7 views

Why do Liquid-state NMR qubit only work with fermionic nuclei?

"The ideal picture of liquid state NMR (LSNMR) quantum information processing (QIP) is based on a molecule in which some of its atom's nuclei behave as spin-½ systems." https://en.wikipedia....
17 views

Complete set of commuting observables for the non-interacting light field

The Hilbert space for the non-interacting electromagnetic field is the bosonic Fock space $\mathcal{B}(L^2(\mathbb{R}^3) \otimes \mathbb{C}^2)$. Here, $L^2(\mathbb{R}^3)$ is the space of square-...
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20 views

Solid mechanics [closed]

my approach I have plotted the graph using wolfram alpha but cannot understand how to plot a double y plot
29 views

Motion of a sphere at the end of a structure

I need help understanding the motion of the sphere given in the figure below... The centre of this sphere lies at some horizontal distance from the vertical line ( If it is extended ) Will it have a ...
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Does the intermolecular forces change during phase transition?

When water is heated but not yet boiling, I understand that the intermolecular attraction does not change, but the molecules vibrate more. But when water boils to gas, does the forces of attraction ...
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Calculus of Variations, Noether's Theorem, need help understanding and solving this problem

I have been given the following problem: Investigate whether the functional $I=\int_{t_1}^{t_2}t\dot{x}^2dt$ is invariant under the transformation $\bar{t}=t+\epsilon$ and $\bar{x}=x$, with $\epsilon$...
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Why the density perturbation of Newtonian and Comoving gauge are the same in the sub-horizon limit?

In Daniel Baumann's Cosmology lecture note for UvA Masters Course Cosmology: http://cosmology.amsterdam/education/cosmology/, when discussing the cosmic perturbation theory of matter, the author ...
8 views

What is the effect of increasing the size interval in the generalized dynamic equation (GDE) to simulate an evolving aerosol?

The following differential equation allows me to calculate the the number concentration of aerosol particles from 2 nm to 3 nm. $$\frac{dN_2{_-{_3}}}{dt}=J_2-J_3-N_2{_-{_3}}.CoagS_2{_-{_3}}$$ In the ...
19 views

35 views

What is aerodynamics function of front active lip spoiler?

In this video is active front bumper lip spoiler. Also here picture show flexibile plate in front of front tyer. What are aerodynmics function of these two devices?
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1 vote
43 views

Friction and electromagnetic force

What is the relationship between friction and electromagnetic force? At microscopic level, how does electromagnetic force cause friction?
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18 views

• 325
1 vote
97 views

Why gravitational constant $G$ does not have the factor of $4π$?

We know that electrostatic constant $K=\frac{1}{4\pi\epsilon}$. This $4\pi$ came from the surface area of the surface in which charge is enclosed. Then, why don't gravitational constant has the factor ...
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1 vote
17 views

General expression for time evolution operator in terms of path integral

Given that I know that the time evolution operator $U^{i\rightarrow f}$ for initial and final states $|\psi^{i,f}\rangle$, defined by $|\psi^f\rangle:=U^{i\rightarrow f}|\psi^i\rangle$, how do I show ...
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18 views

Does it require energy to generate an electric field as well as a magnetic field?

It is known that the electric field as well as the magnetic field carriers energy, so I wonder is the energy of the fields generated by a charge originated from the kinetic energy of the charge?
9 views

System where Energy Dissipates but Frequency Increases

Is there any example of an oscillating system where, as energy is dissipated by some external force, the frequency of the system's oscillation increases? One of the questions from 2022's IYPT asked ...
13 views

Effect of radius of circular flight on energy consumption of rotary wing UAV [closed]

We consider a rotary wing UAV flying in circles arround a stationary point. We do not consider wind. We consider static speed - acceleration equal to 0. I have read in many papers what makes sense - ...
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1 vote
11 views

Simulating electromagnetic propagation from a vector plane

I am using finite element software (COMSOL) to study Photonic Slab, because the Slab is in 3D, it needs quite a lot of periodic unit to observe desired effect. and periodic boundary condition is not ...
31 views

What is the entropy associated with a diffusion process?

Is it possible to calculate entropy from the solution of a diffusion equation(with natural boundary conditions) by using the formula of Shanon entropy? Could anyone help me to understand the entropic ...
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14 views

MC condition in Cellular Potts Model

In the following discussion, Introduction to the CPM I haven't understood the following MC condition: Note the "try" in the previous sentence; this so-called "copy attempt" only ...
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24 views

Would it be possible to design a dart-like object such that it survives re-entry and impact at interplanetary / interstellar speeds?

I was wondering about spacecraft - specifically just getting from point A to B. If you were unconcerned about human survival and damage from g-forces, it would be much easier to deliver it without the ...
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