0
votes
0answers
3 views

What is the typical strength of the electric field in a particle accelerator?

I am working on a research project involving the closed orbits of hydrogen in the presence of an external electric field and I am curious what a reasonable approximation for the electric field ...
0
votes
0answers
6 views

Magnetic field between two rings

Two rings are placed parallel atop each other along an axis with a distance $\epsilon$ which is much smaller than the radius of both rings a. Through one of the rings there is a current I and through ...
0
votes
0answers
7 views

Relativistic Lorentz Force with constant, perpendiuclar, and uniform E and B fields

I am trying to solve the following problem from the Fundamentals of Plasma Physics by Bittencourt (Problem 2.7): Analyze the motion of a relativistic charged particle in the presence of crossed ...
0
votes
0answers
10 views

Where are real limits of evaporative cooling?

There are many projects focused on utilising evaporative cooling for food preservation or computer cooling purposes. I have other thing in mind, however and that's cooling beer. Once you're outside, ...
0
votes
0answers
26 views

Present moment in physics

Here is my first "popular science" "vague" question, which I hesitate to keep for myself until it becomes a precise question. Instead of wondering about what time is, I'll just assume it's a parameter ...
0
votes
0answers
4 views

How close to the wavelength of light have to be to inter-planar spacing for diffraction to occur?

I'm doing past papers for my exam on Wednesday, and I've come to a question I'm stuck on So, you have x rays of lambda = 0.25nm incident on a cubic unit cell with lattice lattice constant a = 0.286 ...
0
votes
0answers
6 views

How to understand a discretized action in Jan Smit's book?

I am reading Jan Smit's book Introduction to Quantum Fields on the Lattice. How did he get the result of eq.4.80, the discretized action for gauge fields? In eq.4.72, he gave the gauge field action ...
0
votes
1answer
12 views

How bright would the Earth be at night without the moon?

How bright would the Earth be at night without the moon? Specifically, how much light would reach the surface of the Earth at sea level?
0
votes
0answers
11 views

Could Bluetooth radio waves be used to pick up UV light

i am a bit of a Physic novice. But i was wondering if someone could answer this and if they might be able to make a possible sugguest. i was wondering if it possible for a bluetooth to be able to ...
1
vote
1answer
22 views

Do bras and kets have dimensions?

I'm trying to understand more intuitively what bras and kets are, but some aspects of them remain a mystery to me. We usually think of $\psi (x)$ as having dimension of $[1/\sqrt{L}]$ so that ...
0
votes
0answers
7 views

Clarification on isotropic sources and fields

For an isotropic radiation field the net flux is zero, something I find quoted in a lot of notes and text on radiation. We often think of isolated stars as isotropic sources, but their net flux is ...
0
votes
1answer
11 views

Is a matter anti-matter collision comparable to Gamma Ray Burst (GRB) energy output?

Is a matter anti-matter collision (please assume two cosmological objects, neutron star sized say), the largest energy release method known? Would it be comparable in order of magnitude to gamma ray ...
0
votes
2answers
29 views

Why bumble bee cannot fly aerodynamically?

I just saw this pic So I got curious and logged in on physics.stack first time, is it true? I am a math major and usually wander on mathstack but I would like to understand why Bumble bee cannot ...
1
vote
0answers
15 views

Pumping water from a well

I have water well $h_1=70~m$ below ground level. A cylindrical tube of diameter $e$ joins the well to a tank of height $h_3=10~m$, $h_2=1.5~m$ above the ground. The tank is initially filled with water ...
0
votes
0answers
10 views

A force in a homogeneous magnetic field

Semi infinite parallel conductors, while on them without friction slides a crossbar . Perpendicular the plane of the conductors is a homogeneous magnetic field. To what extent of force we must act on ...
-2
votes
2answers
47 views

What's outside of the universe?

Assuming you found a way and managed to accelerate above light speed without disintegrating, and went to the edge of the universe, what would happen? Would you instantly explode due to the lack of ...
1
vote
1answer
25 views

How many observations are needed to determine a comet's orbit?

Based on the following facts: We have Kepler's laws of planetary motion. We have a good knowledge of the positions and orbits of the gravitationally significant objects in the Solar System. We can ...
0
votes
0answers
18 views

Is there any matter inside an event horison?

Consider a feeding, growing black hole. We never observe any matter to cross the event horizon, because time stops there. All matter would be "stuck" in a sphere around the event horizon, slowly ...
0
votes
0answers
4 views

Magnetic field at a distance from a metal rod

A massive metal rod of 4 cm has a current of 8000 A running through it and the current density is uniform. What is the magnetic field a distance 1 cm from the rod? Should I use the Biot Savart law and ...
0
votes
0answers
6 views

Derive phase shift equation for two diffirent optical paths differences

i have question. If we have two optical paths differences, call them $\phi_1, \phi_2$, and $\phi_1 > \phi_2$ then phase shift with respect to optical path difference $\phi_2$ is $PhSh = ...
4
votes
2answers
286 views

Is the Planck length the smallest length that exists in the universe or is it the smallest length that can be observed?

I have heard both that Planck length is the smallest length that there is in the universe (whatever this means) and that it is the smallest thing that can be observed because if we wanted to observe ...
0
votes
0answers
11 views

Can magnetic flux density be mechanically augmented into a super conductor?

I'm not a physiscist but i have a creative concept I wish to make into a environmental commercial before my Interactive Feature Film. Apologies, if it sounds like I have no idea what I'm talking ...
0
votes
0answers
20 views

How to prove by symmetry that tension in a section of rapidly rotating wheel act tangentially?

Suppose a thin uniform wheel of radius $r$ is rotating rapidly about its axis; its spokes have almost negligible strength. According to the book, the centripetal force is provided by the tension ...
0
votes
0answers
7 views

Limits on the information obtained through optical measurements

Consider a Gedankenexperiment shown in the figure below. There are two lasers $S1$ and $S2$ with exactly the same specifications on paper. In practice, they are of course somewhat different but ...
2
votes
0answers
15 views

Is it possible to have a line rather than a point where the three states of a substance can exist?

Most of us are familiar with state diagrams that define which of the three states a substance will take given the pressure and temperature. And that some substances, such as water for example, exhibit ...
1
vote
1answer
28 views

Have two identical quantum mechanical experiments ever been done?

Have two experiments ever been done such that the set up is identically the same, (when I say identically I mean down to the atomic level). Of course the experiment would have to be very simple. If it ...
0
votes
0answers
14 views

Resources for Entanglement Entropy in Condensed Matter Systems and Black Hole Thermodynamics

Over the last month or so, I have set it upon myself to teach myself the AdS/CFT correspondence. In particular, I am interested in the connection between black hole entropy and entanglement entropy in ...
1
vote
0answers
6 views

Transformation Diagrams for Ceramics

So, in the field of metallurgy, there are a few varieties of phase diagram that are used to predict the post-processing characteristics of alloys. These include Time-Temperature Transformation ...
0
votes
0answers
32 views

Why can this question about Centripetal Force not be answered in this way?

Here is the question: "A car travels round a bend which has radius $100 m$ and is banked at an angle of $20°$ to the horizontal. The car is travelling at a speed of $30 ms^{-1}$. What is the least ...
0
votes
0answers
15 views

single photon/electron double slit experiment, resetting the detector material after each impact

What is the experimental outcome of a single photon/electron double slit experiment under the constraint that after each detection the detector material is reset to the original state ie, in the ...
0
votes
0answers
12 views

images formed by refraction

While deriving the formula for image formation by spherical refractive surface we assumed that object is placed at the principal axis and is like a point object. What if the object is not placed at ...
0
votes
2answers
11 views

Trying to locate information on alpha particle scattering/peak resonance energies for elements

On our campus we have an ion beam analysis lab. It is used for compositional analysis through the firing of alpha particles at MeV energies at target samples. From here it is a simple matter of back ...
1
vote
3answers
67 views

What can change a photon's frequency?

I found this question: Is it possible to apply force to a light particle? As it states, gravity can change the frequency of light by changing its momentum. My question regards other phenomena that ...
0
votes
0answers
6 views

image motion for projectile motion of object

a ball is projected from top of the table with initial speed u at an angle of inclination 'a' to the table. describe motion of image with respect to the ball on a screen located next to the table My ...
0
votes
0answers
29 views

Can elementary particles be rightfully considered quasiparticles?

Can elementary particles rightfully considered quasiparticles? I have this association, because renormalization makes particle properties, like mass and couplings, energy-dependent quantities, even in ...
-1
votes
1answer
15 views

Period of a spring in SHM (simple harmonic motion)

An object with unknown mass M is hanged on a vertical spring with unknown spring constant K, the spring is in rest and is 14 cm from its normal point (if it didn't had the mass hanged it had less 14 ...
-1
votes
1answer
12 views

combination of mirror and lens

a convex lens forms a real image of a point object at a distance of 50 cm from convex lens. a concave lens is placed 10 cm behind convex lens on image side. on placing a plane mirror on the image side ...
0
votes
0answers
13 views

Exercises with solutions in dimensional analysis - reference request

I am currently trying to brush up on my skills in dimensional analysis, and computing with units. Is there a good source of worked examples, and exercises with solutions? I'd prefer to have solutions ...
0
votes
1answer
22 views

Current and current density

Current, $I$, is generalised as: $I=\iint_{A}^{} \vec{J}. d\vec{A}$. I know that current density always points in the direction of flow of positive charge. I wonder if the infinitesimal element, ...
0
votes
1answer
11 views

Condition for sliding of two blocks placed one over another and connected by spring

A constant force F is applied to smaller mass till M slides. The spring constant is k. Now it is asked to find k. I'm confused with the condition at which the block will start sliding. Can ...
0
votes
0answers
22 views

What exactly happens in an electric circuit?

After reading chapters on Electrostatics, I have been having lots of problems in understanding current electricity.I will be trying to tell what my problems are by telling what I already know.Please ...
1
vote
2answers
281 views

Why does time exist?

So I have been thinking about some subjects and one of it involves time. And I tried writing a story/question on here to summarize the bigger picture but it's not going to happen it's too complicated ...
0
votes
0answers
22 views

Branes at the conifold

How to derive the low-energy gauge theory resulting from $N$ $D3$-branes at the singularity of the conifold? The particular example is the geometry $AdS_{5} \times T^{1,1}$, where the Einstein ...
0
votes
1answer
10 views

Meaning of these terms for stress fields?

I'm from a math & comp sci background and I'm currently looking at facture theory which deals with stress fields. Can someone explain to me what the following terms represent in the context of a ...
0
votes
0answers
23 views

Action-Reaction pair in case of rocket accelerating in space

I understand Rocket works on Newton's 3rd law. So there has to be action-reaction pair acting on two different bodies. I know rockets accelerate in space, where there is nothing. So now I want to ...
0
votes
1answer
41 views

Where does this relativistic relation involving the delta function come from?

\begin{equation} \int\delta(E^2-\mathbf{p}^2-m^2)dE=\frac{1}{2E_\mathbf{p}} \end{equation} Shouldn't integrating the delta function like this just give 1?
0
votes
0answers
11 views

What is the principle used by mangalyan to place it in mars orbit with 0 fuel consumption?

Recently I came to know from a seminar that where most of the satellites need gallons of fuel to be consumed to get placed in one planet's orbit Mangalyan took 0 fuel and it waited for the 'right ...
2
votes
0answers
11 views

Sonoluminescence spectrum

During cavitation created by sound in a liquid the collapse of the bubbles can lead to very high temperatures and pressures resulting in the emission of light - sonoluminescence. Can the spectrum of ...
-2
votes
0answers
7 views

Wind power kneeded standing truck

How big wind is kneeded to flip a standing truck mechanic. https://www.youtube.com/watch?v=kBNUlFyCO-I
0
votes
1answer
6 views

electric potential at the other end of diode

I was brushing my basics about diode & got stuck at a point...my question is Consider a diode let the positive terminal of the diode be connected to +ve of battery Now in the figure let the ...

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