The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Originally, the term only referred to the aft port section of the ship, but eventually came to refer to the entire back of a vessel. The stern end of a ship is indicated with a white navigation light at night.
Sterns on European and American wooden sailing ships began with two principal forms: the square or transom stern and the elliptical, fantail, or merchant stern, and were developed in that order. The hull sections of a sailing ship located before the stern were composed of a series of U-shaped rib-like frames set in a sloped or "cant" arrangement, with the last frame before the stern being called the fashion timber(s) or fashion piece(s), so called for "fashioning" the after part of the ship. This frame is designed to support the various beams that make up the stern.
In 1817 the British naval architect Sir Robert Seppings introduced the concept of the round or circular stern. The square stern had been an easy target for enemy cannon, and could not support the weight of heavy stern chase guns. But Seppings' design left the rudder head exposed, and was regarded by many as simply ugly—no American warships were designed with such sterns, and the round stern was quickly superseded by the elliptical stern. The United States began building the first elliptical stern warship in 1820, a decade before the British. USS Brandywine became the first sailing ship to sport such a stern. Though a great improvement over the transom stern in terms of its vulnerability to attack when under fire, elliptical sterns still had obvious weaknesses which the next major stern development—the iron-hulled cruiser stern—addressed far better and with much different materials.
Consider the Stern Gerlach experiment, where the oven has a temperature such that the most probable velocity of the silver atoms is 750 m/s. The atoms are collimated by two slits of 0.03 mm width. The magnetic field has a strength of 1 T, a gradient of 5 T/cm, and the length of the magnet is...
Hello Everyone,
I am reviewing the SG experiment. I think the experiment was set out to demonstrate that the orbital angular momentum ##L## is quantized producing a quantized magnetic momentum. But silver and hydrogen atoms have no net orbital angular momentum. Still two sub-beams, due to two...
Homework Statement
Hi all, here's the problem I need help with:
Compare the following situations :
A beam of atoms has half of them preselected having spin up along z and the other half having spin down along z. This beam is sent through a Stern-Gerlach (SG) apparatus that sorts in the z...
Homework Statement
Here is the Problem. I have the Solution but am having trouble understanding parts of it.
1.1. Determine the field gradient of a 50-em-long Stem-Gerlach magnet that would produce a 1-mm separation at the detector between spin-up and spin-down silver atoms that are emitted...
Let's say you take a beam of particles and pass it through a Stern Gerlach apparatus and you select one of the outgoing beams, therefore collapsing the wavefunction to certain values of orbital angular momentum and spin angular momentum.
If you performed the Zeeman experiment on that beam, I'm...
I just started reading Stern Gerlach Experiment and this thought crossed my mind. Totally a hypothetical question. If I pass an electron and positron through separate SG apparatuses, I will know in which spin state each particle has collapsed. But afterwords I let electron-positron pair...
When we are measuring the spin of the electron in the experiment, we choose the spin property as its eigen state for the measurement. The eigen vectors corresponding to these states could be time dependent. Can we still break the problem into solving time independent Schrodinger Equation and...
In this paper Caldeira gives a model for the Stern Gerlach device in the vacuum.
the incoming particle is described by the tensor product of a space term and a spin term a |u> + b |d>
the SG is in the vacuum (no air around). Under the effect of the spatial variation of the magnetic field, there...
Since the particles aren’t rotating, but just traveling in a straight line, there should be no angular momentum whatsoever. Since the magnetic moment of magnetic dipoles can be theoretically represented as coming from a loop of electric current, or particle orbiting, thus magnetic moments are...
In the stern-gerlach experiment, silver atoms with a +1/2 would be deflected up, and atoms with a -1/2 spin would be deflected down. With that in mind, would electrons' orbitals within an atom be affected by its spin?
Many books in QM (eg: Sakurai) mention that the stern-gerlach experiment provides enough motivation for the mathematical structure of QM, Sakurai even mentions Gottfried's book. Point is, i didnt find Gottfried's book, so i am looking for other books that develop the math of quantum mechanics...
So, my current understanding of spin is that when particles with a certain spin state hit a stern gerlach device, their wavefunction is split into components, deflection associated with one of the pure spin states aligned with the device. For spin 1/2 particles, there are only supposed to be two...
Homework Statement [/B]
Just trying to find the spin 3/2 rotation matrix, I've found spin 1/2 and spin 1. This isn't a homework problem just studying some other spins.
Homework Equations
For spin 1/2: Rn(Φ) = cos(Φ/2)1ˆ − isin(Φ/2)σn
For spin 1: Un(Φ) = e −iΦSn = 1ˆ − isin(Φ) · Sn − (1ˆ −...
Where does the Stern Gerlach term in the Pauli equation come from? Taken from http://en.wikipedia.org/wiki/Pauli_equation. Following wikipedia's steps the Stern Gerlach term pops out when you apply the Pauli vector identity. I don't understand this step. It seems as if there should be no Stern...
Homework Statement
Given the series of three Stern-Gerlach devices:
Represent the action of the last two SG devices as matrices ##\hat{A}## and ##\hat{B}## in the ##|+z\rangle, |-z\rangle## basis.
Homework Equations
##|+n\rangle = cos(\frac{\theta}{2})|+z\rangle +...
I'm trying to get my head around this spin idea, the idea that particles behave like tiny dipole magnets when passing through a magnet field, either spin up or spin down. Because unlike magnets they don't produce a spread on at the end, they are either top or bottom.
So the problem I have...
Homework Statement
Given the following stern-gerlach setup, find the probabilities for particles to arrive in detectors D1 and D2.
SGx = Stern Gerlach in x direction,
SGx = Stern Gerlach in z direction
(sorry for terrible ascii drawing)
|ψ> = a|+> + b|->, |ψ> is normalized.
..../D1...
I'm confused.So a dipole needs a nonuniform field for the net force to not equal zero, cool.
My question is how do they go from
F = -∇(μ * B) = ((μ_z)(dB/dz))*(z unit vector)
how come the gradient has no x or y parts?
In the Stern Gerlach experiment it would seem that an electron beam moving at some velocity bisecting the upper magnet on a horizontal path would be radially accelerated perpendicular to the direction of motion.
I am assuming from Lenz's Law this can be corrected by increasing the Bf...
Can I get a spin 1/2 particle to deflect with the aharonov bohm effect.
Where the B field is zero but A is not? Or will it just change the phase in the state-vector?
can I get the spin up particles to go one way and the spin down particles to go another way.
Lets say I have a uniform line charge moving at a speed v. This will create the B field for our stern-gerlach experiment. Now I shoot neutrons or some other particle with spin that will be affected by the B field. Now let's say I am moving with this line charge at speed v. In my frame there is...
Homework Statement
An electron starts in a spin state |\psi(t=0)\rangle = |z \uparrow \rangle and evolves in a magnetic field B_0(\hat{x} + \hat{z}). The Hamiltonian of the system is \hat{H} = \alpha \vec{B}\cdot\vec{S}. Evaluate \langle \psi (t_{1/2}) | S_x | \psi(t_{1/2}) \rangle...
I'm reading about the Stern Gerlach experiment in Sakurai's well-known book "Modern Quantum Mechanics". I remember studying this years ago, and somehow back then this question didn't enter my mind. However, I can't seem to figure out the answer.
I understand that a gradient in magnetic field...
Hey,
Ok so basically what i want to do is to realize the stern gerlach experiment, I know it's going to be a lot of work , but I'm highly motivated... oh and btw I'm only 16 so I don't know everything about physics and I'm not a native speaker, so sorry for possible errors concerning my...
Homework Statement
I have a Stern-Gerlach experiment with a beam of silver and a magnetic moment due to the spin of the single valence electron give by μ=e/me S. And |S|=ℏ/2. The magnetic field is 1T.
The problem asks to compute the energy difference of the silver atoms in the two...
Hi all,
This is my first post to the physics forum. I am completely new to quantum physics and have just gone through lecture notes on the Schrödinger equation, infinite square well, hydrogen atom and angular momentum etc.
I am currently starting on the Stern-Gerlach experiment, bras and...
Homework Statement
The last (8 mark) part of this (also in attachment):
http://img189.imageshack.us/i/imag0095l.jpg/
(very sorry for having to post an image, I spent a good hour trying to tex it in this, but there's something wrong with my parsing in the preview post. anyway...)
Homework...
Hello Forum,
Does anyone know of any references on the construction of a Stern-Gerlach magnet? Most of the references I have seen so far discuss magnets that provide a constant field gradient (in the z-axis) over a few millimetres. Since I have a circular beam of about 1 cm diameter, I need a...
Homework Statement
A beam delivering protons is sent through a stern-gerlach splitter oriented to ask whether the spin is oriented parallel to the y axis. What fraction of protons have spin down with respect to the y axis?
\chi=\stackrel{1}{\sqrt{17}} \stackrel{4}{i}
the 4, i thing is the...
In the Stern Gerlach experiment, when does the electron's position get determined? Before/right after it leaves the inhomogeneous field? Or when it hits the detecting foil?
This could be tested by replacing the foil with two slits at each of the expected regions of electron incidence. If...
Homework Statement
The longest passanger liner ever built was the Fracnce, at 66,348 tons and 315.5m long.
Suppose its bow passes the edge of a pier at a speed of 2.5m/s while the ship is accelerating uniformly at 0.01m/s^2. At what speed will the stern of the ship pass the pier...
Homework Statement
If a beam of hydrogen atoms in ground state are passed through an inhomogeneous magnetic field, into how many paths will the beam be split? Assume that the beam is moving towards the plane of this page and the magnetic field is directed in the upward direction in the plane...
How do they make sure the "measurement" process in conventional Stern-Gerlach experiments are clean quantum measurements?
Spins dynamically precess in magnetic fields (uniform or non-uniform) and Stern-Gerlach (especially sequential SG setups) make precise predictions regarding the resultant...
1.Show that one gets a 50% : 50% probability for deflection up and down in a y-Stern Gerlach measurement when atoms that are preselected as +x atoms or -x atoms are used as a source.
What kind of the equation is it? Do we just need to find the coefficients and square them?
2.A source produces...
Hello! i have a trouble with an exercise of a course of structure of matter.
Helium atoms in the excited state 23S1 come out from a box at v=2000 m/s and pass trough an Stern & Gerlach apparatus with dB/dz=25 T/m and length L=0.30m. Atoms spends 1 hour in the box and the average-time for...
Hi everyone
In my attempt to understand the details of Stern Gerlach experiments and measurment issues in quantum mechanics, I have come to believe that there is a lot to be learned from some of the basic thought experiments like interference and Stern Gerlach described in books...
Hi everyone
How do I show that the expression
\sum_{b'}|\langle c'|b'\rangle|^{2}|\langle b'|a'\rangle|^{2} = \sum_{b'}\langle c'|b'\rangle\langle b'|a'\rangle \langle a'|b'\rangle \langle b'|c'\rangle
equals the expression
|\langle c'|a'\rangle|^{2} = |\sum_{b'}\langle c'|b'\rangle...
I am trying to recreate the Stern-Gerlach experiment and am having trouble trying to calculate the gradient magnetic field. I am using two magnets with one having a sharp edge and the other flat. I have calculated what the deflection will be of the electron will be in terms of the gradient...
How can you calcualte the angle of the split of the electrons after passing it thorugh a non uniform magnetic field?
I know how to calculate it by elementary means using the magnitude of S and Sz and doing trig. But is that angle always the same no matter what intensity magnetic field its...
Really simple question:
In the Stern Gerlach experiment they construct an electron spin filter with magnets:
http://www.upscale.utoronto.ca/GeneralInterest/Harrison/SternGerlach/SternGerlach.html
I'm not sure what would happen if you used the first set of magnets to split a beam of...
Having Howard Stern's controversial radio show suspended shows where America is headed when it comes to free speech and the ability to excercise the first amendment. I used to despise the Stern show as I took personal offense to his comments regarding women, but as I experienced some life...
Here is a fascinating article about the story of the landmark SG Experiment.
http://www.physicstoday.org/vol-56/iss-12/p53.html
There are some interesting twists to the tale, but I won't spoil them for you.
Some contemporary reactions to the results:-...
In the Stern Gerlach experiment the Ag beam is split in two beams of half intensity of the original beam due to the equal distribution of spin up and spin down electrons.
Considering that each of the split beams is composed of only one type of electrons (let's say spin up), if we pass this...