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From you question it is not really clear how you calculated the values, so I makes some guesses here. From the 10 measurements for each point you get some statistical error for the measurement device. This includes, however, also fluctuations of the source etc. You don't know systematic errors, like an offset due to stray light or other sources. So for each ...


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The difficulty of the prior experiments consisted in isolating the relativately weak gyro magnetic effect against the background of the purely magnetic forces acting on the studied rod... In order to avoid this difficulties, in the variant of the experiment proposed by Einstein, the magnetic field of the coil acts on the iron rod ... for a very short ...


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I was taught to just take the half of the measuring scale. Determining the error of a measurment in terms of Gauss's error formula etc. is always just an estimate. Check it for a function $f(x)$ and then for $f(g(h(x)))$ with $g(h(x)) = x$ but propagating the error first on $h$ then on $g$ then on $f$. This is not always the same as the error propagation of ...


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The Walter Lewin Classical Mechanics lectures contain lots of good demonstrations. https://www.youtube.com/playlist?list=PLUdYlQf0_sSsb2tNcA3gtgOt8LGH6tJbr


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Regarding your assertions: Events $\varepsilon_{AJ}$ and $\varepsilon_{BK}$ were simultaneous in the inertial frame of participants $A$, $B$, $M$. This is a perfectly reasonable statement and it is the sort of language used in everyday physics. Participant $M$ was the middle between $J$ and $K$, in the inertial frame of participants $A$, $B$, $M$. ...


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I would like to bring the ladder paradox here to explain simultaneity of events.A ladder (an inertial frame) is moving horizontally with a relatively high constant speed with respect to a garage (another inertial frame). The garage has an open door where the ladder can not actually enter if the ladder was at rest in the garage's frame but that is not ...


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I agree with Alfred Centauri that there is no configuration of a monopole, but on the second question, depending on how big the surface of the magnetic floor is, the strength of the magnets, and some other conditions I would imagine that it would levitate over the floor. On the third question, I believe that if it were a perfect sphere, the center ball would ...


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Or at least "functions" as a monopole? I'm afraid not. A magnet is a magnetic dipole and there is, as far as I know, no configuration of magnetic dipoles that can give a monopole field.


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A few comments, since it seems you're about to rephrase this question. When dealing with the caesium standard, you can essentially forget about the energy (of the excited state, and of the photon). What matters is the frequency, and the only uncertainty principle that ever gets involved is of the form $\Delta\omega\,\Delta t\gtrsim1$. This is a standard ...


2

Those two are answers to different questions. When you talk about the $\nu = $ 9.192631770 GHz, $h \nu $ is the separation between the energy levels involved in the transition. This is precisely defined. The second concept you talk about is the amount of time the atom remains in the excited state, also known as the excited state lifetime $\tau$. These two ...


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As noted by Floris, the best way to measure small-value resistance is to use a four-point Kelvin connection; unless the current drawn by the voltage meter is significant (in which case there are other problems) then provided that current-source probes are either the inner two or the outer two (as opposed to being interleaved with the voltage-reading ones) ...


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As with a lot of my questions, I need a lot more background even to pose the question properly, but I think this link Cooper Pairs and the excerpts below have pointed me in the right direction. In particular they have motivated me to do more basic background on Fermi-Dirac statistics before posting similiar questions. I have included two excerpts from the ...


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Short answer - yes, everything in the circuit can contribute. But usually, an ohmmeter is zeroed with the probes in place - in other words, whatever resistance the probes represent is taken out by the meter. There are two other factors that play a role, especially when you try to measure small resistance. The first of these is contact resistance: it is ...


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The most important concept relating Faraday cage hole size to cell phone signal attenuation is the idea of a cutoff frequency. For round holes, you would model them as cylindrical waveguides. For simplicity, we'll consider rectangular waveguides instead. To match the electric and magnetic field boundary conditions, it's necessary that the waves go to zero ...


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I can provide an example for bosonic models. \begin{eqnarray} \mathcal{H} & = & \mathcal{K} + \mathcal{T}_\text{soc} +\frac{U}{2}\sum_{i\tau} \hat n_{i\tau}( \hat n_{i\tau}-1) \nonumber \\ & & + U^{\prime} \sum_i \hat n_{i\uparrow} \hat n_{i\downarrow} + V\sum_{i\tau} \hat{n}_{i\tau}\hat{n}_{i+1\tau} \nonumber ...


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The latest data is from the Planck satellite, and you can find the results in this 15MB PDF. The matter and dark energy densities are; $$\begin{align} \Omega_M &= 0.315 \pm 0.017 \\ \Omega\Lambda &= 0.686 \pm 0.020 \end{align}$$ So we get a total density of $\Omega = 1.001 \pm 0.026$. So within the 2.6% experimental error spacetime is flat.


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Suppose charge is not conserved when we have a change in velocity (i.e. when we move from static to moving or vice versa). Then we wouldn't expect the change in the Coulombs attraction to be solely dependent on $r$ $$F = k_e \frac{q_1q_2}{r^2}$$ because as one particle attracts another, the values in the charges $q_1,q_2$ would change and so $F$ would ...


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The LCD panel consists of elements shown in the figure below. The unpolarized light from backlight panel travels through polarizer, after which the light is linearly polarized. TFT panel controls the voltage on the liquid crystal, voltage applied will cause the liquid crystals to "twist" and thus rotate the polarization of the light. Light then passes the ...


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There are so many ways you can do that: put some sand on the floor (Like Olympics!) Lay some papers on the ground, and put your thrown object in the ink. then when it lands it will make a mark (actually this method were used my famous physicist Galileo Galilei ) pour down some Bean or nuts on the ground, then when object hit them it will make a mark ...


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You can draw a few equidistant lines on the paper that is on the floor and make a video of the falling projectile.


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Does Sphere C have any effect of on the gravitational force between A and B? Nope. C does not make any difference to the force between A and B, but its introduction has the effect that the net force on A has contributions from both B and C. (Likewise for the other spheres too.) This is because gravitation obeys the principle of superposition. Is ...


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The sphere will stay in-between because net force is zero. However, the spheres will all lump together on sphere C because while C will not move, A and B will.


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Use your power meter and graph paper to map out the reflectivity as a function of angle. The Fresnel equations (plots shown below) are rather sensitive to the relative indices of refraction of the glass-foil interface. If the index of refraction of the foil is higher than the glass then you will hit a plateau above the critical angle at which all of the ...


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I don't know the "official" answer but here is what I might try. I am hoping that others will contribute to make this a "good" answer. First - we were not told whether the wavelength of the laser is transmitted at all by the blue foil; but since blue foil typically absorbs red light, and most laser pointers are red (I have a blue one but they are ...


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We would expect the screen to display bright images as dark (and vice versa) as one of the polarisers has changed 90degs


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As John Rennie answered it very clearly, I would like to add some more details too. See, around early 1900 the idea of atoms was floating around the scientists' heads. At first everything was theory, but these things happened: You certainly heard of Joseph Thomson's cathode rays. Well, he actually calculated the ratio Q/m of atoms. (You can search any of ...


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There is no such experiment, though there are lots of experiments where the number of electrons in an atom are measured as a side effect. We know atoms are electrically neutral so there must be equal numbers of electrons and protons. We know successive elements in the periodic table are built up by incrementing the number of protons, so we know how many ...


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It is an empirical observation, with an assumption that there is enough air flow over the temperature gradient (wind) to allow more rapid change in temp. With no wind, we end up with the law of natural cooling, which is proportional to $(\delta T)^{5/4}$, instead of $\delta T$. This law also has separate constants from newtons law of cooling! this is a ...


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Newton's law of cooling is an empirical observation not a fundamental law. The cooling of a body in air is a formidably complicated process because the cooling is dominated by the air flow, and the air flow is complicated to model. However we find from experiment that over a limited range of temperatures the cooling rate is proportional to the temperature ...


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As irish guessed in the comment, this is about beam alignment and tuning. A high intensity beam can damage the beam pipe (as in cut right through to the helium jacket) or cause a unusually hard superconducting magnet quench. The former is disastrous and the latter has some potential outrun the quench protection with similarly unhappy consequences. Having a ...


2

The curve you show is not a Gaussian. It is a binomial distribution with $n=100$ and $p=0.5$ (if it is an unweighted coin). This arises from processes where there are two outcomes. It approximates a Gaussian/Normal distribution when $n$ is large. This distribution has little to do with particle detection other than perhaps as a means of explaining what is ...


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Rather than a definite answer, I can, at this stage, only present a partial collection of information regarding or related to the possibility of using laser power from a launching site on the surface of the Earth and achieving orbit in a single stage launch profile: From: http://www.astrobio.net/news-exclusive/beaming-rockets-into-space/ Beamed thermal ...


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If the accuracy of the experimental measurements is smaller than the width of the gaussian then the shape describes the probability distribution one should get for any decay in particle physics. If the experimental accuracy is larger than the width of the decay then one gets a gaussian from the randomness of the experimental error . Example J/psi in ...


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From Wikipedia Perpetual Motion: A capillary action based water pump functions using small ambient temperature gradients and vapour pressure differences. With the "Capillary Bowl", it was thought that the capillary action would keep the water flowing in the tube, but since the cohesion force that draws the liquid up the tube in the first place holds the ...


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The dripping would occur as you describe it, if the drip ends of your tube or tubes is low enough to let gravity overcome the capillary action. That is what prevents a perpetuum mobile: Just as the water from the container is sucked into the tubes, water from the opposite end is also sucked in. To remove it, you have to expend energy, the same (in steady ...


1

The original problem can be seen in terms of energy and momentum conservation. Before scatter, there are two particles in the center of mass and the center of mass has an invariant mass larger than the mass of the electron. For total absorption of the photon there would be only the electron left. As the electron has a fixed mass and at the center of mass ...


2

As the comments indicate, the answer truly is that the electrons in the solid are not really free. But wait, I hear you say -- the free electron model approximates the electrons in the solid as a free gas of electrons. It certainly isn't perfect, but it can't be that poor of a description. Yes it can, and I'll explain why. Consider what it means to say ...


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That's the venturi effect. There's a nice Khan Academy video here.


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Given that most green pointers are frequency doubled from a 281.8 THz infrared laser ($c$/1064 nm), it's possible that you have a two frequencies $f_1$ and $f_2$ in the original infrared laser (i.e., it is multimode). After passing through the "frequency doubling" nonlinear crystal you see three frequencies: $2 f_1$, $2f_2$, and $f_1 + f_2$. It looks like ...


0

Since you've posited full containment the conceptually "easy" approach is to try to pick out the sign of the beta in the decay state. Difficulties: The decay may happen a frame or two down the data stream. Drat you, oh 2.2 ms lifetime! Both options are likely to shower, and while the positron ought to form a double or triple shower when it annihilates, ...


1

There is no fundamental difference between the signatures found in the two works (Kouwenhoven and Yazdani). Both are tunneling spectroscopy, which roughly measures whether there is a zero-energy single-particle state in the spectrum. Yazdani's setup allowed him to do measurement away from the edge, so that the localization of the edge state can be directly ...


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anna v's nice answer didn't go where I expected: the big acceleration at the LHC isn't in the accelerator, it's in the collisions. Let's suppose we have a proton in the LHC that undergoes an elastic, billiard-ball type collision and ends up with its original momentum in the opposite direction: \begin{align} \vec p_\text{initial} &= +7\,\mathrm{TeV}/c ...


1

The elucidation of the structure of DNA began as an exercise in x-ray crystallography. If you shine a beam of x-rays through a crystal, it will act like a diffraction grating, and the points of constructive interference will show up as dark spots on photographic film. This had been used for decades to determine the structure of relatively simple molecules. A ...


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The ability of a lens to concentrate power is a function of several parameters: area of the lens focal length of the lens absorption of power in the lens aberration of the lens For an ideal (thin, spherical, circular) lens of focal length $f$ and diameter $d$ you can estimate the diameter of the image of the sun (which is roughly 0.5° across as seen from ...


0

This answer is a summary, based on what I consider to be the most salient points made in the comments above. It is closely linked to the answer of my later question, Deflection of Earth directed NEOs using nuclear powered laser beams Below is the answer I received in relation to my second question: Project Excalibur  The idea of a nuclear pumped X-ray ...


0

Crystal growth always needs a substrate. You need a template, which tells the atoms how to arrange. Ideally, the substrate would have the same crystal structure and lattice constant. Since GaN substrates were technologically different to realize, growth on sapphire or Si(111) was studied. A special case for GaN growth is called lateral epitaxial overgrowth, ...


4

From scholarpedia: The Unruh effect is a surprising prediction of quantum field theory: From the point of view of an accelerating observer or detector, empty space contains a gas of particles at a temperature proportional to the acceleration. Direct experimental confirmation is difficult because the linear acceleration needed to reach a temperature 1 K ...


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No definite answer to this question, the effect in some sources is accepted and other sources dispute it. From Wikipedia: The hypothetical Unruh effect (or sometimes Fulling–Davies–Unruh effect) is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none. In other words, the ...


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Yes, wikipedia has a table which lists the 19 free parameters that need to be tuned by experiments. These include, as you already said, the masses of the elementary particles including the Higgs Boson, and some other notable ones are: CKM Mixing angles and CP-violation phase. Gauge coupling of he three symmetries (U(1), SU(2), SU(3)). Higgs VEV



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