Measurement Definition and 1000 Threads

Hi, I've been studying uncertainty in measurement. I'm not sure how to decide if the uncertainty of a given measurement should be ±.01 or ±.02 or ±.03, and so forth. I understand that the number of decimal places in the uncertainty calculation should correspond to the number of decimal places...

1. When the sun was directly overhead in syene, why was it not directly overhead in Alexandria The size of Earth was first measured in Egypt by Erathosthenes about 235 BC. He calculated the circumference of Earth in the following way. He knew that the Sun is highest in the sky at noon on June...

Homework Statement Given a system initially in a state $$| \psi \rangle = \frac{1}{\sqrt{6}} \left(|1\rangle + 2 |2\rangle + |3\rangle \right)$$ where ##{|n\rangle}_{n=1}^{8} ##form an ON basis. If we perform a measurement of an observable corresponding to an operator...

Hello All, We are experimenting with a flame tube design (quite literally, a flame within a tube). We are looking to get a temperature profile along this tube. So, we will need multiple thermocouples along this tube. I'm wondering whether it will be necessary to go to ungrounded (isolated)...

Homework Statement A muon with a kinetic energy of 200 ± 0.05 MeV is produced in a linear accelerator. The rest mass of the muon is 106 MeV/c2. (a) Calculate the speed of the muon (in units of c), (b) Calculate the linear momentum (in units of eV/c), (c) How long does it live during the...

I am looking for a digital device that is able to measure the angle of a rotating device. It will be used to align rotating solar cells with the sun. These cells are attached to a flat panel, that is fixed in the center with an axis, so only circular movement is possible. The panel needs to...

Hai, I have a material related question. I am working with polymeric materials (Poly carbonate's and PMMA's respectively) which have to be tested for impact resistance (at high velocities). It came to my mind if the impact process could be correlated to a sound based measurement. Now i want...

I was reading this article, http://www.nature.com/news/2009/090122/full/news.2009.50.html, and it was talking about how they 'teleported' a Ytterbium ion (Yb+) and mid-way through the article it said that they had to destroy the quantum state of the original Ytterbium ion and they did that by...

Hi, I have a question regarding quantum teleportation. I understand that Alice starts of with a photon A whose state she wants to teleport. Alice and Bob share an entangled pair of photons, B and C. Then Alice does something called a Bell measurement which entangles A and B and the result...

Hi guys I am assigned to do the indoor air quality measurement in 5 buildings which are 2 academic buildings, one residence, a library and a gym. I have to establish a methodology to measure CO2, temperature, humidity, air movement as well as particulates. I have 2 months time to measure and...

I need a simple, intuitive, and easy-to-comprehend example of a POVM measurement, which is not a projective measurement. Any suggestions?

Can someone explain to me the difference (if any) between measurement of the first kind and quantum non-demolition measurement? Thanks!

Hi all, Reading through Peskin and Schroeder, I came across the following statement, with regards to propagators: Could someone explain how the commutator is related to the measurement of the field in this context? Searching online, the only thing that crops up is the usual uncertainty...

I am doing a measurement in a system S with the apparatus A, in an entorn E. If the system is at t0 in Sithe measurement of the apparatus will be, after the decoherence time

Im interested in knowing what kind of sensors are used and it's overall execution, thanks.

Can we measure the spin of a particle by measuring the force on a Magnet? I wish to consider a modified stern gerlach like apparatus where a Magnet of mass M is attached to a spring. Can we measure Spin of the particle by studying the deflection of the magnet? Even if it is possible, I can...

Hello! I have a question regarding measurement uncertainties. This is not a homework problem. Let's say that I want to measure some quantity, and I want to measure it multiple times using multiple identical but separate instruments. That is, -First measurement taken using equipment 'A'...

I am talking about length area and volume. As I reason it out in my own mind area (and volume) is based on length and involves 2 random measurements of length that are combined (with multiplication as the device of convention - could any other function be used to work as well and as...

Hi all, I have a number of underwater transducers that I want to measure the impedance of by using an impedance analyzer. I'd like to create an automated system that cycles the leads of the impedance analyzer to the various transducers, perhaps using something like a decoder or a number of...

Hi all. I've been thinking of how one can measure the speed (& indirectly velocity, since we know it's direction of travel) of an object. The object is not necessarily an airplane or an automobile since they've their special devices built for velocity measurement. I was thinking of measuring...

The general question that I am interested in, is to obtain the number of bits of information one can infer about the horizon by placing measuing apparatus only in a Region of size D. I Imagine a telescore of diameter D that(or devices of that general nature) The standard Theory says that*...

I am designing my own Charpy impact testing machine and I am unsure what would be the best as well as relatively simple and affordable method I can use to accurately measure the angle the pendulum travels after it has broke the sample. I would also appreciate any complex and more expensive ideas...

Homework Statement In class we have to determine whether something is nominal, ordinal, interval or ratio and with the last 2 (ratio/interval) you have to state if they are discrete or continuous. Homework Equations n/a The Attempt at a Solution Height of Mt Everst above Sea level=...

Forgive me for asking such a basic question but say for IDSW1 if we have a wavefunction that is a superposition of the first two energy eigenfunctions so: ψ(x)=(1/√2)*(ψ1+ψ2) then if we measured say E1 we can eliminate the inconsistent part of the wavefunction so the wavefunction collapses to...

I need to calculate the force of a pin impacting a solid metal. I know the shape of the indenter, the precise shape and depth of the indentation and the mechanical properties of the solid metal including modulus, yield and ultimate strength. The pin is being driven by ultrasonic wave guide so it...

Hi, I am trying to measure the center deflection of a simply supported beam with a capacitive sensor. The beam's surface that is the sensor's target is originally flat. After applying equal forces on the two edges of the beam, its center curves upwards (away from the capacitive sensor) thus...

I was reading a book and it said the sun was 10^12 Logarithmic. What is the measurement of a Logarithmic?

What does the thread note 3/8'' - 24UNF 2B x 1-1/2'' mean? I know that the diameter of the thread is 3/8'', but what's the 1-1/2''? Is that the length of the thread?

Suppose it is known that a photon has diagonal polarisation (e.g. it has just passed through a diagonal slit), then Alice comes along and measures the photon using a horizontal/vertical polarisation basis. So, I believe there is a 50% chance she will get a horizontal result and 50% chance she...

Homework Statement Hi All, I have a problem in calculating the thickness of a coating material inside a tube. The tubes inside diameter is measured before and after coating. The coating thickness is calculated by substracting the diameters and dividing by two to get the thickness of the...

Hi, I am currently learning and trying to build an extended kalman filter. However I am not sure how to created the measurement matrix. The measurement matrix H is described using formula 3.6 on page 18 of this document http://www.scribd.com/doc/54702247/UAV-Design My problem is that...

Homework Statement Define measurement in the Copenhagen interpretation of quantum mechanics. Homework Equations The Attempt at a Solution In the Copenhagen interpretation of quantum mechanics, measurement changes the state of a wavefunction, that is, it collapses the wavefunction...

When we use polarisation rotators to measure certain polarisations for entangled photons, the photon usually meets a polarised beam splitter after. When we detect in the |H> or |V> basis, does that mean the photon is in |H> or |V>? What has happened to the polarisation we were measuring...

My book defines accuracy as the closeness of a measurement to the real/actual value, precision as when a set of values are consistent with each other (i.e. close to each other) and sensitivity as the smallest possible reading of an instrument (i.e. to how many decimal places it can measure)...

Hello all, Having read many threads and posts about light, it’s speed c, SR etc, the particular issue of not being able to measure the one way speed of light has always stood out and kept me very interested, so, after pondering about it for a while, I would like to propose an experimental...

I had a problem where we had to write out the sinusoidal function for the rotation of a ferris wheel. My teacher said that because the rotation was a function of time (x-axis was time), we had to use radians and not degrees. Could someone explain to me if/why you need to use radian measurement...

Hi, I was trying to measure DC link current on a switched mode power supply when I came across a quirk of my circuit. I'm using an LEM HX 03-p SP2 hall effect current transducer to measure current. I couple the output node of my current transducer to ground via a 2KΩ resistor. The device's...

Hello all I am trying to measure material displacement using measured thermal data.7 While the specimen is heated up, I want to measure how much it changes its length at particular points. Is this possible? If you have any further questions or suggestions please do not hesitate to...

In the measurement ansatz below, must the state |O,ready> be orthogonal to |O,reads up> and |O,reads down>]? |+x> |O,ready> =1/(sqrt2)[|+z> + |-z>] |O,ready> (1) ---------→ 1/(sqrt2)[|+z> + |-z>] |O,ready> (2) --------→ 1/(sqrt2)[|+z>|O,reads up> + |-z>|O,reads...

Hi everyone, Can anyone tell me what information I'd need to calculate the maximum and minimum bounce angle of a tennis ball being fired at a tennis court? The ball is being fired at 30 m/s at an angle of 16° and the coefficient of restitution of the tennis ball is 0.759. What other...

At another thread under Special and General Relativity the following question was asked: "Why isn't stellar aberration considered to be a one way measurement of c? If the angle of aberration (θ-θ0) is -20.5 arc seconds and the Earth's orbital speed is 29.79 Kilometers/second normal to the...

Hello, as far I understand wavefunction collapse (or decoherence or whatever stops particles from acting as waves) is initiated through something referred to as a measurement. These measurements are thought of as interactions. Now the question I have is, why are some interactions measurements...

Why isn't Stellar aberation considered to be a one way measurement of c? if the angle of aberation (Theta) is 20.5 arcseconds and the Earth's orbital speed is 29.79 Kilometers/second normal to the arriving star light. The value of c should be: c= Vt/tan(Theta) = 29.79/9.94E-5 = 299737.98...

Hi all I have measured the resonance frequency of a resonator as a function of time by mean of a Laser-Doppler vibrometer and a frequency counter. In this measurement there are some fluctuations in the measured frequency as time goes by. My question is: How do I determine the resolution of...

A rectangular park has an area of five hectares (1 hectare = 10,000 meter square) The dimensions of the park on a map are 5 cm * 4 cm What is the scale of the map?

Has anyone tried to apply the following regression equation appeared in the paper "Continuous measurement of systolic blood pressure using the PTT and other parameters" (Proceedings of the 2005 IEEE Engineering in Medicine and Biology 27th Annual Conference Shanghai, China, September 1-4, 2005)...

A Pitot-static tube connected to water manometer is used to measure the velocity of air. If the deflection between the two arms of the manometer is 12.4cm, determine the air velocity when the density of air is 1.25kgm-3 and the density of the water in the manometer is 1000kg/m3. I am not...

What is the difference between observation and measurement in reference to a quantum experiment?

Consider an experiment in which a closed box is set up with a system inside that is initialised at time t=0 with state psi(0). A measurement of quantity w of the box’s contents is made at time T, that is observed by scientist S1. There is another scientist S2 that can, by pressing a button...

I want to calculate the uncertainty in the period for a spring, when I have measured the extension of it under the influence of gravity. Call that x and say I got: x=0.10m ± 0.01 And we know that: T = 2∏√(x/g) Is it then correct to use the following formula for the uncertainty σT: σT =...