Uncertainty Definition and 1000 Threads

Homework Statement m 7.29 7.31 7.3 7.31 7.27 7.28 7.31 7.29 7.28 7.27 7.26 7.3 87.47 mean 7.289166667 using the values in the table calculate the uncertainties on the mean values of m The Attempt at a Solution I thought finding the difference between the...

Heisenberg's uncertainty principle only seems to have implications for our understanding of the body of knowledge produced by science, not reality itself. The uncertainty comes from the inability to make two separate measurements, since each measurement will disturb the system and change the...

Homework Statement Using Heisenberg's uncertainty principle, calculate the uncertainty in the position of a proton moving at a speed of (5.00±0.01) x 10^4 m/s. Homework Equations Δx\geq \frac{h}{4mΔv\pi} The Attempt at a Solution x\geq (6.626*10^-34)/(4pi(1.6726*10^-24)(5±0.01 *...

Homework Statement If I measure A=50, with a minimum value of 48, and a maximum value of 51, and measure B=100, with a minimum value of 92, and a maximum value of 115, and I add the two (C=A+B) together, what is the resulting minimum and maximum value of C? Homework Equations If A...

I'm trying to understand the Heisenberg Uncertainty Principle, as it relates to experimental measurements, because it's kind of confusing me. We just learned the derivations for it in my QM class -- basically it's two standard deviations multiplied together (corresponding to measurements of...

Can someone point me in the right direction or give me a rundown on how to use the least squares method in calculating the uncertainty in a gradient of a graph? We have been given a theoretical experiment with data and so on supplied and we need to find the uncertainty of the graph we have...

Homework Statement If an electronic scale reads 502.4 g, what is the absolute uncertainty in the mass reading. Homework Equations Not sure The Attempt at a Solution Not a clue, it seems that there isn't enough information given. How am I supposed to figure out the absolute...

A simple pendulum is used to measure the acceleration of gravity using T=2pi(sqrt(L/g)) . The period T was measured to be 1.24 ± 0.02 s and the length L to be 0.381 ± 0.002 m. What is the resulting value for g with its absolute and relative uncertainty? So the first thing I did was to isolate...

Hello, I'm trying to figure out a way to calculate a suitable uncertainty value for the accuracy of a human measuring timing values during an experiment. The experiment was designed to determine the frictional force acting on a trolley as it is pulled along by a string attached to a...

The uncertainty principle says that you can't simultaneously measure position and momentum with arbitrary precision. So you can measure one at a time t1 and the other at a time t2 with t2 > t1, thus not measuring both simultaneously, but relativity tell us that there exists a frame of reference...

Please check if my solutions are correct or if I am totally wrong. Thank you! 1. Homework Statement [/b] In an experiment to measure the density of a steel ball. The diameter of the ball is d= 1.76 +- 0.02 cm and the mass to be m= 22 +- 1g. (include error calculations and report values with...

Hi, I was watching Through the Wormhole two weeks ago (I think it was a re-run), and they were talking about the uncertainty principle, and how it was impossible to prove due to the change in momentum of a particle when hit with an observation device, such as light. I think the guy was using...

Homework Statement What is the approximate uncertainty in the area of a circle of radius 5.3 * 104 cm? Express your answer using one significant figure. Homework Equations A = pi*r2 The Attempt at a Solution Using the given radius, I found the area to be 8.8 * 109 cm2. And since...

Homework Statement The centripetal force is given by F= (mv2) / r. If the mass is measured to be 2.8 +/- 0.1 kg, the velocity is 14 +/- 2 ms^-1, and the radius 8.0 +/- 0.2 m, find the force on the mass, including the uncertainty. Homework Equations F= (mv2) / r The Attempt at a...

I understood the Delayed Eraser experiment, and the Eraser experiment and the basic double slit experiment. And all I can conclude is, why? Why is there such a necessity? I now understand that it's most probably impossible to learn the 2 properties at the same time but I don't see any...

If Uncertainty Principle is a result of 'fiddling' of an apparatus with what is being observed (for example light particle/wave of a detector fiddling with particles/waves being observed), then wouldn't uncertainty principle cease to apply if in the future a 'smaller' or 'less interfering'...

A while back, one of my undergraduate physics professors gave an argument for why the uncertainty in a function or quantity F is given by \Delta F = \sqrt{^{N}_{i-1}\sum(\frac{\partial F}{\partial x_{i}})^{2}(\Delta x_{i})^{2}} He argued to think of a right triangle and think of...

Question on "estimated uncertainty" and significant digits Homework Statement The value is 136.52480, and the "estimated uncertainty" is 2. How many digits should be included as significant? Homework Equations Not sure whether estimated uncertainty refers to a 1σ (68.26%) confidence...

I've been exposed to two different interpretations of the uncertainty principle. 1) If an electron is in a certain state, a measurement of its position will yield a definite result. However, if after the measurement the electron could be returned to the same state, then a repeated measurement...

Homework Statement Finding uncertainty in magnetic field strength. N=2, i=1.00\pm0.005 A, R=0.1 m, \tan \theta=0.49\pm0.008 Homework Equations The equation B_{coil}=\frac{\mu_0 N i}{2 R \tan \theta} The Attempt at a Solution I am assuming that the radius R and number of turns N are exact. I...

Homework Statement Ok, I don't have a problem with the question, but what I believe to be an empty set variable is used which I have not covered in a course before. My problem is that I do not know the relevance of an empty set in part b) of the equation. Homework Equations The equation and...

Hi all, I have a question regarding least-squares, and I'm certain I can't be the first one to encounter it, but I've had no luck searching the literature for a solution. Here it is: Say we have a non-linear least-squares optimisation problem. We have data points y_i and a model y(x_i;{\bf...

Hi all, I am sure this is a quite simple question but I just can't figure it out, any helps would be greatly appreciated. If a particle stay in a state in a very short time, then by energy time uncertainty relation, it's energy must has a great uncertainty. Also because of energy is propotion...

Hi - I'm new here - I'm just writing a paper based on an acoustical analysis of a rock/pop performance venue in a college I work at, and I'm up to my uncertainties section. I've read up on uncertainties, and feel confident in working out uncertainties for simple additions, multiplications...

Homework Statement As you eat your way through a bag of chocolate chip cookies, you observe that each cookie is a circular disk with a diameter of 8.50+-0.02cm and a thickness of 0.050+-0.005cm. Homework Equations a. Find the average volume of of a cookie and the uncertainty in the...

couple of questions a) the operators not commuting would also be true of position and momentum operators in classical mechanics (x d/dx -d/dx x) f(x) so the non-commutation does not inherently constitute a proof for the uncertainty principle, or do you just not care about the uncertainty at...

I was recently thinking about the Heisenberg Uncertainty Principle which states that we can not know a subatomic particle's position and momentum at any instant. We can know one or the other measure but not both at the same time. The more we know about one, the less we know about the other...

Here's how I understand it: The light of a shorter wavelength disturbs the momentum of the electron, but shows the electron's position. Why doesn't the light of a longer wavelength disturb the momentum of the electron?

I've come across an apparent paradox in elementary quantum mechanics, and after a little Googling, haven't found a reference to it. Here goes, The 1-D infinite square well is a classic problem in introductory QM. We find that the position-space eigenfunctions of the Hamiltonian (the "allowed...

You are no doubt familiar with Heisenberg's uncertainty principle, putting a limit on the accuracy with which we can measure a particle's position and momentum, \Delta x \Delta p \geq \hbar/2 On my course I was shown the derivation, it popped out of a few lines of mathematics involving the...

While reading Feynman's 6 Easy Pieces, I see he talks about bouncing photons off of the electrons that are passing through two slits. According to Feynman, when a photon strikes an electron near one of the slits, it bounces (sometimes back at the observer) and registered as a sharp point of...

This is actually a GRE problem, I'm just trying to go through and understand them all for studying purposes, but I don't understand how to do this one at all. Homework Statement A student makes 10 one-second measurements of the disintegration of a sample of long-lived radioactive isotope and...

Hello everyone. This is my first post, but I enjoy reading all the forums. I have a simple question that I thought about recently: Would Heisenberg's Uncertainty Principle still hold up if we could somehow observe a particle without the aid of instruments? I know it is entirely...

Homework Statement I need assistance in learning the proper way to calculate error/uncertainty in a few things for my undergrad thesis.Homework Equations 1) how to calculate the uncertainty in the slope and intercept of calibration curves (peak area vs mol of compound) I have made via excel...

Ok I feel a bit silly asking about this, but I have gotten myself confused and need some help sorting something out. In QFT the operators of observable quantities commute over space-like intervals, so we cannot propagate effects faster than light, causality is safe, cool. But I have somewhat...

Please teach me this: In Quantum Mechanics the Heizenbeg principle holds for one particle.In QTF Theory,the creation and annihilation operators corresonding to coefficients of Fourier components of transformation,so it seem that each quantum(particle) has a definite momentum.Then it seem that...

It is stated that electrons orbit the nuclei of atoms not as particles. By the Heisenberg Uncertainty Principle (whatever that is) one cannot pinpoint their actual location and one cannot track the motion of an electron as it orbits the nucleus. What is that all about? Please use 10th...

Homework Statement The radius of a circle is measured to be 2.4 cm +/- 0.1 cm. Find the error in the area of the circle. Find the error in the circumference. Homework Equations Have no idea but I'm taking a guess it could be multiplying fractional uncertainties? The Attempt at a...

Hello everyone, I've run into a little issue with physics homework. During a lab we recently had, we were required to measure the amount of time it took for a ball to drop from different heights (2m, 1.5m, etc) using a photogate. Now that I'm writing the lab report, I have to find the...

Homework Statement 1.0 micrometer diameter dust particles (m=1.0 * 10^-15 kg) are in a vacuum chamber. The dust particles are released from rest above a 1.0 micrometer diameter hole, fall through the hole, and land on a detector at distance d below. Part A: If the particles were purely...

What is Heisenberg's Uncertainty Principle?? Homework Statement Hey everyone, Until very recently, I had always thought that Heisenberg's uncertainty principle was that \Delta x \Delta p \geq \frac{h}{2\pi} (or \hbar) However, I'm doing my final year of high school physics this year...

Hi! I had a thought as to how leptons hold the properties attributed to them by Heisenberg and modern quantum mechanics. It is my belief that the Uncertainty principle is caused only by the fact that the fast moving electrons distort space and time in their local fields. This may be accounted...

First: If subatomic particles have momentum, then don't objects at rest have momentum [since they are made of these momentous particles] ? My main question is: If the position of an electron is uncertain, then isn't the position of an object NOT constant? Even to the slightest degree? Thanks...

I am new, and I don't have a physics background, so please excuse the question if it is incredibly easy... Does the Heisenberg Uncertainty Principle mean that we just can't measure the location of an electron to perfect accuracy, but such a location does exit (we just can't know what it is)...

Recently, I have a look of the Einstein's thought experiments challenging the uncertainty principle. One of the experiments is the Einstein's slit. I found the description about it : "Consider a particle passing through a slit of width d. The slit introduces an uncertainty in momentum of...

I have often seen it stated that the Uncertainty Principle (UP) is a unique feature of Quantum Physics, but surely it applies classically too? For example, if someone throws a ball across a room, and I take a photo with a shutter speed of 1 second, the resultant photo will tell me a lot about...

Homework Statement I wrote a code that calculates pi using accept&reject monte carlo integration. It picks -1000000000 pseudo-random points (x,y), and counts the number of points that fall within a unit circle (let's call that number k). The ratio of k/ N (N = Number of trials = 1000000000)...

(High-school level) I got given some formulas today for calculating uncertainty of a value that has been square rooted, squared, inversed, inverse squared and inverse square rooted. I'm not totally sure what they mean however, but I kinda have an idea. Square root: y=x^1/2...

I've been watching Susskind's lectures on quantum mechanics and he mentions that the time taken for two electrons to entangle their spin is a function of their distance, which in itself determines the energy that is released when two electrons fall into a singlet state. Does anyone here know how...

Hey all, I'm a student curently studying in a Singaporean Junior College (American 12th grade equivalent). I was curious and just thought of the following: Suppose a system with a electron and a proton nucleus, a hydrogen atom. From electrostatic force and circular motion equations- F =...