What is Errors: Definition and 346 Discussions

An error (from the Latin error, meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake.
In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behavior.

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  1. E

    Measurement Errors in Kirchhoff's Voltage Law

    Homework Statement For a lab, we explored Kirchhoff's Laws. I made a procedural mistake while measuring my voltage values across my different elements. I know that all of my calculated voltage sums are correct, so I was wondering what I might have done to have loops ACBA and CDBC have almost...
  2. M

    Mathematica Errors when plotting but not when evaluating

    Hi PF! Attached is a screenshot of my code: The issue I'm facing is not being able to plot at line 21. It's weird because when I evaluate ##\alpha[1/4]## on it's own line I instantly receive a 5X1 vector. When I evaluate the Table[##\phi##] statement also shown in line 21 on it's own line I...
  3. JTC

    What is Artificial Intelligence?

    Please bear with me... In a curriculum in mechanical engineering, there is a set of standard topics: statics, dynamics, vibrations, fluid mechanics, thermondynamics, etc. What is Artificial Intelligence, and what does it entail? (at the moment, it seems like a buzz phrase that does not...
  4. G

    Minimize the sum of Type I and Type II errors

    Homework Statement Given X_1,\dots,X_n a simple random sample with normal variables (\mu, \sigma^2). We assume \mu is known but \sigma^2 is unknown. The hypothesis is \begin{cases} H_0: & \mu=\mu_0 \\ H_1: & \mu=\mu_1 > \mu_0 \end{cases} Determine the rejection region R...
  5. Z

    What errors did Rutherford encounter in his experiment

    Homework Statement What errors did Rutherford encounter in his experiment and how did he account for them. Homework Equations I believe there is an equation to find (b) but I don't know what it is.
  6. M

    Van der Pauw sample preparation errors

    Hello, I'm carrying out electrical resistivity tests with the Van der Pauw method on a round sample (2 mm thick disk) of a doped ceramic but sometimes I have issues in the mounting of the sample. I'm using a 4-probe tube where each of the 4 wires contacts with the "corners" of the sample. To...
  7. Darren Byrne

    Uncertainties - reading errors

    Homework Statement Hi, I have a question about uncertainties. If I am carrying out an investigation I need to record my uncertainties in each measurement. I am aware that instruments have reading errors. So, if I use a stopwatch to measure the time period of a pendulum the reading error is...
  8. M

    I Solar system simulation errors

    Hi, as a side project I am making a solar system simulator in Python, but I am getting extreme inaccuracies. As the image shows - I am comparing the simulation to data obtained from NASA's Horizon. I have written a a basic Verlet integrator in the Python class posten below: import numpy as...
  9. M

    Fortran Handling underflow errors in fortran 90

    I am using fortran 90 to solve a elliptic partial differential equation numerically(Poisson's equation) and I have encountered a underflow error. All the arrays involved are stored as real data types. The original expression is highlighted in the comments and the my attempt at refactoring into...
  10. J

    Measuring 'g' and systematic errors

    Homework Statement Figure 2.2 (attached) shows a graph of distance against time squared for a ball bearing falling through the air. In accordance with s = ut + 1/2 a t^2 the graph should be a straight line through the origin. Explain how a systematic error in s and t could lead to the graph not...
  11. Ethan Singer

    I Truncation Errors Explanation?

    So I just began a course on Linear Algebra, and was curious about how we can estimate derivatives using centered differences: After a few minutes of Research, I find the proof involving something about a truncation error, which led me to the conclusion that when estimating derivatives, the rate...
  12. V

    A How can I resample data with errors linearly in log space?

    I need to resample a set of data and its errors linearly in log space, with the same number of points. I was just going to interpolate between points to get the data - but how do I calculate the errors?
  13. M

    What are the errors in Young's Double Slit experiment?

    Homework Statement I am having troubles trying to figure out systematic and random errors when conducting Young's double slit experiment. Homework Equations NA The Attempt at a Solution I have found one error which could be correct, it is the fact that the laser was not at right angles with...
  14. resurgance2001

    Estimates of Percentage Errors in Cosomology

    Homework Statement Suppose that there is some hypothetical cosmological parameter called C, and suppose that the real value of C is C(real) = 1. Also suppose that everyone in the universe is able to measure C. Our value of C is C(ours) = 1.15 +/- .15 at confidence level 95 % Make an...
  15. R

    I The Normal Distribution - Random Errors

    So let's say I do some measurements and obtain a set of measured values. The measurement is characterized by random errors so by making enough measurements, they approach a normal distribution. In other words, my set of measured values can be approximated by a normal distribution characterized...
  16. A

    Linear Regression with Measurement Errors

    Hello, I have a set of data, two columns, and each datum has its measurement error like illustration shows below: x | y --------------|----------------- x1+/-xe1 | y1+/-ye1 . | . . | ...
  17. Nikhil N

    How to test CST design studio for analyzing data errors

    Hi.. I want to know how can we specify the data(electrical) passing through cable that we are designing in CST design studio to test the effect of EMI on the data passing?
  18. M

    What is the uncertainty in 5.00mm measured by analog device?

    Homework Statement What is the uncertainty in 5.00mm measured by an analog device? Homework Equations No equations, Uncertainty and error analysis question The Attempt at a Solution I know that the uncertainty is half the smallest division but i can't figure out what is the uncertainty and...
  19. E

    B History of Error Bars in Physics

    I was reading an 1803 paper by Thomas Young (of double slit fame), "Experiments and Calculations relative to physical Optics". In it, he lists various dimensions of fringes of light and things. All without any error bars. It got me thinking, what's the history of error bars in scientific...
  20. S

    Pendulum experiment systematic errors

    Homework Statement So we had to the simple pendulum experiment and were measuring the effect of the length of the pendulum on its period of motion. However, our results produced a line of best fit that was significantly higher than the expected line of best fit (with length vs period squared)...
  21. E

    B Solar cell educational graphics - review for possible errors

    Hi, Jake here. I've created some graphics about solar cells that covers high level, general info and even delves into some atomic-level subjects. However, I'm no physicist and I'm sure it shows. If any of you could take a quick look at my work and review for errors, that would be awesome. My...
  22. V

    A Integrate data plot, combine errors including correlation

    Hello I have a set of data points, with errors (X1 , Y1 +- deltaY1) , (X2 , Y2 +-deltaY2) etc I have the covariance matrix for these bins I want to integrate this set of data points: SUM_i ( Y_i * X_binWidth_i ) How do I combine the errors, taking into consideretation the...
  23. psycho_physicist

    Errors/ Uncertainty in measurement problem

    Homework Statement [/B] The surface tension (T) is measured by capillary rise formula T = \frac {rh ρg}{2 cos\Theta} . The quantities of ρ, g and θ are taken from the table of constants while the height and diameter are measured as h = (3.00 + 0.01)cm and D = (0.250 ± 0.001)cm Find the...
  24. Matt atkinson

    Question about errors, Hubble's constant

    Homework Statement I am just looking through some old notes I have from for cosmology, and there's something cropped up that i can't seem to figure out: Say I have two (or more) values for H_o each with errors such as: H_{o_1}=70^{+a+b}_{-c-d} and H_{o_2}=69^{+e+f}_{-g-h} How would I go...
  25. T

    MHB Function errors: Copying one function to create another.

    I am having difficulties understanding this program may someone help me please. Using the CelsiusToKelvin function as a guide, create a new function, changing the name to KelvinToCelsius, and modifying the function accordingly. #include <iostream> using namespace std; double...
  26. G

    I Symbol used in total differential and small errors

    Mod note: Thread title changed from "Sign used in total differential and small errors" to "Symbol used in total differential and small errors" My notes say that z=f(x,y) can be defined as the sum of the changes with respect to x,y respectively. The formula is: dz = ∂f/∂x * dz + ∂f/∂y * dy...
  27. RoboNerd

    Quick question on experimental errors

    Homework Statement A student is testing the kinematic equations for uniformly accelerated motion by measuring the time it takes for light-weight plastic balls to fall to the floor from a height of 3 m in the lab. The student predicts the time to fall using g as 9.80 m/s^2, but finds the...
  28. A

    Calculation of permissible error in physical quantity

    Homework Statement I have doubt in calculating the permissible error. It goes as follows Measure of two quantities along with the precision of respective measuring instrument is A = 25.0 ± 0.5 m/s, B = 0.10 ± 0.01 s. A physical quantity C is calculated as C = A × B. What will be the value of...
  29. H

    B How to calculate the uncertainity errors

    do anyone explain me pl. i would like to know the uncertainty error in measuring the specific activity of the primordial radionuclides
  30. O

    Calculating errors after curve fitting (linearizing) graphs

    Homework Statement I did a lab this week measuring periods of swings of a simple pendulum. We need to curve fit the equation T=k*l^n and we got ln(T)=n*ln(l)+ln(k), and we need to plot the data we collected into the linear graph, meaning out y axes is ln(T) and our x axes is ln(l). So far all...
  31. haruspex

    Insights Frequently Made Errors in Vectors - Elementary Use - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Vectors - Elementary Use Continue reading the Original PF Insights Post.
  32. J

    Comp Sci Errors during executing the program (Compaq Visual Fortran)

    Homework Statement First of all, I used the Window xp & Compaq Visual Fortran 6.6 installed in VMware workstation. In my case, there are no compile and link errors in source code, and excuting that program is also done. But I want to generate 300 random numbers by using my program (Log-normally...
  33. P

    Errors in calculating the acceleration of gravity

    So I did a lab where we are calculating the acceleration due to gravity using a variety of methods. For two of the methods, we have an object attached to a magnet, then the magnet is turned off so the object is in free fall and it makes a spark/mark every 1/60th of a second on a piece of tape...
  34. S

    Error in summation of spectral components

    HI everyone, Imagine we are sampling of a gaussian signal along time and need to know the power/variance associated with the first N spectral components. So we take our favorite fft algorithm to get the PSD. The error associated with a given estimated spectral component f(w) (w is the...
  35. H Smith 94

    Verlet algorithm: Why am I getting this output?

    Hi! I am currently trying to write a code in C to simulate the orbit of planets around the Sun in the solar system. I am using the velocity Verlet approach and finding that my code produces no acceleration in the ##y##-direction (aside from for ##t_n = 0##,) and that the planet just flies off...
  36. S

    Are errors important in calculating integrals in Python?

    I am reading Mark Newman's Computational Physics textbook. He goes over calculating integrals with Simpsons's Rule and the Trapezoidal Rule, and then he goes over calculating their errors. Why would I have to ever worry about the error of the integral? He has the chapters online at his website...
  37. haruspex

    Insights Frequently Made Errors in Climate Science - The Greenhouse Effect - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Climate Science - The Greenhouse Effect Continue reading the Original PF Insights Post.
  38. S

    Errors: Random, Systematic, and Human

    Homework Statement Hello! In our class, we just completed a lab on momentum and energy conservation in collisions. It was a computer simulation. Although, for the lab report, the teacher wants us to write the random, systematic, and human errors. Can someone describe what each error means? What...
  39. G

    Spotting Errors in Transverse & Longitudinal Accelerations

    Let's say you know all 3 cartesian components of a particle's velocity and all 3 for it's acceleration. You can split the acceleration vector into two vectors, one parallel (longitudinal) to the velocity vector and one perpendicular (transverse) to the velocity vector. Then, I found the...
  40. Ahsan Elahi

    Maxwel 3D Wireless Power Transfer setup simulation errors

    Dear All, i am new to Maxwell 3D software. i want to simulate my Wireless Power transmission Project in Maxwell, for this purpose i took help from different toturials whic abled me to draw the Tx and RX coils...i want to simulate these coils to calculate the values of L, M, K and etc. but i am...
  41. ChrisVer

    Combinations of measurements: obtain mean and errors

    I was looking at the attached picture, where it gives the Higgs Mass obtained from the two different channels from ATLAS and CMS. Let's only talk about the diphoton channel : H\rightarrow \gamma \gamma From the ATLAS the mass value is: m_{Ah} =126.02 \pm 0.51 and the CMS: m_{Ch} =124.70 \pm...
  42. N

    Errors in basic current balance experiment?

    Hi guys, so I'm having a little trouble completing my physics lab report here due to not being able to find many errors to discuss about. The experiment that I conducted makes use of a basic current balance: http://www.pasco.com/prodCatalog/SF/SF-8607_basic-current-balance/ As you all know...
  43. ChrisVer

    Averaging measurement with stat +sys errors

    Homework Statement You make a measurement of two variables with 100% correlated systematic uncertainty: x_1 \pm \Delta x_1^{stat} \pm \Delta x_1^{sys} = 1.0 \pm 0.1 \pm 0.1 x_2 \pm \Delta x_2^{stat} \pm \Delta x_2^{sys} = 1.2 \pm 0.1 \pm 0.2 The average is taken by: \bar{x} =...
  44. C

    Accumulating Errors in Beach Volumes: How to Estimate Error Bars?

    I've got GPS nearshore bathymetry/beach topography sand elevation data from the backbeach out to 8 meters depth, with 1 m spacing in the cross-shore, 100m spacing in the alongshore, and stretching multiple kilometers of coast. I have interpolated the data using a couple different interpolation...
  45. haruspex

    Frequently Made Errors in Heat - Elementary Level - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Heat - Elementary Level Continue reading the Original PF Insights Post.
  46. can12345

    Understanding Pressure Measurement Errors: Tips for Accurate Transducer Readings

    < Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > Hello What are the possible errors when measuring pressure value by the using a transducer? And how we can find the amount of errors?
  47. haruspex

    Insights Frequently Made Errors - Pseudo and Resultant Forces - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors - Pseudo and Resultant Forces Continue reading the Original PF Insights Post.
  48. haruspex

    Frequently Made Errors in Mechanics - Springs - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Springs Continue reading the Original PF Insights Post.
  49. M

    Python: Integrating a function but getting large errors

    My code: import numpy as np import matplotlib.pylab as plt import math import random from scipy import integrate R1 = .001 R2 = 7 def G(r,theta): sigma = random.randint(4000., 7000.)/1000. # width of beam is 4 - 7mm r0 = random.randint(0, R1*1000.)/1000. #random centroid theta0 =...
  50. haruspex

    Frequently Made Errors in Mechanics - Momentum and Impacts - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Momentum and Impacts Continue reading the Original PF Insights Post.
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