The statistics tag has no wiki summary.
0
votes
0answers
26 views
What does the difference in odds for Bell's inequality tell us about quantum mechanics?
Bell's inequality defines a lower bound for agreement/disagreement between entangled particles. When the experiment is conducted it shows lower odds.
What does this tell us? Is it possible that we ...
2
votes
1answer
60 views
Experimental measurement of volumetric flow rate
The other day I with my team had to measure the volumetric flow rate through a pipe only using a 2000 mm$^3$ volumetric flask and a chronometer. The end of the pipe discharged to the atmosphere. As we ...
-3
votes
1answer
38 views
How many measurements should be done? [closed]
I am measuring time of a computer operation. The operation should run roughly same time each time I measure it. How many times should I measure it to get good average and standard deviation?
0
votes
2answers
298 views
Microsoft Excel not graphing $x = y^{1/2}$
The experiment was relating the period of one "bounce" when you hang a weight on a spring and let it bounce. I have this data here, one being mass and one being time.
The time is an average of 5 ...
0
votes
0answers
22 views
Removing seasonal and non-seasonal oscillations with least-square method [closed]
I was trying to find help online, but with no luck :( Hoping you will help me!
I have data containing sea temperature with depth. With data I need to remove seasonal and non-seasonal oscillations by ...
1
vote
0answers
30 views
is log-Laplace ever an optimal model for physical phenomena?
In the financial world, the log-Laplace distribution almost perfectly models many phenomena such as price changes.
Does this model best fit any physical phenomena?
1
vote
1answer
107 views
Coherency matrix of partially polarized light doesn't contain all information on polarization state?
The electric field of quasi-monochromatic, partially polarized light can be expressed by the following random process (Goodman, Statistical optics)
...
2
votes
1answer
54 views
Underlying physical basis of an exponential distribution
My data set of upper atmospheric cloud occurrences $N$ versus their thickness (or optical brightness, say $B$) show an exponential variation over more than two orders of magnitude - that is $N$ varies ...
4
votes
2answers
91 views
What's the physical difference between the quantities $\langle v_{i}v_{j}\rangle$ and $\langle v_{i}\rangle\langle v_{j}\rangle$?
What's the physical difference between the quantities $\left\langle v_{i}v_{j}\right\rangle $ and $\left\langle v_{i}\right\rangle \left\langle v_{j}\right\rangle $?
Where $\left\langle ...
1
vote
5answers
219 views
Are Uncertainties in Measurements Important?
In the first lecture of MIT's Classical Mechanics Prof. Lewin highlights the importance of uncertainties in measurements by quoting "Any measurements, without the knowledge of uncertainty is ...
0
votes
1answer
83 views
What is a long-tailed distribution for physicists?
What is the most common definition of long tailed distribution for physicists? I am looking for definition and examples. Examples should have arguments why the distribution is or is not long tailed.
...
2
votes
1answer
51 views
Error in variance
I've been exploring techniques in statistical physics, specifically applying them to spin ices. I'm in the canonical ensemble. By using the fluctuation dissipation theorem you can extract useful ...
0
votes
0answers
6 views
Hardware random number generator Vs. Pseudo random number generator in the battlefield of Markov Chain Monte Carlo processes [migrated]
I'm implementing a Markov Chain Monte Carlo process for a Quantum Monte Carlo routine, in every book and paper I've read so far the success of the routine and quality of the results strongly depends ...
0
votes
2answers
48 views
Has anyone studied a statistical scaling law for the universe? [closed]
How do named objects in the universe scale? Is there a predictable curve for an ordered list, say {atom, animal, planet, solar system, galaxy, etc}? Can you then use the analysis to predict when the ...
5
votes
1answer
5k views
How do you find the uncertainty of an weighted average?
The following is taken from a practice GRE question:
Two experimental techniques determine the
mass of an object to be $11\pm 1\, \mathrm{kg}$ and $10\pm 2\, \mathrm{kg}$.
These two ...
0
votes
1answer
40 views
Initial separation of neutron star/black hole binaries?
How would I go about finding the distribution of initial separations (i.e. the lengths between the centres of mass) of stars that make up binary systems. I am interested in neutron stars and stellar ...
1
vote
2answers
678 views
Physical interpretation of y-intercept in a Current vs Voltage graph
So I collected current and voltage data from a simple circuit with a power source and a resistor, using a multimeter. I created a graph for this data using excel and got the y-intercept (which is ...
0
votes
0answers
32 views
Irregular events within an otherwise cyclic time series
(I have asked the same question on math.stackexchange, but I figured that physicists might actually be more likely to have encountered the same problem before.)
I am considering a time series with a ...
2
votes
1answer
148 views
Maxwell-Boltzmann velocity PDF to CDF [closed]
I asked on Math.SE and was advised to try here instead.
I need to draw from a Maxwell-Boltzmann velocity distribution to initialise a molecular dynamics simulation. I have the PDF but I'm having ...
0
votes
0answers
62 views
Pareto efficiency and Standard Model parameters
Pareto Efficiency is a well understood concept in economics, which basically is a condition where no one actor could be made better off without some one being made worse off. This condition allows ...
1
vote
0answers
171 views
Probability and probability amplitude
What made scientists believe that we should calculate probability $P$ as the $P = \left|\psi\right|^2$ in quantum mechanics? Was it the double slit experiment? How? Is there anywhere in the ...
0
votes
1answer
44 views
Statistical error in a regression
I measured some voltage values ($x$) and some corresponding frequencies ($y$). I know that the voltage can only be measured within an uncertainty $\Delta x$. And the uncertainty of $y$ shall be ...
5
votes
2answers
157 views
statistics for photon counts in photomultiplier
It seems that a common statistical model for the count numbers of a photomultiplier is a Poisson distribution whose parameter $\lambda$ equals to the square-root of the number of counts.(e.g. ...
1
vote
4answers
228 views
Statistics in physics
What are the uses of statistics in physics? I am about to embark upon a study of statistics and I would like to know what the particular benefits I gain in physics.
2
votes
1answer
122 views
Peak deconvolution [closed]
I need some help understanding how much information I can pull out of this data. I have a sample made up of two materials. Materials A and material B. Then I took a picture of the sample.
The two ...
5
votes
2answers
110 views
Averaging decibels
Wikipedia:
The decibel (dB) is a logarithmic unit that indicates the ratio of a
physical quantity (usually power or intensity) relative to a specified
or implied reference level.
If I ...
7
votes
2answers
1k views
How do we know that some radioactive materials have a half life of millions or even billions of years?
If a radioactive material takes a very long time to decay, how is its half life measured or calculated? Do we have to actually observe the radioactive material for a very long time to extrapolate its ...
1
vote
0answers
28 views
Half-Life Question [duplicate]
Possible Duplicate:
How do we know that some radioactive materials have a half life of millions or even billions of years?
I understand how to calculate decay, but it seems to me that the ...
1
vote
2answers
69 views
What is the Schechter luminosity function's domain of support?
I'm trying to fit a Schechter luminosity function to some data points, but it's not clear from this definition what the domain of support of the PDF should be. I'm familiar with the standard Pareto ...
3
votes
3answers
258 views
How to compute the expectation value $\langle x^2 \rangle$ in quantum mechanics?
$$\langle x^2 \rangle = \int_{-\infty}^\infty x^2 |\psi(x)|^2 \text d x$$
What is the meaning of $|\psi(x)|^2$? Does that just mean one has to multiply the wave function with itself?
1
vote
1answer
90 views
How to interpret a negative failure rate?
In statistical engineering the "hazard rate" of a distribution is defined as:
$$r(x)=\frac{f(x)}{1-F(x)}$$
where $f(x)$ and $F(x)$ are the PDF and CDF. Basically $r(x)$ is the odds that, having ...
0
votes
0answers
53 views
Data set from Nanotechnology/Science Experiments
Does anyone know a source where I can get hold of data sets (or papers) generated from nano experiment. To give some examples:
1) Suppose in an experiment, the goal is to produce nanowires or ...
-1
votes
1answer
83 views
Fitting of exponential data gives me a constant function [closed]
I conducted an experiment, where a capacitor is discharged over a (big) resistor for $t$ seconds and then the remaining charge is measured with a ballistic galvanometer. The data I have is:
...
3
votes
3answers
1k views
What are distinguishable and indistinguishable particles in statistical mechanics?
What are distinguishable and indistinguishable particles in statistical mechanics? While learning different distributions in statistical mechanics I came across this doubt; Maxwell-Boltzmann ...
2
votes
2answers
99 views
What is the relation of the release time of fossil fuel emissions to climate change? [closed]
This question presupposes that
The amount of fossil fuels on earth is limited
Mankind will burn all of its fossil fuels eventually
Based on these presuppositions, the total amount of CO2 released ...
0
votes
0answers
203 views
Intensity of the diffraction pattern of the double slit
I am trying another approach for my last unanswered question. (Bounty still on for 3 days. Anyone? Please?) Note that this is not the same question but a greatly simplified version concerning a much ...
2
votes
1answer
131 views
How do you determine the degree of localization of a wavefunction?
Suppose that there is a wavefunction $\Psi (x,0)$ where 0 is referring to $t$. Let us also say that $a(k) = \frac{C\alpha}{\sqrt{\pi}}\exp(-\alpha^2k^2)$ is the spectral contents (spectral amplitudes) ...
4
votes
2answers
192 views
What do “local” and “global” mean when talking about standard deviations in experimental particle physics?
I found the following sentence:
The excess is most compatible with a SM Higgs hypothesis in the vicinity
of 124 GeV and below, but the statistical significance (2.6σ local and 1.9σ
global after ...
2
votes
2answers
122 views
Wave Function Statistical Interpretation vs Oscillation Interpretation
Can the wave function solution to Schrodinger's Equation be interpreted as an oscillation between all possible measurements (obviously with some type of weighting that would describe the shape of the ...
2
votes
0answers
69 views
Randomly sampling a “well-mixed” solution of Brownian particles
I place $N$ Brownian particles in $V$ liters of solution, shake until I assume that the particles are "well-mixed", and sample and randomly sample an $S$ liter volume. What is the probability ...
1
vote
2answers
121 views
How to decide convergence of the ensemble average in a Monte Carlo process
I am simulating electromagnetic scattering off a rough surface. The usual process is to do a Monte Carlo simulation, which is briefly described as follows.
Generate a randomly rough surface, and ...
2
votes
2answers
159 views
Average Neighbouring Impurity Separation in a Random 1D chain [closed]
I have a finite and discrete 1D chain (edit: linear chain, i.e. a straight line) of atoms, with unit separation, with a set number of impurities randomly distributed in the place of these atoms in ...
1
vote
1answer
68 views
Computing an average escape distance for a particle
Somewhere in a two dimensional convex bulk of particles (pic related) on a random position a reaction takes place and a particle is sent out in a random direction with a constant velocity $v$.
What ...
6
votes
2answers
286 views
Use of Monte-Carlo simulation in High-energy Physics
I've been doing some research into the analysis used in particle physics when determining the significance of a finding (e.g. the recent Higgs candidate was announced as a boson in the 125-126 ...
0
votes
2answers
58 views
What is the minimal set of expectation values I need in a statistical model?
At least if $\vec v$ is really only a one dimensional parameter, measuring all the moments $\langle v^n \rangle_f$ seems to give me all the information to compute $\langle A \rangle_f$ with $A(v)$ ...
2
votes
2answers
513 views
Combining multiple theories with 5 $\sigma$ confidence level
Sadly I am not a physicist but I am interested in the topic. Please have mercy with me if you find my question trivial or dumb. Here it comes:
As far I understand physicist express their certainty ...
1
vote
0answers
62 views
polynomial fit and uncertainty [closed]
I am trying to fit a polynomial function by least square method and I want to know the uncertainty on my fitting parameters. In which book can I find a clear answer?
4
votes
3answers
259 views
why the difference between $\langle \hat p^2 \rangle_{\psi}$ and $\langle \hat p \rangle_{\psi}^2$ is NOT zero?
Well, the difference between the two expressions $\langle \hat p^2 \rangle_{\psi}$ and $\langle \hat p \rangle_{\psi}^2$ is exactly $\Delta p^2$ , i.e. the squared uncertainty (variance) of the ...
1
vote
1answer
108 views
Lacking of scale and distribution moments
Given a physical random variable x, $E(x)$ and $E((x-<x>)^2)$ defines mean and variance. From a statistical point of view variance represents the statistic error (isn't it?). If variance is not ...
1
vote
0answers
51 views
Fitting of data to a model
Imagina that I have some observable value predicted with a theory for some process to be:
1+a x + b x^2 and observed value is 1.3 with an error 0.2; a and b are some numerical constants. I also have ...
