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0answers
11 views

Starter projects/visualizations/analyses?

I just renovated a desktop that had been in storage for a while and I am looking for good ideas for data analysis or numerical analysis projects in physics. I have taken up to E&M, and special ...
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0answers
11 views

Data analysis for a magnetic hysteresis loop

I'm a physics undergrad and I have MOKE data for a magnetic material (thin permalloy film on a silicon substrate). Here is one of the hysteresis loops I obtained, plotted using python: The form of ...
2
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1answer
31 views

What does it mean for a map to be “coadded”?

So there is this wiktionary definition of coaddition, but it's rather brief. Could anyone expand on this, perhaps giving a short example and explaining why its useful? The context that I initially ...
1
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1answer
33 views

Karhunen-Loeve transform of a repeating process

This question is inspired by measurements of an unsteady flow. I have some doubts about interpretation of principal component transform using Karhunen-Loeve theorem. I have (centered $\equiv$ zero ...
-1
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1answer
76 views

Decide Refractive index of a unknown piece of glass [closed]

Problem: The task is to find $n_2$ by Fresnel's equation from given data. My attempt at solution: I begin from this equation: $$R= \left|\frac{(n_2\cos\theta_i - n_1\cos\theta_t)}{(n_2\cos\theta_i ...
3
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2answers
64 views

What exactly is an arbitrary parameter?

I was reading the article Turning Points: A meeting with Enrico Fermi by Freeman Dyson (available e.g. here), and I had a question about Dyson's use of the term 'arbitrary parameter'. More ...
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0answers
14 views

Gamma spectroscopy - Extractable information from peak significance changes?

Apologies for the title - I couldn't think of a better way to summarize my question I have a table which contains information on 60 gamma spectra taken over a total period of 20 days, from the hall ...
3
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1answer
27 views

Machine readable database of gamma lines

Friends of mine did a lab experiment where they recorded $\gamma$-spectra in the range from 0 to 1500 keV with a soil sample. The data contains some background and a couple sharp peaks at different ...
1
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2answers
27 views

Gamma spectroscopy - Fitted Singlet

I'm using some gamma acquisition and analysis software. When I ask the software to do some sort of Nuclide Identification, almost every single peak in the generated output is marked with "F". ...
1
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1answer
45 views

Error in total counts

I'm performing a radioactivity experiment where I measure a specific number of counts in some time period t. Later on I take the total count rate. (Number of counts/time: $N/t$) I'm supposed to find ...
5
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3answers
738 views

What does it mean to “bin” in a spectroscopy context

In the following online article http://www.star.le.ac.uk/~sav2/stats/a.html I see the word "bin" used, in relation to x-ray spectroscopy, both as a verb and as a noun (people both "bin" things and ...
0
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2answers
29 views

Filament lamp $(V,i)$ behavior between 0 and 1V

I was wondering why the behavior is more "chaotic" at 0~1V when compared to 2V+ (which is when it starts to glow).
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1answer
44 views

Need Some Help Creating A Couple Of Equations [duplicate]

I've posted about this project before as math is not at all my strong subject anymore. I have a couple sets of data and I need to make some equations for them. I've used Excel to get trend lines, but ...
0
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2answers
70 views

Gamma spectroscopy - Do annihilation photons produce a backscatter peak?

Below is a diagram of part of a structure which I find in a gamma spectrum taken from a hall in which a neutron source is undergoing spallation. The structure which I'm interested in can be seen ...
3
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0answers
135 views

Free-Fall Lab Help - Getting weird results

So, I am doing a free-fall lab for my physics class. We got the values and I have the results here(we used a infrared photo-gate). Basically, we have a brass cylinder and a wood cylinder. Each are ...
2
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0answers
29 views

Searching for a textbook on Imaging

I'm hoping someone can recommend a book that will cover the physics involved in optical range image capture. I have a degree in physics, so I am looking for something on the technical end. To expand, ...
0
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2answers
124 views

Help Writing An Equation [closed]

Truthfully, math past basic algebra was never my strong suit even though I went through stats in college. So I have to write an equation for this for a program and could use some help. I am reading ...
0
votes
2answers
36 views

How does my reference point affect the regresion of data about Hooke's law?

A vertical spring is used (subject to a universal support) whose length is $20$ $cm$ when no force is acting on it. We put on a weight of $1$ $N$ and the new length is $22$ $cm$. When writing the data ...
2
votes
1answer
43 views

Measurements and errors

I've measured several values of $V$ and $I$ in a simple circuit to determine de value of a resistance $R$: $$R=\frac{V}{I}$$ I have a list of points $(V,I)$ with their corresponging error (from the ...
2
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0answers
42 views

Estimate Uncertainties in Rietveld Refinement

I have the output of an x-ray diffraction experiment made on a thin film. Here I report the output of the experiment (I analyzed those data using powdercell and coloured regions have been excluded ...
2
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0answers
37 views

Determining the spatial imaging resolution based on a pinhole diffraction pattern

I aimed a 780 nm/1mW laser at a 1μm pinhole and took a picture of it using a lens and a CCD camera. The magnification of my imaging system is ~25 times. I wrote some code that takes the image of the ...
0
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2answers
77 views

How to find time when temperature crossed certain threshold?

I have a data from experimental system concerning temperature of molten lead. In this system, temperature is increased in one place and then is measured when this increase of temperature travels to a ...
0
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1answer
148 views

X-ray diffraction on thin film

As far as I am concerned, when we perform an X-ray diffraction experiment using a Bragg-Brentano diffractometer using the "powder method" we have that the scattering pattern depends on only one angle ...
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0answers
32 views

Estimation of source irradiance given the spectral sensitivity of the instrument and spectrum of the source

I am trying to measure the irradiance of a UV source, but the available instrument has a different sensitivity. Suppose the black line corresponds to the spectral sensitivity of the instrument ...
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0answers
25 views

Multivariate Analysis: how to start

I'd like to start to know something about Multivariate Analysis before studying this guide..something like a "Primer"... Could you suggest me a link, a file? Thanks!
0
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1answer
677 views

Terminal velocity of a steel ball in water [closed]

I am investigating on the terminal velocity of steel balls moving in water. I used the balls with different diameters, such as 3.17mm, 6.02mm, etc. And I used a full-filled 1L graduated cylinder. I ...
4
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1answer
308 views

White Noise Generator Through Low Pass Filter - Autocorrelation of normalized data dropping below 0 (showing negative correlation)

I am doing the following experiment: http://physlab.lums.edu.pk/images/a/ab/Correlation.pdf It is basically a white noise generator running through a low pass filter. Sample voltages are taken and ...
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0answers
27 views

Significance of a specific event in background data, only described by time stamps

I got a problem in analyzing data. The data only consists of time stamps in Unix Time, when a event was measured with a detector. There are multiple detectors around, a part of them is measuring the ...
1
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1answer
59 views

Log of a quantity and graphs in log-scale

Is there any difference between taking the logarithm of a quantity, and plotting a quantity in logarithmic scale?
0
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0answers
42 views

Simple question relating to physics prac reports

I am writing a physics practical report relating to the elasticity of materials relating to their momentum in a collision. I have values for the elasticities that are all within 2% of each other but I ...
1
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1answer
162 views

Calculating jerk vs Fitts law for smoothness

I've tracked the movement of an input method resulting in this dataset. All data is tracked with equal intervals of 100ms. For example an iteration value of 4 means that this is the position of the ...
5
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1answer
163 views

Statistical significance in Z boson excess paper

In a recent ATLAS paper, a excess of $3\sigma$ was reported from the Standard Model prediction in a search looking for a same-sign dilepton signal with an invariant mass around the Z peak. For brevity ...
0
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1answer
61 views

How to turn this into a straight line

Right now, I am trying to turn my graph (which looks like a exponential graph) into a straight line graph, which starts at the origin (0,0). How would I do this? My values are given in the attachment, ...
0
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1answer
59 views

How to derive time derivate of strain?

Data Time(s) Strain ----------------- 100 0.31 200 0.52 300 0.74 400 0.92 500 1.10 600 1.28 700 1.46 800 1.64 900 1.82 1000 2.00 I want to deduce ...
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0answers
33 views

Data Collection of oscillatory motion

I'd like to study nonlinear oscillatory motion this semester. I plan to build several different mechanical systems (pendula, masses on springs, etc with and without driving forces, large/ small drag, ...
3
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1answer
95 views

How to make sure that two electrons collide head to head?

In high energy experiments, people smash particles into particles. But how to make sure that they really run into each other, instead of just passing by?
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0answers
56 views

Measuring typical distance between patches using 2D Fourier Transform

I need to extract information about the typical distance between the black patches in an image like the one I attached here. I tried to perform 2D FFT on it (using OpenCF fdt function in Python), but ...
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0answers
71 views

Help Interpreting Ultraviolet Photoelectron Spectroscopy (UPS) data

I was given a batch of UPS data without any background other than the materials examined and I don't have any experiencing interpreting it. I wanted to reach out to some experts (hopefully, someone ...
0
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1answer
86 views

How experimentalists put bounds on new physics at the LHC?

I would like to understand how experimentalists search for new physics at the LHC. Lets imagine I want to use the LHC data to put a bound on the coupling of some new physics effective operator, say, ...
2
votes
2answers
97 views

Weighted mean from data [closed]

Suppose we have 3 experimental groups measuring "x", they measure $$x_1=\mu_1\pm \sigma_1$$ $$x_2=\mu_2\pm \sigma_2$$ $$x_3=\mu_3\pm \sigma_3$$ In the 3 experiments, we have done N measurements of ...
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2answers
62 views

How to find gravitational acceleration given $k$ in a power function

I have a problem that has been bugging me for a week, and I can't figure it out. We know the power function: $$ y=kx^n $$ I also have a set of data: I took the natural log of both of these data ...
1
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1answer
31 views

How do I make a Gaussian process generate a stream of events?

I would like to generate a stream of "random" gaussian events (on for event - off for no-event) that obeys a set standard deviation and mean. what algorithm could I use? thank you
8
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2answers
349 views

Arrhenius Fit: Linear or exponential form?

I have a seemingly easy question about performing an Arrhenius fit to the equation $$y = A \times \exp \left( -\frac{E_A}{RT} \right)$$ I can either fit this in the exponential form using a ...
3
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3answers
811 views

Should a Gaussian Curve Always Be Drawn Symmetrically?

This question is more about the appearance of a curve that comes up while I am analysing my data rather than an actual physics question, but I think it's relevant. I have analysed some data from an ...
1
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0answers
61 views

Manager for results of physical simulations [closed]

I have quite a general question. I'm phd student in the field of plasma physics, our team has developed a numerical simulation of a diagnostic method in plasma (langmuir probes), written in fortran. ...
0
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1answer
83 views

Can this type of graph be analysed to produce any meaningful data?

The above is a graph of pendulum length on the x-axis measured in metres, and pendulum period on the y axis measured in seconds. The pendulum period is not squared. If I square the pendulum period, ...
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0answers
59 views

Looking for binning software [closed]

I'm looking for a software which should do the following Take a set of data $X$ and $Y$: Procedure A Finds the max and min in $X$ Divide this interval in a number of bins chosen by me For each bin ...
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2answers
252 views

Does $R=\dfrac{4q^2}{\pi^2a^2gH^2}$ suggest a square root relationship?

I did an experiment involve how R scales with q (the other variables are constant), and I got a relationship like $R\ \propto \sqrt q$ I have been told to evaluate my findings with those in ...
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2answers
76 views

How do you measure neutron energy?

I think you can detect a neutron event with a scintillator (neutron to photon), photomultiplier tube (photon to electric signal) system, but how would a fusion neutron's energy (2.45 MeV) be typically ...
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2answers
47 views

Peak at zero in one device and not the other

I was wondering if anyone could shed some light on this problem. I have placed two accelerometers on an animal one sampling at 50 Hz the other at 100 Hz. They were placed in the same position. I then ...