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0answers
398 views

What about assessing negative Limit of Detection for concentration

I recently came in a work-group discussion where I think some concepts are misused. After seeking for scientific articles on the subject I have found that part of the problem is definition (what ...
4
votes
1answer
307 views

How do I calculate the experimental uncertainty in a function of two measured quantities

I am performing an experiment where I'm measuring two variables, say $x$ and $y$, but I'm actually interested in a third variable which I calculate from those two, $$z=f(x,y).$$ In my experiment, of ...
3
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1answer
240 views

Rutherford Experiment - practical and theoretical questions

I performed the Rutherford experiment the other day, using Au thin foil of $2\,\mathrm{\mu{}m}$, a source/gun of α particles (241Am) and a detector/counter. α particles were shot from the source ...
6
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0answers
113 views

Textbook about the handiwork of a HEP analysis?

I'm wondering if there is a textbook that describes the handiwork of a particle physics analysis. There are a bunch of books about theory, about the experimental aspects like detectors, and about ...
5
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1answer
266 views

Advanced data analysis in Physics experiments

Before answering, please see our policy on resource recommendation questions. Please try to give substantial answers that detail the style, content, and prerequisites of the book or ...
3
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0answers
61 views

Converting impact speed to pressure magnitude

In explosive safety and stability testing, a drop test is commonly used to determine the sensitivity to impact. In the test, an impactor of known mass is dropped. The initial height varies throughout ...
1
vote
0answers
90 views

What could be the distribution of an explosion energy of a mining-grade and seismic exploration explosives?

Seismic exploration involves the excitation of seismic waves using the industrially made explosive charges. What could be the distribution of explosion energy of such a charges? My guess is that it ...
0
votes
2answers
280 views

1/r Counting Rate for Radiation Experiment

In an experiment performed in the lab, I want to justify that, when the width of the Geiger counter window is approximately the same size as the distance between the window and a mildly radioactive ...
2
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0answers
26 views

Expression for combining several probabilities in a single discriminator

I'm doing an analysis of some experiment. Details are not very important, but I've stumbled on an expression that I cannot make sense of. I have several simultaneous measurements of a certain ...
1
vote
1answer
105 views

Curve Fitting and Multiple Experiments

Say I do an an experiment 5 times, each of which gives you a list of data points. Do I fit a curve to each one separately and then average the parameters and their uncertainties? Or do I take the ...
2
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0answers
70 views

Where can I get latest full updated list of supernovae candidates from the SDSS-II Supernova Survey?

I am doing a project where I need the list of supernovae candidates from the Sloan Digital Sky Survey II (SDSS-II) supernova survey. One list is available as part of the data-release-7 (DR7) website. ...
1
vote
1answer
22 views

Choice of color for graphs with filled area [closed]

I am writing an article and the central results are summarized in a graph so I want it to be very beautiful and physically intuitive. It has 3 regions in which a certain quantity is conserved, ...
2
votes
1answer
120 views

What are anticipated events and experimental uncertainty?

I am working on this lab that involved gathering data from two different sources. It involved gathering reaction times from a device and from a web application which was put into our data sets. It is ...
0
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0answers
84 views

Where can I find how to do data analysis for a magnetic hysteresis loop?

I am given a data set that has a hysteresis loop but there's a diamagnetic signal that I understand needs to be subtracted, but I don't know the how this is done. I remember finding the slope of the ...
2
votes
1answer
49 views

Asymmetry in muon energies of public CMS dimuon event data

CMS published for educational purposes (caveat) 100.000 dimuon events: https://cms-docdb.cern.ch/cgi-bin/PublicDocDB//ShowDocument?docid=11583 As one easily sees, column 4 shows the first muon's ...
11
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1answer
289 views

Statistical analysis of data in Physics

Analysis of data is integral in bridging the gap between theory and experiment. How much do the results of the analysis depend upon the choice between Bayesian and frequentist methods? For instance, ...
0
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0answers
3k views

How to calculate lattice parameter of wurtzite struture

I am trying to calculate lattice parameter of ZnO (wurtzite). I have found out the formula for calculating lattice parameter of this system from a research article. $\frac{1}{^{d^{2}}}=\frac{H ^{2}+ ...
1
vote
1answer
657 views

gaussian fitting of xrd peaks

I am reading a paper regarding the nano crystalline material with hexagonal crystal structure. In that paper in order to find out lattice parameter of hexagonal crystal structure they have fitted a ...
3
votes
3answers
2k views

What does a curved natural log graph suggest?

Sorry if this is rather simple, but I've only just started learning about using logarithms in experimental physics. I did an experiment to test the amount of time it would take for an amount of ...
0
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0answers
117 views

Short term track of a hand held sensor (gyro, accelerometer) data with rough precision

I have acceleration and attitude data for the movement of a device in 3d space. what transformations, before numerical integration, are required, in order to produce a 3D track of the the movement in ...
3
votes
1answer
129 views

Galaxy Kinematic Fitting: How to deal with Point Spread Function (PSF)

The past few months I have been studying astronomy and Integral Field Spectroscopy (IFS). What I want to do is to fit a galaxy kinematic model to data (ie: estimate the model parameters that give the ...
1
vote
1answer
74 views

Interpreting the results

I have preformed the muon lifetime experiment at my uni's lab, and got the data. It's text file with 8190 numbers. My TDC unit was set so that the time gates were at 10 $\mu s$, and it has 8192 ...
3
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0answers
163 views

Production vs. Collection, and Contaminants vs. Depositions, what might be missing in cold fusion research

I though cold fusion and LENR were discredited, but just a few days ago I found out that NASA is claiming LENR is real. So I thought if they're detecting something, what could it be, and why wasn't it ...
3
votes
1answer
439 views

How to determine frequency components present in distorted signal, with the set of possible components already known?

I am trying to choose the best approach to digitally analyse a signal, which is a mix of an unknown number (but less than 16) fundamental signals at specific frequencies (e.g., sines). The goal is ...
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vote
1answer
2k views

Uncertainty in Acceleration given the uncertainty in position

I had a motion detector record the position of a dynamics cart and automatically plot Position vs Time and Velocity vs Time plots in Logger Pro on the computer. If the instrument uncertainty in ...
3
votes
1answer
296 views

What algorithms are used for track reconstruction in cloud chambers?

In particular I'm interested in any algorithms that can separate multiple tracks from one another reliably.
1
vote
1answer
109 views

More points vs. precision

I have a dilemma. In my lab exercise, I was measuring spectra with HPGe detector of several sources (gamma spectroscopy). To determine the energy of the unknown spectrum I first needed to calibrate ...
0
votes
1answer
211 views

Dealing with experimental data

I have some experimental data about a value $n$, now, I am supposed to give, in the ending, a single value with an error: $n=a\pm b $. I have originally 6 values of $n$, each one comes as an indirect ...
2
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2answers
10k 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 ...
1
vote
0answers
73 views

How to calculate the correct coordinates from a distorted video of a projectile?

I am working on a high school project that is related to projectile motion. I am exploring how exactly the position of the center of mass affects the trajectory of a long but thin, javelin-like ...
5
votes
1answer
167 views

Data requirement to determine proportionality

A common result of theoretical analysis in physics is some sort of relation derived from physical parameters and typically expressed in the form of a non-dimensional parameter. These scale relations ...
0
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3answers
124 views

How to find exponential values

I have a power equation for flow between two circular disks on a common axis as stator and rotor, which follows, $$P = \frac{n^a}{G}\tag{1}$$ Where: $P$ = power, $n$ = revolution (1200 rev/min), ...
0
votes
1answer
259 views

Analysis of the impulse of 2 colliding carts under the effect of magnetic repulsion

Hi there! I have a question about an experiment that was conducted. It is related to momentum. 2 carts were put on a track on opposite sides. They were then propelled towards one another at ...
3
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0answers
155 views

Obtaining point of application of Ground Reaction Force with use of a hyperstatic load-cell array platform

I'm looking for the theory of an experiment that is giving me a hard time to perform. I have an instrument composed of a rigid horizontal square plate rigidly supported under each corner by a ...
2
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1answer
143 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 ...
0
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2answers
365 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 ...
-1
votes
1answer
737 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: ...
2
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0answers
295 views

How do I do error calculus right using gnuplot as an example?

Given is a set of measurements with their respective errors for example an energy spectrum. In gnuplot one is to fit a function $ f(x;\{p_i\})$ depending on a variable $x$ and on fit parameters $p_i$. ...
3
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1answer
643 views

Lab observation correct? As distance decreases, velocity increases, stderr decreases

The experiment goes like this: Allow a moving cart to move from the top of an incline plane ($x_0$) downwards. The time taken will be recorded by the picket fence (those things you see wired up). ...
1
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0answers
157 views

Digital camera as a measurement device [closed]

It is know that digital camera is not the best device for quantitative measurements. However, it is often used in all sorts of atmospheric physics research, maily due to: Low cost and availability. ...
0
votes
1answer
314 views

Implementing a black-body using Planck's Law in a 3D ray tracer

1_ In one of my software projects, I need to implement Planck's Law in terms of wavelength. I can't be sure if it's right because I've seen different variations of it, and all the implementations ...
0
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3answers
74 views

fit funtion to the Sun electron fluxes data

I'd like to fit a function to the Sun's electrons flux data (blue dots), please note that x,y axis are in the log scale. The green dots are the "best" fit from the gnuplot program. I have taken the ...
11
votes
2answers
801 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 ...
3
votes
1answer
97 views

Measuring tensor rank of the Higgs resonance

The Higgs boson is the first scalar field ever measured that is fundamental rather than composite. How do high-energy physicists determine that a given resonance in the statistics is either a scalar, ...
1
vote
0answers
91 views

Fitting of data to a model

Imagine 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 ...
1
vote
1answer
119 views

Variance of Nested Experimental Uncertainty

I have to find the uncertainty of a quantity $Q$ doing two mean values. For example for a set of parameters I measure ten times $Q$, I obtain a mean value $Q_1$ and variance ${\rm Var}(Q_1)$. Then for ...
4
votes
1answer
428 views

Pendulum: Deduce proportionality from experiment

I know, very easy for all of you, but I'm a beginner in physics ... ;) I have to work with the mathematical pendulum. After some experiments (changing mass, chaning pendulum's length etc.), I could ...
0
votes
3answers
383 views

Sunspots formula

I used the package 'EUREQA', version Formulize, to analyse the monthly smoothed sunspot timeseries from 1750 till 2010. It gives me a simple formula, with 8 coefficients, that match data with a ...
4
votes
2answers
692 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 ...
5
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1answer
411 views

Finding coefficient of proportionality

Recently in my AP Physics class I did a lab in which I measured k for a spring by setting up an oscillating system with it, and timing the period, repeating for different masses. Since ...