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Questions tagged [data-analysis]

Use for question relating the the techniques of data analysis.

Use for question relating the the techniques of data analysis.

The art and craft of turning the collected pile of numbers into a clear statements of what physics was or was not observed, and making those results comparable to theoretical expectations.

There is a huge body of work on this, even when separated from the indispensable tools of statistics and error analysis.

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How do you make more precise instruments while only using less precise instruments?

I'm not sure where this question should go, but I think this site is as good as any. When humankind started out, all we had was sticks and stones. Today we have electron microscopes, gigapixel cameras and atomic clocks. These instruments are many…
Vilx-
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How exactly do you avoid fooling yourself?

In cargo cult science Feynman writes: "Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off, because he had the incorrect value…
Trevor Andrade
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How do we know the LHC results are robust?

Nature article on reproducibility in science. According to that article, a (surprisingly) large number of experiments aren't reproducible, or at least there have been failed attempted reproductions. In one of the figures, it's said that 70% of…
Allure
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How seriously can we take the success of the Standard Model when it has so many input parameters?

The Standard Model of particle physics is immensely successful. However, it has many experimentally fitted input parameters (e.g. the fermion masses, mixing angles, etc). How seriously can we take the success of the Standard Model when it has so…
Solidification
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Easy to perform quantitative experiments at home

What are some easy to perform physics experiments that can be done at home (with not too much special equipment) and that allow to actually measure/plot data and draw conclusions from it? My son is pretty interested in everything physics and we've…
user1583209
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Least squares fit versus averaging

Suppose I want to find the spring constant of a spring from measured $F$ and $x$ data points. There are two basic ways to do this. I could calculate the spring constant for each data point and average the results. $k = \frac{1}{N} \sum_i…
Luke Pritchett
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How do you find the uncertainty of a 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 measurements can be combined to give a weighted average.…
Jonathan Gleason
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Line of Best Fit with or Without Constant Term

Some other physics teachers and I were discussing an AP problem about a potential experiment for measuring $g$ and disagreed on the best way to use a line of best fit to analyze the data. The experiment measures the acceleration of an Atwood machine…
Luke Pritchett
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Is there any advantage in stacking multiple images vs a single long exposure?

Suppose I have a source object that is not time varying, to be concrete let's say it's a galaxy. Is there anything additional that can be learned or done with multiple short exposure images of exactly the same field as compared to a single long…
Kyle Oman
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Did the researchers at Fermilab find a fifth force?

Please consider the publication Invariant Mass Distribution of Jet Pairs Produced in Association with a W boson in $p\bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV by the CDF-Collaboration, already with huge media attention. I must admit that I am…
Robert Filter
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Spinning gyroscope loses weight?

I ran two tests with a toy gyroscope spinning on a weighing scale that is accurate to $1$mg. The scale was reset to zero before the tests. The gyroscope was flipped over between test $1$ and test $2$. Each test consisted of $100$ weight readings…
John Eastmond
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When to average in the lab for indirect measurements?

I am measuring distance and time to calculate the velocity. I repeat the experiment 10 times. What is better, to first calculate the average of distance and time and then the velocity, or to calculate the velocity ten times and then average the…
jrglez
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Plotting the CMB power spectrum - Why $C_\ell \ell (\ell+1)$ rather than only $C_\ell$?

I can't find any convincing answer for the following question : Why do we always (or often) plot the CMB power spectrum in this way? I mean the vertical axis is $C_\ell \ell (\ell+1)$ and not only $C_\ell$. Why? I know it's because of the scale…
AnSy
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Which areas in physics overlap with those of social network theory for the analysis of the graphs?

I am studying social networks in terms of graph theory and linear algebra. I know that physicists have published and worked a lot in this field. This causes me to assume that there are sub-fields in physics which overlap in the essence of their…
Vass
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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, consider experiments in particle physics. This…
Comp_Warrior
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