Questions tagged [data]

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1answer
31 views

What is effective mass of electrons and holes at room temperature of Al${}_{0.52}$In${}_{0.48}$As?

I'm searching for those values, but usually they are given at very low temperatures, usually 77K or 4K. I'm looking mostly for bulk values. I was thinking of applying Vegard's law to AlAs and InAs... ...
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2answers
156 views

Does data compression require energy? [closed]

Suppose I have a $C=1TB$ hard drive $H$, filled to the brim with English text. I'd like to compress this. Suppose the hard drive consists (abstractly) of zeros and ones, and that the number of ones in ...
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0answers
20 views

Selecting graph axes

Hi everyone I think the following graphs for a pendulum and potentiometer are equivalent but when I graph them using Excel I get different curves. I've already checked my dataset and you don't really ...
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1answer
43 views

What’s the difference between ‘decimated‘ and ‘undecimated’ data?

How is ‘decimated’ data different from ‘undecimated’ data?
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10 views

Where can I find the specific details of a gravity assist space mission?

I am writing a research essay where I need to know the specific details of a gravity assist mission such as Voyager 2's flyby of Jupiter for example (but any mission would work as long as it is a ...
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0answers
18 views

$N$-body simulation with varying neutrino mass

I am trying to find a picture of the $N$-body simulations that shows the LSS. Particularly I am looking for different neutrino masses without the CDM. For instance pictures likes this But with more ...
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1answer
38 views

Is there an authoritative data source for EM spectrum assignments?

I'm working on some software to coalesce various standard constants (eg SI, CODATA, AME) into an easy-access library. However, trying to find an authoritative source I can find for EM spectrum ...
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0answers
14 views

Any Open Source ship motion libraries

I wish to generate high volumes of fictional ship/maritime vessel track data - periods of several hours of random manouevres. At one level it's quite easy, since ship motion can be represented via ...
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1answer
51 views

Where could I find a reliable source that states all the existing radioactive decays?

According to searches on many sources on the web and books, I could merge informations to deduce that the general possible radioactive decay modes are the following: $\alpha$ (proof that this is a ...
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1answer
29 views

What is a good database of galaxy luminosities?

I need to do some mass/luminosity relationship calculations. Where can I find good, referenceable absolute luminosity data?
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1answer
18 views

Analysis with CMB Data

I have read about Cosmic Microwave Background Radiation from Weinberg's Cosmology Book. I'm looking forward for specific resources to analyse real time CMB Data recorded by Physicists. Any papers, ...
1
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1answer
26 views

Understanding the 2007 PDG-Review on Constants

I have a question concerning the following table: http://pdg.lbl.gov/2007/reviews/consrpp.pdf Let's take the Weinberg-mixing angle as an example, whose sine-squared is stated as $$\sin^2 \theta_W = ...
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2answers
24 views

Finding Value for Sine Squared of Weinberg-mixing angle

I am searching for an official value of $\sin^2\left(\theta_W\right)$ with an error estimate, where $\theta_W$ is the Weinberg-mixing angle. Since I didn't find this value in books, I searched on the ...
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0answers
31 views

Coefficient of static and kinetic friction of brass over aluminium, brass over wood and brass over perspex plastic

Hi can someone please help with a reference to the following constants static and kinetic friction of brass over aluminium, brass over wood and brass over perspex plastic. I am just looking for a ...
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0answers
26 views

Causes of dB level increasing over distance from source?

I was given some data taken from three microphones placed at three different distances (25, 50, 100 ft) from the railroad track. The sound level increases by 7 dB from 25 to 50 feet and about 1.5 dB ...
12
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2answers
3k views

Can data be transferred using the strong force?

We send data using the electromagnetic force, mainly over the form of radio waves, though this could be and is (mostly for human viewing of images) done with visible light. However, I want to know if ...
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0answers
30 views

How to compute spectral lines from NIST term data?

We know, that Hydrogen has line of 21cm in space. How can we (and can we) find the energy levels, producing these lines in NIST energy levels database? Other example. We know that Nd:YAG laser emits ...
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2answers
29 views

What does a negative percentage difference tell me about my results?

If I am trying to determine the percentage difference between two values, and I get a negative value for the percentage difference between two results, generally speaking what does a negative value ...
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0answers
22 views

Where can I find the star distribution data of our galaxy?

I am doing some research on dark matter and for that I need data of star distribution in our Galaxy. Is there any mathematical law that predicts the distribution pattern of stars in our Galaxy?
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2answers
59 views

Linear Regressions vs Algebra & Averaging in Solving for a Constant

I'm current taking AP Physics, and in both of the labs performed so far (Snell's Law/Refraction and Galileo's Inclined Plane), I have been trying to calculate some constant from a linear relationship ...
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0answers
17 views

Where can I download a simulated CMB map?

I tried looking for non-gaussian map but couldn't find one. I would also appreciate if someone can guide me on how to convert a map in fits format to the map array.
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2answers
394 views

Calculate acceleration and lateral G force from GPS coordinates [closed]

I have a data logger that records time (in tenths of seconds), latitude and longitude. I would like to calculate my acceleration and lateral G force based on the collected data. Is someone able to ...
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0answers
46 views

Where can I find the latest, cleanest data set of Planck CMB data?

In order to better understand the spherical harmonic math, I would like to build a temperature power spectrum chart from the temperature data. I want to be able to generate the $D_l$ data in the ...
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1answer
115 views

Should the electrical charge of $\pi^+$ (positive pion) be considered exact?

According to https://en.wikipedia.org/wiki/Elementary_charge, IIUC, electrical charge of an electron should be considered an exact value of 1.602176634 coulombs instead of an experimental value with ...
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0answers
31 views

The number of particles in PDG, and what the data includes

I checked here for computer-readable PDG particle data, and count about 174 unique particle IDs there, which seems like an awfully small number of particles to be "every particle type there is in the ...
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0answers
22 views

What Dimensionality Reduction method I can follow on a dataset that has Physics Parameter?

I am trying to model data related to Locomotive Train. We have a various set of parameters and we have the possibility to generate a few more parameters from this. Our model is currently using a lot ...
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1answer
39 views

Self-regulated stepwise evolution

Are there empirical examples of self-regulated punctuated evolution (with time)? This is when a quantity grows over time in a stepwise fashion, with each growth step having less amplitude than the ...
2
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2answers
95 views

Uncertainty for a given value

While including a data table for a lab report, the guidelines asked to include an uncertainty value for each raw data. In this particular lab where we used slotted masses the masses were already given ...
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1answer
66 views

How do LF Radio waves send data?

Excuse me I am a complete beginner. If LF radio waves are sent with let’s say frequencies of 100 kHz, how can data be modulated to that signal considering the signal is so long? For example, how can ...
2
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1answer
51 views

What's the mass of $D_1(2430)^{\pm}$?

What's the mass of $D_1(2430)^{\pm}$? The standard reference http://pdglive.lbl.gov/ParticleGroup.action?init=0&node=MXXX035 only shows the data for $D_1(2430)^0$ but not for $D_1(2430)^{\pm}$. ...
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1answer
170 views

Double slit experiment/ fitting data to complicated sine function and vice versa [closed]

As part of analysing the double slit experiment, I've recorded position values for a number of minima and the central peak position. Also, I've conducted a single slit experiment (with unknown width)...
2
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2answers
65 views

What does a double parenthesis in a quoted value ─ like e.g. 157(3)(3) ─ mean?

Sometimes, in journal articles, the author writes a number followed by two parenthesis. For example, $157(3)(3)$, where it seems that the first parenthesis shows uncertainty in the last digit (here, $...
2
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2answers
63 views

What is the solar wind speed as function of distance from the Sun?

Someone must have calculated at least a "zero-order approximation" of the behavior of solar wind speed, density, and pressure as a function of distance from the Sun, but the heck if I can find it. ...
2
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0answers
156 views

Where to find databases from physics experiments?

In some lecture I want to write about data analysis in physics I want to show some real uses of data analysis tools in the analysis of data from real experiments. I tried to search but I couldn't find ...
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1answer
41 views

Measured Earth local gravity

I am looking for measured data of the local gravity on Earth. I know this website (https://www.ptb.de/cartoweb3/SISproject.php). The idea is nice but it looks a bit old and I would like to have an ...
1
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1answer
36 views

File with particle decay data [closed]

Does anyone know of a computer parsable file that has basic physics and decay data for (quite many) observable particles, such as mesons, barions, heavy leptons and $W, Z, H$? To clarify the data I ...
1
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1answer
293 views

Where is the data for work functions of simple metals?

I am looking for actual, published data on the work function of metals (Al, Au, Cu) that I can analyze by myself using Matlab. Google Scholar only offers published articles on the utilization of the ...
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1answer
67 views

Determining Threshold Voltage and Plateau from experimental data

I’ve been trying to figure out how to interpret the following data from the Geiger muller tube There are only seven data points. Where does the plateau begin? Has the data collection begun after the ...
56
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3answers
9k views

Is there a physical limit to data transfer rate?

Is there a physical limit to data transfer rate (e.g. for USB $3.0$, this rate can be a few Gbit per second)? I am wondering if there is a physical law giving a fundamental limit to data transfer rate,...
1
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1answer
34 views

Hulse-Taylor binary data gap in the nineties

I was wondering what is the reason there are no data points in the famous Hulse-Taylor plot of the period decay in the 1990s. Does anyone know why no one collected data during this period?
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1answer
27 views

Comprehensive source of skin effect depths vs frequncy in different metals or method to calculate?

Is there a comprehensive source of skin effect depths vs frequency for different metals? I'm looking for Iridium and Osmium specifically, but it would be good to have them all if possible. Ideally ...
0
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1answer
54 views

Where can I find raw data of neutron energy spectra?

I am looking for raw data of the (normalized) neutron flux of a $^{241}$Am-$^9$Be-source, or in other words, the data of this graph. Where can I find that? Apparently, there has to be an ISO standard....
0
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2answers
374 views

Relation between the hole in a semispherical parachute and the area of the parachute and drag coefficient of such parachutes

I can't seem to find much information regarding the size of the Vent (the hole). Nor can I find a concrete answer to the value of the drag coefficient, $C$. I've read in some websites that $C$ is ...
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0answers
79 views

Is there a database for experimental evidence of different physical theories? If not, how to find up-to-date information? [duplicate]

at present, I write a thesis about how one theory of physics can be "embedded" into another one in the sense that all phenomena that hold in one theory emerge as special cases or approximations in ...
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4answers
411 views

Will quantum computing provide any advantage for storing large amounts of data?

Essentially, does superposition or entanglement provide any advantage for data storage as opposed to classical memory.
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5answers
3k views

How do scientists determine when to disregard a model that has a higher correlation to data than another model?

For any set of data points, you can comprise a 100% correlated and fitted curve using a sum of sloped lines all multiplied by their respective Heaviside step functions to form a zig-zag shaped curve. ...
3
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0answers
67 views

Did early hard drives lose data from it getting read too many times?

According to wikipedia, early HDD drives used to use an electromagnet to 'write' data on a small region by magnetizing it. I also read in that same article, however, that they also 'read' the data ...
3
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2answers
46 views

Data supporting abundance of H and He in universe

I am a science educator, writing a lesson sequence for students on understanding evidence that supports the big bang theory. I am trying to figure out whether there is accessible galaxy spectral DATA,...
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1answer
24 views

Where can I find the light damage threshold of a specific material (in this case, latex)?

I am a part of the University of Maryland Balloon Payload Program, which sends student-built payloads via helium weather balloon to the upper atmosphere. I am interested in developing an Early Flight ...
2
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2answers
812 views

Why do we plot distributions (histograms, etc) per logarithmic interval (i.e. per “dec”/“dex”)?

I was trying to explain why we plot distributions (for example the Luminosity distribution function attached) per logarithmic interval (another example would be spectral energy distributions per ...