Standard Definition and 1000 Threads

Homework Statement Find the formula for the standard deviation (s_h) of heading angle, given the north and east standard deviation of position of two points (s_n1, s_e2, s_n2, s_e2), each point's north-east covariance (s_cov_ne_1, s_cov_ne_2) and the north and east distance between them (d_n...

Homework Statement I have the following task: The Standard enthalpy of formation of gaseous H2O at 298K is -241.82 kJ mol-1. Estimate its value at 100 °C given the following values of the molar heat capacities at constant pressure: H2O (g): 33.58 JK-1mol-1, H2 (g): 28.84 JK-1mol-1, O2 (g)...

Any help would be much appreciated: My data is grouped into 42 categories according to classification of bird catch. Each group contains "X" amount of species, but for ease of input we categorize them into subsets. For example: Group 1: 265.5 kg Group 2: 47 kg Group 3: 213.5 kg etc...

Homework Statement If I'm looking for standard sizes of nozzle thickness. Homework EquationsThe Attempt at a Solution Should I be searching for the standard thickness of plates that are used to form the nozzle?

http://phys.org/news/2015-07-cosmology-standard.html The most popular candidate for the elusive particles that give the Universe extra mass is Cold Dark Matter (CDM). CDM particles are thought to move slowly compared to the speed of light and interact very weakly with electromagnetic radiation...

"A study of long distance phone calls made from the corporate offices of the Pepsi Bottling Group Inc. showed the calls follow the normal distribution. The mean length of time per call was 4.2 minutes and the standard deviation was 0.60 minutes. a.What is the probability the calls lasted...

I just watched a talk from George Ellis about cosmology. I believe there is a serious double standard implied in it. He says (A) the universe is fine tuned for life. Change one of the constants of nature like the mass of the electron and you won't have life in the universe. He also says...

I had a question about how to properly perform error analysis on a series of distance measurements. I need to find the relative error in the distance. I was wondering, should I use the instrument uncertainty divided by the measurement (in this case, it would be 0.005m / (mean measurement)). Or...

When reading about GUTs you often come across the 'Standard Model decomposition' of the representations of a given gauge group. ie. you get the Standard Model gauge quantum numbers arranged between some brackets. For example, here are a few SM decompositions of the SU(5) representations...

I am sure this is very 'basic' :-), I've not read it anywhere - but it's just struck me that every basis in $R^n$ can be row reduced to the std basis for $R^n - (e_1, e_2,...e_n) $ . Row reducing is the way I know to test if a given Matrix of column vectors is a basis. Row reducing also...

Hi, I have a 2 sets (f and y) of 1000 data points each. Also, each data point corresponds to one in the other set. Essentially, I wanted to compute the standard deviation between the two sets, and I did this: ## \sigma_1 = ## IMAGE 1 (check attachment) ## \sigma_2 = ## IMAGE 2 (check...

From a recent thread: Is this true of gluons? Doesn't the color charge invert under CPT? (For example, a red-antigreen gluon's antiparticle would be a green-antired antigluon.)

Hello, Upon following advice from BvU I'm starting a new thread to request help on a concrete issue I have. I have a container with 12x8 wells. Each well contains a roughly equal amount of bacteria. The bacteria are fluorescent, and I am trying to quantify their fluorescence as precisely as...

Homework Statement A business owner makes jars with weights that follow a normal distribution with a standard deviation of 8 pounds. In a random sample of 64 jars what is the probability that the sample mean differs from the population mean by no more than 1 pound? Homework Equations...

Hello, I have an experiment that I'm trying to conduct where I measure quantity A and normalize by quantity B. I then want to report normalized quantity A with error bars showing standard deviation. Quantity B is obtained via a standard curve that I generated (8 data points measured once each...

Hi, I've made a "probability" histogram for my data and it's based on 14000 datapoints in total, BUT each bin is not the same (e.g. bin 1 might be composed on 200 total datapoints while bin 50 is only 3 data points). You can find it in image 1. Now, based on those relative frequencies, I...

First thing i want to do is tell you what i do know. I know to that astronomers use a standard candle such as a Type 1a supernova or a cephied varibale because they are always the same brightness. I know that a light source is four times less bright when it is twice as distant. I know that...

Hi all, I am new to the forum. I have a BS in Chemistry (1984). So I remember a little quantum mechanics. I am trying to wrap my head around cosmology. I started studying GR on my own about a year ago. It took me almost that long to understand tensors. This invariably lead me to start reading...

What is the "consensus" status of the existence of a lattice standard model? These two sets of notes don't seem to be in agreement. Wiese's 2009 notes http://www.itp.uni-hannover.de/saalburg/Lectures/wiese.pdf say "Thanks to a recent breakthrough in lattice gauge theory, the standard model is...

-3 SD -2 SD -1 SD 80 +1SD +2 SD +3 SD mean 65 70 75 85 90 95 The test has...

I am trying to rewrite this constraint as a second order cone constraint of the form $$||Ax+b|| \leq C^Tx+d$$ $$x^2-(x-5)y-yz+3(z-5)^2 \leq 1+x$$ I am having a hard time of knowing where to start.. any information appreciated.

The atom that is used as the standard for the atomic mass scale is the Carbon atom with an atomic number of 6 and a mass number of 12 and this carbon atom is equal to 12 unified atomic mass units. Could another atom be used as the standard, and if so, how would this be accomplished??

Hello there, All Electrical Engineer fellas, :smile: Someday ago, I had been assigned to conduct a building audit of one company in Indonesia. For completing this task, I need all international standard about electrical equipment installation, especially for wiring / cable. Is there anyone...

http://tutorial.math.lamar.edu/Classes/CalcIII/CurlDivergence.aspx In the above link, in the 2nd to last blue box on the page (where it tells how to solve a line integral with respect to a vector field using the curl), it says that the line integral of vector field F with respect to r (with an...

This came up in the arxivs and had me thinking can this be true? arXiv:1506.05478 [pdf, ps, other] Is the baryon acoustic oscillation peak a cosmological standard ruler? Boudewijn F. Roukema, Thomas Buchert, Hirokazu Fujii, Jan J. Ostrowski Comments: 4 pages, 2 figures Subjects: Cosmology and...

Gurus, can you help please? I've been given a set of samples, each has different sample size and mean (but not individual observations). I'm trying to figure out the population standard deviation so that I can estimate required sample size for certain confidence intervals. My question is how...

Is there a standard way of representing numbers of arbitrary size or precision for storage in a text file, JSON message, variable etc.? I am thinking of representing integers as decimal strings e.g. "-12345678901234567" and floats as an ordered pair (array) of strings representing decimal...

Usually, I like to bring up Dark Matter whenever I discuss cosmology or astronomy with someone, and whenever WIMPS (Weakly Interacting Massive Particles) are brought up, the person usually responds saying, "but there is no particle on the Standard Model that possesses all the particles of a...

A new experimental result from BESIII finds that there is isospin violation in the decays of J/Psi mesons in a path involving scalar mesons (with a narrow width in tension with world averages) and notes that a previous experiment found isospin violation in another decay chain...

Does anyone know where can I find the deduction of all terms of the updated SM lagrangian? Although I have already looked at some lagrangians and theories like local gauge invariance, Yang-Mills theory, feynman rules, spontaneous symmetry-breaking and others, I wanted to see the deduction and...

Am just wondering what the currently accepted measurement standard is for the Lyman series spectral lines. At NIST I find the following set of measured wavelengths (nano meters): 91.9342 92.0947 92.3148 92.6249 93.0751 93.7814 94.9742 97.2517 102.5728 121.56701 At...

If I have a function defined over an integral, e.g. ## F(t') = \int_{-\infty}^{\infty} dt \tilde{F}(t,t') ## is there a standard way to denote this integral as being "Open", that is to say if I write ## H = F(t') G(t) ## I want this to mean ## H = \int_{-\infty}^{\infty} dt \tilde{F}(t,t')...

This is problem AP3.7 on page 669 of The Practice of Statistics, 5th AP Ed., by Starnes, Tabor, Yates, and Moore. A certain candy has different wrappers for various holidays. During Holiday 1, the candy wrappers are 30% silver, 30% red, and 40% pink. During Holiday 2, the wrappers are 50%...

If we consider de right-handed neutrino there would be more anomaly-free solutions than hypercharge for a U(1)?

Hi guys, I have a few tries at this but I keep coming up wrong, so can anyone show me how to convert these two standard form equations into slope intercept form? 2x - 11y = 2, -6x + 3y = 9. Greatly appreciate any help offered :) Thank you!

This is take 2.0 of the earlier thread, which got a lot of help from George J., Jorrie, Wabbit, Ken G, and others. I'm exploring this simplification of the flat matter-dominated ΛCDM model (basically anything after year 1 million) to see if there is a presentation that would be suitable for PF...

When tossing a fair coin 1000 times a player correctly predicts 532 outcomes. Then I think I am right in saying that result is about + 2 Standard Deviations from the mean. sqr root 1000 x .5 x .5 = 15.81. 32/15.81= 2.02.However, if the results of the coin toss are given by a Net Gain/ Loss...

I'm working on a school project (Plant layout). In the project, I'm in the planning phase of a new product and I need to have some standard data for motion time study (i.e. assembling) to determine equipment, space and people needed in the plant. Where can I find such data?

Homework Statement The reduction of O2 to H2O in acidic solution has a standard reduction potential of +1.23 V. What is the effect on the half-cell potential at 25 °C when the pH of the solution is increased by one unit? O2(g) + 4H+(aq) + 4e- –> 2 H2O(l) (A) The half-cell potential...

Homework Statement The standard enthalpy of formation for liquid water is: H2 = 1/2O2→H2O ΔHf=-285.8 kJ/mol Which of the following could be the standard enthalpy of formation for water vapor? (A) -480.7 kJ/mol (B) -285.8 kJ/mol (C) -241.8 kJ/mol (D) +224.6 kJ/mol Homework Equations NA The...

http://iopscience.iop.org/0004-637X/803/1/20/ is a link to the abstract of: THE CHANGING FRACTIONS OF TYPE IA SUPERNOVA NUV–OPTICAL SUBCLASSES WITH REDSHIFT Peter A. Milne, Ryan J. Foley Peter, J. Brown, and Gautham Narayan Type Ia supernovae were considered to have fixed brightness, which...

1) The Feynman Diagams which provide the dominant contributions are just those with the greater amplitudes? I have the doubt because I read could be more dominant contributions for a single process and I am not sure amplitude would be the same for them. 2) How to compute the cross section in...

Homework Statement Let T : R2→R2, be the matrix operator for reflection across the line L : y = -x a. Find the standard matrix [T] by finding T(e1) and T(e2) b. Find a non-zero vector x such that T(x) = x c. Find a vector in the domain of T for which T(x,y) = (-3,5) Homework EquationsThe...

I wasn't sure whether I should post this question in this category or "High Energy, Nuclear, Particle Physics", but I decided to post here, since I want to get opinions from the people who are studying the topics discussed in this category, not the experts on standard model or particle physics...

Certain aqueous ions have negative values for SO, such as Ca2+ with -55.2 J/(K*mol); how is this possible when dissolution is usually an increase in entropy? Also, all pure elements seem to have positive standard entropy value; why is this the case? Thank you.

We have two groups measuring the same resistors, the nominal value is unknown. Group 1 is slower and because of that they did not calcute the s1 empirical standard deviation. Group 1: N1=500 , R1=6903 , s1=unknown Group 2: N2=20 , R2=6880 , s2=168.3 ,where N1,N2 is number of measurements...

Dear all, how to 100% know if a process is allowed in standard model? And when a process is allowed, how to know what diagrams contribute, and what of those are the dominant ones? Thank you in advance.

¿Is there a minimal standard methamatematical model for Zermelo set theory in the sense that the other models contains this model ?

It is touted that modern physics has discovered what is actually responsible for force which are particles. Yet, the force responsible for EM is "virtual" particles and then you have the "W" particle in Electroweak. So it seems the issue is not all that clear. I know how the math works, but I am...

average American. The economic pie just isn't growing at a fast enough rate to keep up with the population growth. It's interesting how, when it comes to the big costs in life -- housing, health care, education -- everyone is paying more and getting less, yet no one seems to realize this. As...