Running Definition and 371 Threads

In these notes(at page 71) Bilal put some emphasis on that the running coupling on a certain scale ##\mu## is defined in such a way that the logarithms in the expansions of the vertex function small. Or equivalently it is defined such that running coupling on the scale in question is always a...

Often when one speaks about the effective QED coupling one defines it as $$e = \frac{Z_2 Z_3^{1/2}}{Z_1} e_0 \ \ \ \ (*)$$ when ##Z_1 = Z_2## by the Ward identity this turns out to be ##Z_3^{1/2}e_0## and some authors just define the coupling to be this right away. So why do some make a...

Hey folks i got a doubt, one of the theories of Albert einstein say everytime we run for example our mass become a little tiny for example one person have 80 pounds when you start run you have for example 79 pounds of weight because of the speed, and when you stop running your mass go back to 80...

Homework Statement A person moving towards east with a speed 'v' observes the rain to be falling vertically downwards. When he doubles his speed, the rain appears to come at 30° angle with the vertical. Find the actual speed and direction of rain with vertical. Homework Equations...

What do you quantum experts think of this? http://www.technologyreview.com/view/514581/government-lab-reveals-quantum-internet-operated-continuously-for-over-two-years/ Link to the paper http://arxiv.org/abs/1305.0305

Difference between "running up" and "walking up"? A person runs up several flights of stairs and is exhausted when they get to the top. Later, when they have recovered, the same person walks up the same stairs and does not feel as tired. Why is this? Ignoring air resistance, does it take more...

Can someone explain why the running time of following piece of pseudo code is O(n) and not O(n2)? for i := 0 to n - 1 while A[A[i]] != A[i] swap(A[i], A[A[i]]) end while end for The for loop executes at most n times and the inner while loop executes at most n-1 times...

Hi PF, I am trying out LM565 PLL IC and designed the basic circuit for checking free running frequency f0 (2.5 KHz). I verified the f0 by not giving any input signal (input pin floating, should I GND it ??) Now the problem is that while sweeping the frequencies up and down the free...

Homework Statement You run a race with your friend. At first you each have the same kinetic energy, but then you find that she is beating you. When you increase your speed by 21%, you are running at the same speed she is. If your mass is 81 kg, what is her mass? Your mass: 81kg Your speed is...

Homework Statement A mass of 30kg on a smooth horizontal table is tied to a cord running along the table over a frictionless pulley mounted at the edge of the table. A 10kg mass is attached to the other end of the cord. When the two masses are allowed to move freely the tension in the cord...

Hi, I am a new Fortran User. I have a problem when I run my code (not errors during building), in fact the code is stopped in the last line and this message appears "Error 112, Reference to undefined variable, array elements or function result" ... write(number,100)k1 open...

My question revolves basically around how much energy would be required for a person to exert to remain at a constant speed. While exact numbers would obviously not be possible without a specific example (and would probably be impossible even with a specific example), I am thinking more...

I have noticed an issue I must resolve before writing a GUI for my FORTRAN program in Linux. If I move into the directory (cmd line) and type ./myprogram it works fine. It reads the input file from that directory and creates an output file. If I run it from the file manager it gives me 2...

I need it for my physics class, we are running the plotting tool Grace. I had it running on my computer (with some help) So I think I may have downloaded everything I need to run grace, but when I open up the cygwin terminal and type in xmgrace it says /usr/bin/xmgrace.exe: error...

Hello :smile: As strange thing is happening. I have created a simple file using emacs (on a Mac) that contains the following: def main(): print "hello!" if __name__ == "__main__": main() And I have saved it in the working directory as hello.py In a terminal...

Hi, Homework Statement A man, whose mass is m, is running up a block of mass M (as shown in the diagram, please see attachment) with constant acceleration. The block is laid on a smooth ground. The man starts running from rest and the time it takes for him to traverse a distance L (across the...

Homework Statement Just trying to finish up this assignment, no errors. I run the program, enter a value and a percentage, then click calculate. Program just runs, never displays results. Check my code below, let me know if something is wrong. Driver: package ch7pc1; import javax.swing.*...

I downloaded a free version of the first carmageddon game and apparently it is only compatible with Windows XP service pack 2. I am running windows 7 64-bit. I've read that there is a trick to getting it to work. Could anyone help me out?

Homework Statement A woman is running at a constant velocity of 5.0m/s in an attempt to catch a bus. When she is 11m from the bus, it pulls away with a constant acceleration of +1.0m/s2. From this point, how much time does it take her to reach the bus if she keeps running with the same...

I have a Fortran95 program that I run on my Windows laptop (i7 2.0Ghz); its in serial, so its running on one thread, which seems consistent with task manager results (12.5% processor usage), so I figure it should be using ~1 ghz. I am compiling using the standard one that came with my F95...

Hi, I am having a hard time understanding one thing about this experiment for Time Dilation. I have one observer on a moving train measuring the time it takes for light to travel a distance d and be reflected back and one observer who is stationary, watching the same events. I understand the...

Twice I have had to calculate the speed of algorithms depending on input size. The first time I was working in MATLAB(which is based on C) and was timing the difference in time to perform matrix operations on the identity matrix in standard storage and in sparse storage, as I grew the matrix...

1. Suppose that you're in a moving car and the motor stops running. You step on the brakes and slow the car to half speed. If you release your foot from the brakes, will the car speed up a bit, or will it continue at half speed and slow due to friction? Defend your answer. Homework...

A man is running and walking a distance of 2 km. He will walk for 1 km and run for 1 km. At the end, his average velocity was recorded to be 15 km/hr. His running velocity is twice that of his walking velocity. What was his walking speed? The answer was recorded to be 7.5 km/hr, but cannot...

Homework Statement If a 70kg man is running 3 m/s horizontally, how many watts is he consuming? Homework Equations W = N-m/s N = mass*acceleration The Attempt at a Solution I would assume that in order to get the force in N one would use the gravitational constant of the Earth, but...

[FONT=Arial]I am trying to prove the following scenario of Quicksort has a running time of Theta(n^2). Initially, we only have arrays of size n, where n = ij. The idea is that at every partition step of Quicksort, you end up with two sub-arrays where one is of size i and the other is of size...

Homework Statement I want to create a program that prints the sum of integers k for k(1-20) ie, k sum 1 1 2 3 3 6 4 10 5 . 6 . . . . . . 20 . in that format Homework Equations The Attempt at a Solution #include <stdio.h> int...

An environmentalist friend of mine wants to cool a building on his property (something like a shed or workshop) not with AC, but by blowing air from outside into a pipe underground, running it underground for a distance, and then blowing that air straight up into the building. I need to find...

http://www.itisff.it/dip_eln/tda2030.pdf Couple questions. 1. In the Typical Application diagram on the left there is Vi w/ a 22k resistor. Appears that there's a diode running into the resistor and then the resistor goes to ground. The question is how should I interpret that? The...

http://iopscience.iop.org/0143-0807/8/3/011 I guess it's hard to come by original questions in science these days..

My course on QFT follows Srednicki's book. He derives the running of coupling constants in different theories in the following way: When he uses dimesional regularization (going to x-\epsilon dimensions), he has to introduce a parameter \mu with dimensions of mass in oder to keep the coupling...

Hi I am a user of Mathematica as a tool for calculation in Structural Mechanics. I had a problem recently in the integration of expressions a bit long, and honestly I do not understand what might be causing the slowdown. I want to just evaluate this: This is for the Raileygh-Ritz...

Are Financial "Adivsers" running the US? I recently saw "Inside Job" and realized (or was made to "realize") how the same circle of financial advisers has managed to stay in the white house through several presidencies, left or right. So while we bicker about left vs. right, it seems that many...

Hi I am attempting to calculate the mass of the W boson according to one loop energies using the equation, Mw2=(πα/GF√2)/sin2θw(1-Δr) where (Δr)top=(3GFMt2)/8√2π2tan2θw using values:- α=α(MZ)=(127.916)-1 GF=1.16634×10-5 sin2θw=0.23116 =>...

Apparently aluminium has the highest energy density per unit volume of any material. It can be smelted from ore or recycled oxide using green electricity. People have made batteries using aluminium but they have problems like getting gunked up with Aluminium hydroxide etc. How about burning...

My Firefox seems to be running slow, should I delete my cookies or temporary internet files, what do you guys think I should do?

In the past few weeks, I have occasional trouble with my latex expressions (using the itex tag) running over the text that follows them. I also see this in some posts by others. Is there a good way to avoid this? Is it a browser specific problem? ( Mozilla and Firefox are mine.)

Homework Statement Suppose that you have k >= 1 sorted arrays, each one containing n >= 1 elements, and you wish to combine them into a single sorted array with kn elements. Homework Equations The Attempt at a Solution Can I assume that each array has a size of n elements for...

I'm just doing some reading on stars and I've hit a problem which I can't solve. According to a book I'm using it claims the amount of hydrogen converted in the Sun over it's lifetime so far is 5.4x10^55. I roughly agree with this figure using the method this author calculates the number. He...

Homework Statement A rocket engine has an exhaust velocity of 20,000 m/sec. The mass flow (dm/dt) rate is 1 milligram per second. a) What is the thrust produced by the engine? b) The engine propels a 200 kg space craft. What change in velocity is achievable by running the engine...

Homework Statement someone is late for a job interview and is running at a constant velocity toward a stopped bus, at some distance from the bus, the bus begins accelerating as some low constant rate. What's the minimum speed the person must run to just catch up with the bus...

Homework Statement Hello all, I need to implement iterative (non-recursive) binary search in assembly. The array has 10 elements, starting from 0x10000100, in address 0x10000004 there's the element to search for, and the answer should be put in address 0x10000008 It should be for MIPS and I...

Hi, I'm kind of a noob when it comes to physics so I just have to ask. Me and my friends are kind of in a pickle, so here it goes: IF you run around a tree at the speed of light, thus bending time (correct me if I'm wrong) is it possible to touch yourself in the back?

Homework Statement Obviously I do not believe this to be the case, but when running a car the battery is I assume having current drawn in, reversing its normal means of depletion so that the potential chemical reaction can take place later on. My question is when you turn on the radio while...

I'm trying to use Mathematica to solve a system of equations based on coordinate transformations and Lagrangian mechanics. The code follows here. However, when the system of equations is run, Mathematica never reaches an answer nor does it give an error, it simply runs infinitely. This is for a...

Can anyone tell me what will happen to a length og a rod if it is measured in a running train and why?

Hi everyone, even if I continue reading books about renormalization, I have the same basic doubts. So we have radiative corrections that give infinites etc.. So what we do is regularize and renormalize the theory. What is left at the end? Is it true that loops are no longer there since the...

hi when i run a heavy computation on mathematica in the same time even if i want to calculate 2+2 , mathematica does not calculate it until calculating of heavy computation finishes. why? another problem is that when i do a heavy computation and obtain results , after closing mathematica...

I am attempting to translate the model of peculiar velocity flow given by Tonry et al (1999) from fortran into python, the language we use on my course, however I am experiencing difficulties in getting the thing to run. I have attached the original fortran (sbf2flow) and my attempt at...

Silly question here with a long back story, but basically: how fast can you accelerate by running in space? A few very naive assumptions: You have a cross sectional area of about 1/3 m^2, and the density of space is about 5 protons/m^3, so you have a mean free path of about half a meter, or your...