Scale Definition and 721 Threads

Hi. I have observed that Ryder in his book on QFT before doing dimensional regularization introduces a scale ##\mu## in order to keep the coupling constant dimensionless in the lagragnian. However in two other books; Weinberg and Peskin and Schroeder, they do not introduce this scale in the same...

Not sure if this is the right category but i need help. On a map of a school, 3 inches represents 9 feet. How many inches would represent 1 foot 6 inches?

Homework Statement I have to design a scale to weigh something under 1kg and all am given is a yard stick, 10 ft of fishing line, a 500g known standard mass, and a protractor. Use an angle measurement for weight. Don't just balance weights on a see-saw Homework Equations - The...

So the probabilistic studying of Quantum statistics of Böse-Einstein suggests that we permutate the number of objects (objects, are the blocks (Gi-1), and the particles in the boxes Ni) and divide those by Ni! And (Gi-1)! Because these particles are identical. But the case of Fermi-Dirac, where...

Wondering if anyone has developed a scaling heuristic for the relationship between size of accelerator and smallest size that can be probed with it. With so many data points, something ought to emerge, perhaps a modified power law. Adding a time axis could make a Moore's "law" projection for...

Just watching tweets come out of the conference, apparently there is a large scale anomaly that has come out of PLanck . One tweet says challenge to inflation, another says could be pre big bang physics. Obvioulsy I am just reading tweets, so not sure what's real yet. But this could be exciting...

Hello this is my first post, so if I am supposed to move this to another forum section please advise I would be happy to http://foryourwater.com/mm5/graphics/00000001/3_gallon_dispensing_water_bottle_lg.jpg As for my question, I am referencing the example of a water dispenser above, after...

Are there stringy candidates for reproducing the SM and dark matter etc without low scale supersymmetry?

Hi, I am trying to understand how electroplating works. With help of this wikipedia diagramm (http://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Copper_electroplating.svg/471px-Copper_electroplating.svg.png) I have already figured out (correct me if I am wrong) that it works something...

Homework Statement Harold has a mass of 72.2 kg, and is standing on a scale in an elevator cab. What will the scale read if the elevator is moving downwards at a constant 0.050 m/s?Homework Equations The Attempt at a Solution Since the scale has a normal force upward and Harold has an...

Just a quick question. When you are given two vectors, let's say 5m (E32N) and 6m (S23E) and we are to find the total displacement. Do you draw the first vector and then attach the second vector to do the head of the first vector? or have both vectors start a the origin.

So here is my problem: I'm very bad when using coordinates others than cartesian ones, and I know taking Mechanics of Lagrange and Hamilton and I fin difficult to find the velocities expressions in curvilinear coordinates. So here is my question: is there anyway to relate the scale factors...

Hi everyone, and thanks for reading my very first post in Physics Forums! I have been researching a way to construct a single person aircraft with vertical take-off and landing using a propulsion system similar to that of an RC-blimp. I found a video on youtube that illustrates the principle...

this is not actually for homework, I am no longer in school, this is for a small application I am trying to write that compares dimensions. However, I believe this is the appropriate spot to post after reading the rules. Homework Statement okay, so let's say you got a shape, for example a...

Please can someone tell me if my thinking here is right... I've got a planet with an atmospheric pressure at 6km of 0.5 P0 and at 8km of 0.4 P0 (P0 = pressure at the surface). I want to work out the scale height of the atmosphere. Given scale height = λ and for height above surface...

I was thinking about olbers paradox and how I could apply it to gravity. We assume that their are an infinite amount of planets and that they are all about the same mass or we will just pick a minimum mass. And we assume they are evenly distributed. So the gravitational field falls off...

If at very large scales of matter our intuitive logic fails to explain it (Black Holes) and at very small scales of matter untuition again fails (Quantum effects) then is there a connection between those two groups of phenomena?

This video puts forth the idea that an institution the size of the US (in terms of population) is unmanageable as a republic as the concept because a republic was designed for a smaller scale.

Just a thought experiment. Imagine you made scale models of the sun and the planets with the relational standard of measure being a sun the size of a basketball. Now assume that the sun and the planets were all built to scale with the appropriate diameters, densities and masses of the actual 8...

Hello, I am reading a paper in which the author describes how he scales the velocity profile of a car. He is doing this so that he can compare the velocity profiles of cars. This is an extract from the text: The first methodology consisted of evaluating the similarities between...

Homework Statement Show that by using the Friedmann-equation you can determine the scale factor for a Universe in it's early stages (starting with the Big Bang) to: Homework Equations The equation for the scale factor: Where r(t) is the distance from us to a given galaxy to the time t...

This paper - http://arxiv.org/abs/1211.3816 - by Beckenstein is fascinating. I would like to know if the experimental test proposal is realistic.

This may seem like a really dumb question, but I can't figure out what the answer is, so please just bear with me. Why does a balance that is equal come out straight? If one side is tilted slightly lower than another, shouldn't it just stay that way since the masses are the same on either...

My math is a little weak, so I'm having a hard time finding the elastic and plastic regions on this curve. Any further help will also be appreciated!

I am unsure how bathroom scales work. Does your weight compress or depress the spring? Do scales measure the upward or downward force? Please explain in detail.

Homework Statement A 120 pound person is sitting on a scale during a roller coaster ride. As the roller coaster goes over the top of a curve whose radius is 30 feet, the scale indicates a force of 25 pounds. The average speed of the roller coaster doesn't change while over this curve...

Homework Statement You take a bathroom scale onto a stand-up rollercoaster (the riders are always in a standing position). Before the ride starts, you stand on the scale and note that it reads 65 kg. The ride starts and at the top of the first loop you are upsidedown and your scale reads...

Hi everybody, there is this question that is bugging me and since I neither seem to know enough about physics to find out the answer myself nor to have the time to acquire said knowledge I will try to ask it here. Objects of the microscopic world famously behave in an indeterministic way...

1. Jupiter radiates more energy than it receives from the Sun by 8.7x10-10L0. Jupiter's radius is 7.0x109cm and its mass is 1.9x1030g. Compute its thermal time scale. Could gravitational collapse power this luminosity for Jupiter's entire lifetime of 4.5 Gyr? 2. Kelvin-Helmholtz (aka...

Homework Statement Two masses, measuring 800g and 400g respectively, are attached to spring scales and an Atwood Machine. What will the reading of each scale be? https://www.physicsforums.com/attachments/52223 Homework Equations Fg = mg The Attempt at a Solution I think that...

Hello, I consider myself an up-and-comer theoretical physicist (although getting a bit of a late start), and there's something that continues to trouble me about the way physics is taught both professionally and popularly, and I want to survey how others feel about the issue. The issue is the...

Consider a random walk (in any dimension) with N steps and a step size of 1. Take a real number \alpha > 0 and consider another random walk which takes \alpha^2 N steps but wil step size \frac{1}{\alpha}. I immediately noticed that the mean deviation after the full walk in both cases is the...

Wheeee! More confusing thread titles! Here, let me elaborate: What I intend to do here is figure out a way to roughly model the results of planetary (or larger) bodies impacting, or a planetary (or larger) sized body being impacted by a smaller body that is moving with enough relative...

Homework Statement A student stands on a bathroom scale in an elevator at rest on the 64th floor of a building. The scale reads 828 N. (a) As the elevator moves up, the scale reading increases to 919 N. Find the acceleration of the elevator. (b) As the elevator approaches the 74th floor, the...

How small can a maglev propulsion system be? What's the relationship between the size/strength of the magnets and the load capacity of a maglev vehicle?

can wave particle duality be viewed at macroscopic scale...?? ok so far we have discussed the wave particle duality in case of electrons of-course at microscopic level through the 1) interference phenomenon showing its wave behavior 2)photoelectric effect discussing its particle...

Homework Statement 1. You stand on a spring-loaded bathroom scale in a bathroom. The scale "reads" your mass. What is the scale actually measuring? 2. Similarly, you stand on a spring-loaded bathroom scale in an elevator that is accelerating upward at 2.0 m/s^2. The scale "reads" your mass...

Homework Statement Homework Equations F→scale + F→g = ma That's my guess. The Attempt at a Solution Well, I'm reading it in the book. It's an example with the answer that the scale reading will be less than my weight. But I still don't understand how that works out to be...

Homework Statement The strings attach to a scale which reads the force. What is the force that the scale will read? Homework Equations F=ma according to Newton's Laws. The Attempt at a Solution Thinking logically, I simply calculated the force of the left side: F=ma...

Hello people, I have a question about the log-scale. What happens when we switch a plot from linear scale to the log scale? Let's say I have two arrays: x values and corresponding y values. I plot them using a linear scale and then I switch to the log scale. What happens? Does the program...

Hello all! I'm trying to understand the standard normalisation of the scale factor to be set to 1 at today's time. Looking at the first Friedmann Equation for a spatially flat Robertson Walker metric with no cosmological constant gives \frac{\dot{a}^2}{a^2} = \frac{8\pi G}{3}\rho If we...

An Earthquake measures 6.1 on the Richter Scale. What is the rating on an earthquake that is twice as powerful? I = I0 × 10M I-intensity of earthquake I0-earthquake with intensity of 0 M-magnitude of earthquake on the Richter Scale So I figured I'd use I1 = I0 × 106.1 to find the...

the text tells me that for calculating the Richter Scale magnitude of an earthquake we can use: M = log(I/I0) which can also be written as I = I0 x 10M Where M=magnitute, I=intensity, and I0=intensity 0 How are those two formulas equal? Where did the log go? Can someone show me the...

The mass of the pendulum bob was determined on an electronic scale and its diamter was measured using calipers. The initial height was measured with a meter stick. At the lowest point of its swing, the pendulum bob broke a photogate light beam. The time interval that the light was interrupted...

Pretty funny stuff! https://sphotos-b.xx.fbcdn.net/hphotos-ash4/309379_450399368314413_942684559_n.jpg

If you flip a scale upside down and hook it to the ceiling, then release a helium balloon under it, such that the balloon pushes up into the scale... A. What will the scale reading indicate? Will it really reflect the (negative?) weight of the balloon? B. Will the mechanics of how a scale...

What are the barriers to implementing a large scale "smart-grid" power network? I know that many renewable energies are only available at certain times of the day, or in certain areas. Therefore a "smart-grid" is important for storing and distributing the energy. I see the main issue to be...

I was wondering what are the uses of 200mV scale in voltmeter? I mean isn't it too small for most applications? but it seems to me every meter has such small scale ,so I was wondering what is their actual usage?

An example of what I mean: Suppose you had a blueprint for a chemical rocket. You build one, and it has mass m and provides thrust x. Suppose you scale the whole blueprint up by 1% and build another. The volume (and therefore the mass) of each part in the rocket has increased by a factor of...

How do particle scattering cross sections scale with energy in colliders? Particularly photons, electrons, protons, and gold or lead nucleii? (If necessary, break this into four separate questions.) It is stated that due to the Heisenberg uncertainty principle, it takes more energy to...