Scale Definition and 721 Threads

In early 2010 I attended this inaugural lecture by string theorist- Prof. Mavromatos entitled 'MAGIC strings'. In it he proposes that some string theory models may violate Lorentz symmetry at the Planck scale resulting in a kind-of foamy spacetime that could be observed by differing arrival...

Hi every one. Im new on this forum,and my question is my reason for joining. iv seeked this question for a long time now,and it confuses me.The answer may be very simple to a peron that already knows the answer,me on the other hand... ! hasnt got a clue...

Just a fun question.. If one were to build a 1/60th scale model (example) of a locomotive, say of this one: exactly, meaning the same materials in the same manner, exactly the same in 1/60th scale, I would presume it weighs 1/60th of the original train. But would it.. Have 1/60th...

Does it make sense to try to use the chimney effect/stack effect to increase heat dissipation for a smallish electronic enclosure? I'm thinking that if I hollow out the two vertical ends of the enclosure, I can get a 100mm high 5x5mm "chimney" on each side. On paper I get about 0.09 Pa...

For what it's worth, I came up with this problem, so perhaps it cannot be solved, or there could be a way to solve it without using all of the information given. Homework Statement A chair rests on a weighing scale and a wall. The relevant surfaces of the scale and the wall are...

What is meant by "a certain theory has a scale"? In the context of high energy physics (and in other branches too) I sometimes hear that a certain theory has "an intrinsic scale in it (the theory)". What is implied by that? How do I find out if a given theory has a scale in it? Can there be...

The coupling constant runs so the Planck scale changes. What is it at the AS point?

Light is redshifted and the greater the z, the further the spectral shift is to the left. Is there a point at which low-frequency EM (radio/micro waves) shifts below the spectra and disappear? The real question - Is there a z, and thus an implied distance, at which the highest energy...

Renewable Energy (RE) Sources are a hot topic, but careful study of the solutions thus far offered make realizing RE as more than a tiny percentage of demand unrealistic. I have been thinking on an idea for a very large scale wind generator that I think is a potential solution for many of the...

I'm not a science student. Therefore, please keep your replies as simple and straightforward as possible so that your help can be fully appreciated. Thanks. Is entropy 'S' measured on some fixed scale? If yes, then what's the maximum value? When oxygen and hydrogen react to form water, the...

Hi guys. I am new here. Is there a bluetooth module which you can configure the range of the the module? For example from a 5 meter range to about 1 ft or less... Currently planning on using BTSerial1 Bluetooth module. Any idea of a less expensive and better bluetooth module? Im new to this...

Hi. I'm an absolute noob at physics, so I went to the library and checked out a couple beginner books. Basic Physics: A self-teaching guide and Science 101 Physics. I'm just getting started reading physics 101 and read the following statement: "...all you have to do to determine your...

Hi, I've received a new accelerometer with a scale factor declared in datasheet as: 800 mV/g @ 1.5g. I googled and searched the forum but still can't fully be sure I understand the accelerometer and its functioning, so please correct me where I'm wrong: One thing that very helped me to get...

Howdy! I saw this question posted on someones blog the other day and just could not for the life of me reason out an answer that i could 100% agree with. Say a block of mass, M1, hangs from a hypothetical hanging scale of 0 mass, which in turn hangs from a second identical scale, which in turn...

can someone tell me what is wrong with my code. i get the graph that i want but not with the log scale... i have tried multiple methods. this is the last one i tried (its part of a canvas which is split into quadrants) TH1F* h3 = (TH1F*) inputfile3 -> Get("pdg"); c->cd(3)...

Homework Statement A scale is adjusted so that when a large, shallow pan is placed on it, it reads zero. A water faucet at height h = 3.1 m above is turned on at t=0 and water falls into the pan at a rate R = 0.16 kg/s. Determine a formula for the scale reading as a function of time t for t...

Homework Statement To determine the mass of a car, a student (with a friend at the wheel) pushes the car holding a bathroom scale between himself and the car. The scale maintains a constant reading of 433 N while the car accelerates on level ground. At the conclusion of the experiement, his...

Hi everyone this is my first post so forgive me if i leave out details A friend of mine tried to measure buoyant force by the following means Using a regular scale where the setup is sitting on top of it 1) Using a scale, he measured the object and found the scale to give x[grams] 2) Then...

Has the following explanation for the large scale structure of the universe been considered and discounted?Consider a universe many billions of times the size of the observable universe, so big that the homogeneous nature of the universe could even be an illusion. At a very large distance...

Homework Statement A metre scale made of steel is calibrated at 20 degrees Celsius to give correct reading. Find the distance between 50cm mark and 51cm mark if the scale is used at 10 degrees Celsius. Coefficient of linear expansion of steel is 1.1 x 10-5 C-1 Homework Equations...

Homework Statement Can someone please explain to me the meaning of the term 'small scale yielding'? Homework Equations The Attempt at a Solution I know it's in the field of fracture mechnics and has something to do with the stress at the crack tip but i don't have any idea what...

hi, how can we be sure that quantum gravity effects appear only at the Planck scale? when i look at the quantum mechanics effects, there seem to be a relationship with general relativity so both could be the same phenomena . i thought that the aim of quantum gravity is to find out the...

Homework Statement You place a 8.10-kg television on a spring scale. If the scale reads 77.95 N, what is the acceleration due to gravity at that location? Homework Equations f=ma fg=mg fnet=mAnet Ff=μῦF The Attempt at a Solution Fnet = T - Fg mAnet = T - Fg 8.1(Anet) = T -...

A woman stands on a scale in a moving elevator. Her mass is 60.0 kg, and the combined mass of the elevator and scale is an additional 815 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force of 9410 N. What does the scale read...

Homework Statement A 72.0 kg man is standing on a spring scale in an elevator at rest. The elevator ascends, attaining it's max velocity of 1.20 m/s in .800s. It travels with this constant velocity for 5.00s. The elevator then undergoes a uniform acceleration in the negative y direction for...

in what scale can we consider the uncertainty principle?can it be considered in the non atomic scale?

The meter in the circuit shown in the image has an uncalibrated linear scale. With the circuit as shown, the scale reading is 20. Find the scale reading when another 2000Ω resistor is connected across XY.

Why? Some measurements confirm this statement? Or this is a theoretical conclusion?

Stephen Hawking's recent book The Grand Design uses M-theory to predict a multiverse, which then does away God via the anthropic principle. A common criticism that string theory makes no experimentally falsifiable predictions which is countered that experiments do not have enough energy to...

I feel like playing with a scale model of this: http://en.wikipedia.org/wiki/Rotational%E2%80%93vibrational_coupling Do chemistry supply stores sell any? For educationnal purposes? Or do I have to build one?

Homework Statement Two random variables, x and y. Density functions are m(x) and f(y), respectively. x is defined on [0,1] and y on [0,1-\rho]. I also know that \int_{0}^{1} m(x) \,dx = 0.5 \int_{0}^{1-\rho} f(y) \,dy = 0.5 Knowing that f(y) is essentially a transformation of m(x)...

I didn't make this, but I think it's one of the coolest things ever. http://www.newgrounds.com/portal/view/525347 enjoy

Hi I am looking into the design of gliders with good L/D / Glide Ratio. It seems hard to find what is the most efficient full size glider, and the same goes to a scale r/c type one too. So any ideas? If i was to start from scratch, what should i be looking at to get the best l/d...

Much recent economic efficiencies have come from economies of scale and specialization of labour. http://en.wikipedia.org/wiki/Thomas_Robert_Malthus but at what point is there diminishing marginal return. The more people we have the more tasks can be broken down into smaller and smaller...

Homework Statement Hi guys, I'm stuck on this question in exam revision: I need to estimate the area under the following curves (I don't have the equations of the curves) http://img819.imageshack.us/img819/3249/question.jpg The curves are magnitude diagrams in the log-log scale...

hello std dev is the square root of the variance. assume we measure lenghts of something normally distributed. we use millimeter. we calculate our variance to be 100mm and thus std dev to be sqrt(100)=10mm but, if we instead would measure the same objects in meter, then we'd get the...

I would like to find out which functions retain the same structure when they are scaled. Particularly I am interested in projections. For example, a parabola 3d space viewed at another angle can still be represented by at^2 + bt+c. A circle however can not (ellipse) I am guessing conic...

Homework Statement Barbara has a mass of 60.0 kg. What would a metric bathroom scale (a scale that uses Newtons) read if she steps on it in the following situations: On the Earth in an elevator experiencing an acceleration of 3.0 m/s2 while speeding up and moving upward. Homework...

Hey, the coupling constant in QFT is scale dependent. This scale \mu, it seems to me, is a mathematical tool used to regularize the infinities that arise at the loop level. Thus physical quantities have to be independent of this scale \mu. This implies that the coupling 'constant' is a...

Can someone please tell me if I have done this correctly? "2 cylinders are similar. The area of the ends of the smaller and larger cylinders are 16cm2 and 100cm2 respectively. The height of the larger cylinder is 12.5cm. Calculate the height of the smaller cylinder." Firstly, if the scale...

Hi, Ive been readin about relativity, I am a little confused. The faster speed an object has, the faster time passes on the object. So how long does say a ray of light take to get from teh sun to the earth? It is ~8.5 of our minutes, but say I were on the ray of light; traveling with...

My biology teacher asserted to our class that compared to the vastness of the atmosphere of our earth, the amount of harmful gasses we are emitting is a fraction of a percent and therefore can be dismissed as harmless, and instead we should be worrying about more fragile ecosystems down here on...

Above what scale is the universe considered to be homogeneous? What sort of measure is used? I've looked at a few cosmology texts and they don't really discuss it much. Weinberg states 300 million LY. With 250 million LY diameter voids and 1370 million LY long filaments, 300 million LY seems...

Homework Statement http://j.imagehost.org/0069/thermo.jpg Homework Equations The Attempt at a Solution OK, so I tried to derive θ in respect to r as in θ(r): \frac{d\theta}{dr} = \frac{-100}{(r - 1)^2} Then, I multiplied both sides of the equation by 'dr', d\theta = \frac{-100}{(r -...

If you had an extremely sensitive scale (use your imagination) and shone a beam of light upon it, could you measure the force that the photons were exerting on the scale? would there even be a force?

What is the thermodynamics temperature scale, both in theory and in practice? Is it really independent of physical substance? Why?

so that visually everything appeared the same, could you use physics (e.g. gravity or something) to prove that you and everything else is bigger than it was before?

i have took a basic course in fluid mechanics: Bernoulli equation states that: P + (1/2)*ρ*v^2 + ρ*g*h = constant where P is the pressure , ρ is the density , g is the garvitational acceleration and h is the distance from the center of the Earth , and that constant is our reference. that...

Confirmation of general relativity on large scales from weak lensing and galaxy velocities. http://arxiv.org/ftp/arxiv/papers/1003/1003.2185.pdf

This is a general question, not requiring an equation. If I travel near the speed of light, I know my mass will increase. I am assuming my weight will increase, but since there is little gravitational pull, since I am not near any large objects, then my scale would say near-zero, if I stepped...