Scale Definition and 743 Threads

https://arxiv.org/pdf/1710.11425.pdf The dark matter/dark energy issues has not made any sense to me since 1996 when it was evident that the ratio of dark matter increased as the volume of space measured increased. This was an obvious affect of empty space in the dark matter question that was...

https://www.sciencedaily.com/releases/2017/11/171122113013.htm A University of Geneva researcher has recently shown that the accelerating expansion of the universe and the movement of the stars in the galaxies can be explained without drawing on the concepts of dark matter and dark energy…...

Can someone clarify this for me. Is it the case that Planck scale unit is the smallest unit of measurement that can can observe/make, but not the smallest unit of measurement that exists? If so, is there some name for that which is smaller? Is there some fundamental measuring unit that...

Hello, Not really sure where this belongs (more sci fi) But, suppose the Earth were 10 times bigger. Would it be possible for everything on Earth to scale with this increase - Earth systems, land masses, trees etc (but also remain unchanged to us (except everything everything would be bigger)...

Anyone here do research with time scales (differential equations(dynamic equations) combining both the continuous and discrete). I know its more of a new topic from Hilger, but I think it is a new wave of modeling that will be prevalent in the future. If anyone is interested on the topic or...

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 = 4.0 m above is turned on and water falls into the pan at a rate R = 0.20 kg/s. A) Determine a formula for the scale reading as a function of time t if at the...

what is a b c and d so that all values of s are true \begin{align}\displaystyle &f_{15}=\\ &-17d+11s^2-4s+10as^3=(b+2)s+90s^3+(3c-1)s^2+85\\ &-17d+11s^2-6s+10as^3=bs+90s^3+3cs^2-s^2+85\\ &(s=0)\\ &-17d=85 \therefore d=-5\\ &11s^2-6s+10as^3=bs+90s^3+3cs^2-s^2\\ &(s=-1)\\...

There are two square scale. That is, it has marking where there are square i.e marking at 0,1,4,9,16,25 and so on. When one scale is moved, it slide over the other. Now if one scale is moved odd number i.e say 123 , that is, it's zero is placed at 123 over the other scale, now. Now, can one...

In obtaining the Press Schechter function, the variance on mass scale is differentiated with respect to mass. The variance on a mass scale is a function of wavenumber k through the Power spectrum and transfer function. To eliminate k dependence, some value of k must be inserted into the...

I'm not sure I understand how to correctly scale flux density with redshift. That is, if I observe say 10 Jy at my observing frequency coming from a source at z = 0.3, how can I estimate the flux density I would expect from the same source at z=2? From what I understand, the final scaling is...

Dear folks Yes I do understand scale ration 1:25 means 1 unit on a map equal to 25 units on a real and scale ration 1:75 means 1 unit on a map equal to 75 units on real Question my Kent tri scale ruler for the ratio 1:25 showing first number as 0.5 m (i.e 50 cm, 500 mm) While first reading...

Is our concept of scale, of micro and macro, of quantum and cosmic, relative to our perception as humans? If General Relativity and Quantum Physics both yield truth, then perhaps it is an error in human cognition that seems to perceive a disconnect between the two. The universe is just the...

Does #Time have uniform Scale??

As a kind of off-thread elaboration on a thread on protein evolution, here is a Science news article on the evolution of mammalian chromosomes. By using full genome sequences, they are trying to trace back the evolution of mammalian genomes to their ancestral set of chromosomes. They only...

I am currently engineering my v2 version of my f1 in schools car, it is a small scale car powered by a CO2 cartridge designed to go down a 25m track, my current version does 25m in under 1.4s, however, I would like to shave off another 0.3-0.2s I believe my main issues are the bearings (only...

Is the energy density ##\rho## in the early universe and the Hubble scale ##H## during inflation related by the formula $$H^{4} = \frac{9}{64\pi^{2}} \frac{\rho^{2}}{M_{P}^{4}}?$$ Here, ##M_{P}## is the Planck mass. Can you suggest any resources where this is explained?

Homework Statement A uniform rigid scale is held horizontally with one of its end at the edge of the table and the other supported by hand. Some coins of negligible mass are kept on the meter scale. As the hand supporting the scale is removed, the scale starts rotating about its edge on the...

It will take a particle accelerator that size of the solar system or more to peek inside the Planck scale.. does this mean the Planck scale is a no man's land.. or empty? but for a passing electromagnetic field or strong field.. doesn't it pass thru or touch the Planck scale at all? If it...

So I've heard it talked about how how at high energies all the strength of all fundamental forces are expected to merge together to single force, but don't quite get how you get from "all the forces have the same strength at high energies" to "all the forces are really the same force."...

There's something that has been bugging me for over a year now and I seem to be unable to find the answer. I would appreciate it very much if somebody could help me out. The thing is that I don't understand how it is possible that in second order phase transitions the correlation legth becomes...

Yesterday, I was thinking about a problem I had encountered many years before, the central force problem with a ##V(r) \propto r^{-2}## potential... If we have a Hamiltonian operator ##H = -\frac{\hbar^2}{2m}\nabla^2 - \frac{A}{r^2}## and do a coordinate transformation ##\mathbf{r}...

I was asked in an exam the following question: Q: How is the absolute Kelvin Thermodynamic temperature scale defined ? My answer is the following: A: The absolute zero kelvin thermodynamic temperature is defined as the temperature for which the entropy of the system is zero, i.e ##S|_{T=0} =...

Hi all, This is a followup to a question from a couple of months ago regarding vacuum energy and cutoffs, basically to clarify some ideas. Given the usual picture of the vacuum as containing quantized harmonic oscillators at every point, it is not possible to apply a 'fixed' energy cutoff (at...

So when my dad first explained the fundamental idea of thermodynamics to me, that entropy never decreases, he pointed out the odd fact that according to basically all other laws of physics, any motion or reaction could be run backwards and be just as valid as it is run forwards. It would break...

Homework Statement In order to provide full scale deflection the coil current required in a galvanometer is 190μA and the resistance of the coil in the galvanometer is 35Ω - What is the value of the resistor to be connected in parallel with the meter so that full scale deflection is obtained...

Visualize a simple balance, a pan at either end of a beam which balances on a fulcrum. The way it works is that if each pan carries the same weight, it balances horizontally. If one pan carries slightly more weight, it tips slightly off horizontal. If one pan carries more weight yet, it tips...

Hello, I was enjoying Zee's book on GR when I noticed the location of this "a(t)" thing in the metric sound quite disturbing to me. BTW: I experience the same annoyance and went down to the same conclusions, when I watched a related Theoretical Minimum lesson...Here's the setup, the flat...

Homework Statement http://imgur.com/a/X7mWA Homework Equations 1. ΣF = m a 2. Στ = Iθ" The Attempt at a Solution First , assuming small motion, all movement of the scale can disregard x components (so the spring stretches only in vertical direction without an impact from the x directional...

If an object was traveling fast enough relative to an observer such that it's length is contracted down to the Planck scale (as with time), I would imagine that any further increase in speed would result in no more observable relativistic effects? Please correct me if I'm wrong.

Homework Statement a. A particle in circular orbit is experiencing an attractive force F towards its center of the orbit. It its period T scales as rn, where r is the radius of the orbit, how does the force scale with radius r? That is, find p in the relation F = arp, where a is an arbitrary...

Homework Statement Man standing on scale and pulling on a rope connected to two pulleys Homework Equations The mass of the man is: m=100 kg The weight of the pulleys, cables, balance, and the frictions are not taken into account g=10m x s-2 3. The Attempt at a Solution the force that the...

I have data (all less than 1) and I need to round down to the nearest 1/2, 1/4, 1/8, 1/16, and 1/32. I have no idea how to do this mathematically, but I'm guessing I use log or pow functions. For example: 0.81 = 0.5 or 1/2 0.33 = 0.25 or 1/4 0.18 = 0.125 or 1/8 Any help would be appreciated...

What made anders celcius(founder of °c temperature scale) to use water as a bench mark for measuring temperature, why he used water's freezing point as 0°c and boiling point as 100°c, is there a reason or he just used water so that it can work easily.

Hello. I am doing a review sheet for my Pre-Calculus final and one of the questions has me stumped. I'm going through our notes and we never did a problem like this in class. Any help would be greatly appreciated. Thank you. Find the Richter scale magnitude of an earthquake that releases energy...

in 2 recent papers by Lee Smolin and Erik Verlinde it is claimed that the scale of acceleration as required by various MOND theories is on the same order as the cosmological constant both researchers suggest that instead of cold dark matter, or even modified Newtonian dynamics, MOND-like...

I have been reading lately about the University of Sussex work on large scale quantum computing that doesn't require the Laser beam approach to controlling the atom. This seems like a huge breakthrough in the development of quantum computers however a forum search doesn't have any mention of it...

I am trying to calculate and draw a relation between (IL) and the Growth rate (m). I have used Il as range from 10^15 to 10^18 in the calculation and when I draw the relation (x-axis ) is Il and (y-axis ) is m. I converted the IL to be in log scale. I noticed unacceptable output. So, I am...

What is the difference between the concept of scale in the SM QFTs and the scale concept in geometry? In other words, QFT is a scale-dependent theory that is living on a scale-invariant space(either R4 or M4, related by Wick rotations). Mathematically scale-invariance and scale-dependence appear...

Dear friends, I am unable to solve the following scale factor problem. Will appreciate your help here. Thanks in advance. 'ET Pizza' produces two pizzas that are similar in shape. The smaller pizza is 20 cm in diameter and costs $10. The larger pizza is 30 cm in diameter. What is a fair cost...

Homework Statement We have an object, whose mass is accumulated in its center. The mass is m. We let an object positioned at the height of h over the scale free fall. Let R be the number that will be displayed on the scale right when the item hits it. Find R(h). 2. The attempt at a solution...

Hi, I am recently working on a project involving simulations and I'm pretty confused about the parameter energy scale Q (contained in TruthEvent pdfInfo). I tried to figure out what that parameter means and from some sources online I think Q is the absolute value of momentum transfer q...

Hello every one. Today's question is: if I'm writte a graph using logarithm scale, must i use the dimensions of the graph "logarithmized" too ? i.e : A Distance x Force graph must have its dimensions as log (m) x log (N) ? or it is just valid for the module ? Thanks for the tips

Homework Statement Given three spring scale readings, positioned at unknown angles, find the mass of the weight hanging from all three scales without using trig, and without measuring the angles. You have only a yard stick. This is a static equilibrium problem. Homework Equations Not allowed...

How does Hubble parameter and scale factor's derivative differ geometrically? I am reading S. Caroll's GR book. But I cannot get the full representation of these two parameters. On the book, it says How can \dot{H} and \ddot{a} be opposite of each other on the same instance if both are...

Any suggestion on a good (but as usual not that expensive) scale that can measure at least to centigram precision? Searching online (e.g. Amazon) I did find some options but the reviews are usually mixed regarding precision (users will say that scales with milligram precision specs are not that...

I understand the inflation predicts a nearly scale invariant power spectrum but some have claimed this was predicted before inflation (by Harrison and Zeldovitch?) My understanding is that perfectly scale invariance would predict ns=1 but inflation predicts ns =.96. So did the prior prediction...

Homework Statement (From Di Francesco et al, Conformal Field Theory, ex .2) Derive the scale factor Λ of a special conformal transformation. Homework Equations The special conformal transformation can be written as x'μ = (xμ-bμ x^2)/(1-2 b.x + b^2 x^2) and I need to show that the metric...

Homework Statement Light intensity is measured by monochromator and is given by I(\lambda ) = I_{0}\lambda ^{3} How to change it to the energy scale I(h\nu ) = ? Homework Equations Photons energy E = h\nu, E =\frac{hc}{\lambda } The Attempt at a Solution It's kind of strange to relate...

Homework Statement This is a basic cosmology problem. The Friedmann equations are ##\Big( \frac{\dot{a}}{a}\Big)^{2}+\frac{k}{a^{2}}=\frac{8\pi}{3m_{Pl}^{2}}\rho## and ##\Big( \frac{\ddot{a}}{a} \Big) = - \frac{4\pi}{3m_{Pl}^{2}}(\rho + 3p)##. Using the density parameter ##\Omega \equiv...

I drawed a relation between the growth rate of the material to the laser intensity. After drawing, My professor told me that I must convert both values of the growth rate and the laser intensity to their values in the logarithmic scale. I don't know how. May I get a help.