What is Shift: Definition and 653 Discussions

Shift work is an employment practice designed to make use of, or provide service across, all 24 hours of the clock each day of the week (often abbreviated as 24/7). The practice typically sees the day divided into shifts, set periods of time during which different groups of workers perform their duties. The term "shift work" includes both long-term night shifts and work schedules in which employees change or rotate shifts.In medicine and epidemiology, shift work is considered a risk factor for some health problems in some individuals, as disruption to circadian rhythms may increase the probability of developing cardiovascular disease, cognitive impairment, diabetes, and obesity, among other conditions.

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  1. Nono713

    MHB What happens to the phase of a wave during scattering?

    Hi, I can't seem to find any straightforward information on this. I know wave transmission does not change the incident wave's phase, and wave reflection shifts it by $\pi$ if the wave is reflected by a denser medium than the one it is in... But what happens to the phase when the wave undergoes...
  2. A

    Why is a Blue Shift in Kruskal Szekeres not Physical

    In my intro. to GR class we recently covered the Kruskal Szekeres diagram and trajectories within the diagram. My question comes from a comment made by my professor about time-like trajectories emerging from v=0 and that if an emitter sends a light signal to an observer it will be blue shifted...
  3. W

    AC Circuits Terminology: Phase shift vs Phase Angle

    We talked about AC circuits and phase shifts were discussed. Voltage changes "lag behind" current changes so that's how we get phase shifts. It's like a sinusoid so fine. Then we talked about impedance. There's a real and "imaginary" component to impedance, graphed on x-axis and y-axis...
  4. H

    If doppler shift can be caused by gravity

    ... In other words a photon is energy-mass equivalent so it is effected by gravity. If the photon comes from a place of very high gravity, and we see it shifted, does the emitter have to be moving? ( this is a trick question. I'm heading to Mach's Principle :-) If high gravity can dopple...
  5. L

    Many body 2nd order energy shift of ground state

    This is more of a math question I suppose, but its in the context of calculating the second order energy shift in the ground state energy for a non relativistic collection of electrons. We end up showing that the energy shift has a finite and divergent piece. The divergent bit is proportional...
  6. G

    Red Shift: Questions About Light & Big Bang

    This might be obvious but i was listening to someone talk about how he believes the big bang is cyclical and the universe is constantly expanding and contracting. now i don't believe this but one of the points he raised was (and i know it doesn't support his argument) we don't know if galaxies...
  7. N

    Find the number of fringes that will shift in young's double slit experiment

    Homework Statement Monochromatic light of wavelength 600nm is used in a young's 'double slit experiment . One of the slits is covered with a thin transparent layer (1.8 * 10^-9m ) made of a material of refractive index n(1.6). How many fringes will shift due to the introduction of the...
  8. C

    Is the only evidence for an expanding universe the doppler Red Shift?

    Basically, all more distant galaxies have a Red Shift that increases with the distance to the galaxy, the Universe is expanding. 1) If there are other pieces of evidence that indicate the Universe is expanding, what are they? 2) Any internet links describing exactly how the other...
  9. E

    Variable shift positive clamper

    for the given circuit and waveform , i am not getting how output for ωt < π is Vs + E1 ? given Vs is input and equal to Vm Sinωt
  10. M

    Calculating Doppler Shift for Radar Gun and Moving Ambulance

    A police car is traveling at a constant speed of 100. km/h with a radar gun which generates and detects radiowaves. The police car and the ambulance drive directly towards each other. The radar gun produces radiowaves with a wavelength of 0.0650 m. What doppler shift (Δf = f′–f) is detected...
  11. R

    Can New Galaxies Appear Due to Doppler Shift at High Speeds?

    I recently heard about the effects from The Doppler Effects at high relative speeds (significant fractions of c). For example you will eventually will even get burned/die by the radiation of the CMBR being ao intensly blueshifted while you're approaching the speed of light (relative). So...
  12. T

    News Does libertarianism just shift tyranny from the government to individuals?

    Ron Paul may very well be the most honest Congressman, but are any of his ideas really practical in increasing freedom? I agree with him that we don't need more government, but I don't think we need less either; we need more direct and accountable government. Please correct me if you think I am...
  13. 1

    Can objects be redshifted to the point of becoming invisible?

    I was wondering if something could be redshifted to the point that all of the EMR it was emitting was outside of the visible spectrum, thus not being able to be viewed. I googled it and found some people discussing it, there answer was essentially no, because the object would be emitting all...
  14. P

    Red Shift and Receding Galaxies

    Hi, I understand the idea of red shift and how that explains that galaxies are receding, etc. I just don't understand how the measurement is made. I know that, in labs, we can shine white light at hydrogen and analyze the absorption spectrum. Some black lines are going to show up, due...
  15. O

    Understanding Einstein's Special Relativity: A Brief Introduction

    What I want to know is... if objects apparently traveling away from us at high speed, shift the light towards the red end of the spectrum ( and towards us, the blue )... surely the same effect would be experienced if the distant object was in fact stationary (hypothetically) and it was us...
  16. Y

    Transformation of Doppler shift

    Given the Doppler shift equation quoted here: http://en.wikipedia.org/wiki/Doppler_effect#General \frac{f_r}{f_s} = \left(\frac{c + v_r}{c + v_s} \right) where c is the velocity of waves in the medium; vr is the velocity of the receiver relative to the medium; positive if the receiver is...
  17. W

    Triplet S-wave (l = 0) phase shift in n-p scattering at low energy

    Homework Statement Evaluate the triplet S-wave (l = 0) phase shift in n-p scattering at low energy assuming the interaction potential is given by a square well of depth V0 = 38.5 MeV and width b = 1.73 fm. Deduce also the value of the triplet scattering length. Homework Equations...
  18. B

    Making a Shift Register Using NOR Gates

    Hi - I am trying to make a shift register using NOR Gates. I have been given multiple HD74LS02P Quad 2-Input Positive NOR Gates, LED lights, resistors, a breadboard and an Arduino UNO. I have been trying to do this for a long time now, but I don't think I really understand how it works (the...
  19. R

    Calculating the doppler red shift

    Homework Statement I'm working on this problem here: http://hyperphysics.phy-astr.gsu.edu/hbase/astro/redshf2.html The answer is already listed, it's the steps I'm worried about. I don't see how they get from step 1 to step 2 here. They don't even tell me what T is. It seems...
  20. C

    Determining Frequency Shift for Moving Sound Sources

    I was considering the following question; 'A fire engine traveling at 70m/s drives past a van traveling at 30m/s. The speed of sound in air is 330m/s and the fire engine has a frequency of 200Hz when stationary. At what frequency does the van driver hear the siren?' I understand you have...
  21. A

    Red/Blue Shift for measuring absolute velocity

    Would it be possible to stand at a point, surrounded by sensors and fire beam of light of at specific frequency at every sensor and determine our absolute velocity without a reference based on the amount of red/blue shift detected in the frequency of each beam? Wouldn't light observed by the...
  22. S

    Understanding Phase Shift in Trigonometric Functions

    Find the phase shift of a function. Y=-5sin(x-pie/2) The Phase shift is (pie/2)/1 which equals to pie/2. The correct answer is units to the right though..which is where I need clarification on. My book said if phi is less than 0, it is too the left.. being -pie/2 wouldn't this...
  23. V

    Red shift and blue shift as relating to time dilation

    I was listening to a lecture about the expansion of the universe and found myself confused about the light we see from very distant galaxies. These galaxies are red shifted because they are moving away from us and the photons are being stretched. Does this mean that the galaxy will appear to...
  24. A

    Fourier effect of time shift + convolution

    Ok, I know the Fourier effect of a time shift is a multiplication with an exponential: x(t-t0) → exp(-j2∏f*t0)X(f) Now say Y(f) is the Fourier transform of y(t). What I am wondering what is the difference in the Fourier space when convolving Y(f) with either X(f) or exp(-j2∏f*t0)X(f)...
  25. L

    Doppler Shift and photons with a wavelength of one Plank length

    If this is the wrong place to be posting this, feel free to lock this thread. I wasn't sure if this belonged in "classical physics" or "quantum physics"; this seemed like the appropriate place, but I'm not 100% certain, as it does involve subatomic particles. Anyways, to get to the matter at...
  26. E

    Can a single capacitor circuit have phase shift?

    Hi guys, Short question here, just wondering if it's possible for a capacitor, alone in a circuit with an AC sinusoidal voltage source to experience phase shift? Meaning can the voltage over a capacitor have a different phase to the voltage from the voltage source. Thanks!
  27. N

    Why do people think red shift is caused by big bang?

    Question: as title says. I'm not a physicist at all and I do not know much about how people obtained the big bang theory from red shift. So here is what I thought from red shift: In a time period t1, a distant body emits a light wave with a certain amount of energy with n oscilations(I don't...
  28. A

    Doppler Shift as Applied to Nuclear Structure and Spectroscopy

    Homework Statement a) Calculate the Doppler shift due to a relative velocity of 3cm/sec. b) Fine \Delta E/E, where E = 14.4keV and \Delta E is the Doppler shift obtained in (a). Homework Equations \frac{f_{0}}{f_{s}}=\frac{c}{c+v_{s}} The Attempt at a Solution So I'm working on...
  29. T

    Qualitative implications of parameter shift in non-autonomous ODE

    Hi everyone, I've got a one-dimensional non-autonomous ODE of the following form: dy / dx = f(x,y;w) x_{0} = g(w) y_{0} = h(x_{0};w) --- i.e., w is a parameter that influences both the derivative dy/dx along with both coordinates in the initial condition (x_{0},y_{0}). I basically want to...
  30. L

    MTW Gravitation Ex. 25.16: Comparing Equations & Expressing u_0 in \tilde{L}

    Hello, I am trying to work out this exercise for my personal research connected with my bachelor thesis. The task is to compare equations (25.42) and (25.47) and express $u_0$ in terms of \tilde{L}. I have so far put the two equations together getting \begin{equation}...
  31. D

    Economics: Shift in Supply Curve

    Hello guys, I have a quick question: Would a leftward shift of the supply curve result in a shortage?
  32. F

    What is the reason behind inductive reactance in an AC circuit?

    This is quite a frustrating problem for me so hopefully somebody can describe it in such a way that it settles in my mind. It is the concept of voltage and current being out of phase. Inductors are frequently described as responding to changes in current but does this really make sense...
  33. C

    Free fall and blue shift question.

    Lets say I am in free-fall towards some massive body and I have 2 mirrors and photons bouncing in between them. Now as I fall closer to the massive body the light should get blue-shifted right? And let's say that the frequency of light that I started with is x. As I fall closer I put a jar of...
  34. V

    Explaining Gouy Phase Shift: Simple Explanation

    Hello friends, Could you please explain me Gouy Phase Shift, i have gone through the wikipedia article and i know that it occurs because of the focusing although i am not able to get a physical picture of the same, so it would be really nice if anyone can explain me in simple words about this...
  35. D

    Energy of photons and the red shift

    Was just learning red shift for my A level final exam and thought about this: Okay so I have a galaxy with a fixed amount of stars (for the duration of this thought experiment) producing a fixed power of light, which can be assumed to be from its centre. The galaxy is receding from the Earth at...
  36. K

    Expansion of space - Red shift

    I have always been puzzled by how we see an object from the past and can tell what it is doing now if it is billions of light years away. Given that; 1. the shift in the measurement of the light spectrum indicates the speed at which an object is retreating or getting closer. 2. that...
  37. N

    Laplace Transform Time Shift problem

    Homework Statement Determine the Laplace transform: g(t) = 2*e^{-4t}u(t-1) The Attempt at a Solution Essentially we're told for a time shift we multiply the Laplace transform pair of the function (without the delay) by e^{-as} So here a = 1 (for the delay) The Laplace transform for e^{-4t}...
  38. P

    General Relativity: Gravitational-Red Shift Confused with Doppler Effect?

    From the special relativity theory , for explaining the red-shifting of a photon, that has been red-shifted, is the following: point O: origin point of emitted photo, in Galaxy GlxO point R: receiving point of photon, in Galaxy GlxR GlxO, O ---------->----------------R, GlxR Suppose...
  39. Y

    Measuring Frequency of Trans Planckian Blue Shift

    Consider a source of radiation that is emitting the radiation at the highest possible frequency inversely proportional to the Planck time interval as measured in the rest frame of the source. What frequency would an an observer that is moving towards the source measure? What frequency would an...
  40. Y

    Doppler shift of a signal reflected in a mirror moving away from the observer.

    I have re-written this as as I accidently deleted my original post. I was wondering if the relativistic Doppler shift of a reflection from a mirror moving away from the observer was the same as the Newtonian equation in the special case that the mirror is orthogonal to the direction of motion...
  41. S

    13.56MHz Signal Phase Shift by 90 Degrees

    Homework Statement I have a 13.56MHz signal to be used in a power sensor. However, in order for it to go through the RF/IF Phase and Gain Detector [AD8302], I need to shift the phase of this 13.56MHz signal by +90 degrees. I want to avoid using Transistors, due to the variation in β of...
  42. M

    Black Hole Singularity Blue Shift

    Theoretically, would everything be REALLY REALLY blue at the singularity of a black hole because of the blue shift caused by all the light racing to it (the singularity)? Arigato, -llama
  43. C

    Can LED Shift Indicators Be Created Without Arduino?

    hello I'm working on a manual shift override on an automatic transmission i have most of my design completed but have no clue where to begin the second half. the idea is to create something to tell me what gear i am in, i wanted to connect a circuit in parallel to the triggers for shifting to...
  44. J

    Phase Shift and Time Shift - Fourier Transform

    Homework Statement I'm trying to relate phase shift and time shift Fourier Transformers Homework Equations x(t-t_0) → e^(jwt0)X(jw) The Attempt at a Solution I've attached a picture of my work. I'm a bit confused as to how I would be able to make that simplification towards the end...
  45. L

    Nuclear Physics - Find the s wave phase shift

    Homework Statement In a pp differential cross section, we have the differential cross section dσ/dΩ = 0.111 b/steradian at a lab energy of 4.3 MeV and a lab scattering angle of 30°. What is the s wave phase shift δ? Homework Equations dσ/dΩ = sin2δ / k2 [1] k = (2mE)(1/2) / h...
  46. S

    A simple application of dirac delta shift theorem help

    A "simple" application of dirac delta "shift theorem"...help Homework Statement show that for a, b, c, d positive: δ(a/b-c/d) = bdδ(ad-bc) Homework Equations ∫f(x)δ(x-a)dx = f(a) The Attempt at a Solution Ok so I start with ∫δ(a/b-c/d)f(x)dx But I am not sure how to apply the shift...
  47. T

    Proving S^n = 0 using Shift Operator Properties

    Homework Statement http://desmond.imageshack.us/Himg810/scaled.php?server=810&filename=screenshot20120131at923.png&res=medium The Attempt at a Solution So in particular I want to look at the last part of this problem. That is, "Show that S^n = 0" I know that dim(KerS^k) = k and...
  48. A

    Randomize phase shift in Fourier Transform

    I have some questions regarding shifting the phase of a Fourier transformed spectrum : I have a spectrum with flux on the Y-axis and wavelength on the X-axis. What I want to do is take the Fourier transform of this spectrum. Then add a random phase between 0 and 2pi to the phase only. Then...
  49. J

    Can Someone Explain the Ac Stark Shift in Layman's Terms

    Can someone explain how the Stark Effect works in Layman's terms? I'm trying to understand how an electric field can cool down atoms. What is the electric field doing exactly to the atoms? How is it lowering the atomic energy levels? Is there a difference between Stark Shifting and Stark...
  50. H

    How can I compare bits and perform bit shifts in SystemVerilog?

    Hi, i am trying to do a bit shift in systemverilog and compare the bit. For example: i give a input A=011. Then the input will compare with another digital that i have already setup in fsm like 010. Now it will do the compare, 0 to 0---> bitmatch=1 1 to 1 ---> bitmatch=1 1 to 0 ---> bitmatch=0...
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