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. S

    Shift in energy due to weak interaction

    Homework Statement A particle is in a box of length L on x-axis. 0<x<L. What is the first order shift due to V(x) of the wavefunction? Homework Equations H=p2/2m Sin=sqrt(2/L)cos(npix/L) En=n2pi2hbar2/2mL2 V(x)=kx2/2 The Attempt at a Solution I'm super confused because the shift in the...
  2. S

    Designing a 4 bit ALU Shift LR

    Homework Statement HI This 4 bit ALU requires 8 functions in a bit slice, and satisfies following criteria Also, it can only be constructed via basic logic gate..and,or,not,xor... No filp-flop...etc. S1 S2 S3 OUTPUT 0 0 0 Shift A Through (X = A) 0 0 1 Shift input A Left (X = A...
  3. C

    Energy shift using perturbation theory

    Homework Statement I am looking at the relativistic correction to the kinetic energy for a hydrogen atom. I am told that the perturbation is usually written as H = -p^4/(8 m^3 c^2) and need to find the energy shift Homework Equations I know that from the perturbation theory the energy...
  4. B

    Measuring the Accuracy of EM Spectrum Shift: Red vs Blue

    How accurate is it possible to measure the EM spectre ?
  5. F

    Calculating Circular Polar Orbit Parameters and Fractional Doppler Shift

    Hii guys.I have this problem.Can anybody help me on this.tq Homework Statement A satellite is in a circular polar orbit at a height of 870 km, the orbital period being approximately 102 min. The satellite orbit passes directly over a beacon at sea level. Assuming an average value of...
  6. G

    Determing frequency shift of an ultrasound

    Homework Statement A Doppler blood flow unit emits ultrasound at 5.0 MHz. What is the frequency shift of the ultrasound reflected from blood moving in an artery at a speed of 0.20 m/s? Express your answer using two significant figures. Homework Equations f' = f0(v/v-Vs) frequency shift = f'...
  7. C

    Compton shift, lorentz factor

    Hello everyone! I've got a problem I've been working on for the past two days and can't seem to figure out. The problem is as follows: Homework Statement Two different experiments use two different wave lengths for the Comptom Shift. The scattered photons wavelengths and scatter angles...
  8. D

    Doppler shift with microwaves i think

    Doppler shift with microwaves...i think... Homework Statement Microwaves, which travel at the speed of light, are reflected from a distant airplane approaching the microwave source. It is found that when the reflected waves are beat against the waves radiating from the source, the beat...
  9. L

    Red or Blue Shift: Moving Light Sources Forward/Backward

    I want to know if the red or blue shift apply if I am moving away or toward a light beam and if it still apply if I am moving the light beam source with me forward or backward.
  10. J

    Gravitational lensing and red shift

    Hi I'm new to the forums. I have a question I hope you guys can help me understand. When gravitational lensing produces multiple images of the same object, do they undergo any red/blue shift? And if so, is the frequency shift the same for each image?
  11. H

    Anharmonic Oscillator - Energy Shift Calculation Using 1st Order Perturbation

    Homework Statement V(x) = \frac{1}{2}mw^{2}x^{2} + \lambdax^{4} Using first-order perturbation theory to calculate the energy shift of: 1. The ground state: \psi_{0}(x) = (2\pi\sigma)^{\frac{-1}{4}}\exp(\frac{-x^{2}}{4\sigma}) of the harmonic oscillator, where...
  12. L

    Red shift photons: where does the energy come from?

    The photon energy is given by E = h*f. Now, i am aware of the dual wave/particle character of photons. But let's say i emit ONE SINGLE photon, when moving at, say, 0.99c towards the observer. The observer will observe a huge blue shift in this photon. In fact, with respect to the source, it...
  13. H

    Testing System Linearity and Shift Invariance

    please anyone can help me how make check the linearity and shift invarient for the system I want to determine whether the system is linear and shift invarientby steps g(m,n) = f(m,-1) + f(m,0) + f(m,1) g(x) = (integration from +infinety to - infinety) f(x,z) dz please help me...
  14. B

    Arithmetic shift divison question

    If I have the following function: a = b * c/255 The following function is apparently equivalent using only shifts: product = b * c; a = (product + (product>>8) + 1)>>8; I am having trouble following how this function works. Since an arithmetic right shift is division by a power of...
  15. S

    Phase Shift Oscillator: Why, What & How

    hi i want to know why R-C oscillator is called phase shift oscillator? does it only shift the phase?How the amplitude and the frequency of oscillator ca be changed? thanks
  16. M

    Proving the Shift Theorem in an Inverse Fourier Transform

    Homework Statement We are asked to prove that if F(\omega ) is the Fourier transform of f(x) then prove that the inverse Fourier transform of e^{i\omega \beta}F(\omega) is f(x-\beta ) Homework Equations F(\omega)=\frac{1}{2\pi}\int^{\infty}_{-\infty}f(x)e^{i\omega x}dx...
  17. L

    Calculating Cosmic Redshift & Age of Universe

    The cosmic microwave background (CMB) radiation detected by Penzias and Wilson at Bell Labs in 1965 has the spectrum of a blackbody, with an observed peak at λ = 1 mm. It is believed that when the light was emitted the spectrum peaked at a wavelength of λ = 1000 nm (close to the peak of the...
  18. M

    Relativistic Doppler Shift Theory Question?

    Homework Statement What sort of frequency shift does a rocket ship traveling along the x-axis as some speed close to c observe when it passes directly over a light source emitting photon on the y-axis (so when the angle between them is 90 degrees). At this angle, the rocket is neither...
  19. J

    Understanding the Fourier Time Shift Property

    The time shift property of the Fourier transform is defined as follows: x(n - n_o ) \Leftrightarrow e^{ - j\omega n_o } X(e^{j\omega } ) I am confused by this notation...what does X(e^{j\omega } ) mean? I know that X(\omega) is the value of the Fourier transform at a given angular frequency...
  20. daniel_i_l

    Bacteria make major evolutionary shift in the lab

    I recently came across this article: http://www.newscientist.com/article/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html Has anything on this scale ever been observed before? Lenski's freezer must be an immensely valuable source of evolutionary information. And one question, why...
  21. B

    Red Shift and Blue Shift: Is It Possible?

    I was thinking today and had an idea but didn't know if it was possible. When an object moves toward or away from an observer, the light (such as visible light) "shifts", the wavelengths become closer together (moving toward you) or further apart (moving away from you). Say for example we...
  22. mnb96

    Symmetries and shift of coordinates in 3D

    Hello, given a vector x=(a,b) in 2D, and considering another vector obtained by shifting cyclically the coordinates of x, we get x'=(b,a). It is straightforward to prove that x and x' are simply the reflection of each other on the line k(1,1). Now let's suppose we are in 3D space. Given a...
  23. T

    What would be the consequences of a magnetic pole shift?

    What would be the potential consequences posed by a shift of the Earth's magnetic poles? I know this has happened many times before in Earth's several Billion year history. Hypothetically, what would happen if there was a shift tomorrow?
  24. P

    Red shift and the train thought experiment

    It seems there is usually no mention of "redshift" when train thought experiment is used to teach relativity. Is there a reason for not bringing redshift (blueshift) into the experiment?
  25. S

    Absolute velocity, CMB, and doppler shift

    I've heard it said that it is impossible to determine an objects absolute velocity, all one can do is find it relative to some other object... but, if the CMB is everywhere, why could you not just measure the doppler shift in all directions, and adjust your velocity so the CMB has no doppler...
  26. I

    Derivation of Doppler Shift from Frequency to Wavelenght

    Homework Statement Derive the doppler shift equation from the equation in terms of frequency to one in terms of wavelenght. Clues: frequency=c/lamda, use Taylor's expansion, velocity of source is much smaller than velocity of wave. c-velocity of wave v-velocity of source f-frequency...
  27. H

    Red shift distance relationship and dark energy

    It is my understanding that there is evidence from the red shift/distance relationship that while the rate of universal expansion was once decreasing (from the Big Bang until about 6-7 billion years ago -BYA for short), at about 6-7 BYA it began increasing. This, as I understand it, is the main...
  28. N

    Can gravitational blue shift happen without gravitational time dilation?

    First, a simple scenario to set our expectations: Consider a "stationary" massless non-relativistic test particle in empty space. We'll call the particle "P". At a very large proper distance to the cosmological "west" of P there is a neutron star, at proper rest relative to P. Let's call...
  29. Z

    Geomagnetic reversal and pole shift

    im having a hard time finding any reputable information or scientific backing to support the theory that our magnetic field will reverse and/or shift anytime soon. also would this mean that the equator areas would remain almost the same as before in terms of magnetic field?
  30. N

    SR and classical Doppler shift

    Alice and Bob are each in their own spaceship, and are traveling radially, initially away from each other, and subsequently toward each other, at some highly relativistic relative speed, say 99c. Each ship emits light flashes toward the other. Alice observes the light from Bob's outbound...
  31. C

    Phase Shifts and Interference in Reflection: Understanding the Differences

    Hi all! I have a problem about the phase shift an e.m. wave acquire when, traveling through air, it's reflected back by a mirror (or a beam splitter) with n > n(air). Now, I know the example of the thin film interference due to a π shift of the wave reflected by the medium. But I see...
  32. C

    An unmodelled component in astronomical and cosmological spectral shift

    The standard model of accelerating expansion is successful in matching parameters to observation, but substantial observational problems with both CDM and MOND are now well reported in the literature. While there is no true reconciliation between general relativity and quantum mechanics, science...
  33. S

    Next Paradigm Shift in Physics: Exploring Questions with Steve

    Hello all, I have just joined this forum and am taking the bold step right off the bat of starting a thread. I am looking for folks who are interested in discussing what the next paradigm shift of physics will look like. I have read a few books in this area such as Kuhn's Structure of...
  34. L

    Shift register with or without latch

    hi guys, i want to ask a question. what's the difference if i use shift register with and without latch. I've done some experiments and the output is the same but will it effect its efficiency? thank u. =)
  35. ChrisXenon

    Expanding Universe & Red Shift

    We hear that the universe is expanding, and this accounts for red shift as all objecsts are accellerating away from each other. But I have also heard that it is the space itself, of which the universe made, that is expanding - not that things are moving in that space. If so, then the...
  36. A

    Maxwells equation and Doppler Shift.

    I am trying to grasp how Maxwell's equations and energy/photons are related in a doppler shift problem. The way I stated it seems to have attracted non-serious hecklers; so I am trying to restate the problem for people who know Maxwell's equations and are familiar with engineering. In...
  37. P

    Huygens' principle and phase shift

    I wonder why the amplitude of Huygens' wavelet is equal to the amplitude of incident wave multimpled by i / \lambda. I found this formula in 'Modern Optics' by Guenther p. 335 unfortunately without proof. Has anyone seen the derivation of this fact. Could you recommend me some good books in...
  38. A

    Understanding Phase Shift in Wave Light

    phase shift in wave light?? when doing reflecton/refraction/transmission of wave light exercise,we must take phase shift into account. but in what situation there is a π phase shift ? or other phase shift? i cannot apply this well! help~
  39. C

    Find Phase Shift & # Squares to Move Trig Graphs

    Hi i was just wondering if someone could tell me how one can find the phase shift and the number of squares to move the graph over by from an equation?. We are doing cosine and sine graphs and my teacher has been away for a few days so the supply teachers haven't been really that great in...
  40. K

    Does the observed frequency approach infinity or does it become negative?

    I chose to write an essay on the "interesting" question I stumbled upon For part of it I am trying to calculate the Doppler shift in light with the relative motion of C. I suppose in the effort to not drone on for days I will first limit it to small, more simple questions and later,if we...
  41. C

    Doppler Shift for Traffic Light Colors

    Homework Statement How fast would a motorist have to be traveling for a yellow (l = 595 nm) traffic light to appear green (l = 550 nm) because of the Doppler shift? Homework Equations v=[(c)(f0/fs)2-c] / [(f0/fs)2+1] The Attempt at a Solution v= Speed of motorist c= Speed of light...
  42. B

    Treble and bass audio controls w/o phase shift?

    Simple treble and bass controls in audio equipment use RC networks that have a phase shift equal to a radian per neper, or about 6.6 degrees per dB of boost or attenuation. Are there analog treble or bass control circuits that have no phase shift?
  43. Z

    The source of gravitational red shift

    On the following website; http://www.cfa.harvard.edu/Walsworth/Activities/Atomic%20clock/old_atomicclock.html" I read that; The gravitational red-shift is a consequence of the local position invariance of the Einstein Equivalence Principle. I know what gravitational red shift is and...
  44. P

    Quick easy clarification (redshift vs blue shift)

    i just have the two mixed up, and need an example to set it straight... lets say you're source is a red light (hight wavelength, low frequency) to green light (lower wavelenght, higher frequency)... that would be a blue shift? redshift = wavelength (H->L) frequency (L->H)...
  45. J

    How Does Compton Scattering Affect X-ray and Gamma-ray Wavelengths?

    Homework Statement X-ray beam with wavelenth= 1 X 10-10m and a gamma-ray beam from a Cs137 sample with wavelength= 1.88 X 10-12m. If the radiation scattered form free electron is viewed at 90 deg to the incident beam a) What is the Compton wavelength shift in each case? b) What kinetic...
  46. D

    Two people in spaceshift shift seats

    Two people in a spaceship shift seats... Homework Statement Simma (mass 60kg) and Stan (mass 90kg) are testing an ultralight spacepod. They swap seats, with the seats being 4.0m apart, located at equal distances from the center of mass of the space-pod. The space-pod's mass is 50kg. Why does...
  47. F

    Why shift the Mann Whitney distribution?

    I'm reading up on the Mann Whitney test, and I can't wrap my head around one thing. Most of the test makes perfect sense. If two samples come from populations with similar medians, then the sum of ranks of both of those populations should hover around some expected value. The "T" or "U"...
  48. G

    Phase Shift Independent of Frequency: Circuit Solutions

    Hi Is anyone aware of a circuit that could provide a phase shift independent of frequency? I have thought of doing it digitally but the number of components needed are ridicules. Thank you
  49. J

    The Mystery: The Truth about Time Shifts in Wormholes

    A typical device in (theoretical) time travel is a wormhole, and the usual method of inducing a time shift, i.e. the two mouths at different times, is to subject one mouth to relativistic time dilation. However, I can't see why a relativistic boost will result in a time shift. It seems that...
  50. B

    Are the formulas that account for aberraion and doppler shift compatible?

    Presenting the aberration of light effect we consider that two observers at rest in I and I' in the standard configuration equipped with laser guns start to emit light when they are instantly located at the same point in space. The problem is to find out a relationsship between the directions...
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