Wavelength Definition and 1000 Threads

In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter lambda (λ).
The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids.Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.Wavelength depends on the medium (for example, vacuum, air, or water) that a wave travels through. Examples of waves are sound waves, light, water waves and periodic electrical signals in a conductor. A sound wave is a variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary. Water waves are variations in the height of a body of water. In a crystal lattice vibration, atomic positions vary.
The range of wavelengths or frequencies for wave phenomena is called a spectrum. The name originated with the visible light spectrum but now can be applied to the entire electromagnetic spectrum as well as to a sound spectrum or vibration spectrum.

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  1. Samuel Williams

    Determine the Transition Wavelength

    Hi all, the question is as follows: 1. Homework Statement From the energy level diagram for OH in the study guide, it can be seen that the first rotationally excited level of OH (2∏3=2 J =5\2) lies 120 K above the groundstate. What is the wavelength of radiation associated with a transition...
  2. S

    Peak wavelength and Spectral Bandwidth

    Homework Statement Calculate the expected peak wavelength and spectral bandwidth (in units of wavelength) of the emission for both a GaAs and silicon LED at liquid nitrogen temperature (77 K) and room temperature (300 K). Which of these cases would you expect to result in the best emitter and...
  3. P

    Compton Scattering- finding photon wavelength

    Homework Statement An electron moving to the left at 0.8c collides with an incoming photon moving to the right. After the collision, the electron is moving to the right at 0.6c and an outgoing photon moves to the left. What was the wavelength of the incoming photon? Homework Equations p=γmv...
  4. YMMMA

    Physics: transverse wave & wavelength & motion

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  5. YMMMA

    Physics: wavelength of sound waves

    Homework Statement Stated in the attached file. Homework Equations Wavelength = 2 times length divided by harmonic I don’t know if it’s the relevant equation The Attempt at a Solution I used the equation I wrote. So, if the left side is 10cm longer, I guess it might be 2(10).
  6. Helloworld

    Frequency and wavelength of a wave on a vertical rope

    Homework Statement A long, heavy rope hangs straight down from a high balcony on an apartment building. The lower end of the rope hangs about 1.0 m above the ground. If you grab onto the lower end and waggle it back and forth with constant frequency f, a wave travels up the rope. What would...
  7. B

    Resonant Lengths in open air column question

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  8. S

    Angle of Incidence, Propagation Constant and Wavelength

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  9. M

    Two loudspeakers emit waves, find wavelength

    I solved it, but then saw another solution online and am wondering if is is correct (since it is much faster than mine) and if my reasoning of it is correct 1. Homework Statement Two loudspeakers emit sound waves along the x-axis. A listener in front of both speakers hears a maximum sound...
  10. N

    With the info given, what are 3 ways to calculate wavelength?

    Homework Statement In an investigation into single-slit diffraction, a laser is used to produce an interference pattern on a screen. With the following information determine the wavelength of the light in 3 different ways. · The angle to the third dark fringe is 2.6˚. · The...
  11. Amaterasu21

    I SR Light Wavelength & Direction: Questions Explained

    Hi all, I have two questions about light in Special Relativity. (I'm going to pad these questions out with a few statements about my understanding of length contraction and time dilation, so you can see how I currently think about it and clear up any misconceptions if I've got the basic idea...
  12. B

    A Nanotube diameter versus emitting wavelength

    Can somebody please help me I am looking for the diameter required of a carbon nanotube to emit a wavelength of 800 nm. If I could just find a graph of nanotube diameter versus emitting wavelength.
  13. enter

    I What is the highest frequency of electromagnetic radiation?

    Title says it all. Also, if the frequency of electromagnetic radiation is limited, why? My guess is the wavelength is limited to the Planck length, and when I plug those numbers into the calculator, I get 1.855 * 10^43 Hz. The maximum (Edit: observed) frequency of a gamma ray is 3 * 10^20 Hz...
  14. Krushnaraj Pandya

    Wavelength = deBroglie Wavelength?

    Homework Statement Find the retarding potential required to stop electron of de-broglie wavelength 0.5 nm Homework Equations 1)de-broglie wavelenght=h/momentum 2)eV=KE of electron 3)KE=p^2/2m The Attempt at a Solution Using the above three relations is giving me an incorrect answer for V...
  15. M

    Light wavelength transmission through ice

    I am studying hailstones. I have set up an experiment to pass colored light through hail, one color at a time for the colors of the visible spectrum, Red, Orange, Yellow, Green, Blue, Indigo and Violet (ROYGBIV). I have measured the dominate wavelength for each color with a photo spectrometer...
  16. P

    Finding the mass of a photon with given wavelength

    Hi, stuck on this question, hoping someone could help 1. Homework Statement Two identical photons of wavelength 4.22x16^-7m are created when a certain amount of matter M, is converted into energy, calculate the Mass (M) The Attempt at a Solution E= hf which is hc/wavelength E= 4.71x10^-19J...
  17. Sandeep T S

    I How the wavelength of a photon is measured experimentally?

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  18. J

    De Broglie wavelength of electron and proton

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  19. B

    I Effect of impedance changes less than a wavelength

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  20. T

    Zeeman Effect: Splitting of Lyman-α Wavelength

    Homework Statement The Lyman-α line (n = 2 → n = 1) has a wavelength of 121.6nm in the absence of a magnetic field. When B = 1 Tesla, into how many wavelengths will this split and what are their wavelengths? (You may need the values μ B = 9.274 × 10 −24 J/T, h̄ = 1.054 × 10 −34 Js and c =...
  21. O

    Wavefunctions and the de Broglie wavelength

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  22. Kenneth Boon Faker

    Why do cars crash? (Instead of passing through each other)

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  23. FredFlintstone

    Obtaining 700nm light wavelength

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  24. C

    Finding a third method to determine light wavelength

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  25. M

    Inteference Fringes of Double Slit Experiment in Water

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  26. G

    Maximum Wavelength and Scattering Angle for Triangular Lattice

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  27. Sahar ali

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  28. harambe

    What is the wavelength of a pulse on a hanging rope with changing tension?

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  29. Buzz Bloom

    What fraction of long wavelength EM gets through a small hole?

    Assume a source of EM radiation at wave length λ hits a barrier with a small circular hole of diameter d << λ. What fraction of the radiated power (watts) that hits the hole passes through it? Does it depend on the thickness of the barrier? I understand that after passing through the hole, the...
  30. I

    What is the wavelength difference based on a mini spectrom.?

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  31. R

    Composition of Light: Questions & Answers

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  32. Sritika

    I De-Broglie Wavelength of a captured electron?

    For a proton to capture an electron to form a neutron and a neutrino (assumed massless), the electron must have some minimum energy. For such an electron,how can the de-Broglie wavelength be found out?
  33. V

    Mathematica Color by Wavelength in Wolfram Mathematica: Easy Guide & Tips

    Hello, I'm wonder if is possible in Wolfram Mathematica to fill some object or just set a color of object by a entering a wavelength, i.e. I write 450 and the line will be blue etc. Please advise me, I didn't find anything useful. Thank you all.
  34. S

    I Energy-momentum formula and deBroglie wavelength

    Hi everyone, Im a little bit confused about deBroglies procedure on introducing his famous Matterwave formula. People already knew that the wavelength of the light was equal to Lambda = h/p. The term p comes from the energy-momentum formula; for the light the restmass = 0 so E =pc etc. As...
  35. S

    A What is the Wavelength of the Pilot Wave in the Pilot Wave Theory?

    Hi, I am new to the Pilot Wave theory. In my understanding this theory gives a hope for reconstruction of the realism. But I have several maybe naif questions. What is the wavelength of the pilot wave? Is it the same as deBroglie wavelength formula? Very often people use the walking droplets...
  36. A

    Optics: How would you determine wavelength?

    If there is an light source that is emitting light with the wl of 450nm (blue) and it illuminated a low reflective red object. How would the wavelength be different then if the object was a white object or the emitted light is from a white led. How would we determine this. I am working on a...
  37. Simon Peach

    B Exploring Echoes of Electromagnetic Wave Lengths

    In the electromagnetic wave lengths say from x-rays to the 21 cm hydrogen line, the wave has a wave length. When it hits a receiver, eye, camera sensor whatever, it is turned into an electrical signal that can be interpreted by that device. Now we get to my question, is there an echo of that...
  38. Pushoam

    De – Broglie wavelength of O_2

    Homework Statement Homework EquationsThe Attempt at a Solution [/B] De – Broglie wavelength of ## O_2 ## molecule is ## \lambda = \frac h p ## Assuming that the speed of molecule is small enough to take non – relativistic calculation, ## \frac {...
  39. Richie Smash

    Wavelength of Sound: Solve Using X & Y

    Homework Statement Hello, If one can see the image I posted, the question that follows is this: Use the information provided to obtain a value for the wavelength of sound emitted. The signal is at maximum intensity at X, and minimum at Y. http://uploads.im/7wJOq.jpg Homework Equations Now I...
  40. G

    I How energy of light is conserved when passing through medium

    The velocity of light changes when it passes through a medium of a different refractive index. So let's suppose the light is traveling through a vacuum at a velocity c and then passes through a glass wall. Its velocity decreases while traveling through it but then speeds back up to c after...
  41. Pushoam

    Wavelength of em radiation of H - atom

    Homework Statement Homework EquationsThe Attempt at a Solution E = (13.6 – 3.4 = 10.2)eV = ## \frac {hc } { \lambda } ## =1.22 * 10^{-5} cm So, the correct option is (a). Is this correct?
  42. A

    Can we vary the wavelength of an LED light

    I would like to start growing plants in an artificial simulated environment with very low cost, hence i would like to know whether if i could vary the wavelength of light using a normal led light by varying voltage or current
  43. N

    Find Wavelength Homework: Solve with Plank's Constant

    Homework Statement https://imgur.com/a/9UhMA Homework Equations Wavelength = planks constant/ mass*velocity The Attempt at a Solution (6.626*10^-34)/((9.11*10^-31)(.01*10^8)) = .728nm which is an option but they have .243nm as the answer and I don't know where I did it wrong or what I...
  44. W

    Calculating Index of Refraction with Wavelength

    Homework Statement A beam of white light goes from air into water at an incident angle of 75 deg. What is the critical angle that the violet (410 nm) parts of the light is refracted? Homework Equations n1sin(θ1)=n2sin(θ2) n=c/v c=λf The Attempt at a Solution So sure, I get that the answer is...
  45. M

    Wave interference - coherence and wavelength

    I know to produce an observable inteference pattern two waves must be coherent(same frequency/phase differnce). Do coherent waves therefore always have the same wavelength? Is it possible to have interference between two waves with the same frequency and different wavelengths, and if so what...
  46. M

    Frequency and wavelength of vertical string wave

    Homework Statement A long, heavy rope hangs straight down from a high balcony on an apartment building. The lower end of the rope hangs about 1.0 m above the ground. If you grab onto the lower end and waggle it back and forth with constant frequency f, a wave travels up the rope. What would...
  47. J

    B What is the relation between wavelength and orbital?

    I am in a chemistry class, and there was an in class example on how to do this type of problem, but then when I looked in the book, there wasn't an equation. the questions are related to what the wavelength will be when electrons are moving between orbitals.
  48. Y

    A What frequencies allow for the long wavelength limit in solid state physics?

    In the "Introduction to Solid State Physics" by C. Kittel, there is a long wavelength limit in chapter 4 -Phonons I. When Ka << 1 we can expand cos Ka ≡ 1 - ½ (Ka)2 the dispersion relation will become ω2 = (C/M) K2 a2 Does anyone know what frequencies can allow this long wavelength limit to hold?
  49. M

    How does the wavelength change the amount of refraction?

    Using a green laser instead of a red laser seems to change the way the ray changes during refraction. Why is that so?
  50. J

    B Understanding Wavelength Size in Electromagnetic Waves

    Hey everyone hope you're doing well. I've always been confused about one particular aspect of electromagnetic waves. I understand that each frequency has a corresponding wavelength that is inversely proportionate and that the wavelength is the distance between successive crests or troughs. But...
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