What is Wavelengths: Definition and 231 Discussions

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.

View More On Wikipedia.org
Recent contents Top users
  1. O

    Filtering certain wavelengths from the camera RGB videostream

    Hello, We are using ordinary CCTV cameras to grab color pictures. The representation of the picture in our image processing application is in RGB format. Is it possible to determine wavelength of the light at particular pixel from RGB values ? The purpose is to cut out all the white light...
  2. K

    Universe smaller than wavelengths?

    How did particles exist in the very, very early universe when its diameter was smaller than their wavelengths? Are we just supposed to be content with the supposition that wave descriptions are impractical in this situation?
  3. A

    Diffraction Grating, Light with two wavelengths

    Homework Statement Light with wavelengths of 520 nm and 630 nm passes through a diffraction grating containing 6000 lines/cm. a. Sketch a diagram of the image produced from m=0 to m=2, labeling the order of each fringe. b. Calculate the angles for the first and second order maxima that...
  4. D

    Chemistry: Electromagnetic Wavelengths and Frequency

    Hi guys, I was reading through some Chemistry papers when I came across these two lines; When solids are heated, they emit electromagnetic radiation over a wide range of wavelengths. The amount of radiation energy emitted by an object at a certain temperature depends on its wavelength. However...
  5. B

    Finding Green Light Wavelengths for Dissertation

    Hi sorry if this is very basic, I am an animal final year student and have come across a problem for my dissertation. I am looking at wavelength of light. Now the question, is a green bulb purely giving off green light, ie if it more blue green is it giving of predonimantly light of around 500...
  6. T

    What Happens to Photons During Ionization?

    If a photon is used to ionize an atom then what happens to the photon? If the wavelength of the photon corresponds to the ionization energy, then the photon is absorbed/annihilated, yes? What if the photon has more energy. Is a lower energy photon emitted during ionization?
  7. D

    Light Wavelengths: Causes & Frequency Explained

    What causes the difference in wavelengths of light? Is it frequency or something?
  8. E

    How can objects have wavelengths?

    I'm really confused about the de Broglie wavelength thing. Like I understand that according to the formula large objects have wavelengths that could not be observable in the real world but i still don't understand what type of wave de Broglie is referring to. Is he referring to longitudinal...
  9. V

    Diffraction & Interference: Investigating Wavelengths with Fresnel Biprism

    I'm doing a lab report on diffraction and interference. I've done several diffraction experiments (single slit, double slit, diffraction grating, Fresnel Biprism) to find the wavelength of the laser used. with Fresnel Biprism, wouldn't the refraction within the prism cause a change in...
  10. D

    Identifying wavelengths of sound waves

    Hey guys, I'm kinda having some problem with this question on finding the frequency of the sound wave of the picture provided. The speed the sound wave is traveling at is 340m/s. I know that in order to find the frequency, I hve to tke speed / wavelength. However, I'm not sure how to find the...
  11. H

    Oxygen energy levels and resonant wavelengths?

    How many energy levels the oxygen atom have? What energy (in eV) is required to get to each level. From my research i have only been able to find the first two levels, the first of which is a forbidden level. 1.=.98eV 2.=1.63eV
  12. H

    Atom Excitation: Absorption Peaks or short wavelengths?

    I just have a quick question. Which way of Atom Excitation is more efficient? Photon Energy which matches the absorption peak(s)? Or Photon energy of a Shoter wavelength than the absorbtion Peak?
  13. D

    Short wavelengths carry no energy?

    short wavelengths carry no energy? Hey guys (and girls), I'm reading the book "The Black hole war", by Leonard Susskind and on the page 208 it has written something that kind of surprised me. I ll just quote an entire paragraph: "The hypothesis that light is composed of indivisible photos...
  14. E

    Calculating de Broglie Wavelengths of Rb Atom and Electron

    Homework Statement What is the de Broglie wavelength of a 10 microKelvin Rb atom? A 5000K electron? Homework Equations \lambda=\frac{h}{p} V=\sqrt{\frac{3KT}{m}} The Attempt at a Solution I used the velocity equation to find the velocity relating to temperature and mass. Then, as...
  15. S

    How Does Soap Bubble Thickness Affect Color Wavelength Interference?

    Homework Statement Ok I have two questions. 1. Light waves of which wavelength will destructively interfere due to the thickness of the bubble film? The bubble film thickness is 165 nm, with an index of refraction of n = 1.3. a= 430 nm b= 650 nm c= 860 nm d= 285 nm 2. You are...
  16. I

    EM Shielding Dilemma: Understanding Transverse Wavelengths

    In the classical picture of an electromagnetic wave, the wavelength is specified along the direction of travel. However, with EM shielding that is using a grid (microwave, chicken wire), I've heard that so long as the spaces are less than the wavelength, you will achieve electromagnetic...
  17. B

    Double slit experiment and wavelengths

    Homework Statement A double-slit experiment is performed with light of wavelength 558.0 nm. The bright interference fringes are spaced 1.84 mm apart on the viewing screen. What will the fringe spacing be if the light is changed to a wavelength of 335.0 nm? Homework Equations d=...
  18. R

    Double Slit, different wavelengths change in X

    Homework Statement Two slits are 0.158mm apart. A mixture of red light (wavelength = 665nm) and yellow-green light (wavelength = 565nm) fall onto the slits. A screen is located 2.2m away. Find the distance between the third-order red fringe and the third-order yellow-green fringe...
  19. H

    Calculating Wavelengths & Energy Levels of Hydrogen Atom

    Homework Statement the wavelengths of the emission lines produced by the hydrogen atom are given by the formula: 1/lambda = 1.096776 x 10^-2 ((1/n2^2) - (1/n1^2)) nm^-1 (a) what are the wavelengths of the first two lines in the Balmer series, H-alpha and H-beta (involving transitions...
  20. L

    Solve de Broglie Wavelength of Atoms in eV: Urgent Help

    Homework Statement http://www.strings.ph.qmul.ac.uk/~russo/QP/r06QPHYEX.pdf Question 3. The Attempt at a Solution I can easily derive the equation I need, which is: lamda = h/p Which after some playing around with K.E =1/2mv^2 etc we obtain: lambda (de brogile) = h/SQRT(2mKE)...
  21. C

    CMB Redshift Question (Visible Wavelengths)

    I've looked quite a bit on this forum and also elsewhere online and I cannot really find any information on my inquiry. If this is a double post please delete and send me in the right direction. Now I may be totally off on my thought process, but as I understand it the CMB first started off...
  22. S

    Longest Wavelengths in 128 cm Tube: Open at Both/One End

    Homework Statement What are the three longest wavelengths for standing sound waves in a 128-cm-long tube that is (a) open at both ends and (b) open at one end, closed at the other? Homework Equations W=V/F The Attempt at a Solution 128 cm because nothing bigger could fit in the tube
  23. Lisa!

    X-ray Imaging with Anstegrom Wavelengths

    What's the use of X-ray with angestrom wavelengh in imaging? Do you know of any good source to study more about that?
  24. D

    Diffraction grating and wavelengths

    diffraction grating URGENT Homework Statement A spectrometer is used to analyze a light source. The screen-to-grating distance is 50.0 cm and the grating has 5000 slits/cm. Spectral lines are observed at the following angles: 12.98, 19.0, 26.7, 40.6, 42.4, 63.9 and 77.6. How many different...
  25. C

    Two wavelengths, max/min at same angle

    Homework Statement Light goes through two slits 40 mm apart. Does an angle exist at which light of wavelength 440nm has a maximum and light of wavelength 660nm has a minimum?Homework Equations dsin\theta=m\lambda1 = maximum dsin\theta=(m+ 1/2)\lambda2 = minimumThe Attempt at a Solution I...
  26. S

    What is the Correct Value of k for a 94.8 nm Photon Emission in Hydrogen?

    Homework Statement The wavelength of the photon emitted when a hydrogen atom undergoes a transition from the k state to the n = 1 state is around 94.8 nm. How much is k? Homework Equations 1/lambda= 1.97x10^7(1/1^2-1/k^2) The Attempt at a Solution...
  27. S

    Exploring the Balmer Series: Counting Spectral Lines with Increasing Wavelengths

    Homework Statement In the Balmer series, how many spectral lines have the wavelength greater than 400 nm? Homework Equations 1/lambda= R(1/2^2-1/n^2) lambda=wavelength r=rhydberg constant 1.097x10^7 n= 3,4,5... balmer series is visible light The Attempt at a Solution...
  28. P

    Two wavelengths, find time between successive beats

    Two pianos each sound the same note simultaneously, but they are both out of tune. On a day when the speed of sound is 348 m/s, piano A produces a wavelength of 0.765 m, while piano B produces a wavelength of 0.772 m. How much time separates successive beats? So I know: v=348 m/s...
  29. K

    Dangerous Wavelengths In Glassblowing

    Hello all, this is my first post on physics forums. I recently started working in a glass studio and am curious to know what radiation is being emitted by the equipment so that I can purchase appropriate eye protection. What wavelengths of harmful light are emitted from burning oxygen and...
  30. S

    Comparing Electron Wavelengths?

    Homework Statement An electron makes a transition from the third energy level to the lowest energy level in a box of width 0.1 nm. what is the wavelength of the emitted photon? Compare this wavelength with the wavelength associated with the transition from the third energy level to the ground...
  31. R

    Laser Scanning: Wavelengths & Pulse Durations

    Detailed ideas on how different wavelengths and pulse durations can limit scans
  32. A

    Question on electron orbitals and wavelengths?

    Question on electron orbitals and wavelengths?? Hi I have a couple of dumb laymans questions: (1) I have seen various diagrams of electron shells where some of them appear as ,roughly , rotating figure eights. Is there any physical conceptual interpretation of this? It would...
  33. L

    Method for determining the difference between two similar optical wavelengths

    Hi optical engineers/physicists, I'm designing an optical sensor system, and it would be very beneficial if there was a method for determining the difference between two very close (down to tens of femtometers) optical wavelengths. The difference measured can be relative, although absolute...
  34. G

    What Frequency is Needed for Effective Ultrasonic Cleaning?

    Homework Statement Particles approximately 3.0 X 10-2 cm in diameter are to be scrubbed loose from machine parts in an aqueous ultrasonic cleaning bath. Above what frequency should the bath be operated to produce wavelengths of this size and smaller? Homework Equations speed of...
  35. D

    How many wavelengths could appear in the spectrum of hydrogen atom

    How many wavelengths could appear in the spectrum of hydrogen atoms initially in the n=5 state?
  36. M

    How does black absorb all the wavelengths?

    How does black absorb all the wavelengths ? & why does the reflection capacity of a transparent glass increases if black is put behind it .
  37. C

    Calculate X-Ray Wavelength for Lead Target

    Homework Statement The tube in a medical research X-ray unit uses lead (Z=82) as it's target. Assume the electrons are accelerated through the voltage calculated in part (b). What is the wavelength of the Kα line? Homework Equations KE=-13.6 ev ((Z-1)squared) / (1squared) KE=PE=VQ E=QV λ=hc/E...
  38. E

    Find index of refraction of the prism for 2 wavelengths

    Homework Statement Homework Equations Snell's Law: na*sin(theta of a) = nb*sin(theta of b) wavelength = index of refraction / n n = c / v The Attempt at a Solution The only information given in the problem is the 2 angles of refraction and of course n of air is 1, I do not understand how to...
  39. L

    Wavelengths of lowest and highest audible frequencies

    Homework Statement What are the wavelengths in air of the lowest and highest audible frequencies if te range of human hearing is 20 Hz to 20 kHz and the sped of sound is 342 m/s? Homework Equations v= \lambdaf The Attempt at a Solution v= \lambdaf 342 = 20 Hz \lambda \lambda = 17.1...
  40. O

    Need help calculating wavelengths of L(alpha) and L(beta

    Hi, I need some guidance on a particular question for my coursework. The questions states: Calculate the wavelength of L(alpha) and L(beta) x-ray photons produced from a copper target (Z=29) I have tried finding the wavelength using E=hc/lambda and re-arranged for lambda (lambda=hc/E)...
  41. N

    What does it mean when it says for long wavelengths?

    Homework Statement Light is incidence on a metal surface. For long wavelengths find E and B. What does it mean when it says for long wavelengths? Homework Equations The Attempt at a Solution
  42. R

    The difference between Compton and DeBroglie wavelengths?

    Hi. As you can see, the question is pretty straightforward. What is the difference between the Compton and the DeBroglie wavelength? I have looked into Wikipedia and other sites but I'm still somewhat confused. Thanks.
  43. R

    Diffraction Grating wavelengths

    light wavelengths of 520nm and 630nm passes through a diffraction grating that contains 6000lines/cm. a) sketch a diagram of the image produced from m=0 to m=2. label the order of each fringe.b) calculate the angles for the first and second-order maxima that would appear on the screen. c) What...
  44. S

    Is There a Gravitational Spectrum for Measuring Wavelengths?

    Contemplating the propogation of Gravitation at roughly c in the form of a wave, has anyone ever attempted to quantify lambda, or the wavelength, in terms of meters or some other unit? Is there a gravitational spectrum, like there is an electromagnetic spectrum? And finally, could there be any...
  45. M

    De Broglie Wavelengths: Need clarification for questions.

    Thanks for any help you can give. I just started modern physics and my teacher has a tendency to give questions that were based on things not mentioned in the book and only briefly mentioned in the lectures, so I'm a bit confused. Homework Statement 1) Calculate the distribution function of...
  46. P

    The Electromagnetic Spectrum: Wavelengths, Limits, and the Universe

    Are there wavelength limits at either end of the Electromagnetic spectrum? Is it true there could be a wavelength the size of the universe? What happens at the other end? Is there a quantum limit?
  47. P

    If we see wavelengths from 0.4 mm (blue) (not 400nm) and 0.7 mm(red) (not 700nm)

    Hello everyone, here's a question that I have: Imagine your eye was sensitive in wavelengths of 0.4 mm to 0.7 mm rather than 400 nm to 700 nm. In this case, your mind would identify light waves that were 0.4 mm as blue and 0.7 mm as red. What would your world look like? How would it be...
  48. L

    Diffraction effects and wavelengths

    Do higher wavelength radiation have more pronounced diffraction effects than low wavelength radiation, and why is that?
  49. N

    Calculating quantum wavelengths

    Homework Statement Ok,as part of my dissertation I'm trying to explain about how quarks have a bigger quantum wavelength than protons so when you localise a quark inside a proton, the uncertainty in energy of the system becomes really big so there's a load of creation/anhilitation of other...
  50. I

    Phase difference and number of wavelengths

    Homework Statement A light wave is propagated from point A to point B in space. We introduce along the way a glass lens with parallel faces of index 1.5 and width L=1mm. The value of teh wavelength is 500μm in space. How many wavelengths are between A and B with and without the glass lens...
Back
Top