What is Visible spectrum: Definition and 20 Discussions

The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 THz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions these limits of human perception can extend to 310 nm (UV) and 1100 nm (NIR).The spectrum does not contain all the colors that the human visual system can distinguish. Unsaturated colors such as pink, or purple variations like magenta, for example, are absent because they can only be made from a mix of multiple wavelengths. Colors containing only one wavelength are also called pure colors or spectral colors.
Visible wavelengths pass largely unattenuated through the Earth's atmosphere via the "optical window" region of the electromagnetic spectrum. An example of this phenomenon is when clean air scatters blue light more than red light, and so the midday sky appears blue (apart from the area around the sun which appears white because the light is not scattered as much). The optical window is also referred to as the "visible window" because it overlaps the human visible response spectrum. The near infrared (NIR) window lies just out of the human vision, as well as the medium wavelength infrared (MWIR) window, and the long-wavelength or far-infrared (LWIR or FIR) window, although other animals may experience them.

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    I The Science Behind Rainbows: Explaining the Center of a Rainbow | Gooood Morning

    Gooood Morning I was traveling with my son and he noted the rainbow out the window and asked why we see only half. I informed him that the earth blocks the other half and if we were in an airplane, we could see the entire circle. Set that aside. When we look at the electromagnetic spectrum...
  2. Z

    Aromatic amines having a brown color

    Aromatic amines having a brown color
  3. J

    Optical Converting non-visible light to visible spectrum for photography

    I am trying to capture corona discharge on metal conductors. I am using a Canon DSLR and it works pretty good. I think there may be light from outside of the visible spectrum being emitted during these discharge events so I would like to see if it's possible to capture this light and actually...
  4. B

    Angular width of first-order visible spectrum

    This is a diffraction grating problem I have been given that I am trying to answer Made a attempt at it and just wanted to see if I done this correctly or not? I get an angular width of 0.71 degrees which is very small Any help is much appreciated! Thanks
  5. T

    I High resolution visible spectrum

    I'm trying to find a high resolution image that shows the visible electromagnetic spectrum with a fine graded scale. It should be detailed enough to pinpoint which exact colour corresponds to a particulate wavelength (integer in nanometer) of light. I find a lot of images through searches but no...
  6. M

    White light vs visible spectrum

    Does white light contain only the wavelengths of visible spectrum (i.e only from 400nm to 800nm)?
  7. Sterling Lutes

    Amount of single photons to make white light?

    First off I hope I'm putting this in the correct forum. My question is more than just the minimum amount of photons to make a single blip of white light, but more so the base photons in the visible spectrum of light. We have all seen a prism split light into violet, blue, cyan, green, yellow...
  8. T

    Can I Reach the End of a Rainbow with a Shovel?

    I'm interested in rainbows. I'm talking about good old fashioned arc/halo rainbows like those you see in the sky. Sometimes you see rainbows from lawn sprinklers. How small would the smallest rainbow arc conceivably possible to view be? Could I make a rainbow at night using a sprinkler with a...
  9. E

    How would you convert visible light to infrared or microwave

    Is it possible to convert light in the visible spectrum to infrared or microwave light. What processes would be used to do this? Thanks, EJ
  10. X

    Wavelength in the visible spectrum most strongly transmitted

    Homework Statement A camera lens (n = 1.29) is coated with a thin film of magnesium fluoride (n = 1.71) of thickness 87.0 nm. What wavelength in the visible spectrum is most strongly transmitted through the film? Homework Equations λ = 2nt/m The Attempt at a Solution λ = 2(1.71)(87E-9m)/(1)...
  11. K

    The spectrum of the blue part in a candle flame

    Homework Statement In the spectrum of the blue part in a candle flame, there’s a violet emission at 432 nm due to excited CH* molecules (chemiluminescence). Why 432? Why not 400 or 500? There are emissions at 436, 475 and 520 nm too. Why these numbers? 2. The attempt at a solution Is it...
  12. R

    Mean colour of visible spectrum?

    How the Mean colour of visible spectrum is yellow? Shouldn't that be green according to acronym VIBGYOR?
  13. S

    Light emission and energy of states

    Homework Statement The emission spectrum of thermally excited sodium atoms practically consists of a single intensive line at 589 nm wavelength. What is the energy difference (in eV units) between the excited and ground states of the sodium atom? Homework Equations E = hc/lambda, we also know...
  14. robotpie3000

    Improving the Efficiency of Light Bulbs: Possible Solutions?

    I just finished an experiment on blackbody radiation, and one of the post lab questions asked me on the possible ways in which a light bulb can be made more efficient such that the majority of the light it produces falls in the visible spectrum. After some quick research I think one of the...
  15. V

    Determining index of refraction and wavelength of a visible spectrum?

    Homework Statement You decide to become a forensic pathologist because you enjoy working with dead people-they don't talk back-more than with the living. In one murder investigation, you find an unknown liquid in the victim's stomach. To identify this liquid, you pour a known amount of it onto...
  16. S

    Question about the order of colors in the visible spectrum (NOT philosophy)

    Is it a silly question to ask *why* we see the orders of colors the way we do in the visible spectrum with respect to wavelength? For instance, I know that comparisons to dogs are often made with the following visible spectrum comparisons...
  17. D

    Can IR Rays Be Shifted Into the Visible Spectrum Using Simple Materials?

    Hi, I'm trying to think up a way to shift IR rays into visible light spectrum so that the human eye can effectively see the IR image. Is it possible to do such a feat with something as simple as goggles made from a special material (e.g. anti-stokes pigments)?? If not possible with such...
  18. I

    Why Iron Produces Green Light in Visible Spectrum

    Homework Statement Iron produces many lines in the visible spectrum when given energy. Suggest why a sample of iron sulphate only produces lines in the green section of the spectrum. Sorry if it doesn't sound very scientific, I am recalling the question from memory since I've already handed...
  19. D

    Visible Spectrum: All Colors & Where Is Brown?

    ... is the visible spectrum of light supposed to contain all the colors that we are able to see? if so, where is brown?
  20. W

    Visible Spectrum and the Compton Effect

    Hi,I need some help here. Why the Compton effect can not be noticed when we are using light from the visible spectrum?