Wavelength vs. Frequency?
Since white light is made up of all of the rainbow colors, when it enters a prism and the light bends, the white light spreads out into the different colors of the rainbow, which is of course known as dispersion.
My confusion is this:
When the light wave goes from one medium to another, the frequency of the wave remains UNCHANGED. However, the wavelength CHANGES, causing the wave to change speed as it moves from one medium to another. The larger wavelengths have a greater speed (red and orange), and the smaller wavelengths have a lower speed (blue and violet). Since they have different speeds through the prism, they bend by different amounts as they exit the prism.
To sum up my question: Doesn't the SAME wave in the spectrum have to have the SAME FREQUENCY, and therefore the SAME WAVELENGTH? For example, as the spectrum below indicates, Red has one single wavelength with its corresponding frequency. So how can you reconcile this with an UNCHANGED frequency but a CHANGED wavelength? That won't be Red anymore! Would it?
What am I missing/misunderstanding here?
Can't wrap my head around this at all!
Thanks for your help!
- D gLv 77 months ago
you are not seeing the light inside the other medium
you see the light after it has LEFT the medium and come back into our medium of air..
the white light goes in and each frequency bends at slightly different amounts based on its frequency ..
then when it reaches the other side of the prism it is bent so far that when it comes back into our medium it only bends a TINY bit back and does NOT completely go back to the original place it was before when it entered
it is now far separate from the other colors so it makes an individual color of each colour
you must also know that say you are in water
and you look at a red light shining into the water you will see red because the wavelength has a relationship with C to produce a energy of a certain frequency
you do not perceive wavelength you perceive the effect the light has hitting the cell in your eye ... and I think this has to do with energy and frequency
if the change in wavelength is great enough the color of the light does change this is what is called red shifting or blue shifting .. similar to doppler shift with sound the light we perceive can be changed because the speed of the object is so large that it moves from one color to the next in the color chart
- StevenLv 77 months ago
The speed of light is slower in the glass so parallel rays have to travel more perpendicular to the surface of the glass in order to remain in phase, ie the phase difference between two points on the glass surface remains the same inside and outside. The wavelength is smaller inside the glass. The color is a function of frequency and each color is a range of frequencies, not a single frequency.
- goringLv 67 months ago
Color is a function of Power of light radiation,the higher the frequency to more Power. Ultra violet light shows more power than light in the red spectrum.
Solids indicate a continuous spectrum. we must burn a solid in order to get discrete frequency.
Hence solids reflect different frequency which we see as a color.Different materials different colors.All gases indicate a discrete spectrum.The human eye can only detect certain frequency. Animals are able to detect infra red and ultraviolet light.When light goes thru the gases of the atmosphere it cause the sky to fluoresce as blue and at night a very dark blue.Light slows down while moving inside a medium of glass prism and exists at its normal speed.Hence at different mediums the light speed changes.Wavelength is really the spacing for each string of photons which indicates how many particle of light in the radiation ray.
- ZirpLv 77 months ago
What am I missing/misunderstanding here?
light that comes from air or vacuum and goes into a prism of glass will suddenly have a lower speed. Frequency stays the same, frequency times wavelength still equals speed, so wavelength is down
red light gets slowed down more than blue light
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- Dr. ZorroLv 77 months ago
Color is determined by frequency only (frequency determines energy determines which molecules in your retina are brought to an excited state).
Wavelength depends on frequency and wavespeed but does not determine color, so it can change without affecting color.
- CarolOklaLv 77 months ago
What you are missing is The speed of light IS NOT CONSTANT. Each color has a RANGE of wavelengths and frequencies and is bent at different angle which changes the speeds of light and red shifts the range of wavelengths for each color.
White light going into a prism has different wavelengths and frequencies, each color is refracted at a different angle and each color has a different speed. The the frequencies do not change but the wavelengths become longer and the speeds become slower. What you are missing is each color is bent at a different angle AND has a RANGE of wavelengths and frequencies, not a single wavelength and frequency. Some of the red light goes into the short infrared wavelengths and frequencies. The speeds become Lowe and different for each range of frequencies bent at slightly different angles.
Triclinic minerals can have three indices of refraction. There are seven different atomic lattices.
Just because humans can't see infrared or ultraviolet doesn't man it doesn't exist. Cats and dogs see further into the infrared than humans. Bees and other insects see ultraviolet light. Humans are blind to most of the electromagnetic spectrum. It's like we are deaf and can hear only one octave of sound.
- Anonymous7 months ago
Since in a vacuum (which is what that spectrum is based on though it's not stated), the speed of light is fixed. A change in wavelength, necessary for different colors means a change in frequency.
- JonLv 67 months ago
What you're missing is that charts such as this are meant to describe the relationship of wavelength and frequency for light in a vacuum, or in a particular medium. They're not meant to describe all possible relationships between frequency and wavelength.