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Visible Light Spectrum
Join us here to ask and answer questions on the "illuminating" topic of the visible light spectrum. This includes questions about: refraction, reflection, rainbows, prisms, mixing colored lights, and the spectrum of colors that make up white light.
1,220 Questions
What can you use to separate visible light?
You can use a prism to separate visible light into its different colors through the process of refraction. This creates a rainbow-like spectrum of colors ranging from red to violet.
Is red a higher frequency color of visible light in the electromagnetic spectrum?
Red is about 405 to 480 THz
Orange from 480 to 515 THz
Yellow from 515 to 525 THz
Green from 525 to 575 THz
Cyan from 575 to 610 THz
Blue from 610 to 680 THz
Violet from 680 to 785 Tz
The first to observe (but not explain) the photoelectric effect were Hertz and Hallwachs in 1887.
Albert Einstein received the 1921 Nobel Prize for physics:
...for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.
His 1905 paper explaining the photoelectric effect was rejected by physicists of that time and only accepted after experiments by Robert Andrews Millikan in 1914 showed that predictions made by Einstein's theory were correct - such as that the energy of individual ejected electrons increases linearly with the frequency of the light.
What is the white light of sun called?
The white light of the sun is called sunlight. It is a mixture of all the colors in the visible spectrum, which combine to appear white to our eyes.
What is the color of rainbow to first to last?
Red ...........................Richard
Orange ........................Of
Yellow .........................york
Green .........................gave
Blue ...........................battle
Indigo .........................in
violet ..........................vain
One way to remember the order is the phrase Richard of York gave battle in vain
What frequency range of light is visible?
The visible light spectrum ranges from approximately 400 to 700 nanometers in wavelength, corresponding to a frequency range of about 430 to 750 terahertz. This spectrum includes the colors of light that human eyes can perceive, from violet to red.
What property determines a visible light region of the electromagnetic spectrum?
The property that determines a visible light region of the electromagnetic spectrum is wavelength. Visible light has wavelengths ranging from about 400 to 700 nanometers, with shorter wavelengths corresponding to violet light and longer wavelengths corresponding to red light.
What are the uses for visible light waves?
We use Visible Light to see. Without it, plants won't be able to go through the process of photosynthesis. We get all our light from things hot enough to produce light. A light bulb is over 3,000 degrees hot, and the sun is over 5,600 degrees hot, which is why a lot of light we see, somes from the sun.
Light is also used to make electricity.
How is mass of an object related to its optical density?
The mass of an object is not directly related to its optical density. Optical density is determined by how transparent or opaque the material is to light. Mass, on the other hand, is a measure of the amount of matter in an object. They are two different properties of an object and are not inherently connected.
The solar energy you are referring to is called infrared radiation. It has longer wavelengths than visible red light and is felt as heat when it is absorbed by an object.
Why microwaves are dangerous for us and visible light is not?
The degree of interaction between water and microwaves is much greater than that between the former and visible light. As such, microwaves heat up water while visible light does not -- visible either goes though water or bounces off it.
Since our bodies consist of a lot of water, microwaves hitting us would cause us to heat up fairly rapidly -- exactly like food in a microwave oven.
Getting cooked in a microwave oven is a LOT more dangerous than being illuminated by a lot of visible light.
Which region has the longer wavelength-visible light or infrared?
Infrared light has longer wavelengths than visible light. Visible light ranges from about 400-700 nanometers in wavelength, while infrared light ranges from about 700 nanometers to 1 millimeter. This difference in wavelength determines how these types of light interact with matter and are perceived by our eyes.
What reaches the earth first x-ray radiation or visible light?
From the same event on the same source both should arrive at the same time, unless delayed by an intervening medium.
What are the colors of visible light and how can you see them?
light is invisible you can only see the things it bump in to...
and when you're saying visible light i think it
's only lasers who fits that description and they are many different colours
What electromagnetic waves does a fire give off?
IR, Red, Orange in a typical fire. A pure hydrogen fire however gives off only IR and a barely visible amount of Blue. Metallic salts in the flame will add their own characteristic colors (e.g. sodium: Yellow, copper: Green).
If the glass appears purple, it means it is absorbing most of the green, yellow, and red light frequencies. This leaves mainly blue and red light to be transmitted through the glass, giving it a purple appearance.
What adverse effect can result from overexposure of human tissue to ultraviolet light?
Ultra violet light is responsible for skin cancer. It can also be a problem for individuals with ultra violet sensitive conditions such as Lupus. One would think that staying inside would keep a person safe from this harmful radiation. This is not completely true. Fluorescent lights put off UV light. While this exposure is much smaller than that of sunlight, it is important to keep it in mind. The current guideline limit in the UK is 30 J m-2 for the eye and skin, which is equivalent to a constant irradiance of 1 mW m-2 effective for 30,000 seconds or 8 hours, a normal working day. At close proximity (2 cm or ¾ inch), the exposure limit would be exceeded in less than 10 minutes by about 20% of the CFLs tested. About half of the CFLs exceeded the exposure limit at this distance after 30 minutes. The good news is that if the distance is increased to about 8" only around 8% of the CFL bulbs exceed this limit. Also, encapsulated bulbs that have a globe of glass around the CFL itself emit less UV radiation than the traditional bulbs.
This CFL limit can be overcome with some planning. CFL developers need to keep the guidelines in mind when developing new CFL models. Also, government regulation would help ensure that the UV from CFLs is limited.
Do supernovas emit gamma rays?
Yes, supernovas emit gamma rays as part of the explosion process. These gamma rays carry a significant amount of energy and are one of the most powerful forms of radiation emitted during a supernova event.
Is blood blue if you did not have red blood cells?
Everyone has red blood cells. You could not live otherwise.
When someone says 'blue blood' they are speaking metaphorically or comparatively.
There is a common misunderstanding about the color of blood that unfortunately actually sometimes is passed along by elementary school biology teachers who are not up to date. Your blood is never blue, always shades of red.
When arterial blood leaves the lungs to circulate through the body, it has just a little bit more oxygen in it than does venous blood. The reason it appears bright red is that the combination of iron, oxygen, and hemoglobin absorbs higher energy wavelength light (blue and green) which leaves the red wavelengths available for our eyes to sense.
The venous blood is never blue, it is a darker color of red than arterial blood, not blue. The color is a burgundy red or maroon color. Blood is bright red in the arteries and dark red in the veins. The reason venous blood is a darker red can be partially attributed to the slightly less oxygen in the blood in the veins. But its color change is more due to the "waste" it carries away from the body tissues and back to the kidneys for filtering and elimination. This "waste" darkens the red color of the blood (think of it as a little like dirty dish water).
Although a popular belief, being in contact with air does not cause venous blood to instantly oxygenate and turn red. It is red outside the body because it is red inside the body as well. When you look at unopened veins inside the body, in endoscopy, for example, they are a dark red color.
The blue appearance of the veins that you see when looking at them through the skin is not caused by blue venous blood. As explained, that is always red. The blue appearance is caused by a reflective factor of the skin itself. It is an optical property of the reflection of light off light colored skin and the difference in that reflection from the veins under the skin (but near the surface). That reflective process is complex, but the blue-looking veins are mostly all about the skin and reflection.
If arteries were not too deep to be visible through the skin, then they, too, would have a blueish appearance, the same as the veins for the same reasons.
The blue color of cyanotic lips and skin is not because the blood is blue.
What color do we perceive for the highest visible freguencies?
The highest visible frequency of light is perceived as the last color
you can see on the blue-violet end of the rainbow.
What is a visible object that is not a light source?
A visible object that is not a light source is any other object in the universe. Objects that are not light sources reflect light and are thus made to be visible.
Examples include:
- planets
- people
- the moon
- cars
- dogs
- flowers
- books
- rocks, either in daylight, or else illuminated by a flashlight
- a light bulb or LED with the power switched off
How do scientist know that a black hole exist if these object don't emit viable light?
Scientists cannot view a black hole directly, but they can see the effects of the black hole in the surrounding space. For example, matter being sucked into a black hole emits radiation which can be detected, or a its gravitational effects on neighboring stars and dust.
How much of the electromagnetic spectrum can your eye detect as light?
The human eye can detect a small portion of the electromagnetic spectrum, known as visible light. This range spans from approximately 400 to 700 nanometers in wavelength, corresponding to colors we perceive as violet to red.
