The color of a star’s appearance is a rough indicator of its temperature, as most stars emit most of their electromagnetic energy in visible light. The absorption spectrum is not a continuous spectrum because some elements of the star leave their spectral signature in the spectra. Blue colors dominate the visible light output of very hot stars, with much additional radiation in the ultraviolet. Cool stars emit most of their visible light energy at red wavelengths, with more radiation.
All stars, including our sun, emit light at every frequency, from radio waves to gamma rays, all following the same formula, called Black-body radiation. Gamma radiation is generated deep in the interior of stars and by violent phenomena in the universe, such as the deaths of stars. Visible light is detected by fireflies, light bulbs, and stars, while ultraviolet radiation is emitted by the Sun and other stars.
The electromagnetic spectrum consists of gamma rays, X-rays, ultraviolet radiation, visible light, infrared, and radio radiation. Gamma rays have the shortest wavelengths, while radio waves have the longest. Visible light is in the middle, and gamma rays, X-rays, and radio waves are the main sources of light. Some stars, like Antares and Betelgeuse, have an orange or reddish hue, while others, like Rigel, suggest a bluer color.
To determine the wavelength at which emission peaks are located, scientists can use the SDSS database to find stars that emit most of their light in the green wavelength (stars whose g magnitude is less than 1). Most stars appear white, but some, like Antares and Betelgeuse, have an orange or reddish hue, while others, like Rigel, have a bluer color.
📹 Light: Crash Course Astronomy #24
In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength …
Do stars give off infrared?
Astronomers use light to study the Universe, using telescopes to collect data and develop theories about the past, present, and future. The nature of light depends on an object’s temperature, with infrared radiation being emitted by cooler objects like exoplanets and cosmic dust clouds. Infrared astronomy allows astronomers to observe regions of space obscured by cosmic dust, revealing more stars than visible light images. By combining observations at different wavelengths, we can develop a more complete picture of celestial objects’ structure, composition, and behavior.
Webb, designed for infrared wavelengths, has four instruments: MIRI (mid-infrared), NIRSpec, NIRCam, and NIRISS (near-infrared), enabling it to collect high-quality images and spectra. Its primary science goals include studying exoplanets, stars, galaxies, and the early Universe.
What type of light do stars give off?
Stars emit most of their electromagnetic energy as visible light, with hotter stars emitting higher energy light. Red stars are cool, while blue stars are hot. Beyond violet lies ultraviolet (UV) light, which is too high for human eyes to see. UV light traces the hot glow of stellar nurseries and is used to identify the hottest stars. X-rays come from the hottest gas containing atoms, emitted from superheated material around black holes, neutron stars, or heated gas clouds.
What type of spectrum do stars emit?
A continuous spectrum is a type of light spectrum that contains all wavelengths in a certain range, such as those of stars. This spectrum travels out in all directions and interacts with other materials in space. An infographic illustrates the relationship between the continuous spectrum of a star whose light is shining on gas, the emission spectrum of glowing gas, and the absorption spectrum of that gas.
The graphic is divided into two parts: the top half shows a light source, a light wave, and a cloud of gas, while the bottom half shows the three types of spectra in picture and graph forms. The wavy line representing light is dashed after entering the cloud and remains dashed to the right after leaving it.
Do stars emit infrared light?
Astronomers use light to study the Universe, using telescopes to collect data and develop theories about the past, present, and future. The nature of light depends on an object’s temperature, with infrared radiation being emitted by cooler objects like exoplanets and cosmic dust clouds. Infrared astronomy allows astronomers to observe regions of space obscured by cosmic dust, revealing more stars than visible light images. By combining observations at different wavelengths, we can develop a more complete picture of celestial objects’ structure, composition, and behavior.
Webb, designed for infrared wavelengths, has four instruments: MIRI (mid-infrared), NIRSpec, NIRCam, and NIRISS (near-infrared), enabling it to collect high-quality images and spectra. Its primary science goals include studying exoplanets, stars, galaxies, and the early Universe.
What is the spectrum of the stars?
Starlight can be separated into its component colors to form a spectrum, which reveals details in the brightness of different colors that are not visible to the naked eye. Telescope detectors can measure the precise brightness of individual wavelengths. A spectrum is a long horizontal rectangle with a rainbow coloring from blue to red, broken up with vertical black lines of varying width. The spacing between these lines increases from left to right. A graph of the same spectrum shows brightness on the vertical y-axis versus wavelength on the horizontal x-axis, aligned vertically for clarity.
Do all stars have the same spectrum?
The spectrum of a star is a unique tool for studying its light, similar to the fingerprint of a person. Each star has a unique spectrum, which can be used to distinguish two stars apart or to reveal what two stars share in common. The spectrum of a star is similar to the spectrum of colors seen in rainbows, with the wavelength of light determining its color. The wavelength is measured in units called Angstroms, which are equivalent to 1 x 10 -10 meters.
Do stars give off UV?
The emission of visible light, ultraviolet (UV), X-ray, and gamma-ray radiation is dependent upon the surface temperature and activity of the star in question. The emission of stellar radiation is contingent upon the temperature of the stellar surface and the level of stellar activity. ScienceDirect employs the use of cookies, and all rights are reserved for text and data mining, AI training, and similar technologies. The open access content is licensed under Creative Commons terms.
What is the wavelength emitted by stars?
The maximum radiation intensity of a star is 289 ergs per cubic centimeter. This value is 8 nm, with the application of Stefan’s constant of 5. The luminosity of a star is given by the equation: 6. 7×10⁻⁸ W m⁻² K⁻⁴, where b is a constant equal to 2898 μm K. To gain full access to our articles, please complete the BNAT examination and receive a scholarship of 100 for BYJUS courses. We encourage you to explore the free classes available on the BYJU’S platform.
What is the light coming from a star?
Starlight is the visible electromagnetic radiation from stars other than the Sun, observable from Earth at night. Sunlight is the Sun’s starlight observed during daytime, while albedo describes solar reflections from other Solar System objects during nighttime. Observation and measurement of starlight through telescopes is the basis for many fields of astronomy, including photometry and stellar spectroscopy. Hipparchus, without a telescope or accurate instrument, made estimates with his eyes and sorted stars into six brightness categories, which he called magnitudes.
The brightest stars are referred to as first-magnitude stars, while fainter ones are referred to as sixth-magnitude stars. The study of starlight has been instrumental in the development of fields such as photometry and stellar spectroscopy.
What are the spectrum classes of stars?
Astronomers have long been fascinated by the different sizes and colors of stars. In 1817, German instrument maker Joseph von Fraunhofer discovered that different stars have different absorption lines in their spectra. In the early 1900s, a team of astronomers at Harvard College Observatory began a project to examine the spectra of hundreds of thousands of stars and develop a detailed spectral classification system based on these absorption lines.
They adapted an existing spectral class system, assigning stars a letter from A to O based on the strength of Balmer series absorption lines. The new system reordered the classes into the order OBAFGKM, with O stars being the hottest and M being the coolest. The new system was published in the 1920s and included 225, 300 stars, known as the Henry Draper Catalogue. The work on the project was done by Annie Jump Cannon, Williamina Fleming, Antonia Maury and Edward Pickering.
📹 Light waves, visible and invisible
Each kind of light has a unique wavelength, but human eyes can only perceive a tiny slice of the full spectrum — the very narrow …
What is (visible) light? It is a wave, period. At last, somebody who can explain this clearly. Inspired by the article from Phil Plait, I would highlight the following: Photon: Each photon is an oscillating wave which push and pull the electric field as it propagate in free space – creating local increase and decrease of electric field pressure – the same way as sound wave propagating by pushing and pulling on air molecules. Fourrier Series for light Our eye perceive exactly one octave, the red being equivalent to bass and blue equivalent to higher pitch instrument. According to Fourrier series, any wave that is not sinusoidal (produced by an object circulating around a sphere) can be simulated by adding a few sinusoidal wave which have integer multiple of the fundamental. For example, a square wave at 60 Hz can be simulated as follow: a*60 Hz + b*180 Hz + c*180 Hz where a, b and c is the intensity (how loud the volume is set) for each of these frequency. Changing these coefficients (and adding also the even numbered) would produce saw tooth or any other waveform. Brief, when a wave is not a pure sinusoidal shape, then it contains harmonics, which is small amount of wave with frequency exactly double, triple, etc. The color detectors in our eye may react when a wave of exactly double or half the frequency hit them. That may explain why light going up after blue appear as purple ; the red detector become activated. What are electrons Atoms are not like as small solar system with proton/neutron in the center and electron rotating around like the planets around the sun.
godddddd…jesus………i’m living for these 3 websites…1..crashcourse….2….it’s okay to be smart….and 3…kurzgesagt in a nutshel…………………..love these 3 websites…………guys keep making more stuff like this,,,i feel so powerful and enlightened when i watch these kind of articles………….much appreciation,,love and respect from india,,,
I love science and learning in general, I never stopped being curious. I always had an interest in light. recently learned that light, visual light,and radio waves were all on the same spectrum… well, I knew they were for the longest but it didn’t fit into place until recently. this article definitely help this knowledge fit into my mind. currently having my mind blown and loving it! i’m super excited with this knowledge and wondering what I can do with it. I’m an IT guy in the US Army (I’m a soldier) and wanting to pursue a degree in Engineering and Computer Science. Gonna continue my Mind Blown trip and sharing the vid!!! 😀
Just a small correction: we didnt evolve to see the light which the sun emits most strongly (it emits electro magnetic waves outside our visible spectrum too, and granted it is not as strongly, it probably would be useful to see and differentiate the wide band of IR that the sun emits, which is much wider than our visible spectrum); we evolved to see the light frequencies that water lets through instead of absorbing. Considering where we come from, there wouldnt be much point, evolutionary speaking, to waste energy on being able to detect light waves that wouldnt penetrate water anyway. So water is very much the key in the evolutionary “decision” for what light we can see, and not what light is “emitted the strongest by the sun”. If we had evolved on land instead of water, then no doubt our visible spectrum would look different and be expanded a fair bit into the IR section.
This is a great series, thank you. I feel compelled to correct something here, it’s a very common error, it’s even in many textbooks, but it is wrong and it shouldn’t keep getting spread. The Cosmic Red Shift is NOT a doppler shift, maybe the easiest proof of this is that we’ve measured red shifts that imply faster than light motion away from us, which of course makes absolutely no sense if it’s a doppler effect. The shift is caused by the expansion of space stretching out the wavelength of photons on their journey to our eyes/telescopes. Another way to think about it is to consider two subjects, they have zero velocity wrt each other and to the microwave background radiation. Test procedure is that neither subject will accelerate, ever. Wait. Wait. … Wait till the expansion of space separates them so that they have a redshift indicating they’re a billion light years apart. They will look at each other and see a good sized redshift, but both will know that neither have moved-they have zero motion through space wrt the CBR, and their inertial nav systems will tell them zero motion through space and wrt each other. The CBR will have shifted a bit, meaning cooled off over this immense time, but all over, there is still no blue-tinged view in the direction of motion and red-tinged view in reverse direction that motion would give. How would a doppler shift be indicated given such a scenario? This brings up a topic I’d love to see, which is a discussion of distance at the cosmic level, I just saw your next article and it’s limited to lesser distances.
I have been using Crash Course articles in my daughter’s history, science and A&P classes for the last two years. This teacher is the best. He explains the information about light with just the right balance of energy and calm (he is very easy to follow, others tend to go too fast for even me to understand 🤯). Well done.
Why do our brains interpret the different wavelengths of light our eyes receive as the experience/qualia “colour”? Or, to put in another way, is there anything particular about the wavelength that produces blue light that relates it to my subjective experience of blue? Is it arbitrary? Might an alien organism receive the same sensory information but experience it wholly differently? Have we any way of investigating this? Any input would be greatly appreciated.
I have a question. To get the electron to move up a step ( I think you mean quantum leap by this) you need an exact amount of an exact type of light energy to give it. but doesn’t exactness, go to infinity, isn’t it impossible to give the electron an exact amount of energy, experimenting with this would be like getting the universe to define exactness- for itself.
I just love the fact that this man never feels the need to shoehorn ‘comedy’ into his presentations. Plait don’t need no pyrotechnics. Just him and the facts is all the magic we need. (Can’t say the same about Craig over at CrashCourse Politics. How many failed attempts at dry humor does it take to realize you’re consistently coming across as a cantankerous mope?) Phil Plait For President!
Question: I wonder wether the Earth-magnetic field is of influence on the speed of light and maybe it can be explanation for the constant lightspeed from the MichelsonMorley-experiment? So I even wonder if speed of light can be different at different planets, because of magnetic fields, and also: In 1919 Einstein was proven right that light would be bent by the sun, and I wonder: Not only the direction of the light was bent by the sun, but also the velocity? Or not?
NOTES: Most information about the universe comes in the form of light Light is an electromagnetic wave and a form of energy Wavelength is the distance between the crests Shorter the wavelength, higher the energy (tighter wave) Shorter the wavelength, higher the frequency That’s what differentiates colors in the visible spectrum Blue, Ultraviolet, x-ray and gamma rays are the shorter ones Red, Infrared, microwave and radio waves are the the longer ones Heating up a system raises the energy and to get rid of that it might emit light Temperature and the light emitted are therefor related In atomic structures electrons only get to occupy specific volumes of space That depends on their level of energy Light hitting the atom can provide the energy required to raise the energy level Upon loosing that energy it would emit light Different atoms have a different set of energy levels and emit different colors That’s how we identify the components of far away bodies Spectrometer is a device to measure the wavelength Doppler effect is the compression and extension of wavelengths caused by movement In sound pitch changes, and in light color So we can tell the direction of movement of bodies The red-shift revealed the expansion of the universe to us We also can learn about their spinning, electromagnetic fields and densities
Shout out at 3:04 to the GBT in the lower right hand corner. It is the largest moveable land object in the world. The dish alone is 100m in diameter. It’s hard to imagine until you’re standing on top of it. I had the pleasure of attending a summer school there and it was truly a great experience. Astronomy, bitch!
If we can see a distant galaxy from Earth, then it means that its light has reached us. If light is/has energy, then it means energy was spent for that light to reach us. Thus, if we can see light with precision from a distant galaxy, does it mean it’s wasting a lot, I mean, A LOT, of energy? How does that work?! I’m just curious.
This is one of the most informative and accurate articles on the physics of light that I have seen, and I’ve seen quite a few from private youtubers and universities. I’m happy that he did NOT mention photons, or particle properties of light, but just the wave properties, he is more correct then other people. That being said the article is not 100% accurate
Thank you very much, Phil Plait and the others at CrashCourse Astronomy, for making this article! Honestly, I knew most of the physics of light and the Doppler effect from elementary school but I did not realise the importance of light in astronomy. Literally everything we do in astronomy and everything we know about the Universe depends on light/radiation in one way or the other. I do have a question after perusal this article. You said that an atoms of an object emit different wave lengths of light, containing different levels of energy, depending on how hot the object. How can we differentiate between a cooler object which emits a shorter wave length than a hotter object of another element? What happens when wave length and the element compensate for each other? How can we tell the difference between a hotter object that of element A from a cooler object of element B if they emit the same wave length of light?
You said that the colour of a substance is dictated by the energy level of the valence shell electrons and used hydrogen and helium as an example (in their normal state is presume) but both hydrogen and helium are both colourless gases. If that was only an example to show how the energy level changes i guess my argument is invalid.
Uh… Sorry Phil, but the energy of light is tied to its frequency, not its wavelength. This is true because the frequency doesn’t change as it passes from medium to medium, but the wavelength changes based on the refractive index, n. Frequency’s ratio to energy is given in the Planck’s constant equation: E=hf.
I don’t know if you are going to read this Phil, but anyways I would like to thank you very much for this series. You managed to make astronomy more interesting to the masses, and you did it by not making it too hard to understand. I am a civil engineer and I love astronomy,physics and math. So I felt very happy to see this, and I hope we have more episodes of Crash Course Astronomy. (also recomended to some friends interested in astronomy to watch this ASAP!) A big fan of yours, André Gomes
A miss application of the Doppler Effects has lead to the belief the universe is expanding. The ‘Red Shift’ only proves the light wave is lengthening. That can be due to Slowing of Light also. Something that doesn’t violate the Law of Thermodynamics, as does the current theory of an expanding universe accelerating. Slowing light speed would account for the larger shift in speed the farther you look back.
I have watched almost every article of every series of C.C. and the Astronomy series is by far my favorite. This episode was especially awesome because it helped me appreciate how astronomers gain knowledge of the universe. The visuals and explanation of light, atoms and their correlation were the best I’ve seen.
CrashCourse No, light’s energy is not really tied to its wavelength. It’s tied to its frequency. energy(E)=plancks(h)*frequency(f) When in vacuum, frequency(f)=speed-of-light-in-vacuum(c) / wavelength(λ) But when light enters an optically denser medium (practically any medium other than vacuum, eg water, glass), its frequency doesn’t change, but its wavelength because it has to compensate for the change in speed of light in that specific medium. And from energy conservation, it is implied that frequency musnt change. So energy of a light is tied to its frequency rather than wavelength.
Can someone help me with these 4 questions 1 – how are electromagnetic waves produced? ( describe what happens with the electrons? 2 – what examples of electromagnetic waves and there application in everyday life ? 3 – Why can’t we see radio waves and ultraviolet radiation 4 – why is it possible to figure out the composition of far away stars and the planets by only viewing their color Please put the time we’re I would find the answers in this article if possible please help me 👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻😭😭😭😭😭😭😭😭😭😭😭😭😭😭
Why do you leave out One of our most familiar wave lengths of light? I speak of Sound. Sound is the same as radio, visible light, and Gamma… It’s goes much MUCH faster (and slower) Mind you Every One of our known six senses are in fact detectors of various frequency bandwidths we label as taste, touch, smell sound sight and thought. Infinite waves in an infinite ocean. 😉
I cannot tell you how many hours I’ve spent regaling my friends and passing strangers alike about the wonders of the physical world, and the fantastic story that is cosmology, only to be asked, “Well, that all sounds like it makes sense, but how do you really know all of that is true?” So usually I think for a moment, find a connection to another scientific principle and use it to back up the first point; but this is sometimes unacceptable. Around and around we’ll go with doubt and rebuttal yet we always return to the exact same question, “But, how do you know though?”, implying that I haven’t been there, and neither has anyone else, so, it’s in a way ultimately impossible for me to know what’s inside a star just by looking at it. While it’s true that I’ve never been inside a star, I’ve also never been inside a car engine while it’s running, but that doesn’t disturb my preconceptions of plausibility when it’s loosely explained to me by a friend in an adjacent bar stool. What, “How do you really know though?” is actually asking is if I have the ability to have any knowledge at all; knowledge by its nature being perpetually subject to scrutiny and prone to drastic change. That is a conversation I believe I can have, but it’s certainly not a point that can be made in brevity, or one that will help me prove my point in the immediate. Arthur C. Clark’s third law of prediction states that, “Any sufficiently advanced technology is indistinguishable from magic.” Essentially: If I don’t understand how it works I can’t verify the validity of its existence.
So, Phil, question. Can we affect the light waves? I mean, when you touch water, is ripples. Does light ripple as well? And if so, what are we doing to ripple it, and, is making it ripple bad for the earth? I mean, if someone were to ripple the sun, I think it would create a big problem. Isn’t light as important as the sun?
if anyone can help answer my question would be much appreciated… what happens to light? end state? surely the wave does not go on forever!? perusal this I’m guessing that if I had a pen laser, aimed it at the sky & emitted a red beam for say 5s, that beam would have “x” J of energy and as it travelled through space, it would lose energy (?) the wave length would increase & digress into a radio wave of increasing wavelength then…… ?? I may be ignoring some aspect of conservation of energy, but i cannot fathom that it would propagate forever
so electromagnetic waves give energy to electrons…I’ve been reading on this topic now for 2 days and I have the impression that the whole concept is deliberately made cumbersome…one has to gather the knowledge from Chemistry, Physics, electromechanics, and the theorems are also seemingle overly complicated (not to mention that they decieve by removing the physical elements by purpose of simplifying the matter for calculation purposes…but then that leaves you being good at calculating stuff while not understanding what it is that you’re “looking at”)
A little bit confused here. I hope you can “shed some light” and I mean it. If light emitted from celestial bodies is blue or red-shifted, and I understand that as the universe is expanding, they mostly are red shifted, how can the band of absorption be determined to know the elements in a star for example, if the received light is already modified (redshifted)? Isn’t its wavelength already changed or modified? Kinda spoiling the test? How to reconstruct the sample? Am I getting this wrong? Thank you.
I like these articles a lot. Great information. The thing that’s annoying though is the editing. There are no natural pauses between phrases. It makes the presenter seem robotic and hard to follow at times. It’s distracting. Whoever edits the clips needs to chill. It’s not as bad in the other CrashCourse article series; mainly this one.
What is light anyway? I only know how light “appears” to me. There is no way I can know if/how light exists “out there” (what the nature of it really is). The “thing” from out of my skull called light that hits my rods and cones is transformed into electrochemical signals and creates an hologram in a total darkness of my skull. My experience of sight is the only expression of light I can be aware of and it might be wrong (if for example my rods and cones are damaged or if “they” misinterpret the information from within the “outer” realm).
Excellent article, but I have a slight issue with the “one of these red squares is a slightly different spectrum of light” illustration; because if one wanted to be an insufferable pedant like me, they could say it’s not really true. Monitors only really display three different wavelengths of light; one quintessential “red”, one quintessential “green”, and one quintessential “blue”. If you were to google image search a close up of an LCD monitor, you’d see a pixel is really a little vertical bar of red, green, and blue adjacent to each other. The colors other than those three that we see are merely an optical illusion tricking our brains into seeing something different by displaying those three specific wavelengths together in varying intensities. So technically speaking, those two red squares are displaying the exact same wavelength of red light, with a slightly different amount of green and/or blue mixed in.
So, specific elements emit specific wavelengths (and, thus, colors) of light when their electrons lose energy. But, there was a time when we only knew so many of the naturally occurring elements on the periodic table–though, we had predicted the existence of many of them a while before actually discovering them. I know that much, already. However, it has me wondering: Did we ever confirm the existence of certain hypothesized elements purely through spectroscopy? After all, if a spectrometer can tease apart the colors of light that atoms emit so well that it can identify the specific element of those atoms, then it’s only natural that each element known on the periodic table has its own color within a spectrometer. So, what if you were to come across an unknown, or uncategorized color whilst using a spectrometer? It must mean that you’ve discovered a new element, right? Did that ever actually happen?
Obviously the wave definition of light was most convenient for this article and quantum mechanics is confusing, but it is upsetting that the particle nature was never discussed. It is not particularly relevant to the topics discussed but now thousands will leave this article not understanding the wave particle duality of light. This phenomena was proven in the early 20th century by Hertz, Einstein, and de Broglie and is fundamental to our modern understanding of physics.
I understand everything about EM waves! But the thing with which i am having a tough time is getting my head around the physical nature of the movement of light. Is it like the photons move up and down like a wave? EM waves have waves. But what are waves physically? How do they pass through everything and go anywhere?
The whole time I was perusal this, I could only focus on how abusive these people are being towards this girl. 0:13 Glad she isn’t a guy 0:57 she was definitely set up 1:06 they made her believe that there was actual fishing wire on that rod. 1:21 thats just mean. 1:41 SOUP CANS HURT! and is that wine? 2:24 they definitely spiked her drink… 3:47 VR gone wrong 4:00 they stranded her in the desert and tried to drop things on her head. 4:44 Youtube Rewind TIME 2019! 5:30 her reminiscing the time before she got captured by TED-Ed…she was told that she is going to be beheaded the following day. Can we get some F’s in the chat? R.I.P wooden lady…
Light can be powered by thermo-nuclear fusion like we see in stars, however their are other ways to power light like nuclear fission, chemical molecular reaction, mass colliding with other forms of mass, etc., etc. Light particles/waves can move so fast because they have almost no mass, making it relatively easy for those waves/particles to move at the speed of light.
Jesus said “So it will be at the end of the age,the angels will come forth and take out the wicked from among the righteous,and will throw them into the furnace of fire,in that place there will be weeping and gnashing of teeth.”Matthew 13:49-50.Jesus also said “You are my friends if you do what I command you.” John 15:14. Jesus taught that the only way to be saved is to choose him as your Lord and Master, repent and believe that he died for the sins of his people on the cross see John 14:6.
the energy comes from various places. sometimes it’s an electron jumping between orbits with the difference in energy being released as light. So if one orbit requires 3x energy to be in and then the electron drops to an orbit that requires only 1x energy, light with energy 2x is released. And it moves so fast because it is massless and everything that is massless moves at the same rate (popularly called the speed of light)
Nice article, but … by definition, light IS visible. It is that part of the electromagnetic spectrum that is visible (to us, humans), covering wavelengths between 380 and 780 nm. There is no such thing as UV light, IR light, Röntgenlight, gamma light, radio light, .. . Use UV radiation, IR radiation, gamma radiation, radio wave radiation please.
There is a mistake in how you depicted so called Twinned rainbow (around 2.55 in the article). First, one couldn’t see two rainbows that are not concentric (yours aren’t), but even more generally, we can see such two rainbow rings only in case of ‘twinned rainbow’ – however, in this case their colors are in different order (purple to red for the inner one, but red to purple in the outer). A bit shameful too see such mistakes from TED.
“do they convert the wave lengths that are usually out of our spectrum in order for us to see them?” Yeah, you can say that. In order to see the picture we must use visible light, yes.All you need to do is to multiply or divide the values, so you get wave lengths you can see. The cool thing here is that there’re more colors than we can experience and see. There are more colors than we know. That’s quite mind blowing, actually.
I wonder why we have all kind of uses not directly related to seeing for the invisible vawe leghts, such as microvawe or radio, but we only use visible light for seeing? Why there’s no other useful characteristics for the visible light, but we have found these other uses for the wave lengths of the light we can’t even see? Haven’t we just figured them out or is there simply none? 🤔 Also, not seeing some wave legths doesn’t mean we wouldn’t see items that have these colors (we wouldn’t be blind to them)? But we should see them just as different color. For example, many animals have colors we can’t see (but these animals can), and we still see them. But the invisible wave leghts seem to not just change the color, but actually have additional information, such as internal vision to human body. The wave leghts we see are just colors, but the other wave legths seem to be “more” than just the color. I kinda don’t get that 😄
I think the idea of the article was how blind we are and how much we cannot see. If we evolved differently we could maybe see magnetic waves, gamma waves or radio waves. They say the amount of the Electromagnetic spectrum that we can see, if you extended it from New York to Los Angeles is only the size of one single golf ball. That is completely mind blowing.
I know that there are a few other replies to this, but I think this one is better. Imagine your favorite song, and imagine you play it at 1/100 the speed. The pitch is lowered and it isn’t likely to be recognizable. But if someone in the room records it in full, and then speeds it up by 100 times, they will essentially have the original track. In the same way, if the frequency of light is too high for the eye to see, they will stretch it out until it is in the visible spectrum.