Usually people talk about the amount of light which is emitted by a lamp (just
an example). The light they are referring to in this case is usually white or
yellow, but it is in fact made up of literally billions of different wavelengths. The
human eye can only see light of approximately 400 to 700 nanometres, this is
called the visible light and it stretches from purple (<400 nm) all the way to
red (700> nm). Just to compare, the entire light spectrum reaches from 10-14
m, which equals 0.01 picometre, to 104 m, which is equal to 10
kilometre.
We only need to have knowledge
about visible light to answer the question, so let’s forget about the other
spectra. From now on the term ‘’light’’ will be used, meaning the visible
spectrum.
Now that we know that light
can be split into different colours, there is only one more thing applicable to
the situation in our sky. It's generally known that we have an atmosphere around us which protects us from space, however the atmosphere has another very important function: in fact it has the same function as the prism in the previous example. The light source, the sun, sends its light beams towards the Earth and they hit the Earth at such an angle so that the atmosphere bends the light just enough to make sure the light blue light ( get it ;) ) is the light which hits the surface. The same magical event happens when the sun sets and the sky partly turns green, yellow and red; only this time the beams hit the atmosphere from another angle so the green, yellow and red colours hit the Earth's surface instead of the blue.
Fun fact: the (Dutch) handbook
for natural sciences and mathematics describes a metre as the distance light
travels in 1/299792458 second in a vacuum space. At first this seems like some random
number but it actually corresponds with the speed of light, which is almost 300
million meters per second.
I call utter nonsense, why does the sky have to be blue! MY PARENTS DIED UNDER A BLUE SKY! TRIGGERED!!!!!!! Also this is discriminating to otherkin like me who identify as giant pterocosolics who can only live in red light! ever thought of people like me sky? ye take that one. Also those wavelenghts should be in whatever shape they like and should be able to be any colour they like because we live in a free world with democracy. white male privileged scum
BeantwoordenVerwijderenyou are by far my favourite physics teacher :)
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