Slashdot Mirror
Parents Baffled By Science Questions
Pickens writes "The BBC reports that four out of five parents living in the UK have been stumped by a science question posed by their children with the top three most-asked questions: 'Where do babies come from?', 'What makes a rainbow?' and 'Why is the sky blue?'. The survey was carried out to mark the launch of a new website by the Department for Business, Innovation and Skills called Science: So what? So everything."
The sky is not blue due to refraction. It is blue due to Rayleigh scattering, which increases as the wavelength decreases.
My mum just left a copy of the book Where Did I Come From? on the bottom shelf in the living room. I used to love that book (and the sequel "What's Happening to Me", about puberty) when I was a little kid - the pictures are adorable and it's pitched at a good level.
It's not really refraction. There actually is a refraction effect which is why we can see the sun at sunrise before it would be strictly visible over the horizon, and still see it at sunset after it's gone below the horizon. It's really more of a reflection -- think of light being scattered around by glitter except on a much smaller scale.
Rayleigh scattering preferentially scatters shorter (bluer) wavelengths more strongly. When the sun is directly overhead, as in midday, light nearer to the reddish end of the spectrum will reach you directly while only the bluer wavelengths will have been scattered. The blue that you see is light from the sun that has been scattered towards you by the air molecules in the atmosphere. The opposite happens at sunrise and sunset to make it appear red; the light reaching you has a much longer optical path to go through so nearly all of the the blue wavelengths have been scattered away leaving only the reddish light to reach you.
There's also a minor effect due to Mie's scattering off the dust and other particulates in the atmosphere. Mie's scattering deals with scattering by slightly larger particles than Rayleigh scattering.
How come I don't learn English in school even though it's my country's official language ?
If you are talking about the US, it has no official language.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
I am a test designer.
What you are describing is what happens to every test anyone ever writes with the best of intentions. We make a test to, say, place students into the right level of language classes, and the department starts using their gain scores for their grades in those classes, muddling placement and outcome--two different testing situations that would need different methods.
Administration wants an instrument that matches the curriculum closer; you make it; they demand to know why it doesn't have X, Y, or Z. You point out that it isn't in the curriculum. They say "It should be!"
It happens every time. Even BMI, which was basically designed to find starving people, has been repurposed to define physical fitness--something it is not designed to do and cannot accurately assess.
People always misuse measures and then blame the person(s) who made them.
Welcome to my world.