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Projects and Fun Activities Index
Homeschoolers and unschoolers do most of their learning by doing projects and fun activities: it's a creative way to learn! Perhaps you've done a project that you'd like to share with others? You can write and tell us about it if you like, or if you've developed a webpage then we can create a link to it...
Science projects and experiments, history projects, art and craft projects - we'd love to publish or link to any type of project! See the submission guidelines below to find out how to have your project published in Unschool~Kidz!
Why is the sky and sea blue and clouds white?
... and other questions answered...
Snow is white for a reason. But I don't know it. Does anyone? The sea is blue because it reflects the sky. Why doesn't snow reflect the sky. And why are plants mostly green? Is it because chlorophyll reflects only green and absorbs the other colours in the light spectrum? White and black aren't
colours, are they? So does that mean that snow reflects all the colours of the spectrum? Is that why clouds are white? Why are some clouds white and others grey, and others dark grey?"
Peter Adderley, http://www.abc.net.au/science/io/faqsm.htm , wrote: Although I'm no expert, I think snow appears white because, like clouds and steam, we see it on a macro scale. I think also that if you could look at a snowflake at a microscopic scale, you would see not only reflections of ambient light but also myriads of tiny rainbows from internal refractions from the crystalised water. But what colour is snow on a dark moonless night?
White clouds are white when they are lit directly by the sun. Grey clouds are such when they are in the shade of other clouds. It's much the same as those little road reflectors. Without direct illumination, they appear just white (or whatever colour), but when hit by direct illumination, they really shine. The sea is blue, yes, but the reflection is much more direct, that is from the sky above. Snow or clouds are reflecting light from up, down, and all around. What I don't understand is why the sea is SO blue. Even on a crappy cloudy day, it can still appear much more blue than the sky, so there's probably another better explanation out there.
Black/White - GREAT question. Although it's technically correct to say black and white are not colours, I reckon it's very misleading. White is composed of light of every colour (or frequency), whereas black is the absence of light. Sort of all or nothing. It's confusing to say that black and white aren't colours, because artists, photographers, printers, and most of the rest of us do so in daily life.
They're descriptive terms which have common understanding in our world, and our language.
The green question is pretty much on track. Sorry if this is coming in at an over simplistic level, but I take it your are looking for analogies to pass on to kids', always brilliant, questions. Wonderful line of questions. But so many questions about colour, it prompts me to suggest a book I found many years ago. It's called: "Colour - why the world isn't grey", by Hazel Rossotti, published by Pelican (as a paperback) ISBN 0 14 02.2201.4 It's a lay book, written in clear, technically correct, and reasonably
simple terms, but certainly not a kids book. If you're home teaching and have at least secondary education you'll find it a fascinating read. Quite illuminating in fact ;-)
Interesting to note the difference between the RGB and CMYK colour systems. The RGB (red, green, blue) in display systems such as TV and computer screens where the three coloured light beams ADD together to produce all other colours. Thus to produce white, the three colours are combined - to produce black, they turn the beams off. Of course remembering that the unlit screen is black (or close to it). The CMYK (cyan, magenta, yellow, and black) system is used for printing colours onto white paper. Therefore you need an extra "colour" of black to produce darker shades. But in this system the coloured inks are used SUBTRACTIVELY; that is, just like when you mix artist's paints. But a little searching on the net will find some much more graphic examples of the above.
Podargus, http://www.abc.net.au/science/io/faqsm.htm , wrote: The sea is not blue from reflection. The sea is blue because water is blue, and there is a lot of it in the sea. Water is blue because it absorbs light at red and yellow wavelengths, but reflects blue. The ocean is normally bluest in deep water away from land. This is because it is generally cleanest in such areas. Other colours of the ocean are from 'pollutants of one kind or another. I.e. Green from chlorophyll, both from phyto plankton and leakage of same from them into the water; turquoise from coccolithophores. To see blue water in the comfort of your own home. Obtain 1 WHITE bucket. Fill with CLEAN water. If your local water supply is not clean enough wait for rain and collect in a clean manner. Snow, frozen water, is also blue. However clean snow reflects all wavelengths. Like other water it can be 'contaminated' by micro organisms such as algae etc.
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Unschool~Kidz!
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