Children's Wikipedia. Need?

"Why the sky is blue?"

• How to explain this to a three-year-old child? About the spectrum - is still unclear. The simplest explanation I have found is suitable for primary school age.
• And if global: who knows the right literature or Internet portals? Answers to children about nature, but for 3-4-year-olds. Or do I want too much?
• We have a lot of encyclopedias, good and different. But they do not always help. For example, with the same sky.

Branch of the forum.

In my childhood I had such a book.

For those who suddenly do not know - a book for the youngest curious researchers who have just learned to read. I will not praise for a long time, but I can safely say - for me, in due time, she was like Wikipedia now. From there I learned the basics of our universe. Difficult questions were explained in very accessible language, even thermonuclear reactions in the stars.

But this article is not about the book. It became interesting whether there is a similar collection of answers for children on the Internet. It turns out this is not very cool. A long search revealed only 2 seemingly suitable sites: potomy.ru and children.claw.ru. Let's see what they represent ...

potomy.ru

The project Because it is the only children's encyclopedia online, which contains a huge amount of material on children's topics.

Oh, the only one! Modestly. But in general, they are almost right.

All answers are moderated and only with a positive assessment allowed.
Only teachers or educators can register and place an unlimited number of articles on the site potomy.ru for FREE!

You stick, you write articles, you could have been flooding money! This could be explained by the following line:

We retain your copyright and a link to your profile and website of your school is placed at the end of each article posted by you.

Nothing like that. Maybe I think anonymus is not supposed to know? Registered to clear my conscience. No, the authors are still unknown.

I will try to find answers to difficult, but popular questions in children. For example, I was wondering why the sky is blue. Found 2 articles, one short, the other longer. Here are the explanations of them:

When sunlight penetrates the atmosphere, the gases that saturate the air decompose the white light into its constituent parts - the spectrum: red, orange, yellow, green, blue, blue, violet. It turns out that among these colors a strip of blue and blue prevails, that is why the sky seems to be blue.

The air itself is colorless, but when the sun's rays penetrate into it, the light in it breaks down into the main seven colors of the spectrum. As we know, these colors consist of a rainbow - red, orange, yellow, green, blue, blue, and purple. Since the blue color is obtained more, it therefore seems that the sky is blue-blue.

Why is this more? I understand that it is difficult for children to explain Rayleigh scattering , but lying is not good either.
I would also be interested in an explanation why cats purr? I will cite the article in full.

Developed cat language wonderfully meets the needs of communication with relatives and people. Cats can make sounds that vary in duration, pitch, timbre. The voice of a cat can shyly ask and insist.
A short open meow means greeting. Muffled meowing or loud womb sounds - complaint, offense. Fear creates heart-rending screams. Gentle purring most often means gratitude or pleasure.
According to the observations of French scientists, a cat can pronounce seven consonant sounds: M, H, H, X, F, C and R.

Yes, it conveys emotions. But reading is boring. Usually a cat for a child is the real friend he sees every day. Therefore, in the list of objects of study it is in the very first lines. Will this explanation suit you? Hardly.
')
Next, I notice the section "preschool age." Oh, what you need! I go there. I see this, not very convenient, grouping: “How?”, “When?”, “Who?”, “Why?”, Etc., a total of 17 sections. I look through the questions "Why ...". In general, the questions are very interesting. Sometimes come across not quite for preschool children. Just imagine, a 5-year-old child comes to you and asks, “Why does the value of money be determined by gold?” Or “Why does the Egyptian queen Nefertiti always draw in profile?” Although children can now be so advanced, but I just fell behind.

Well, okay, better look at the article "Why does nettle burn?". Clearly explained about the villi with acid. I also found out that “If you break off nettles very tightly, these villi will break at the base and their ends will not be able to penetrate the skin, that is, there will be no irritation.” Unfortunately, it does not say why nettle needs this acid and whether it is dangerous.

I read a few more answers. Most consist of 2-5 small paragraphs. In general, quite interesting and written in understandable language, but not enough. After reading, I still have questions.

children.claw.ru

I was greeted first by a healthy banner. A cross was found in the lower left corner, I press. Oh, miracle, the banner just silently disappeared! Now you can look around. Advertising top, right and bottom. One of the links suggested lengthening yourself, you know what, and the other to make it thicker.
Description of the encyclopedia is missing, or I was looking bad. But it is written that the children. On the left 6 sections. There are no questions about the blue sky and purring cats (well, how is that), so I just look through the section “Earth and the Universe”. So why do stars twinkle?

At first glance, the planet and the star are really very similar. But if you look more closely, you can see that the stars twinkle, and the planets shine with an even calm light. This happens because the stars, like our Sun, are a hot gas ball, and the planets do not have their own light, we see them because they reflect the sunlight falling on their surface.

The reason is not the point. By the way, for example, Jupiter on the horizon is also flickering.

I spent some time there, but I will not tire, I will immediately summarize. There are a lot of articles (but there are no about cats). Written in a dryish form, somehow messy. Do you know what they remind me of? But such topics like: "London - the capital of Great Britain", etc. Another trouble with the answers to complex questions. In general, the encyclopedia is not very childish: “V. Herschel was the first to conduct purposeful and systematic observations of binary stars, measuring the angular distances between their components. ”

I think it would be nice to create an analogue of Wikipedia for children. Available for everyone to edit. However, pre-moderation of changes is probably necessary. Simple experiments are very desirable for better consolidation and understanding. For example, to explain the blueness of the sky, you can skip a narrow beam through an aquarium. It will also be like the books of Perelman. It seems to me that there is something to think about.