Saturday, November 13, 2010

What is Life? 素数について(About Prime Number)

皆さんお早うございます。夏の暑さで今年の秋は冬はどうなってしまうのでしょうか。さて、本日の一枚は地元のお菓子屋さんの主力商品のものです。それと、初めてこのWhat is Life?をご覧になった方は、「難しい」とお感じかも知れません。そうした場合は、どうか第一回からご覧になることをお勧めします。徐々に難しくなってきているのですから、。

Good morning everyone. This summer was quite hot in Japan. So I do not know how the autumn and winter come in this year. Anyway, today's picture is about sweets, as you may like. If you arrive to my country, please check it out. Notice, to first visitor. If you think that this blog is too difficult for me, please check the first class of "What is Life?". The difficulty or speciality were gradually progressed with these course. I had started to explain bases of biology. Don't afraid me. If you have any questions, please ask me whenever you want. I can answer whatever you want (^^;).


OK, let's start. Sammy had explained about the relation of Biology, Chemistry, Physics, and Mathematics. I do not discuss that "which science area is important or not". However, the Mathematics is the most basic category in all of science, as you may understand. So today's theme is one of the mystery of Mathematics. It is Prime Number.

皆さんは高校生のときに「素数」について習ったかと思います。2, 3, 5, 7, 11, 13……。この不思議な数は1とそれ自身でしか割り切れない数とされています。ただし1は素数ではないことは重要なことのようですので、覚えておくことをお勧めします。

You might lean about Prime Number, when you are a student of senior high school. Do you remember it? 2, 3, 5, 7, 11, 13……. These numbers are defined as follows "A prime number (or a prime) is a natural number that can be divided by 1 or itself". However, 1 is not included into this gout. Please remember it.

ここで、どうやって素数を探すかについて簡単に説明します。まず、2から100までの数字で考えてみましょう(Fig. 1)。

Let's think about numbers from 2 to 100. I explain the method to find prime numbers from it (Fig. 1).

2の倍数を消します(Fig. 2)。

Delete 2's multiple numbers (Fig. 2).

3の倍数を消します(Fig. 3)。

Delete 3's multiple numbers (Fig. 3).

5の倍数を消します(Fig. 4)。

Delete 5's multiple numbers (Fig. 4).

7の倍数を消します(Fig. 5)。

Delete 7's multiple numbers (Fig. 5)

11の倍数を消します(Fig. 6)。あれ?ありませんね。

Delete 11's multiple numbers (Fig. 6). Un?? Nothing.

完成です(Fig. 7)。

Completed (Fig. 7).


In this method, we can find more big prime number. But Sammy has not understand the beauty of these prime numbers. So, would you teach me about the beautifulness for me?


Today's class is over. Have a nice day. Click the button at the bottom of this What is Life?, if you are a student of this class. 

にほんブログ村 科学ブログ 生物学・生物科学へ人気ブログランキングへ



  1. ぶらっとWeb TVというものを発見しました。お越しの際にご参考になさって下さい。

  2. 銀杏について教えて下さる植物学者は本当にいらっしゃらないのでしょうか?




  3. HELP! >> iPhoneユーザの皆様。




Thank you!