草舟、与那国島出発＝コース修正し西表島へ－３万年前の航海再現・沖縄

草舟、与那国島出発＝コース修正し西表島へ－３万年前の航海再現・沖縄



日本人の祖先による３万年前の航海を再現するため、草舟で出発する前に気勢を上げるこぎ手ら＝１７日朝、沖縄県・与那国島のカタブル浜
　日本人の祖先による３万年前の航海を再現する国立科学博物館などのプロジェクトで、２そうの草舟が１７日朝、沖縄県・与那国島を出発した。こぎ手ら７人ずつが乗り込んで西表島を目指したが、速度が上がらず北へ流されたため、午後に航海を一時中断。こぎ手は伴走船に移り、草舟をえい航してコースを修正した上で、１８日朝に航海の再開を試みる。
祖先、いつ日本に？＝アフリカ起源説で浮上－草舟航海

　草舟に帆はなく、６人が木のかいでこぎ、１人がかじを取った。１７日午前６時５０分すぎに与那国島南部のカタブル浜を出て、１８日午後に約７５キロ離れた西表島西部のシラス浜に到着することを目指している。成功すれば、来年７月に台湾から黒潮を越えて与那国島に渡る航海に挑戦する計画。
　草舟は南米ペルー、ボリビア国境にあるティティカカ湖のアシ舟をモデルとして、与那国島に自生する丈夫な草「ヒメガマ」で作られた。長さ６．４メートル、幅１．３メートル程度。与那国島を意味する「どぅなん」号は同島で居酒屋を経営する入慶田本竜清さん（３３）、「シラス」号は西表島のシーカヤック（レジャー用小舟）ガイド赤塚義之さん（３７）がキャプテンを務めた。

　出発は１２日朝の予定だったが、強風や高波のため延期を重ねた。プロジェクト代表で国立科学博物館人類史研究グループ長の海部陽介さん（４７）は「ようやくスタートだ。３万年前の人々が何をしたのか知りたい」と話した。
　こぎ手は平均３５歳で、救命胴衣を腰に巻き、現代の服装と食料、水を用意。キャプテンは無線機で海部さんらと連絡を取り合うが、針路は太陽や星の位置などを手掛かりに決める。３万年前の集団移住を想定し、各舟のこぎ手のうち１人は女性が選ばれた。（2016/07/17-21:16）http://www.jiji.com/jc/article?k=2016071700014&g=soc

考古学にとても興味があります：

Announcement 213: An interpretation of the identity $ 0.999999...... =1$

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\begin{document}

\author{{\it Institute of Reproducing Kernels}\\
Kawauchi-cho, 5-1648-16,\\
Kiryu 376-0041, Japan\\

\date{}
\maketitle
{\bf Abstract: } In this announcement, we shall give a very simple interpretation for the identity: $ 0.999999......=1$.
\bigskip
\section{ Introduction}
On January 8, 2008, Yuusuke Maede, 8 years old boy, asked the question, at Gunma University, that (Announcement 9(2007/9/1): Education for genius boys and girls):
What does it mean by the identity:
$$
0.999999......=1?
$$
at the same time, he said: I am most interesting in the structure of large prime numbers. Then, a teacher answered for the question by the popular reason based on the convergence of the series: $0.9, 0.99, 0.999,... $. Its answer seems to be not suitable for the 8 years old boy with his parents (not mathematicians). Our answer seems to have a general interest, and after then, such our answer has not been heard from many mathematicians, indeed.
This is why writting this announcement.
\medskip
\bigskip
\section{An interpretation}
\medskip
In order to see the essence, we shall consider the simplist case:
\begin{equation}
\frac{1}{2} + \frac{1}{2^2} + \frac{1}{2^3} + ... = 1.
\end{equation}
Imagine a tape of one meter length, we will give its half tape: that is,
\begin{equation}
\frac{1}{2}.
\end{equation}
Next, we will give its (the rest's half) half tape; that is, $\frac{1}{2}\cdot \frac{1}{2} = \frac{1}{2^2}$, then you have, altogether
\begin{equation}
\frac{1}{2} + \frac{1}{2^2} .
\end{equation}
Next, we will give the last one's half (the rest's half); that is, $\frac{1}{2}\cdot \frac{1}{2} \cdot \frac{1}{2}= \frac{1}{2^3}$,
then, you have, altogether
\begin{equation}
\frac{1}{2} + \frac{1}{2^2} + \frac{1}{2^3}.
\end{equation}
By this procedure, you will be able to obtain the small tapes endressly. Imagine all the sum as in the left hand side of (2.1). However, we will see that this sum is just the division of the one meter tape. Therefore, we will be able to confim the identity (2.1), clearly.
The question proposed by Y. Maede is just the small change the ratio $\frac{1}{2}$ by $\frac{9}{10}$.
\bigskip
\section{ Conclusion}
Y. Maede asked the true sense of the limit in the series:
$$
0.999999.....
$$
that is, this series is approaching to 1; however, is it equal or not ? The above interpretation means that the infinite series equals to one and it is just the infinite division of one. By this inverse approarch, the question will make clear.
\medskip
\bigskip
\section{Remarks}
Y. Maede stated a conjecture that for any prime number $p$ $( p \geqq 7)$, for $1$ of $ - 1$
\begin{equation}
11111111111
\end{equation}
may be divided by $p$ (2011.2.6.12:00 at University of Aveiro, by skype)
\medskip
(No.81, May 2012(pdf 432kb)
www.jams.or.jp/kaiho/kaiho-81.pdf).
\medskip
This conjecture was proved by Professors L. Castro and Y. Sawano,
independently. Y. Maede gave later an interesting interpretation for his conjecture.
\medskip
(2015.2.26)
\end{document}

\title{\bf Announcement 214: Surprising mathematical feelings of a 7 years old girl
}
\author{{\it Institute of Reproducing Kernels}\\
Kawauchi-cho, 5-1648-16,\\
Kiryu 376-0041, Japan\\

\date{}
\maketitle
{\bf Abstract: } In this announcement, we shall give the two surprising mathematical feelings of 7 years old girl Eko Michiwaki who stated the division by 3 of any angle and the division by zero $100/0=0$ as clear and trivial ones. As well-known, these famous problems are historical, and her results will be quite original.
\bigskip
\section{ Introduction}
We had met, 7 years old girl, Eko Michiwaki on November 23, 2014 at Tokyo Institute of Technology and August 23, 2014 at Kusatu Seminor House, with our colleagues. She, surprisingly enough, stated there repeatedly the division by 3 of any angle and the division by zero $100/0=0$ as clear and trivial ones. As well-known, these famous problems are historical and her results will be quite original.
\section{The division of any angle by 3}
\medskip
Eko Michiwaki said:
divide a given angle with 4 equal angles; this is simly done. Next, we divide one divided angle
with 4 equal angles similarly and the three angles add to other 3 angles. By continuing this procedure, we will be able to obtain the division by 3 of any angle. Her idea may be stated mathematically as follows:
$$
\frac{1}{4} + \frac{1}{4^2} + \frac{1}{4^3} + ... ...= \frac{1}{3}.
$$
However, her idea seems to be more clear than the above mathematical formula. For this sentence, see \cite{ann3} for the sense of the limit.
\bigskip
\section{The division by zero $100/0=0$}
\medskip
As we stated in \cite{ann1}, she stated that division by zero $100/0=0$ is clear and trivial for our recent results \cite{cs,kmsy,s,ttk}. The basic important viewpoint is that division and product are different concepts and the division by zero $100/0=0$ is clear and trivial from the own sense of the division, independently of product \cite{ann1}. From the viewpoint, our colleagues stated as follows:
\medskip
On July 11, 2014, Seiichi Koshiba and Masami Yamane said at
Gunma University:
The idea for the division of Hiroshi Michiwaki and Eko Michiwaki (6 years
old daughter) is that division and product are different concepts and they
were calculated independently for long old years, by repeated addition and
subtraction, respectively. Mathematicians made the serious mistake for very
long years that the division by zero is impossible by considering that division
is the inverse operation of product. The division by zero was, however, clear
and trivial, as z/0=0, from the own nature of division.
\medskip
On February 21, 2015, Seiichi Koshiba and Masami Yamane visited our Institute and we confirmed this meaning of these sentences and the basic idea on the division by zero.
\medskip
(2015.2.27)
\bigskip
\bibliographystyle{plain}
\begin{thebibliography}{10}
\bibitem{cs}
L. P. Castro and S.Saitoh, Fractional functions and their representations, Complex Anal. Oper. Theory {\bf7} (2013), no. 4, 1049-1063.
\bibitem{kmsy}
M. Kuroda, H. Michiwaki, S. Saitoh, and M. Yamane,
New meanings of the division by zero and interpretations on $100/0=0$ and on $0/0=0$,
Int. J. Appl. Math. Vol. 27, No 2 (2014), pp. 191-198, DOI: 10.12732/ijam.v27i2.9.
\bibitem{s}
S. Saitoh, Generalized inversions of Hadamard and tensor products for matrices, Advances inLinear Algebra \& Matrix Theory. Vol.4 No.2 (2014), 87-95.http://www.scirp.org/journal/ALAMT/
\bibitem{ttk}
S.-E. Takahasi, M. Tsukada and Y. Kobayashi, Classification of continuous fractional binary operations on the real and complex fields, Tokyo Journal of Mathematics (in press).
\bibitem{ann1}
Announcement 179: Division by zero is clear as z/0=0 and it is fundamental in mathematics,
Institute of Reproducing Kernels, 2014.10.22.
\bibitem{ann2}
Announcement 185: The importance of the division by zero $z/0=0$, Institute of Reproducing Kernels, 2014.11.28.
\bibitem{ann3}
Announcement 213: An interpretation of the identity $ 0.999999...... =1$, Institute of Reproducing Kernels, 2015.2.26.
\end{thebibliography}
\end{document}