In this classic children's adventure story, "time travel is explained as a tesseract, a five dimensional figure. By traveling along the tesseract, one bypasses the space in between."

"Now," Mrs. Which said. "Arre wee rreaddy?" "Where are we going?" Calvin asked. Again Meg felt an actual physical tingling of fear as Mrs. Which spoke. "Wwee musstt ago bbehindd thee sshaddow." "But we will not do it all at once," Mrs. Whatsit comforted them. "We will do it in short stages." She looked at Meg. "Now we will tesser, we will wrinkle again. Do you understand?" "No," Meg said flatly. Mrs. Whatsit sighed. "Explanations are not easy when they are about things for which your civilization still has no words. Calvin talked about traveling at the speed of light. You understand that, little Meg?" "Yes," Meg nodded. "That, of course, is the impractical, long way around. We have learned to take short cuts wherever possible." "Sort of like in math?" Meg asked. "Like in math." Mrs. Whatsit looked over at Mrs. Who. "Take your skirt and show them.' "La experiencia es la madre de la ciencia. Spanish, my dears. Cervantes. Experience is the mother of knowledge." Mrs. Who took a portion of her white robe in her hands and held it tight. "You see ," Mrs. Whatsit said, "if a very small insect were to move from the section of skirt in Mrs. Who's right hand to that in her left, it would be quite a long walk for him if he had to walk straight across."

Swiftly Mrs. Who brought her hands, still holding the skirt, together. "Now, you see," Mrs. Whatsit said, "he would be there, without that long trip. That is how we travel."

Charles Wallace accepted the explanation serenely. Even Calvin did not seem perturbed. "Oh, dear," Meg sighed. 'I guess I am a moron. I just don't get it." "That is because you think of space only in three dimensions," Mrs. Whatsit told her. "We travel in the fifth dimension. This is something you can understand, Meg. Don't be afraid to try. Was your mother able to explain a tesseract to you?" "Well, she never did," Meg said. "She got so upset about it. Why, Mrs. Whatsit? She said it had something to do with her and Father." "It was a concept they were playing with," Mrs. Whatsit said, "going beyond the fourth dimension to the fifth. Did your mother explain it to you, Charles?" "Well, yes." Charles looked a little embarrassed. "Please don't be hurt, Meg. I just kept at her while you were at school till I got it out of her." Meg sighed. "Just explain it to me.""Okay," Charles said. "What is the first dimension?" "Well-a line: "Okay. And the second dimension?"

"Well, you'd square the line. A flat square would be in the second dimension. "And the third?" "Well, you'd square the second dimension. Then the square wouldn't be flat any more. It would have a bottom, and sides, and a top."

"And the fourth?" "Well, I guess if you want to put it into mathematical terms you'd square the square. But you can't take a pencil and draw it the way you can the first three. I know it's got something to do with Einstein and time. I guess maybe you could call the fourth dimension Time." "That's right," Charles said. "Good girl. Okay, then, for the fifth dimension you'd square the fourth, wouldn't you?" "I guess so.""Well, the fifth dimension's a tesseract. You add that to the other four dimensions and you can travel through space without having to go the long way around. In other words, to put it into Euclid, or old-fashioned plane geometry, a straight line is not the shortest distance between two points." For a brief, illuminating second Meg's face had the listening, probing expression that was so often seen on Charles's.

"I think that this was one of the best books I read as a child and it certainly inspired me as an adult."

Madeleine L'Engle's books distort the nature of scientific research and use mathematical concepts as though they were metaphors. I have only one word for her work: meretricious. Two generations of readers in my family have detested and despised her work.

Entertaining and thought-provoking. While the math and science involved may be a bit fuzzy, it can definitely generate some ideas for discussion. I read this as a child, and it still remains one of my favorite books.

Quite a good book as far as entertainment value, but it was a little vague about the tesseract. It did, however, spark my mind to the idea of multidimensional space.

I liked this story a lot as a preteen but it didn't inspire in a mathematical way. I liked that the main character, a preteen girl, who is intimidated by a younger brother's sheer genius is encouraged to do math by her mother. While I didn't have any genius siblings growing up, I did get intimidated by a few genius kids I met at math contests and appreciated my parents' similar encouragement. So I strongly recommend this book and the whole trilogy to preteens who like math and science and those who maybe think they don't. I think the model tesseract as constructed by the brother is correct. It was a pretty common science fair project when I was in junior high. I don't think the rest of the fantasy really added to an understanding of higher dimensions at all. Just that one can travel in time.

I REALY LIKED [THIS] BOOK IT IS VERY INTERESTING TO ME AN 11 YEAR OLD BUT I WANT TO LEARN MORE ABOUT THE 1 2 3 4 5 DEMENSIONS AND TESSERACTING

This book was really great. It makes you ponder about space and out beyond.

A young teenage girl (Meg) and her baby brother Charles Wallace go off traveling through space time and dimentions. Along the way Meg learns about the dangers of conformity. Time travel is achieved through the use of a tesseract. Mathematics, are used in such a creative way as to add understanding to the possibilities of other dimensions unexplored. The “tesseract” is one example. “In geometry, the tesseract, also called 8-cell or octachoron, is the four-dimensional analog of the cube, which is in turn the three dimensional analog of the square. The tesseract is to the cube as the cube is to the square; or, more formally, the tesseract can be described as a regular convex 4-polytope whose boundary consists of eight cubical cells. A generalization of the cube to dimensions greater than three is called a “hypercube”, “n-cube” or “measure polytope”. The tesseract is the four-dimensional hypercube or 4-cube (Wikipedia)”.

Every character in this outstanding novel is identified as either good or evil. Some of the good characters include Meg, who is the protagonist of "A Wrinkle in Time", Charles Wallace, Megs baby brother, and their family, Calvin O'Keefe, the three Mrs. W.'s,--Mrs. Whatsit, Mrs. Who, Mrs. Which, Aunt Beast and the Happy Medium; the evil characters include IT, the dark thing and the man with the red eyes. In the absence of any ambiguities or shades of gray, the book's central conflict is clearly and starkly dramatized in order to make the reading easier to understand its teams and its message. There is a light and dark balance. Contrast is an important theme, if the ending were to be changed, this could interrupt the balance and the darkness could win, thus making the entire plot superfluous. It must end happily; the “Happy Medium”.