The Road to Reality
01-16-09, 09:07 PM
#1
DVD Talk Gold Edition
Thread Starter
Join Date: Jun 1999
Location: st paul mn
Posts: 2,028
Likes: 0
Received 0 Likes
on
0 Posts
The Road to Reality
My sisters have been buying me pop science books and the math is accelerating. This last book, The Road to Reality, by Roger Penrose, is a thousand page tome with a fair amount of mathematical glyphs. It is the paperback version, published in New York during 2005.
I may not have enough time to comprehend it all, but I intend to give it a shot. The book proclaims itself a national best seller, so some person who is reading this now, may have it in their hands or knows something about it.
It didn't take me long to bump into a problem. On page 35 there is a simple equation, pi - (x + B + y) = C, the area. It is referring to the angles of a triangle, pictured above.
I can easily find the uppercase B and lowercase y, but cannot find the italic x. My neighbor thinks it's a t and my sister thinks it's an n. I think it is a lowercase a, which is not part of the equation.
It is hard to imagine that a book of this sort would have a typo so early in the text, and, if it can happen here, there may be more typos to follow. It is either that or I have interpreted it incorrectly and am just another dummy.
I have not been around for several years, but I remember identifying a musician by describing his talents publicly, and another member clued me in as to who he was. I'm hoping someone here might have the clue I'm looking for.
I may not have enough time to comprehend it all, but I intend to give it a shot. The book proclaims itself a national best seller, so some person who is reading this now, may have it in their hands or knows something about it.
It didn't take me long to bump into a problem. On page 35 there is a simple equation, pi - (x + B + y) = C, the area. It is referring to the angles of a triangle, pictured above.
I can easily find the uppercase B and lowercase y, but cannot find the italic x. My neighbor thinks it's a t and my sister thinks it's an n. I think it is a lowercase a, which is not part of the equation.
It is hard to imagine that a book of this sort would have a typo so early in the text, and, if it can happen here, there may be more typos to follow. It is either that or I have interpreted it incorrectly and am just another dummy.
I have not been around for several years, but I remember identifying a musician by describing his talents publicly, and another member clued me in as to who he was. I'm hoping someone here might have the clue I'm looking for.
Last edited by LtlPhysics; 01-16-09 at 09:14 PM.
01-20-09, 03:25 AM
#3
DVD Talk Gold Edition
Thread Starter
Join Date: Jun 1999
Location: st paul mn
Posts: 2,028
Likes: 0
Received 0 Likes
on
0 Posts
It's Greek to Me
I knew someone here had read the book.
I can only remember a "little physics," hence my name. If I were to write, cursively, a lower case "a" it would look exactly like the alpha in the diagram, but not the equation. If I were to write the symbol in the equation, it would be unlike any other version of "a." The stroke is completely different. I found some very strong reading glasses and am not just confused. They meant different things.
Penrose is, no doubt, a very famous guy. This book is written for people like me, which is why it's a thousand pages instead of fifty-thousand pages. This is very disappionting, to stumble with terminology just outside the gate.
So, I dug out some old textbooks out of the basement, to see what I may have forgotten. The alphas and the "a's" are different things, they are used in diagrams and exercises simultaneously, they do not change form. They have the same appearance, wherever they show up. There is no confusing one for the other. The lower case "a" is not used as a measurement of degree, as Penrose has used it in his diagram.
Is this an English convention, theatre rather than theater?
I can only remember a "little physics," hence my name. If I were to write, cursively, a lower case "a" it would look exactly like the alpha in the diagram, but not the equation. If I were to write the symbol in the equation, it would be unlike any other version of "a." The stroke is completely different. I found some very strong reading glasses and am not just confused. They meant different things.
Penrose is, no doubt, a very famous guy. This book is written for people like me, which is why it's a thousand pages instead of fifty-thousand pages. This is very disappionting, to stumble with terminology just outside the gate.
So, I dug out some old textbooks out of the basement, to see what I may have forgotten. The alphas and the "a's" are different things, they are used in diagrams and exercises simultaneously, they do not change form. They have the same appearance, wherever they show up. There is no confusing one for the other. The lower case "a" is not used as a measurement of degree, as Penrose has used it in his diagram.
Is this an English convention, theatre rather than theater?
01-20-09, 09:56 PM
#4
DVD Talk Hero
Re: The Road to Reality
Reading through it again my best guess is
The "a" in the hyperbolic triangle is a typo, it should be an alpha. The other "a" in the picture is just used to label the line.
My guess why they use the greek letters with the hyperbolic triangle is because they don't follow Pythagorean theorem like the Euclidean triangles where a, b, and c are commonly used to represent angles of a triangle.
This is why I always hated geometry so that's the best I can do
The "a" in the hyperbolic triangle is a typo, it should be an alpha. The other "a" in the picture is just used to label the line.
My guess why they use the greek letters with the hyperbolic triangle is because they don't follow Pythagorean theorem like the Euclidean triangles where a, b, and c are commonly used to represent angles of a triangle.
This is why I always hated geometry so that's the best I can do
