Seeing Further edited by Bill Bryson

Seeing Further

Seeing Further: The Story of Science, Discovery, and the Genius of the Royal Society is an uneven collection essays nominally about the Royal Society of London- celebrating its 350th anniversary. Sadly this isn’t a Bill Bryson book: he only wrote the introduction. Yet, I was heartened to see: James Gleick, Margaret Atwood, Neal Stephenson, Richard Dawkins, and Gregory Benford listed as contributors. The essays deal with history, science, engineering and math. Some are good and some are almost unreadable. If the book had been a straightforward history of the Royal Society and its notable members it would have been a better book rather than a random collection of science essays.

C
512 pages

Table of Contents

Grade Chapter Author
C+ Introduction Bill Bryson
B+ At the beginning:
more things in heaven and earth
James Gleick
C Of the madness of mad scientists:
Jonathan Swift’s Grand Academy
Margaret Atwood
C Lost in space:
the spiritual crisis of Newtonian Cosmology
Margaret Wertheim
A Atoms of cognition:
metaphysics in the Royal Society
Neal Stephenson
C+ What’s in a name?
Rivalries and the birth of modern science
Rebecca Newberger Goldstein
B- Charged Atmospheres:
Promethean science and the Royal Society
Simon Schaffer
C- A new age of flight:
Richard Banks goes ballooning
Richard Holmes
C Archives of life:
science and collections
Richard Fortey
B- Darwin’s five bridges:
the way to natural selection
Richard Dawkins
B Images of progress:
conferences of engineers
Henry Petroski
C+ X-ray visions:
structural biologists and social action in the twentieth century
Georgina Ferry
B- Ten thousand wedges:
biodiversity, natural selection and random change
Steve Jones
B+ Making stuff:
from Bacon to Bakelite
Philip Ball
C Just typical:
our changing place in the universe
Paul Davies
B- Behind the scenes:
the hidden mathematics that rules our world
Ian Stewart
B Simple, really:
from simplicity to complexity – and back again
John D. Barrow
C- Globe and sphere, cycles and flows:
how to see the world
Oliver Morton
C- Beyond ending:
looking into the void
Maggie Gee
C Confidence, consensus and the uncertainty cops:
tackling risk management in climate change
Stephen H. Schneider
C Time:
the winged chariot
Gregory Benford
C+ Conclusion:
looking fifty years ahead
Martin Rees

Chapter 15 “Behind The Scenes: The Hidden Mathematics That Rules Our World” by Ian Steward

JPEG starts by splitting the data into three separate arrays. One lists how bright each pixel is. The other two take advantage of the fact that the colours perceived by the eye can be specified as points in a plane, the colour triangle. A plane is two-dimensional, so each point can be defined using just two numbers, its horizontal and vertical coordinates. These colour components form the other two lists. The human eye is more sensitive to variations in brightness than in colour, so the two lists of colour components can be shortened – usually they are reduced to one quarter of their original size – by using a coarser list of colours. The next step uses a trick introduced by the French mathematician Joseph Fourier in 1824 – a year after his election to the Royal Society, as it happens – who at the time was working on the flow of heat. In general terms, Fouriers idea was to represent a pattern of numbers by combining specific patterns with different frequencies – much as the note played by a clarinet is made up from a fundamental pure note and various higher-pitched harmonics, all added together in suitable proportions. JPEG uses a similar trick for spatial patterns of numbers, treating each of its three arrays in the same way. First, the array is broken up into 8×8 blocks of pixels. Then each block is transformed into a list of its spatial frequencies in the horizontal and vertical directions. Roughly, this splits the pattern into black-and-white stripes of various thicknesses, and works out how much of each stripe you need to reconstruct the actual image. This step employs a fast Fourier transform, exploiting number-theoretic features of binary numerals to speed up a difficult computation; this is why 8×8 blocks are used, eight being a power of two. The Fourier transform does not compress the data, but rewrites it in a compressible form. The eye is fairly insensitive to high-frequency stripes, so these can be ignored. Medium-frequency stripes can be specified using smaller numbers, which occupy less space on the memory card. This is not the end: two more tricks are used to squash even more pictures into the same space. If you run through the resulting array of numbers in a zigzag order, from low frequency components to high ones, you typically find runs of repeated numbers, such as 7 7 7 7 7 7 7 7 7. Coding this as 9 consecutive 7’s converts it to 9 7, which is shorter. Finally, another coding method called Huffman coding is used on the resulting file, which compresses it even further. So JPEG coding is quite complex, with sophisticated mathematical features. You don’t need to know how it works to use your digital camera, but without the underlying ideas, that camera could never have been made. Now think of future developments, video cameras, cramming a camera into a mobile phone along with dozens of other applications … We desperately need people who can understand that sort of mathematics. (Kindle Locations 4530-4535)

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About craigmaas

I do a little web design work and support a couple web sites and blogs. My primary focus is lighting and energy consulting where I use a number of computer tools to help my customer find ways of saving money and improving their work environment. See my web site for more information: www.effectiveconcepts.net
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