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Huginn
24-01-2012, 01:44 PM
Title: Practical Astronomy With A Calculator or Spreadsheet
Edition: 3rd (1988)
Author: Peter Duffett-Smith
Publisher: Cambridge University Press

Link:
http://www.amazon.com/Practical-Astronomy-Calculator-Peter-Duffett-Smith/dp/0521356997

Firstly, I will concede that this book is extremely old and outdated. The good news is that there is a 4th edition published mid 2011. The contents look exactly the same as the 3rd edition. However I have only had the opportunity to read/used this book and it has provided me with hours of entertainment.

Link to the new edition http://www.amazon.com/Practical-Astronomy-your-Calculator-Spreadsheet/dp/0521146542/ref=dp_ob_title_bk
(including a preview)

Don't let the title of the book scare you away. Yes this book does involve mathematics, but I'm quite sure that amateur astronomers wish they could be astrophysicists. I know I do... I'm not a mathematician, I have only done High School Mathematics and a semester of university mathematics. 5 and 3 years ago respectively. The mathematics are not exactly hard, however if you haven't done any mathematics, unfamiliar with equations and think tan is something you only get at the beach, you might have some difficulty. Luckily, Duffett-Smith does a great job in explaining concepts and equations while holding the readers hand in a step by step process to get the answer to various topics listed below.

Chapter one is calculating time. A fairly easy topic, Duffett-Smith looks at calendars, julian numbers, the date of easter and local side real time.

Chapter two is calculating celestial bodies and their position in the sky. Ever wanted to calculate the position of a star in terms of Alt-Az, and only know the RA and DEC? Well using Julian numbers and local sidereal time it is possible. Moreover there are more calculations including the angle between two celestial objects and geocentric parallax.

Chapter three is a short section on the sun - orbits, the suns distance and size.

Chapter four is for calculating planets, comets and binaries stars. Calculating the coordinates and phases of the planets, a small section on comet positions, binary star orbits

The last Chapter is on the moon. It goes through the rules of eclipses, calculating the eclipses, the phases of the moon and the distance and size of the moon.

I have only picked out a few main calculations in this book. I'm sure readers can spend hours doing calculations knowing they are following the path of astronomers hundreds of years ago.

One of the downsides I found was in terms of accuracy. There is not a reasonable way to know if some of your answers are correct. However, the few calculations I had done, corresponded with star apps close to a degree.

A DIY project that I will write up in the next few days will entail how I wrote a program using the equations in the book to determine the current alt - az position with only RA-DEC known.

During the testing phase, the equations gave an initial position within a degree for both alt -az in respect to the star app. Over a period of 12 hours, that error margin did not change staying close to a degree.

I hope you enjoyed my first review. I've been meaning to write it for a while.
:)

Barrykgerdes
24-01-2012, 02:48 PM
That is quite a useful book and it gave the equations for solving astronomival calculations on a scientific calculator.

A more useful book I found is the "Astronomy with your personal computer" by the same author.

This gives all the calculations in GWbasic form and is suitable for just about every astronomical calculation. The code is modularised so that all the sections can be assembled into different programs.

The code will work in Qbasic without modification but basic/qbasic will not work in Windows 7.

I have all the source on my computer (painfully entered by hand over a number of years) plus many programs using this source modified to make it more managable. I also have most of the code patched to run on the current version of QB64 which allows all the programs I have written to run in Windows 7 64 bit. QB64 will also run in Linux and on a Mac

The current version of QB64 does not recognise DEF FUN(W) or OPEN COM properly yet and also has some protected words that were available for use in Qbasic. The source needs to be edited to process this code differently not a major problem.

There are some programs here using the code from this book although not all these have been updated to QB64 state yet.

http://barry.sarcasmogerdes.com/observatory/page3/page3.htm

Barry

mithrandir
25-01-2012, 05:05 PM
Barry, the links within that page are bad. For instance http://barry.sarcasmogerdes.com/observatory/page3/%5Cobservatory%5Czips%5CDUFFET.ZIP should be http://barry.sarcasmogerdes.com/observatory/zips/DUFFET.ZIP

which looks like they are relative to the wrong point in the directory tree and have M$ \ rather than correct / separators.

Barrykgerdes
25-01-2012, 09:11 PM
Sorry about that Andrew

It worked last time I tried it. That link should have gone to the page so that the download would work . I can't fix it at the moment because I can't log onto the server from this computer while I am in Melbourne.

If anyone wants the modified source for QB64 I will make a link.

Barry