# Gravity and Motion: The Early History of Modern Astronomy

## WWW Icons

Incorrect:
Angular momentum is the same as "momentum."

Correct:
"Linear momentum," often called simply "momentum," is the tendency of a body to keep moving straight ahead. "Angular momentum" is different, and is a measure of the spin taking account also of the distribution of weight with distance from the axis. Note that both linear momentum and angular momentum are "conserved," that is, they do not change without some outside force changing them.

www.galileo-galilei.org
Tycho Brahe exhibit at Museum of History of Science, Oxford
Kepler's biography from the Kepler mission
Working Group for the History of Astronomy
History of Astronomy
History of Astronomy and Space Science
Newton on the Web from CERN
The Galileo Project: documents on early astronomers
Galileo's finger
Views of the Solar System by Calvin J. Hamilton
List of Solar System Info
Center for Archaeoastronomy, University of Maryland
History of Astronomy and Physics references from MIT
Newton on the Web: Newton's unpublished manuscripts are being put onto the Web.
The Harmony of the Spheres: See a nice illustrated summary of the main line of astronomical history
Tycho Brahe site, Museum of History of Science, Oxford

## Errata

In the solutions manual available to professors, the solution for Chapter 5 problem 14 would only be correct if the central black hole had a mass of one solar mass. In all other cases, the proportionality constant between P^2 and a^3 is not 1 when using A.U.s and years.

The solution for Chapter 5 problem 16 states that (semimajor axis in AU)^3 x (central mass in solar masses) = (period in years)^2
In fact it should be (semimajor axis in AU)^3 / (central mass in solar masses) = (period in years)^2

## Images through a replica of Galileo's original telescope

Jim Moser and Tom Pope have made a replica of Galileo's 1" telescope and obtained photograph of the moon, sunspots, etc., with it. See http://www.pacifier.com/~tpope/

## Archaeoastronomy Web page

See Paula Giese's page on Aboriginal Star Knowledge,

## Census of Stone Monuments

A tour of megalithic sites in Western Europe, and links to other archaeoastronomy sites.

## Galileo and More

See the homepage of the Institute and Museum of the History of Science of Florence, Italy.

## Galileo's notes posted from PEN

The American Institute of Physics Bulletin of Physics Education News June 1998 Number 2.
GALILEO PER TUTTI
Galileo Galilei laid the groundwork for classical mechanics in his book, Discorsi, published in 1638. Discorsi is based on Galileo's studies of the motion of objects and the records he kept in his "Notes on Motion." These notes, due to their high historical and scholarly value, have been kept safe -- and unpublished -- at the National Library in Florence, Italy. Now, in a joint effort by the National Library, the Institute and Museum for the History of Science in Florence, and the Max Planck Institute for the History of Science in Berlin, Galileo's Notes have been partially published on the Web. 270 pages have been posted in facsimile form, with transcriptions, translations, and hyperlinks. To make use of this valuable resource, go to http://www.mpiwg-berlin.mpg.de/Galileo_Prototype/.

## Galileo on the Web

Albert Van Helden has a Galileo Project Home Page, including information about Galileo and his experiments, in the form of a tour of his villa.

## NASA Solar-System Exploration Newsletter Available On-Line

Dr. Carl Pilcher, Science Director for Exploration of the Solar System in NASA's Office of Space Science, announces the first issue of the new Solar System Exploration newsletter. It is online at http://sse.jpl.nasa.gov/results/newsletter/newslet.html in pdf format. The newsletter is published several times a year to keep the planetary science community informed about activities and plans at NASA Headquarters. The first issue discusses the Congressional budget status, the Mars reports and replanning efforts, and education and public outreach. We hope to facilitate dialog between the science community and Headquarters, and invite your feedback comments, and suggestions. Send to cpilcher@hq.nasa.gov or Ronald.S.Saunders@jpl.nasa.gov

## Solar System Simulator from JPL

See the location, look, and phase of any of 32 planets and moons on any date, as simulated at JPL. The site includes texture maps of various planets and moons.

## Spacecraft Kits

\$14 paper models of Voyager, Galileo, Magellan, Hubble, Keck, and Mars Global Surveyor.

## Solar System Resource List on the Web

### A List of Beginner's Resources About the Solar System For Teachers and Students

An annotated reading and resource list, compiled by Andy Fraknoi, is available for beginners who want to learn more about our solar system is now part of the educational web pages of the non-profit Astronomical Society of the Pacific.

The resource listing can be found at:
www.aspsky.org/education/solarsys.html

The listing discusses some of the most useful books and articles for teachers and students on:

```* the solar system in general,
* each planet,
* asteroids and comets,
* impacts, and
* the search for life on other local worlds.
```

There are also brief lists of useful web sites and places to get slides and posters of solar system images.

This list is part of the work of Project ASTRO, a national program to train professional and amateur astronomers to "adopt" 4th - 9th grade classrooms in partnership with a local teacher in their communities. The project is currently operating in 11 regional sites from Boston to San Francisco.