Astro Resources.

  • Life history of a star. Very nice links with text and photos of real things. I like this one very much.
  • Astronomy in the deep freeze. Infra red astro in the Antarctic. Astro in different parts of the spectrum.
  • Hyperphysics. An encyclopedia of physics including a section on Astro and relativity. Very useable, simple and complete.
  • In case you don’t have it, this is the Hubble site.
  • This is like an On-line course in first year Astro. Very pretty very sensible very well organised.
  • Sloan Digital Sky Survey. Up to date pics of great things eg the most distant objects etc.

Intensity vs distance prac. Project a photographic slide of an array of dots onto a small target with a slide projector. Prepare a graph of the number of dots on the target vs the distance from the target. You will get a perfect inverse square trace. This models intensity of light vs distance which is a key astro measurement idea.

Expanding Universe Prac. Place about 6 texta dots randomly along a 30-40cm piece of white elastic. (Use the wider stuff ‘cos it looks better.) Fasten one end to a solid fixture. Choose a home dot to represent your galaxy. Record the distance from home to all the other dots. Stretch the elastic out to any sensible length and measure the distance from your home dot to all the other dots. Say that the universe has taken the time of one yonk to reach its stretched state. Subtract the initial distances from the final distances and plot these on the vertical axis. Divided by one yonk, these represent the speed of recession of the galaxies. Plot these against the final positions of the galaxies. You will get a straight line, the gradient of which will be the same regardless of which dot was chosen as the home galaxy. (To prove this, get the students to repeat the experiment choosing another dot as the home and be sure to stretch the elastic the same amount as you did the first time. The reciprocal of the gradient is the age of the universe in yonks. Ie the time since all the dots were co-incident. Clearly this prac models the obtaining of Hubble’s Constant.

The Parallax Viewer. In the older PSSC prac manuals there is a prac called “Measuring Large Distances.” Get someone to build the viewer if you can’t find any around the lab.

For Unit 1Astro Because both Mercury and Venus are between the Earth and the Sun, they effectively do SHM across the Sun from our perspective. If you subtract the time of setting of the Sun from the time of Setting of either of these two planets you will get a slightly distorted sine curve over the period of a few months. These curves can be interpreted to find the period of revolution of the planet. The distortions can also be interpreted. The data can be downloaded from a website and put into a spreadsheet if you don’t want to drag it out.

Books. A walk through Dymocks or Borders will reveal a luscious array of Astro books because in recent years it has become such an popular subject. The early chapters of “Wrinkles in Time” by George Smoot, give a great account of the story so far wrt the Universe. “The Birth of Time” by John Gribbin is a terrific account of how we got to grips with what a star is and how we measure distances to them and to galaxies. This great book gives some insights into Edwin Hubble’s character, (Gribbin does not like him) and celebrates the work of Alan Sandage who took over the work in the early ‘50’s.

In the States you can do Astro as a college course and their text books are very useful and nicely presented. I am using “Explorations” by Thomas Arny (Mosby ISBN 0-8016-7423-9) with some satisfaction. I suspect there are other newer titles available now.