Apple Menu:

About GalaxSee...

Provides version number and copyright information.

Help

Once configured, tells Netscape to open the help documentation for GalaxSee. The first time this option is selected, it will act like "Find Help...", allowing you to browse your mac and locate the document "GalaxSee_Help". Once you have located the help document, selecting this menu option will simply open the document. If you make a mistake or find that this has been misconfigured, simply choose "Find Help..." and browse until you find the correct file.

Find Help...

Opens the standard Macintosh file opening dialog that allows you to find the help documentation for GalaxSee on your computer. This documentation should have been included in the distribution of GalaxSee. The file you want to find is a Netscape Navigator document called GalaxSee Help. You can also open this document by double clicking on it from the Finder or opening it from Netscape or a compatible browser.

File Menu:

Open Galaxy...

Opens a previously saved galaxy.

Close Galaxy

Closes the current galaxy. All of the galaxy's data is deleted.

Save Galaxy...

Saves the masses, locations, velocities, and color(s) of the stars in the current galaxy in a text file.

Save Galaxy Pict...

Saves a snap shot of the current galaxy as a PICT file.

Quit

Exits the GalaxSee program.

Edit Menu:

Copy Picture

Copies a PICT file of the current galaxy to the clipboard.

Save Preferences

Saves the current settings of the GalaxSee program. Will reload them upon start- up.

View Menu:

Perspective

Adjusts the 3-D distortion on the framing box from perfectly square (none) to highly exaggerated (10) in steps of one. The default is three. A good way to understand this option is to try both extremes of the scale and observe the difference.

Star Size

Adjusts the size of the stars or represents them as balls.

Star Color

Changes the stars to any one of seven colors choices.

Hide Color

Makes all the stars of a particular color invisible (or makes them visible again)

Redshift

Turns on (or off) a (highly exaggerated!) redshift indicator. All the stars moving away from a particular viewpoint (that point being the bottom of the screen when the image is centered with command-M or when "New Galaxy" is chosen) are colored red and those moving toward the viewpoint are colored blue. (This particular viewpoint was chosen because it works well with a rotating galaxy.) It should be noted (and explained to the students!) that in actuality, redshift is a very small effect and is only detectable with instruments that separate the spectrum of a star.

Depth Cueing

When checked, adds a depth gradation to the edges of the framing box and the stars themselves to make them appear darker when they are at the back of the viewing frame.

Show Box

When checked, frames the current galaxy in a 3-D cube to help orient the user.

Black Background

When checked, displays a black background instead of a white background.

Mono

This is the normal, default view. This view can be changed to the stereo view, described below.

Stereo

This option activates the stereo menu, allowing the user to see the galaxy using either 3-D glasses or visual blending techniques. These features are discussed under the Stereo Menu section of this manual.

Full Size

Enlarges the view of the current galaxy to its maximum size.

Small Window

Reduces the view of the current galaxy to a small window.

View Reset

Resets the view controls to their default values.

Stereo Menu:

Note: This menu becomes active when stereo is selected in the View Menu. It allows the user to see the current galaxy using either 3-D glasses or visual blending techniques.

Cross-eyed

This function creates two images of the galaxy that can be visually blended by focusing your eyes on a point nearer than the screen. When done correctly, the two images form a third, three-dimensional image between them. Use the Angle and Separation functions described below to optimize the effect.

Parallel

This function creates two images of the galaxy that can be visually blended by focusing your eyes on a point farther than the screen. When done correctly, the two images form a third, three-dimensional image between them. Use the Angle and Separation functions described below to optimize the effect.

Red Green

This function splits the image into red and green components that can be blended by wearing red/green 3-D glasses. Use the Angle functions described below to optimize the effect.

Red Blue

This function splits the image into red and blue components that can be blended by wearing red/blue 3-D glasses. Use the Angle functions described below to optimize the effect.

Set Angle

Allows the user to vary the angular separation in the two views of the image between zero and ten degrees to create the optimum 3-D effect.

Increase Angle

Increases the angular separation between the two views of the image in half degree steps.

Decrease Angle

Decreases the angular separation between the two views of the image in half degree steps.

Increase Separation

When using either the Cross-eyed or Parallel functions, increases the distance between the two views of the image for optimal 3-D effect.

Decrease Separation

When using either the Cross-eyed or Parallel functions, decreases the distance between the two views of the image for optimal 3-D effect.

Action Menu:

Zoom in

Zooms in on the galaxy view. Hold down for continuous zooming.

Zoom out

Zoom out from the galaxy view. Hold down for continuous zooming.

Grab & Spin

When checked, allows the user to spin the image by clicking on the image and holding down the mouse button while dragging the mouse. If the button is released while the mouse is still moving, the image will continue to spin in the direction the mouse was moving. With a little practice, you'll get the hang of it.

Rotate Z Axis

Begins a slow, continuous Z-Axis spin of the image.

Wobble

Slightly rotates the image back and forth about the Z-Axis to allow the viewer to get a sense of the three-dimensional location of the stars without significantly disrupting the overall view.

Note: Spinning the image of the galaxy on the screen does not affect the rotation factor selected in the Galaxy Setup dialog box. Spinning simply changes your view of the galaxy.

Center Image

This is the default. The image, when spun or turned, turns on a point in its center. This keeps the image from "migrating" around the screen. This function is best understood by moving the image right or left with the following functions and then spinning it to see the difference.

Move Right

This moves the image of the galaxy on the screen to the right of it's central spinning axis. Try it. Center Image, above, will return it to the centered position.

Move Left

This moves the image of the galaxy on the screen to the left of it's central spinning axis. Try it. Center Image, above, will return it to the centered position.

Galaxy Menu:

New Galaxy

Creates a new galaxy according to the variables selected in the Galaxy Setup dialog box. The current galaxy will be deleted unless saved before this function is executed.

Run

Starts the current galaxy moving continuously through the timestep intervals selected in the Model Settings Menu.

Stop

Stops the current galaxy from moving continuously through the selected timestep intervals.

Forward One Step

Moves the current galaxy forward in time for a single timestep.

Show Info

Displays the Information window. This window contains the settings of the Galaxy Setup dialog box and the Model Settings dialog box along with information about the progress of the current galaxy . If Do Bookkeeping is checked, then it also displays the conservation of momentum and energy values for the current galaxy. More information about the information window can be found in the tutorial.

Hide Info

Hides the information window.

Resume Bookkeeping

Resumes the process of keeping track of the total energy, overall momentum, and center of mass of the current galaxy. This information is displayed at the bottom of the information window.

Stop Bookkeeping

Stops GalaxSee from keeping track of the total energy, overall momentum and center of mass of the galaxy.

Halve Timestep

Reduces the timestep by one half of the current timestep setting selected in the Model Settings dialog box.

Double Timestep

Doubles the current timestep setting selected in the Model Settings dialog box.

Show List

Displays a list of the stars in the current galaxy with their masses, positions, velocities, and color. The list is updated at each timestep.

Hide List

Hides the Star List.

Note: Hiding the Star List will significantly increase the rate at which GalaxSee runs.

Galaxy Setup...

Displays the Galaxy Setup dialog box. A more detailed description of each item in the Galaxy Setup box can be found in the GalaxSee tutorial.

Model Settings...

Displays the Model Settings dialog box. A more detailed description of each item in the Model Settings box can be found in the GalaxSee tutorial.

Scale...

Displays the Scale dialog box with the following options:

• Galactic
• Solar System
• Earth-Sun

Choosing one of these options will result in a change of scale affecting the entire system being modeled. The lengths, times, masses and the size of the box (which is visible when Show Box, under the View menu, is checked) are all affected. This allows you to conveniently model systems much smaller than a galaxy. The scale feature is discussed in more detail elsewhere.