Menus and scenarios - Planets
Menus and scenarios - Planets
Please see the Manual → Overview for a more general information about this program.
What follows relates to the Planets operation.
Hotkeys and useful hints
With the Planets window in focus -
|Esc||stop, close Planets window|
|Ctr+S||fast save current state to file|
|L+Arrow keys||rotate launcher left/right/up/down|
|F1||start (Special positioning, from file)|
|G+Arrow keys||move group left/right/back/front|
|G+Page keys||move group up/down|
|V+Arrow keys||rotate view left/right/up/down|
|V+S||reset view (60º up)|
|Z+Arrow keys||zoom in/out (No hook camera)|
Whether with the Main window or the Settings window in focus, Alt+P will start the Planets window. The Esc key will stop the Planets operation and exit the window.
The title bar in the Planets window indicates, from l. to r., how many planets are active vs the number initially selected; the angle of horizontal view and/or vertical view (default is 0º forward and downwards from a 60º elevated position); frames per second.
Planets remain active as long as they move around the space somewhere (they may be out of view temporarily). Crashing into the sun, colliding with one another, or veering off into space makes them inactive.
When a planet crashes into the sun it adds its mass to the latter, making it bigger and increasing its gravitation value. The same goes for a collision with another planet.
The Planets window can be repositioned and stretched to suit your liking, including full screen. If opened from Settings window (Main window → File → Settings - Grid / Spheres / Planets) the Planets window will open as per previous position and size. If opened from Main Window (Main window → View → Show Planets) the Planets window will always open in centre position and default size selected in Options (Main window → File → Options - Planets). You can reset the Planets window this way.
In the Settings window, anything within the Dynamics panel on the right can be used with the Planets in operation. Within the Planets panel on the left only the Fragments after collision item can be changed during operation. '0' means no fragmentation after collision with another planet (and the larger planet absorbing the smaller or simply one absorbing the other if both are the same size), whereas any other number determines the number of fragments in such a case.
With Custom setup and Special positioning selected, the Planets force fields strength slider on the right will reflect the colour of the group selected in the Group box and the Colour selector. This means any change made through the slider will only affect this group.
Using the P hot key will launch an additional planet at any time.
To launch additional planets that are less likely to crash into the sun because its force field has increased substantially, increase the planets' force field strength with the Planets force fields strength slider and launch them in quick succession. This will cause the planets to collide with each other after leaving the launcher due to their heightened gravitation, and the resultant fragments are thrown into various trajectories, thus possibly avoiding the sun's pull. On the other hand, if Fragments.. is set to 0, the collisions will result in larger planets.
The above technique can also be used to simulate two or more suns. While there is only one actual sun available, an effect similar to having more can be achieved by using one or more large planets. Create a large planet by increasing the planets' force field, have it collide with another straight away (point the launcher to the far left, right, up or down or in combination of its horizontal and vertical orientation). The planet is less likely to crash into the sun but will become a large body orbiting very fast around the sun. Check Activate sun (top right panel) and the sun will now respond to the gravitational field of the planets, but mostly to the large one. The scenario is similar to having two or more suns around the centre, especially if the sun's and planet's force fields are made similar. Repeat the operation if you like.
If the frame rate has dropped too low because additional planets have been launched or many planets have been added due to fragmentation, click the Reduce planets to initial number button (right panel, bottom) to rid the system of the added planets. In this case only the active planets remain visible.
Fast saving (Ctr+S) allows the Planets operation including all its settings to be saved at any time with the Planets window in focus. The operation will not be interrupted and the files will be numbered consecutively. See Menus → File - Load Planets Settings Ctrl+L below for more.
Ctr+L loads such a file with the Settings window in focus and the Planets tab selected. After loading use Alt+P to open the Planets window, and F1 to start the operation. If the Planets window is closed (Esc) and reopened again the specific settings are removed and the operation reverts to the basic format (ie, the number of planets is the same but the planets have to be launched one by one). This is to avoid potential conflicts with other setting parameters. Note: during such an operation the S hotkey to reset is inactive.
For further explanations see the Menus section below.
Go to Main window → File → Settings - Grid / Spheres / Planets and select the Planets tab, or press Ctrl-O.
File - Load Planets Settings Ctrl+L
- together with Ctrl+S while Planets window in focus (see also Options → Save files to)
Once a file has been fast saved, capturing the state of the system during operation, it can be loaded this way. After clicking the Apply button open the Planets window (Alt+P) and the operation continues from the point of saving after pressing F1. Files are given consecutive numbers, starting with userfs0000.ufpf. Go to Main window → File → Options - Planets to set the default location for these files. Note: If the Pause button had been pressed while saving a file, after loading it needs to be pressed as well to start the operation.
Initial number of planets
Sets the default number of planets. They can be exceeded at any time by pressing P during operation. To reset the number to this value click the Reduce planets to initial number button on the bottom right panel. If the number is exceeded the Planets window title bar will show the current number vs the default value.
Fragments after collision
If set to 0, when two planets collide one will absorb the other and/or the larger one will absorb the smaller. The planet's mass will be added to the survivor, which means a larger radius, and the larger mass influences the effect the force fields have on this planet, in turn affecting its velocity (ie, speed and direction). Anything above 0 will break both planets up into so many fragments. Each planet's mass is divided among the fragments, resulting in a new radius, different velocity, etc. For example, if the total number of planets is 10 and fragmentation is set at 4 for both, the 2 planets will be removed while 4 more each will be added; thus the current number becomes 10 - 2 + (4 * 2) = 16. This setting can be changed at any time during operation.
Enables the settings below.
Number of groups
Up to five groups are possible. Several groups allow for specific settings per group.
Select the group to which particular settings should be applied. If a setting has been applied to a group, selecting that group will show those settings.
Select how many planets should be included in a group. The blue number directly below indicates how many are left to assign.
Selects the colour for a group. If there are planets left over, they will be assigned to the first group, hence will have that group's colour etc.
Special positioning - Random
All planets will be distributed randomly across the space with a randomly selected velocity for each. In the case of several groups the planets will also be mixed randomly. This setting requires F1 to start the operation (after clicking Apply and pressing Alt+P). Pressing S during operation will reset all planets with different distribution and velocities. Press F1 again to start. Note: Due to the default view from above and at a certain distance from the centre not all planets may be visible. To bring them into view zoom out (Z+Arrow key down). If this item is not selected, group settings are still valid and planets will be launched into space via P one by one, starting with the first group.
Special positioning - Cluster
Planets will be placed in groups, and randomly distributed within each group's space with randomly selected velocities for each planet. The sequence is, Group 1 - left rear, Group 2 - right rear, Group 3 - right front, Group 4 - left front, Group 5 - centre front. Each group can be moved with the G+Arrow keys for left, right, back, front respectively, and with the G+Page keys for up and down. Type the number of the group to be moved in the Group box. S will reset the groups to their respective positions by having used the G+.. keys. Requires F1 to restart. Note: Placing one group within the space of another will not affect any possible collision between planets at that point. Only after F1 will any collision be taken care of (this is one way of creating fragments).
Any changes made in this panel (with the exception of Fragments after collision) need to be formally applied to the graphics module.
Just as the planets are influenced by the sun's gravitation (as well as by their own gravitational fields), so is the sun influenced by the planets. Ticking this box allows the sun to move accordingly. Note that it can drift off the window very quickly.
The position of the sun is reset to its original position in the centre of the space. Note that this by itself does not change the positions of the planets, although they would respond to the altered origin of the gravitational field.
No hook camera
The view is from the outside in, according to the zoom and view settings using the hotkeys.
Hook camera to sun
The 'camera' is placed just above the surface of the sun. The orientation can be changed by using the V+.. hotkeys. Zoom is not available (the zoom effect is created by moving the scene towards the viewer, it is not a lens; hence it would not make sense here).
Hook camera to planet - Look forward
The 'camera' is placed on a planet, looking in the direction of movement. The orientation can be changed by using the V+.. hotkeys. Zoom is not available.
Hook camera to planet - Look towards centre
The 'camera' is placed on a planet, always looking towards the sun. The orientation can be changed by using the V+.. hotkeys. Zoom is not available.
Select the group out of which the planet for hook camera is chosen. Usually it is the first one in the group. However, should this planet have become inactive (collided, crashed into the sun, veered off into space) the next in line is selected. If all planets in this group have become inactive this selection will make the view 'freeze'. In this case select No hook camera or select another group (if available).
Pause the operation. The button changes to Continue.
Instead of spheres the planets are shown as lines, indicating their trajectories. It is useful for making stable and/or not so stable orbits apparent, and for observing the emerging patterns of orbits. The button changes to Show planets.
Central force field strength
The gravitational value assigned to the sun. The value can be modified via slider or text box. An increase results in greater velocity of a planet when moving towards the sun and/or a smaller velocity when moving away from it. A different velocity affects the trajectory of the planet, thereby changing its perihelion and aphelion. More on this under Scenarios.
Planets force field strength
The gravitational value assigned to the planets. The value can be modified via slider or text box. In the case of several groups its value is applied to the group selected in Group on the left. The background colour of the slider reflects the colour of this group. Changing this value affects the planet's overall interaction with the sun as well as with all the other planets. More on this under Scenarios. Note the values are smaller than the Central force field and any changes occur in smaller increments.
Speed factor for planets
A scalar that is applied to all planets when changing its value. At that point it becomes part of their velocity vectors but is immediately influenced by gravitational factors. The overall result depends on the latter's respective significance given the current context. More on this under Scenarios.
The Speed factor for planets value is applied constantly, and becomes part of every instant of the overall force field (sun and all the other planets). Gravitational factors are therefore less significant should they mitigate its effect, they are more significant if they happen to amplify its effect. More on this under Scenarios.
Slow down frames
The frame rate of the Planets window is decreased. The actual calculations and results are not affected.
Reset planet parameters
All three planet parameters are reset to their default values. The Apply always selection is not affected.
Reduce planets to initial number
If more planets had been added with the P hotkey, or have been added due to fragmentation, this button will remove those planets. 'More planets' means in addition to the Initial number of planets value. This also helps to improve the frame rate (FPS in the Planets window title bar).
Below are examples of various scenarios (at 30% of their original size or equivalent).
Planets - launched one after another (l.), paths showing relatively stable orbit patterns (r.)
Random placement of 5 groups (l.), cluster placement of 5 groups (r.)
Example of a larger planet after collisions/absorptions (l.), fragmentation after collision (r.)
In non-linear systems the participating elements influence each other through their inherent states, which in turn are affected by the factors applicable at the time. The elements' inherent states modify the overall factors, setting up the feedback mechanism characteristic of such systems.
In this case it means there is a gravitational force coming from the sun (the centre), as well as gravitational forces emanating from each planet. Gravity is a function of mass (where each radius is derived from the respective mass), and here is inversely proportional to the distance. Hence at any given time each planet is subject to mutual dependencies as the system goes through its paces.
Although changing the parameters along the way affects the planets' states, the immediate effect is overcome by the aggregate result of the total number of factors resulting from those parameters. While patterns can be identified, the exact behaviour of each member cannot be predicted.
If a planet moves towards the sun its speed increases due to the greater effect gravity has. It also means it will pass the sun more quickly and hence take longer to move back towards the sun again, but a larger gravity value also increases the rate of deceleration towards its aphelion (its greatest distance from the sun). Since mass plays a (constant) part, planets which have enlarged their size due to collisions with other planets will tend to be in tighter orbits around the sun and move faster.
Orbits can be in the usual single elliptical form with their perihelion and aphelion (closest and furthest point from the sun) followed continuously, or they can be a combination of two or more ellipses entered into in sequence (see second screenshot above). Although they may appear to be stable, slight changes in parameters add up until an entirely different orbit is entered. Non-linear systems are subject to such sudden changes. When and how often they occur depends on the scale of these changes. In CauseF it may take 5, 10 or more minutes of observation to encounter a jump in the system state of a planet.
A planet crashes into the sun if its velocity is insufficient to allow it to pass by. Its mass is added to the sun, making the latter bigger and adding to its gravitational force. A planet will veer off into space if its velocity is able to overcome the sun's gravitational pull at its theoretical aphelion, a slingshot effect.
If fragmentation upon collision occurs the fragments' smaller sizes will result in velocities less affected by the force field, which means they are more likely to be captured by the sun if trending towards it, and are more likely to move away from it if trending away to begin with. The velocities of fragments is determined by the speed of the source planets at impact and the resultant deflection given their respective angles. Therefore a collision of this kind away from the sun may eventually lose such smaller planets due to the slingshot effect, if close to the sun they may be lost because they crashed into it.
On the rare occasion when the fragmentation results in the additional planets being mostly in line with the original orbit's trajectory, they may remain within that orbit leading to the beginning of something like an asteroid belt.
Hint: To enhance the probability of this occurring, after there are several planets orbiting the sun closely in a cluster, launch additional planets via the P hotkey. Because the sun is now stronger they will immediately move towards the sun's closer neighbourhood and will more likely collide with the planets already there, unless they are bound to crash into the sun anyway. Now the conditions for forming such an asteroid belt are more favourable.
Note: This is a simulation only; the focus is on the principles underpinning non-linear systems. As such the scenarios are true to these system's dynamics. A proper planetary simulation would entail many more factors (including the entire range of mass and density parameters from metals to gas, as well as radiation, solar wind, etc), in addition to the millions of meteorites and dust particles within a solar system. Quite apart from the vastly different time and distance scales.
...and: Another aspect additional to the above concerns the history of an event; in other words, what would have had to happen before the current scenario including all the manifested interdependencies of factors. For example, refer to the remarks about having two or more suns (see Hotkeys and useful hints → The above technique...). What pre-existing gravitational force values would have been necessary in this simulation to arrive at an orbiting suns event once everything is set in motion? On the other hand, using the technique described in that paragraph, the event is created 'naturally', out of the existing scenario. This would be a general issue with many simulations.
The Options window allows you to select a folder as the default storage for fast saved files with the Ctrl+S hotkey, reset the automatic file counter, choose the preferred Planets window size, set the default number of initial planets, select the default colour for the planets and restore the original default colour.
Save files to
- together with Ctrl+L from Settings window (see also Menus → File - Load Planets Settings Ctrl+L)
Select the default storage folder for files saved with the Ctrl+S hotkey. Type in directly or use the Browse button.
Reset file counter to 0
Fast saved files are automatically numbered within their generic file names, such as userfs0000.ufpf userfs0001.ufpf userfs0002.ufpf and so on. Starts the numbering with 0 again.
Select window size
Sets the default format/size of the Planets window. There are 14 available, from 320 x 240 pixels in the 4:3 (standard) format to 1408 x 792 in the 16:9 (wide screen) format. Note all these numbers are divisible by 8, thus avoiding possible visual artifacts with some encoders should any scenarios be recorded on video. It is possible however to resize the window to your liking. Opening the Planets window from the Main window will set it to the actual default size again.
Set initial number of planets
Sets the initial number as default. It can be changed temporarily from the Settings window.
Select default colour
The original default colour of the planets is a blue-green (#3AABAB, or #FF3AABAB incl. transparency). It can be changed temporarily from the Settings window once Custom setup is checked (including variations in groups). The small panel to the left of the colour dropdown box reflects the current default colour.
Reset to original colour
Resets the default colour of the planets to a blue-green (#3AABAB, or #FF3AABAB incl. transparency).