Play and Learn 2

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Text File | 1994-02-04 | 14.2 KB | 338 lines

Version 4.1 Oct 2, 1988 This Program computes information relating to the position, distance, magnitude, orbit view, skyview, etc for the major planets, four minor planets or halley's comet on a specified date and time. Also, orbital data for any desired planet or comet can be entered and saved in a disk file. Skyview and orbital views can show forward or backward motion. The moons for each planet can be displayed. The following programs files are available (the source code can be obtained from the author if it is not included). PLANETS.EXE 90K bytes Execution Code PLANETSA.EXE 100K bytes Execution Code for use with 8087 PLANETS.DOC 20K bytes This File PLANETS.PAS 57K bytes Source Code for Turbo 5.0 PLANETS1.PAS 42K bytes Include file for Turbo 5.0 PLANETS.3TP 56K bytes Source Code for Turbo 3.0 PLANETS.3TP 42K bytes Include file for Turbo 3.0 PLANETS.SAV 1K bytes Save file made with setup command Command List 1 - 9 Entering a single digit will display detailed information relating to the selected planets. Use the "T" command to set the time and date, and the "L" command to set the longitude and latitude. Also the "S" command may be used to select the format for representing angles. A- Entering A followed by a single digit will display detailed information related the selected minor planet or comet. The last selection in this column is user selectable, via the "R" and the "W" commands. B- Entering B followed by a single digit will display the sky view of the nine major planets and the selected minor planet. Use the T and the L commands to select the time/date and longitude/latitude. C- Entering C followed by a single digit will display the orbits for the four inner planets and the selected minor planet. The planets are each shown in its own orbital plane. The distance between the earth and a comet with a large inclination will be misleading in the orbital view. However, The distance calculation using the "A" command does take into account the large inclination of comets (update from previous versions). D- Entering D followed by a single digit will display the orbits for the five inner planets and the selected minor planet. The planets are each shown in its own orbital plane. E- Entering E followed by a single digit will display the orbits for the earth and the five outer planets plus the selected minor planet. The planets are each shown in its own orbital plane. F SideView shows the orbit of the selected planet. The scale is the same as the last scale selected using the C, D or E command. H Displays this file. I Plots the orbits and locations of the four inner planets: Mercury, Venus, Earth, and Mars. The "S" command may be used to enable/disable the planet names. If the names are shown, sometimes a name will overwrite a previously displayed planet. K1,2,3 Gives Keplers three laws along with an example. Note that Keplers laws refer to the Sun and Planets, but the law applys to any small body orbiting a large body. L Allows entry of the longitude and latitude. The longitude is then used to compute the time zone; which can be changed if desired. M Displays the Menu. A second depression switches to the second page of the menu. O Plots the orbits and locations of the five outer planets and the Earth. The "S" command may be used to enable/disable the planet names and to correct for the aspect ratio of the monitor. Q Goes Back to DOS S The Set-Up is command is used to select the form of numeric printout for angles: hour/deg/min, decimal deg, decimal hours etc. The screen aspect ratio may be set so that circles come out correctly on the screen. Also, planet name may be enable/disabled from orbital and sky plots. One the setting are entered they can be save in file planets.sav. This file will be read and the setting updated the next time planets is initialized. R The read command reads a file made by the (W)rite command and loads the orbital data into the last minor planet position. The A through E commands may then be used to make calculations for the new planet selected. T The change time/date command allows entry of the time and the date. Note that spaces (not commas) should be used between the entries. V The View command shows how the planets would appear in the sky on the date selected by the T command and from the location selected by the L command. If the planet names are shown, sometimes a name will overwrite a previously displayed planet. U The U commands shows the sun and the moon as they would appear on the date selected by the T command and on from the location selected by the L command. W The write command is used to enter orbital data for a planet or comet that is not included in the main program. The data is then stored in a disk file and read into the last position in the minor planet column. If the epoch is entered as "0 0 0" the orbit is assumed to be entered in standard form for a comet; therefore no prompt is made for the longitude at epoch. X Two objects are selected from a list of moons and planets for size comparison. A graphical view is then so that the sizes can be easily compared. Y This command shows the sun and the moon against the a grid showing declination and ascension. Z This command shows the planets against the stars. A grid with declination and ascension is shown. The + and - commands can be used in star view mode. + The Plus command is used after a view or orbit command to advance planets forward in time. Successive depression causes faster motion in the following order: one hour, one day, one week, one month, and one year. - The Plus command is used after a view or orbit command to advance planets backward in time. Successive depression causes faster motion in the following order: one hour, one day, one week, one month, and one year. space The space key is used to stop advance or backward time travel. The planets will continue to blink until any other key (except =,-, or space) is depressed. An M command will then go back to the main menu. F1 - F9 Function keys show the selected planet and its inner moons. IF there are outer moons, they are selected by a shifted function key. The earth date and time do not apply to moon positions. A seperate earth day count is shown so that the speed of the moons can be compared to an earth day. Glossary of Terms Azimuth : The angle from the North measured East to West. When applied to set and rise times for a planet this indicated where on the horizon, 180 deg. for South, 270 deg. for West, etc. Daylight Savings : If Daylight savings time is enabled then the local time is advanced one hour on the last Sunday in March and set back on the last Sunday in October. Ecliptic Coordinates : Are related to the earths orbit, Long is the angle around from the first point of Aries and Lat is angle Up or Down Equatorial Coord. : Are related to the earths equator, DEC is how far north or south of the equator and RA is angle around the equator from the first point of Aries First Point of Aries : This direction remains fixed with respect to the stars (except for Precession) and is used as a reference for ecliptic and equatorial coordinates. GMT : Greenwich Mean Time, time at longitude 0 deg. GST : Greenwich mean sideral time, is related to the position of of the stars rather than the Sun. JD : Julian Day Number is the number of days since January 1st 4713 B.C. HA : Hour Angle is the time since the planet crossed the meridian helio ecliptic lat. : Angle north or south of the earths orbit heliocentric long : Angle from the first point of Aries that planet makes round the sun Horizontal Coord. : Are related to the observers horizon, Alt is angle above the horizon and Azim is angle from the north going east. Lat : Latitude of observing site LCT : Local Civil Time (time locally used) LST : Local Sideral Time, is related to the position of of the stars rather than the Sun. Long : Longitude of observing site long of ascend node : The point where a planet rises out of the plane of the ecliptic Mag : Magnitude on a logrithmic scale which measures the brightness of the planet ( the calculation here is accurate to only 1 or 2 mean anomaly : Angle a fictitious planet, moving in a circle, would make with a line from the sun to the planets perihelion Phase : Area of the disc which is illuminated true anomaly : Corrects the mean anomaly to account for 9the eccentricity of the orbit radius vector : Distance from the Sun to the planet Extended Notes: **** How orbits are shown **** The orbits for the planets and moon are each shown in its own orbital plan. This means that the view is not the same as would be seen from space. Projection of the orbits would have slowed the motion commands considerably. **** Entering planet date **** The (W)rite command makes a file containing the orbital data for additional planets (one file per planet). A good source for data is the Astronomical Alamanac is for sale by The Superintendent of Documents, U.S. Government Printing Office, Wahington, D.C. 20402. When using data from the Alamanac the Period is calculated: Per = (360 / 365.2422) / Daily Motion The Longitude at Epoch is calculated: Long at Epoch = Long of Asc Node + Long of Per(bar) + Mean Anomaly The Longitude of Perihelion is calculated: Long of Per = Long of Asc Node + Long of Per(bar) **** Sun and Moon rise and set times **** The calculation assume a fixed location for the sun and the moon based on the date and time setting. More accurate times can be obtained by setting the time to the first value given, then doing a second iteration. **** Moon orbital view **** The orbital views of the moons do not correspond to the date. An earth day counter is shown to give an idea of the speed of motion. This program is placed in the public domain and may be freely copied and distributed for a nominal distribution charge. The Turbo Pascal source code and the latest version of the program can be obtained from the author for $10.00. The following is a list of other scientific programs available form the author: CHEMICAL (Current Version 3.1) CHEMICAL is a molecular modeling Program to aid in the formation of three dimensional pictures of chemicals. Atoms are selected from a Periodic Table (using the A command) and electron orbital information retrieved. The Atoms are then bonded (using the B command). The chemical is displayed as it is being constructed. The chemical can be viewed from different directions by using the up and down cursor keys and the V command. If desired the Hybrid and Ionize commands can be used to alter the orbitals before bonding. Atoms can be bonded into groups, then the groups bonded to other groups to make large chemicals. CHEMVIEW (Current Version 2.0) CHEMVIEW is a companion program that shows 3-dimensional animation of the models generated with CHEMICAL. CHEMVIEW requires an EGA board and monitor. CHEMVIEW is written in Turbo PROLOG with the graphics I/O done in Turbo C. To use CHEMVIEW simply start the program and select the file desired. CRYSTAL (Current Version 1.0) CRYSTAL is a companion program that shows 3-dimensional development of crystals. Atoms and multi-atom ions are and placed on a lattice to form 3 dimensional models. These programs are are placed in the Public Domain and may be freely copied. However, the source code is only available from the author. The latest version, with source code is available according to the following price schedule: First Copy Updates Enclosed Planets $10 (1 disk) $5 _______ CHEMICAL CHEMVIEW $20 (3 disks) $10 _______ CRYSTAL OverSeas Shipping $5 _______ 3 1/2 in disks $2 _______ TOTAL Enclosed _______ Send To: ____________________________________ ____________________________________ ____________________________________ Larry Puhl 6 Plum Ct. ____________________________________ Sleepy Hollow, Ill. 60118