Post by tenochtitlanuk on Dec 22, 2020 8:07:33 GMT -5
Season's Greetings to all my on-line LB friends...
I was very annoyed by two things about the present conjunction of Jupiter and Saturn.
First, the weather in the UK has not allowed viewing it ( surprise!)
Secondly, the BBC used this image. Artistic, perhaps, but totally wrong scientifically. Wouldn't mind the scaling distortion- you can't avoid that! But the Earth has to be on the other side of the Sun!
Anyway, it pushed me this morning to do an LB 'orrery' to show planetary paths to scale. Image animates the start ( with all planets aligned) and steps into the future before another snap 1 earth year later..
' name, period in days, radius in AU
data "Mercury", 87.97, 0.387
data "Venus", 224.70, 0.7233
data "Earth", 365.26, 1.0000
data "Mars", 686.98, 1.5273
data "Jupiter", 4332.82, 5.2028
data "Saturn", 10755.70, 9.5388
data "Uranus", 30687.15, 19.1914
data "Neptune", 60190.03, 30.0611
for i =1 to 8
read in$: planet$( i) =in$
read in: period( i) =in
read in: radius( i) =in
angle( i) =0
next i
global scaleInnerOnly
scaleInnerOnly =50
nomainwin
WindowWidth =1010
WindowHeight = 840
open "Solar System" for graphics_nsb as #wg
#wg "trapclose quit"
#wg "down ; fill black"
#wg "size 5 ; color yellow ; set 500 400 ; size 2 ; flush"
do
for i =1 to 8
call orbit i
next i
scan
loop until 1 =2
wait
sub orbit i 'planet$, period, radius
xS =int( 500 +radius( i) *scaleInnerOnly *cos( angle( i)))
yS =int( 400 +radius( i) *scaleInnerOnly *sin( angle( i)))
angle( i) =angle( i) +0.0005 *( radius( 3) /radius( i))^( 3 /2) ' Kepler Third Law
#wg " color 70 70 70 ; size 5"
#wg "set "; oldPos$( i)
#wg "color "; word$( "red yellow cyan green blue pink lightgray white", i)
#wg "size 3 ; set "; xS; " "; yS
oldPos$( i) =str$( xS) +" " +str$( yS)
end sub
sub quit h$
#wg "getbmp scr 1 1 1000 800"
bmpsave "scr", "action2.bmp"
close #wg
end
end sub
