Feed and Weed

Now it is halfway through June. I took a half day today and accomplished nothing, but I am full of ideas for the planetary accretion simulation. Mass, luminosity, and a mass inventory based on derived frostline. I will create a disk so many AUs in radius, 50 times mass^½, where each 0.01 AU has mass^½ earths, for a total of mass times 5,000 earths; I am assuming most of this will be ejected, or dropped into the star, but a lot of it will remain, as part of the giants, mostly because even they can’t hang on to a lot of the lighter elements. About 95% of the mass is gases and inside of frostline it will be evaporated, leaving five percent, which would be about 20 earth masses inside of 4 AU., most of which would have gone into Jupiter.

I start subdividing the disk randomly, bisecting the whole at some random distance, then each of them at some other random distance, five times is 2^5=32 subdivisions. Then with each of this subdivisions generate a random seed at some random distance and have it randomly accrete some mass inward or it, some mass outward of it, kick some mass inwards and some mass outwards. Grabbing mass inward will move it a little inward, and outward will move it outwards, but kicking mass in or out will move it twice as much. The amount each seed to ‘feed or weed’ depends on its mass, so a bigger seed will acrete faster and have more influence over the surrounding bands of mass in the disk.

I need adjacent seeds eating each other’s lunch, so that they will interact indirectly and then directly. I will need a rule for what happens if the accreting bits get too close together, smashing together or kicking each other around with some momentum swapping. Ending conditions? Not sure. I will probably just have it run a short loop to see what happens and watch for interesting things. This is a pretty simple model, a schematic and it will give me a mass and general composition when it’s ‘done’, whatever ‘done’ means.