Making a moon, and a suggestion

[OmegaRed]

Hello,

I just installed the simulator and spent a night playing with it.  My favorite scenario that I have setup so far is a modification of the earth, and 250 moons.  I changed it to have 500 moons and made them all about 1/200th of the moon's mass.  I gave half a low density (ice) and the other half a higher density (rock).  I also changed collisions too absorb.

Letting this run for a little while eventually produced objects within a wide range of masses and sizes.  I did not let it run long enough to every get a 1 moon mass object.

Another thing I had fun with was running the above simulation with a slight modification.  I would immediately select one of the pieces and increase its mass and size.  I would then change it's direction.  Depending on the mass of the body it will quickly loose its orbital speed due to collisions and then fall to Earth.  Sometimes I will help it out by increasing its speed at certain points of its orbit.  This kind of becomes a game of keep the moonlet alive.

As for my suggestion... The controls are optimized for those with full keyboards and mice with scroll wheels.  As a laptop user I do not have a full keyboard (ie no numpad) and no mouse at all.  I have not been able to find a way to zoom without a moose, and some of the other controls on the numpad are troublesome to access via the menus whilst the moonlet you are trying to save is plummeting towards the Earth at 20km/s (lol).  I suggest that you setup an option to switch to a laptop optimized keyboard setting or to give the user the ability to map their own keys.

Thanks for the awesome piece of software.  I hope to continue using it well into the future.

-Phil.

[Dan Dixon]

Phil,

I'd love to see these simulations that you've created. There's a link under New on the main menu to easily send systems my way.

Or post them to the forum... You can attach the file to a message. Click on the link "Additional Options" under the text box after you click 'reply'.


Your suggestion for better laptop keyboard support has been implemented in the latest version of Universe Sandbox. Just rerun your copy of Universe Sandbox to update.

You use 'W/S' to zoom and 'E/D' to change the time step. 'A' sets the time step to auto.

You should get info on the update on the first screen after the new version loads. Please let me know how these controls feel or if you have an alternate suggestion for a keyboard arrangement.

Thanks for the great suggestion.

[OmegaRed]

Wow, the controls are great.  I did not expect that quick of a fix!

Here is the system I mentioned in my above post.  There are three kinds of bodies (besides the earth) in this program ice, rock, and glue.  Glue is added to speed up the simulation.  It is big enough to actually have a good chance at catching some of the other bodies.  If you edit the .xml file and play with the size and mass of the glue like I have you will find that size is the most important thing inorder to quickly buildup a moonlet.  You can also edit the distance the objects orbit the Earth.  The further out they are the more they influence each other.

Anyway check it out.  If you want to play 'save the moonlet' just select any object orbiting the Earth and increase it's size (to increase it's chances of getting hit) and reverse it's direction.  If the mass is the same the very first collision will nearly zero it's velocity sending it plummeting towards the earth.  If you raise the mass a bit, the moonlet will enter a dangerous elliptical orbit that will put it at risk of more collisions.

Have fun.

[OmegaRed]

I just noticed how badly I had done the densities.  I played around and have come up with another version of this simulation "without the glue".  Seems to work well for building up multiple moonlets.

[Pete_G]

That's great. I tried the same thing but didn't modify densities or introduce glue objects. All that happened was the tiny moonlets either crashed into the Earth or remained in perfect orbit, as the bodies themselves were of too small a mass and size and the ring too diffuse for them ever to come together.

[mattie]

Another thing to try is fooling around with the mass of the central body. I figure that a larger central mass with have stronger gravity that overpowers the attraction between moonlets, decreasing the rate of collisions. Not being a physicist, I can't be sure though

[OmegaRed]

Glad you guys like it.  You can try playing around with the new simulation I made.  It is basically the same thing as above but I managed to get it to orbit around the sun.  It seems to have new interesting effects.  Try playing around with the values in the .xml file for various effects.

[Dan Dixon]

Very cool OmegaRed and thanks for sharing. It's fun to see what others come up with.

[polop1234]

a soloution to your mouse probeblems, you can get sheap usb mice with wheels on them now (im using one