Osmos follows the laws of physics - almost
Posted: Fri Dec 24, 2010 1:51 am
Osmos is a very cleverly designed game, with a wonderful variety of physics inspired mechanics. As a physicist, I was impressed and entranced after downloading it to my iPhone earlier today.
However, as the developers probably realize, Osmos does not quite follow the laws of physics.
The trouble is that it violates the principle of conservation of energy. Here's an experiment to prove it (I recommend trying it on one of the "Impasse" levels):
1. Grow your mote until it absorbs everything else.
2. Note the speed of your mote (it's probably moving pretty slowly).
3. Now, accelerate your mote to a higher speed by repeatedly ejecting mass in the direction opposing its motion.
4. After waiting some time, your mote will reabsorb all the emitted mass. However, now it is moving at a faster speed -- your mote has somehow gained kinetic energy!
Where did this energy come from? Mote appear to have infinite stores of internal energy, some of which released each time they shoots off mass. They're perpetual motion machines!
This may appear to be a bit of nitpicking, since the violation is practically necessary for the game to be played. But there is a fairly elegant solution. Each mote would have an additional quantity of internal energy -- an amount of "gas" or "food" illustrated by internal shape, color or motion. This internal energy could be transfered between motes as is done with mass. The important aspect is that to assure conservation of energy, it is required for propulsion: every time mass is ejected, it costs internal energy equal to (or greater than) the amount of added kinetic energy.
It's a tricky question whether adding a finite supply of energy would make the game more fun or not. On this matter, I'm not sure. But it would certainly fix the only physics problem I could find without looking at the source code!
Anyways, well done! I had a blast -- especially when I was trying to come up with experiments to test your physics .
However, as the developers probably realize, Osmos does not quite follow the laws of physics.
The trouble is that it violates the principle of conservation of energy. Here's an experiment to prove it (I recommend trying it on one of the "Impasse" levels):
1. Grow your mote until it absorbs everything else.
2. Note the speed of your mote (it's probably moving pretty slowly).
3. Now, accelerate your mote to a higher speed by repeatedly ejecting mass in the direction opposing its motion.
4. After waiting some time, your mote will reabsorb all the emitted mass. However, now it is moving at a faster speed -- your mote has somehow gained kinetic energy!
Where did this energy come from? Mote appear to have infinite stores of internal energy, some of which released each time they shoots off mass. They're perpetual motion machines!
This may appear to be a bit of nitpicking, since the violation is practically necessary for the game to be played. But there is a fairly elegant solution. Each mote would have an additional quantity of internal energy -- an amount of "gas" or "food" illustrated by internal shape, color or motion. This internal energy could be transfered between motes as is done with mass. The important aspect is that to assure conservation of energy, it is required for propulsion: every time mass is ejected, it costs internal energy equal to (or greater than) the amount of added kinetic energy.
It's a tricky question whether adding a finite supply of energy would make the game more fun or not. On this matter, I'm not sure. But it would certainly fix the only physics problem I could find without looking at the source code!
Anyways, well done! I had a blast -- especially when I was trying to come up with experiments to test your physics .