I find the simple explanation just as awe inspiring (in its simplicity and effectiveness) as the complex one. Nice work Dan. Mark Tilden, the Beam guys, and ...er... the MIT dude who is building COG and who built Attila... can't remember his name, blow me away by showing what wonderful, high level things can be done with very simple behaviors and rules. --- James Newton, Admin #3 mailto:jamesnewton@piclist.com 1-619-652-0593 VM 1-208-279-8767 FAX PIC/PICList FAQ: http://www.piclist.com or .org -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Dan Michaels Sent: Wednesday, September 05, 2001 17:29 To: PICLIST@MITVMA.MIT.EDU Subject: Re: [OT]: Mr Hawking loses the plot Russell, Good example. How about the following explanation ?????? [doesn't require any learning whatsoever, BTW]. > >It seems highly likely that > >- The first fish found the area randomly. it sensed the warmth flowing out of the region "immediately", but it took 2 days for it to randomly find its way in. >- Thereafter it returned daily purposefully. it went towards the warm area and then followed the "pheromone" trail it had laid down the day before. >- The other fish learned from the first fish. they followed the first fishs' pheromone trail. [one might assume fish lay down pheromones of different chemical composition for different instances - acidic for bad places, nicely sweet smelling and alkaline for warm cosy places, etc - Alice's slugs or their cousins, BTW, lay down a heavy slime trail where they travel] >- Thereafter they all returned daily purposefully. they all followed their own pheromone trails laid down the day before. >- The fish preferred the warmer area. instinct - ie, hard wiring. >- They chose to go to it when they knew it would be warm and left when they >knew the main tank would be more desirable. they didna know nuttin - they simply move towards the temperature they feel most comfortable in. >- They develop and retain memories with spans of 1 day plus and probably >rather longer the pheromones stay in place at least until they come and re-do the spots the next day. >There are still many explanations of the fine mechanism. >eg the 'following" fish may be working on sensory detection of their >fellows. >"Follow the leader" pertains - this seems unlikely as they do not do so in >the main tank. > they only lay down pheromones when it advantageous to do so. ============ Salmon, of course, swim upstream 1000s of miles to the place of their birthing several years after leaving same and going out to the open sea. They apparently do this by being able to "taste" the unique chemicals in the water and follow it upstream - or some similar mechanism. [following a poop trail 10 feet in a tank may be a slightly easier job]. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.