On Wed, Mar 05, 2014 at 04:13:26PM -0800, [email protected] wrote: > > On Wednesday, March 5, 2014 10:57:30 PM UTC, Russell Standish wrote: > > > > On Wed, Mar 05, 2014 at 02:26:50PM -0800, [email protected] > > <javascript:>wrote: > > > > > > > So....you're saying its about resting the sensitive visual machinery? > > Why > > > not do that with an extra pair of eyes and a shift rota? That seems like > > a > > > legitimate challenge John, since it seems very doable, and the > > > benefit would be 24 hour action. Maybe even a pair of day eyes, and > > another > > > pair of night eyes. > > > > > > > Dolphins do something like this - they sleep one brain hemisphere at a > > time, so they don't drown in their sleep. > > > > -- > > > Very interesting indeed, and not something I knew. I suppose the > issues/questions would hinge on whether Dolphins are fully functional 24 > hours, or they have an advanced sleep mode. If the latter then the null > hypothesis as it were, would be whether that's an extension of the norm in > that all life has to keep the cardio vascular system going, and preserves a > degree of environment monitoring for basic threats. Sharks need to keep > swimming forwards not to suffocate.
Not all species of shark. The ones we have around here are quite happy sleeping lying still in a cave, which is usually how you see them, as they're nocturnal. Re dolphins, the problem is that they cannot breathe underwater, so need to surface periodically to do so. Consequently, they need quite a bit of brainpower (essentially to be awake) to be active all the time. Fish (like sharks) do not face this problem, so can rely on autonomous "breathing" via their gills. This all points to the necessity of sleep for some reason to do with the brain. Liz listed a couple of plausible hypotheses. -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
