I've been enjoying indoor rock climbing recently, and thought of a variation that would be fun: disco rock climbing.
The concept is analogous to disco bowling. One evening a week, the indoor rock climbing center would start playing 70's disco, use UV lights to light up the walls (which would have been sprayed with luminescent dye), and illuminate a mirrored ball suspended from the ceiling.
Safety hazard? Just require a waiver form. I'd sign it in a heartbeat!
I just finished reading this Digg posting about why we dream, and decided to post my own theory.
The theory is based on a simple premise; that individual brain cells accumulate waste products while they are awake and thinking, and that they need to rest and stop thinking in order to purge the waste. The ability for a cell to operate normally decreases as waste accumulates. A typical cell requires 4-6 hours a day to purge its waste. Many other cells in the body need to rest after periods of activity, so this premise seems reasonable.
Sleep and dreams are an inevitable and emergent consequence of this premise; here's why:
If every individual neuron independently decided when it would go from normal mode into rest mode, then at any one point in time, 2/3 of your brain cells would be operational and 1/3 would be at rest. Now let's assume that a particular cell is more likely to stay in its operational mode if adjacent cells are also in operational mode. This would make evolutionary sense, because if you're focused on a task and 1/3 of your cells are asleep, it would presumably make the task harder. Since there is less stimulus at nighttime and typically less tasks to accomplish, a brain would quickly enter into an emergent rhythm in which during the daytime, *most* cells would probablistically be awake and at nighttime *most* cells would be at rest, dumping waste. Note that these are only probabilities, and there's still a finite chance that during the daytime portions of your brain would be at rest, and a finite chance that during the night some portions of your brain will awake. In addition, the probability of portions waking up during the night rises as the cells dump their waste products and increase their chance of entering waking mode.
As the majority of cells enter the saturation phase of waste, you'd expect to see a fairly rapid collapse into sleep mode, since when a cell goes into rest phase, it stops stimulating its neighbors and makes it more likely that they'll also go into rest phase.
During the night, most cells would initially go into rest phase, dumping waste products. but as the night progresses and cells being to "lighten their load", the probability that cells will transition into operational mode begins to rise. Mathematically, there's a good chance that various subsets of a brain will spontaneously go from sleep mode to operational mode and back again throughout the night, with the probablility of the entire brain going into operation mode by the morning rising to 1.
When one or more subsets of your neurons go into operational mode during the night, they form a "partial mind" which is missing the parts that are still sleeping. A dream is the thoughts and memories experienced by this subset of your mind, and its content will vary based on which parts are awake.
For example, say you are partially awake and you hear an alarm clock. An awake portion of your mind might associate the alarm with a police siren, and another awake portion of your mind might extrapolate this to the possibility that you are in a car chase. The part of your brain that would normally suppress this possiblility with the higher likelyhood that it's simply your alarm clock happens to be asleep, and so the waking part of your brain rightly operates with the highest probability deduction that is available to its parts, and you dream of being in a car chase.
Dreams are often abstractions of an underlying concrete concept/problem in ones life. This makes sense, because if a set of, say, 10 parts of your brain represent and constrain a complete concept under normal operation, and then you send 3 parts to sleep, the remaining 7 parts would tend to represent an abstraction of the original concept (as you remove constraints one by one). For example, the concept of a chair might be represented by a simultaneous constraining of the following facts: 1) 4 legs, 2) has a back, 3) wooden, 4) on the floor, 5) seat, 6) 5 letters, 7) begins with "C". If you remove constraint (3), then you might also end up with a camel. If you remove constraint (3), (6) and (7) then you could also end up with a table or elephant. In general, dream abstraction should be proportional to the percentage of your brain that is asleep.
Each neuron needs to rest several hours a day in order to dump its waste products.
A neuron cannot participate in thinking while it is resting.
A neuron is more likely to enter its rest phase when it is not being stimulated.
Most neurons tend to rest at night.
As neurons become rested, subsets of your mind begin to work again.
Dreams are nothing more than the workings of a partial mind.
Dreams are often abstractions because a partial mind cannot completely resolve constraints.
It's 4:30 am in the morning and I'm in the zone thanks to Imogen Heap and her incredible album Speak for Yourself. She reminds me a lot of Kate Bush; a truly gifted composer/musician. Her music is so far beyond anything else out there it's not even funny. A bit like Roger Federer at Wimbledon!