The Meaning of Music and Art

I agree with Steven Pinker that music is most probably a by-product of being able to discriminate sounds which come from distinct resonating objects. Clearly it is useful to be able to do this , just as it is useful to pick out objects visually from our environment. These abilities are clearly advantageous , so it gives us pleasure to seek out such objects.....

We can get that same pleasure in a more concentrated form by creating and listening to Music; or creating and looking at Art. The same pleasure centres in the brain are stumulated as when we see an object or hear a sound in our environment. In the case of Art it becomes easy to see why we like pictures of flowers, trees, and animals; as well as man-made shapes such as zigzags and geometric shapes which stand out from the environment.

In the case of Music it is not quite so obvious, until you realize where the most common harmonies and scales come from. Any resonating object produces a fundamental note of a particular frequency and a series of overtones of related frequencies. The most audible overtones are simple multiples of the fundamental frequency, if the fundamental is C

Frequency multiple 1 2 3 4 5
Note sounded C C' G' C'' E

Already we have the major chord CGE. The note which produces C as its first overtone is F with the major chord FAC. The strongest overtone of C is G which would give the major chord of GBD. So there we have all the notes of the major scale arising naturally - in music we layer them to give resonating harmonies, or we separate them out into a melody, in a particular key.The ear can hear these properties without needing to know the theory!

Green Sea Turtles and sea floor spreading

I've always been fascinated by the migration of green sea turtles. They are found all over ther world, but the ones which nest on Ascension Island in the mid-atlantic, where there is a major nesting colony, then migrate to their feeding grounds off the coast of Brazil. It's a distance of over 2,000 km and the mother turtles make the return journey every few years to the beaches where they were born.

Ascension Island is located on the mid-atlantic ridge, and the foraging grounds for this colony of turtles is at the Eastern extremity of South America at Recife in Brazil. One rather romantic theory for this extraordinary migration is that when the Atlantic was starting to open up, several hundred million years ago the ancestors of the green turtles were to be found in the place where Recife and Ascension Island were very close together. As the sea floor spreading continued, the turtles evolved a mechanism to find their way back and forth as the two places moved apart (and continue to do so) at a rate of about 2cm per year.

Laser Nuclear fusion could be the answer

So a British- lead team of scientists has won support from the EU to construct an experimental nuclear fusion reactor - which could make nuclear fusion energy a commercial reality within 20 years.

This is the Physicist's dream - unlimited energy with no harmful waste products, from a freely available unlimited resource - hydrogen (from seawater). The worlds most powerful laser would generate the required temperatures of millions of degrees, at which hydrogen burns to form helium, the process which drives the sun.

The fuel would be the heavy isotopes of hydrogen, known as deuterium and tritium. Deuterium can be made cheaply from seawater, and tritium is produces as a by-product in the reactor. When fusion of these isotopes occurs, helium is produced, and a stream of neutrons which release vast quantities of energy in the form of heat.

At the moment, the energy required to start fusion is greater than the energy released. With laser fusion, a powerful laser is directed at a fuel pellet about 2mm across - the pressure compresses the pellet and generates temperatures of tens of millions of degrees. How cool is that?

Overpopulation is our biggest threat

The world contains over 6 billion people. Obviously there is a limit to the carrying capacity of the earth - some say that this is about 12 billion as a maximum (could be uncomfortable though). Sounds like we are OK then? NO!!!!!

At current rates of population growth, the worlds population is doubling every 40 years or so. This is within our own lifetimes and unless we address this critical issue we are in trouble. It is a far greater threat to our lives and lifestyles than our "carbon footprint", but it is not seen as being an issue although the maths is quite simple really... Is anyone listening?

Aquamarinegreen

I think the colour I'm imagining when I think of the most vivid aquamarine green is a "fundamental primary" - it would be the colour you might see if you could stimulate only the "green" receptor(cone) in your eye - (It should be emphasized that the colours you actually perceive are coloured by processing in the brain as light itself has no inherent colour, the colours we see are determined by the wavelengths of the light rays). Of course you can't just stimulate one cone, the other cones would also be stimulated to a lesser degree.

Professor Andrew Hamilton of the University of Colorado talks about psychedelic aquamarine -

"The colour of the green fundamental, at (l, m) = (0, 1), is quite another trip. I call it psychedelic aquamarine because it lies well outside the range of physically realizable colours, at least for people with normal three colour vision. The nearest monochromatic colour, obtained by adding white to psychedelic aquamarine, is around 497 nm, about the colour of the water around the reefs of Heron Island in the Great Barrier Reef of Australia, which I had the privelege of visiting in 1995. You should mentally subtract white to imagine psychedelic aquamarine in its vivid primal hue. "

http://casa.colorado.edu/~ajsh/colour/primary.html

Enjoy this summer - next glaciation is overdue

We live in a glacial age and have done for the last 2.5 million years. Right now we are in an interglacial period which has lasted longer than usual. The periodic cycles of the glaciations within this era correlate with known orbital variations of the earth, which affect the intensity of sunlight reaching the earth. These are known as Milankovitch cycles, after the Serbian engineer who proposed the theory in 1912 - (he was well ahead of his time.)

The cycles are -

1. Rotation of the elliptical orbit of the earth and variations in eccentricity, affecting the distance of earth from the sun 2. Variation of Tilt of the earths axis which affects the angle with which the suns rays hit the earth 3. Precession of the axis of rotation of the earth affecting the angle of the rays for a particular season

The various cycles combine together such that the ice advances and retreats according to their combined effect on intensity of sunlight and therefore temperature of the earth. It is possible we have contributed to the unusually long interglacial period we are in but the ice will come - enjoy this summer....

http://en.wikipedia.org/wiki/Image:Vostok_420ky_4curves_insolation.jpg

The earth has a finite lifespan

The earth has a lifespan of about 12 billion years before it will be destroyed or seriously burned by the Sun when it becomes a red giant star. Earth is now about 4.5 billion years old and the age of animals started at around 4 billion years - and will probably only last until about 5 billion years - there is a predictable sequence for the breakdown of habitability of the earth, due to the increasing luminosity of the sun and its consequences.

Every species has a finite lifespan due to changing conditions on the earth . Think of the age of the earth as a clock starting at 12 noon and ending at 12 midnight- each number on the clock represents 1 billion years. The end of the Earth will be at midnight. First life was around 1pm, oxygen appeared in the atmposphere just after 2pm, the age of animals started at 4pm and it is now 4.30pm. The age of animals will probably end at around 5pm and the age of man is the blink of an eye.

Ref "The Life and Death of Planet Earth" by Peter Ward and Donald Brownlee first published 2002