Astronomy

The cornerstone of any system of mythology is a cosmological image. Strange to say, even with ground breaking advances such as the detection of the Higg's particle at the level of particle physics the bigger picture still eludes us.

Dark Matter Ring: staggering scale on which the effects
of dark matter are visible. Hubble Photos - Wikisky

Modern Cosmology

The Milky Way is far more dramatic than a simple spiral galaxy. Above it is a huge arc consisting of the large and small Magellanic clouds, these are are small galaxies that have been stretched out by the gravity of the Milky Way. There is a small galaxy of stars called the Sagittarius Dwarf Elliptical Galaxy which is like a fountain, careering through the plane of our Milky Way every 10 million years or so. In a few billion years all of these will be engulfed by the huge trillion star Andromeda Galaxy which is heading our way at 300,000 miles an hour. And, as if all that were not dramatic enough it will probably drag the Triangulum Galaxy in to the mix with it. Yet all of this pales into insignificance when we view the Milky Way as part of the Laniakea Supercluster.

Cosmologists now tell us that the hitherto detectable material of the Universe constitutes (based on gravitational anomalies) only 4% of the total. They posited something called dark matter as constituting 26% and something called dark energy as making up the remaining 70%.

Do the stars still talk to us?

They do and astronomers have battalions of radio telescopes pointed at the heaven picking up their messages on many different frequencies.For instance in August 27th 1998 a gamma ray pulse hit the earth above the Pacific Ocean knocking many satellites into shutdown mode. The inner edge of the ionsphere was pushed down 25Km for a period of five minutes causing considerable excitement and concern among astronomers working the night shift.This was not the first such event observed by astronmers, in 1979 a similar pulse that pushed radiation detectors off the scale was detected and its source was found to be high above the Milky Way in the Large Magellanic Cloud Galaxy.
(Scientific America Feb.2003 - Magnetars)

Nebraska Astronomy Applets Project

The University of Nebraska-Lincoln has created a series of excellent interactive animations which allow the non specialist to get a feel for the extremely rich field of astronomy. Below under the Astro Movies tab is a selection of movies pertinent to the DMRT's interest in the origins and evolution of civilisation.
( Title: The Nebraska Astronomy Applets Project - Team headed by Dr.Kevin Lee; see all applets at http://astro.unl.edu/ )

TitleDescription
Sunrise and Sunsets at the different Latitudes
Due to the tilt in the earths axis relative to the plane of the Elliptic, the earth in the northern hemisphere is tilted towards the sun in summer and away in winter. Correspondingly, in summer the sunrise moves to a maximum point in the northeast at the summer soltstice and to a maximum south east point at the winter soltstice. The latitidue of the observer also affects these sunrise and sunset points.
Solstices and Equnoxes
The mid winter and summer solstices are due to the tilt in the earth's axis being, respectively, directly away from or directly towards, the sun. At the spring and autumn equinoxes the axis is exactly sideways, giving 12 hours day and twlelve hours darkness.
Sunrise and Sunset through the year
The animation illustrates the positions on the horizon of sunrise and sunset throughout the year.
23.5 degree tilt in Earth's axis at Solstices
The earths axis at the summer solstice is tipped 23.5 degrees towards the sun relative to its orbital plane (the Elliptic). At the winter solstice it is tipped 23.5 degrees away from the sun. At the spring and autumn equinoxes this value is zero degrees.
Phases of the Moon
The oldest Bayblonian astronomical writings, about 1,800BC, relate to the moon. Not only its phases but its rising and settings. The moon rotates anti clockwise around the earth as seen from above the north pole.
Paths of Sun and Moon relative to the Elliptic
The tilt in the earth's axis makes it look like the sun moves above and below the elliptic plane.
The Zodiac
In the period from the Sumerians to the Babylonians, the patient star gazers noted the motions of the moon,sun,mercury,venus,mars,jupiter and saturn relative to the Zodiac (the twelve divisions, or houses. Into which they divided the heavens).
Precession of the Spring Equinox (YouTube)
The tilt in the earth's axis changes completes one slow wobble every 25,765 years. Ancient (Sumerian,Babylonian) observers of the spring equinox using alignment stones noticed that the location of sunrise on the horizon moved back about one degree every seventy two years or 30 degrees every 2,150 years.
The tilt in the Earths Axis
Considered from above the earth rotates counter-clockwise on its own axis and orbits counter clockwise around the sun. Away from the Equator, the tilt is reponsible for the changing seasons in northern and southern latitudes.
The Plane of the Elliptic
As the earth sweeps around the sun, the plane swept out is referred to as the Elliptic. As the earth is tilted on its axis we are typically viewing this plane at an angle (of +- 23.5 deg a the solstices, 0 deg at the equinoxes).
The Little Dipper or the Plough
Due to the earth's orbit around the sun
Big Dipper, Orion and other stars turing around the North Star.
Some stars are always visible, some stars rise and set, and then part of the southern sky (i.e. the Southern Cross) is never visible in the northern hemisphere.
The stars Sirius and Vega
The rise of the Sirius star above the horizon in September heralded to the ancient Egyptians the imminent flood of the River Nile. Vega is the second brightest star in the northern hemisphere, and about 11,000 years ago when domestication of plants and the sowing of cerals commenced, it was the pole star.
Hydrogen Atom Simulator
Hyrdogen is the simplest and by far, the most common element in the Universe. It is not only the main fuel of the stars but forms an invisible gaseous web between galaxies. This wonderful applet shows how photos of light are ignored, absorbed and emitted, by a solitary electron orbiting the Hydrogen nucleus.
Basics: Longitude and Latitude
The Equator is at zero Latitude and the poles at 90 degrees. Greenwich in London is at zero degrees and the International Date Line is at 180 degrees on the far side of the world. The longitude is given as West or East of Greenwich as you move west or east respectively up to 180 degrees.
Distance and Size of Astral Objects using Geometry
The arcsecond is the visual diameter of a distanct object as measuered as an angle.
Altitude Demonstrator
Shows how the position of a star is specified using its azimuth and altitude.