Friday, August 24, 2007

Earth and Sky

NGC 1818: A Young Globular Cluster  - Credit: Diedre Hunter (Lowell Obs.) et al., HST, NASA

Google Earth with Sky has grabbed a lot of attention, as anything Google Inc does. But I hope it helps the astronomy software field. It's got some competitors that do things alittle differently. It's really part of a spectrum of softwares for astronomy. The main free alternatives I use are Stellarium and Celestia. All three are free - there are other softwares that aren't free but since I work for a school system, free software is very welcome, and versions of each software run on various platforms, allowing for diversity of use.

Stellarium represents one end of that spectrum - it's more your classic planetarium software - you are on the Earth looking at the sky. You can anchor yourself to a particular place, though you can zoom out to look closely as if you were using a telescope. But there's no illusion that you are off the planet. You can add random meteors and twinkling in the stars, atmospheric effects. It's also got a feel for the way stars move across the sky - that things go around the poles. You can adjust things so they follow that pattern and change the day/time or the rate of time passing forward or backwards.

Google Earth with Sky is similar but it takes you somewhat off the planet. It has a few minor options as if you were on the planet but there's never a horizon. Being a bit more "out there" it has a better zooming view of things in the night sky - and it has a large database of pictures available. It goes deeper than Stellarium does by default.

Celestia is the other end of the spectrum - it's way out there. It's designed to actually leave the Earth and wander the stars or even among galaxies - it has a kind of warp speed function and a variety of navigation controls. It comes with a database of 35 MB or so but there's some 250GB of stuff over at Motherload of both real data and fictional data. There's a very big universe out there.

credit:National Optical Astronomy Observatory/Association of Universities for Research in Astronomy/National Science Foundation, Copyright WIYN Consortium, Inc., all rights reserved.

Astronomy and the natural world are commented on in the Bahá'í Writings - here's some snippets:

..whatever I behold I readily discover that it maketh Thee known unto me, and it remindeth me of Thy signs, and of Thy tokens, and of Thy testimonies. By Thy glory! Every time I lift up mine eyes unto Thy heaven, I call to mind Thy highness and Thy loftiness, and Thine incomparable glory and greatness; and every time I turn my gaze to Thine earth, I am made to recognize the evidences of Thy power and the tokens of Thy bounty. And when I behold the sea, I find that it speaketh to me of Thy majesty, and of the potency of Thy might, and of Thy sovereignty and Thy grandeur. And at whatever time I contemplate the mountains, I am led to discover the ensigns of Thy victory and the standards of Thine omnipotence.

Nature in its essence is the embodiment of My Name, the Maker, the Creator. Its manifestations are diversified by varying causes, and in this diversity there are signs for men of discernment. Nature is God’s Will and is its expression in and through the contingent world. It is a dispensation of Providence ordained by the Ordainer, the All-Wise. Were anyone to affirm that it is the Will of God as manifested in the world of being, no one should question this assertion.

So learning of the world of nature has much to teach us - and these astronomy softwares are a venue to learn about some of that world that might be a bit removed from the average person. It expands our minds of what is and what might be - how far and wide and high things are, and beautiful in ways no thing on the planet can be. It can wet the appetite for a more direct experience - laying out in the grass watching the night sky, or visiting area observatories where you can see for your self with your own eyes, or setting your camera to a long exposure time to capture the night sky in more detail then you would just by glancing up. The Pleiades are held up as a symbol of the unity we should strive for!

The Pleiades Star Cluster  Credit & Copyright: Robert Gendler

Expanding on this theme is the question of life in the universe beyond our planet. A subject that gets little or no comment in other Books of God has now been given some attention - perhaps there is something we need to be more aware of.... Not only does the Bahá'í faith accept that all the well known religions are inspired of one God and the aboriginal faith traditions are reflections of that same inspiration, but Bahá'í writings refer to Prophets "bearing a Message to God's creatures in each of the worlds whose number God, alone, in His all-encompassing knowledge, can reckon" which are "inhabited by beings capable of knowing God."(see "our planet" link for refs.) Some of us even have a Seti team for Seti@Home- Bahá'í Seti!

One of the qualities of nature and our perception of it is that our appreciate shows a limit of itself. Let me explain - Bahá'u'lláh says in the Valley of Unity: "In like manner, colors become visible in every object according to the nature of that object. For instance, in a yellow globe, the rays shine yellow; in a white the rays are white; and in a red, the red rays are manifest. Then these variations are from the object, not from the shining light." So things we see by reflection or emission show the part they share in common with light but of which they are not internally. Green leaves reflect green, yet are not of themselves green - they are, internally, red. Likewise things we see by their emission are sharing a part of themselves with us - but they remain behind, and some part not seen. Think of it like reading braille - we perceive the bumps of things, not the paper of which they are made - our senses are geared to read the bumps. Indeed in a curious way we also do not see the light itself - we see what the light is carrying and don't see what the light is itself. So light and all things are, like God, the manifest and hidden!


alisacaroline said...

Try the DS2 system at MPSC, which wasn't out at the time you posted this! I'll let you know when my next show will be!

SMK said...

I don't get "DS2 at MPSC" and searching isn't getting there I think.

As for your show, I hope the logistics come together - it would be good!

alisacaroline said...

Hey Steve. It's this:

We now use it for shows al planetario.

SMK said...

AH - so I see. My review was of free home user software. Deep Sky 2 is full planetarium software. Cool of course.