Today it's my pleasure to welcome a distinguished author friend of mine, Shelagh Watkins, who is here to talk about the new "Forever Friends" anthology from Mandinam Press:
 

Was the Earth created by God or did it happen purely through random chance?

See my latest discussions here :

http://authorsociety.proboards103.com/index.cgi?board=worldfaiths&action=display&thread=1176532987&page=1

Below picture of the Earth was snapped by astronauts on their way to the Moon back in December 1972:

What a serene and beautiful looking globe that is indeed. In the current era, here in the early 21st century, the future of this globe is threatened by global warming which is evidently due to man made industrial pollution.There are many positive things we can all do to help counter the effects of global warming. Please see my discussion topic in the  environment forum  for one promising solution (the AA Institute's "Green Sahara Initiative"  )

Questions or comments? Please leave them below. Thanks!

Search the internet for "Ahad's constant" and you'll get an inordinate amount of discussion and yet an equal amount of contention about how this number ought to be calculated and what it should be called. Two years ago, when I first calculated a one number solution for the universe's total background illumination, it never occurred to me that the net value of such a logarithmic series could become the subject of so much controversy even to this day. It is understandable, however, on the grounds that in reaching the exact value one comes up against many unanswered questions about the size and scale of the universe and how we've come to define the number of emitting sources of light within it to be *finite* as opposed to being *infinite*... After all, there are more stars in the observable universe than all the grains of sand on all the shores of every single ocean across the world added together...
What is "Ahad's constant"?
If we exclude all light coming directly and indirectly from the nearby Sun, the rest of the universe collectively supplies us with a mere 1/300th of a Full Moon's worth of illumination. That's "Ahad's constant"
A key thing to stress here is this all about "ILLUMINATION" provided by visible starlight, in the same sense as "sunshine" and "moonlight". The two questions: "How bright is the night sky?" and "How much light illumination does the night sky provide?" are not the same things! The latter is what this whole concept is about. 
Astronomers measure the brightnesses of stars across the night sky using something called the magnitude scale, first introduced by the Greek astronomer Hipparchus in the second century B.C. The scale in itself can be somewhat confusing, since a first magnitude star is actually brighter than a second magnitude star...opposite to what you'd expect going purely by every day common sense. You can learn more by searching Google for  'magnitude scale for star brightnesses' Here's one site that goes into much elaborate detail.
Back to the definition of "Ahad's constant".
Suppose we have two stars of apparent magnitudes m1 and m2. Then their luminosities L1 and L2 are related by the formula:-

L2/L1 = 10^[0.4*(m1-m2)]

The luminosity of the pair of stars is L1 + L2 = L1(1 + L2/L1), and their combined magnitude is then given by:-

Mc = m1 - 2.5*log10 (1 + L2/L1)

For the general case, where the magnitudes of "n" stars need to be aggregated, we can generalise this by computing all the ratios:-

Li/L1 = 10^[0.4*(m1-mi)]   ...............................................equation (1)

for all stars i from 2 through n. The combined magnitude is then:-

Mc = m1 - 2.5*log10 (1 + L2/L1 + L3/L1 + ... + Ln/L1)   ..........equation (2)

"Ahad's constant" is simply defined to be the sum of all the individual magnitudes of every single star across the entire night sky, right down to the faintest star that could ever be seen with the most powerful telescope ever invented or is likely to be invented in the future.
In other words, the value of "n" in the above formulae (i.e. the star count) will tend to infinity. Based on my own numerical integrations, I have found that as n tends to infinity, the variable Mc in the above equation tends to a net figure of -6.5 magnitudes (1/300th of a full moon equivalent worth of light). That is what some are calling "Ahad's constant".





It can be appreciated by someone sailing more than a couple of light years beyond the neighborhood of the Sun in any direction. When you're that far out, you'd want certain physical barometers to pinpoint your overall "existence". One of them might be knowing whether the environment your ship is sailing through is a complete vacuum. Another might be knowing your distance from the next nearest planet or star. Yet another might be to know how much net starlight illumination the sky is providing (i.e. "Ahad's constant").
It will not be a true celestial constant, but vary slightly, to a traveller located in deep interstellar space within several hundreds - if not thousands - of light years from here. All that humanity can ever hope to physically experience or meaningfully contemplate over within the foreseeable future of our species...
Stars in the neighborhood of the Sun are extremely feeble in their intrinsic brilliance - most of them being tiny red dwarves of  < 0.1 x Sun power - and the average spacing between them is approximately 5 light years. Hence, 99.9% of the time during an interstellar voyage between any two stars in this part of the galaxy, you will be travelling under the feeble illumination quantified by "Ahad's constant":

Above: Stars in the neighborhood of our Solar System, going 20-light years out in all directions. If you place your finger randomly anywhere on this map, 99.9% of the time when you're physically there, you are going to be surrounded by a perpetual cosmic night. The net illumination from all the pinpricks of starry light in the 360-degree celestial sphere around you will then equate to "Ahad's constant". FACT, not fiction!
To make my work somewhat "official", preliminary results of the above integrations were published in Journal of the British Astronomical Association, Volume 115, No. 5, October 2005 edition, page 297.
Ahad's constant has significance to Einstein's Special Theory of Relativity and relativistic interstellar travel. See this page for more details.

(Note: "Ahad's constant" is not to be confused with something called "Olbers Paradox")
Please leave your comments on this blog below. Thanks!!!
Abdul Ahad

This is a very popular question!
The conventional logic of past sci-fi authors who have written about trips to Alpha Centauri in various ways has been that you can go at 10% light-speed as an absolute minimum. Since Alpha Centauri is only 4.3 light years away, you get there in 43 years. It's as simple as that, end of story.
Now, my concept is based on a vastly different timescale of 50,000 years  for no simpler reason than the fact that this ark happens to be a gargantuan, super-heavy, super tanker.
Please see this thread:-
Escape time lines for my interstellar ark

The 50,000 year long voyage duration I am projecting is what I like to call a "least-propulsive energy requirement versus most-safe, optimisation". If the ark moves much slower and it takes any longer than this order of timescale, you can see that Alpha Centauri will soon start to drift out of range, and the vehicle will be playing 'catch up' with its destination. If it speeds much faster, and aims to reach Alpha Centauri in say just 5,000 or 10,000 years from now, then the craft will need a lot more propulsive energy on its way out of our Solar System, suffer major impacts from any Oort cloud bodies encountered en-route and also require excessive delta-v at the other end in order to slow right down and successfully rendezvous with New Earth.
Alpha Centauri is 4.3 light years away from the Earth and our Solar System. Light travels at a speed of 186,282 miles per second, or about 5.9 trillion miles in one year. This means in normal every day distance measure, Alpha Centauri is roughly 25.3 trillion miles away from us.
The Centauri Princess ark has spent several decades within our own Solar System, doing a series of speed-gaining maneouvers to achieve a final Sun-relative escape velocity of circa 60,000 miles per hour:-








 
At that speed it will take just under 50,000 years to cross the 25.3 trillion miles of interstellar space to reach New Earth at Alpha Centauri. Simple arithmetic!
Let us compare my concept with a couple of others. In Sid Meier's Alpha Centauri strategy games series, a ship called the Unity reaches Alpha Centauri in just 40 years
In Mary Doria Russel's world renowned novel 'The Sparrow' another fantasy ship gets to a planet called Rakhat at Alpha Centauri in just 17 years
Well, I certainly wont be stopping anybody if they want to bypass my interstellar ark and settle on New Earth at their faster-invented speeds, if they can demonstrate how they will slow down at the other end.

"... If you have the power to pass beyond the zones of the heavens and the earth, then pass beyond them! But you will never be able to pass them, except with authority (from God)!" - Qur'an (55:33)

Mine's is a massive 200-trillion kilogramme vehicle that is going to accelerate using planetary gravity-assisted slingshots from our Solar System and decelerate using similar means at the destination. The world's *first* blueprint for the safest way that humanity will eventually reach another Solar System beyond our own... 
At first glance, people are quick to point out: "Oh, but our technology would improve vastly in the future... we'll find newer and faster ways...". Yes I accept that we'll have improved technology in the future, there's no question about it, but my argument is that the fundamental laws of nature, the physical distances and the dynamical constraints will never ever alter. Not now, not in a thousand years from now.
One study concluded that a solar sail craft of  (249 foot by 249 foot) could theoretically propel a tiny 3-kg probe to the stars in... wait for it.... 100,000 years!
It seems to me that the only way humanity will ever hope to bridge the gulf to the stars is via a multi-generational mission concept of this type. The asteroid belt  is there to provide material for us to utilise to build our interstellar arks and the two primary suns of Alpha Centauri are there to serve as our first stop destination. Human interstellar travel is no longer a fantasy-filled dream! "Warp drives" from Star Trek may never happen in the real world...


Abdul Ahad

When the first settlers from our Earth eventually reach New Earth someday in the far distant future, what is the likelihood that they could communicate with someone still around on *this* Earth?

Or, looking at this conversely, if an intelligent species was already resident there today and capable of radio communications, can we pick up their broadcasts using our current technology?

I initiated precisely this kind of discussion a while back (2004) with science colleagues on sci.astro.seti - the dedicated 'search for extraterrestrial intelligence' (SETI) forum. Here is the thread:-

Whispers from New Earth?

(Click on the above link to view; AA Institute is my alias  )

Abdul Ahad