Ahad's Sphere is an imaginary sphere centered on the Sun, marking out the 3D space within which the amount of illumination provided by the light of the Sun is greater than that provided by the collective light of the rest of our universe added together.
The Sun is the most supreme source of all light and heat to our livelihoods here on Earth, and will continue to remain so for a great distance as we venture outward from our Solar System in any particular direction into deep space. Its brightness will attenuate, however, with increasing distance due to the so-called inverse square law in physics. In other words, when we have doubled our distance from the Sun, we would find the strength of its light to have diminished to just one quarter ( ¼ ) of its original intensity; when we have quadrupled our distance, we would find the apparent energy flux of the Sun to have diminished by a factor of 16 (1/16th) of its original intensity, and so on.
In July 2004, Abdul Ahad postulated that on such interstellar journeys going outward from our Solar System we shall eventually find ourselves at a point in space where the amount of sunshine we get from the far away Sun is no greater than the amount of "starshine" we get from everywhere else in the universe. That point is said to exist on the outer edge of Ahad's Sphere. It's distance from the Sun (i.e. the radius of Ahad's Sphere) is consequently known as the Ahad Radius.
Although Ahad's Sphere of Solar Illuminance may have featured first in the fictional works of Abdul Ahad, readers should keep in mind that this is a genuine scientific phenomenon, provable as a mathematical theorem, that has been published in formal scientific literature.
The theorem may be formally stated thus: "On any interstellar journey going outward from our Solar System, one eventually reaches a point where the total amount of light received from our Sun is exactly matched by the total amount of flux coming from all cosmic sources external to our Solar System. The heliocentric distance of that boundary is dubbed the "Ahad radius", and exists at the edge of "Ahad's sphere of solar illuminance", some 11,500 astronomical units (roughly a trillion [10^12] miles) from Earth. "
In the fictional context, residents of the Centauri Princess become especially vulnerable to nightmares after crossing the outer edges of this sphere, where interstellar demons are said to rule without the spiritual protection cushion provided by the solar dominion of light. The precise point of crossover (the Ahad Radius ) was alerted by Sharuk Rashid on starship television at the opening of chapter 3 ('Entering the night of 45,000 years') of First Ark to Alpha Centauri.
Philosophy of Ahad's Sphere Edit
Genesis 1:4 : God Divided the Light from the Darkness Before Creating the Sun, Moon and Stars...
In numerological spheres of thought, the Ahad's Sphere is being viewed as an aura of Good and Godliness surrounding the Sun. A governing candle of Light, an imperious beacon of Good guarding Humanity, the Earth and our Solar System from the vast underworld of the celestial Dark and of otherworldly Evil. It demarcates Humankind's greatest hopes from its darkest fears.
On first definitions of the Ahad's Sphere, Abdul Ahad wrote: -
"Beyond the outer edges of this theoretical sphere, the feeble currents of light coming from its core [i.e. our own distant Sun] will cease to make any noticeable ripples in the calm waters of the surrounding cosmic ocean..." - July, 2004.