Sentience Quotient
From The Book of THoTH (Leaves of Wisdom)
The Sentience Quotient concept was invented by Robert A. Freitas Jr.. The theory is controversial because it defines sentience according to a relationship between information processing rate and brain mass, yet there is no evidence that such a relationship is in any way related to a measurement of sentience. There is currently no accepted method to measure sentience or any data to connect sentience with brain mass.
This theory is similar to discredited theories which, in years gone by, attempted to relate intelligence to cranial size.
In Robert Freitas Jr's theory the Sentience Quotient (SQ) of an individual is defined as:
SQ = log10(I / M)
where I is the information processing rate (bits/sec) and M is the mass of the brain (kg). The lower (astrophysical) limit of SQ is approximately -70, while the upper (quantum) limit is about 50.
According to this equation, humans have an SQ of +13. A human neuron has an average mass of about 10-10 kg and one neuron can process 1000-3000 bits/sec, giving us an SQ rating of +13. And there is still room for a great deal of improvement! Even more interesting; most other animals in this world with a nervous system have neurons equipped with roughly the same SQ. An important reminder on how much the design, size and programming of a brain actually means.
Obviously the SQ alone is not enough to describe the maximum intellectual potential of a brain. If it is very small (like a mite's brain), poorly designed or poorly programmed, there is a big chance it would be rather stupid even with a relatively high SQ.
The theoretically dumbest brain possible would have just one neuron with the mass of the whole universe (1052 kg) and require a time equal to the age of the universe (1018 seconds) to process just one bit, giving a minimum SQ of -70.
What would be the smartest possible brain? According to Dr. H. Bremermann at the University of California at Berkeley, there is a fundamental limit to intelligence imposed by the laws of quantum mechanics. All information, to be acted upon, must be represented physically and be carried by matter-energy "markers." According to Heisenberg's Uncertainty Principle in quantum mechanics, the lower limit for the accuracy with which energy can be measured-the minimum measurable energy level for a marker carrying one bit–is given by Planck's constant h divided by T, the duration of the measurement. If one energy level is used to represent one bit, then the maximum bit rate of a brain is equal to the total energy available E ( = mc2) for representing information, divided by the minimum measurable energy per bit (h/T) divided by the minimum time required for readout (T). or mc2/h = 1050 bits/sec/kg. Hence the smartest possible brain has an SQ of +50.
--Angel 16:01, 15 May 2006 (CDT)
