The gravitational constant, in terms of force, is "set" at:
G = 6.674 * 10 (-11th power) * N * (m/kg)(2nd power).In layman's terms -- helpful, since I'm a layman :- ) -- there is a certain "amount of pull" between two objects with mass. We refer to this "amount of pull," or "attractional force," as gravity. How hard do objects pull together? It is in proportion to the products of their masses and is inversely proportional to the squares of the distance between them. In other words, the Sun would pull on Jupiter much harder than the Earth pulls on the moon, but you also have to factor in distance: Jupiter is much farther away in this comparison. This is a fairly simple relationship (not measurement) and is referred to as Newton's constant. Newton understood the relationship that he diagrammed, but of course did not measure its strength or weakness. Another way to speak of the strength of this constant was given in the January 5, 2007 issue of Science (page 74), where J. B. Fixler et al described the gravitational constant as
G = 6.693 × 10?11 cubic meters per kilogram second squared, with a standard error of the mean of ±0.027 × 10?11 and a systematic error of ±0.021 × 10?11 cubic meters per kilogram second squaredSo, as the amount of force a weightlifter is exerting can be measured by the pounds on the barbell, the amount of force that gravity is exerting can be described as above. ................... What you might not have spent much time reflecting on is this: is that the amount of this pull could have been "set" to a stronger or weaker force. A man who weighs 200 lbs. might have weighed 205 if the attractional force were stronger, or 195 if the pull had been weaker. Silly to spend your time thinking about things like this? Interest in such questions -- "What if the speed of light were 10 times slower or faster?" -- has set the Einsteins and Newtons apart from other scientists. A man who weighs 200 lbs. might very easily have weighed 1,000,000 lbs, in fact, if the strength of the gravitational constant had been "set" to a strength comparable to that of other natural constants. Meditate on that for a few minutes ... :- ) ................ At first glance, science students tend to assume (intuitively) that if the natural constants were different, then everything else would have simply evolved differently to accommodate. For example, if gravity were 1,000 times stronger, then men "weighing" 200 lbs. would simply be strong enough to move around despite weighing as much as a building. That, or perhaps life would evolve only on much smaller planets. Nothing could be further from the truth. There are many ways in which even the smallest changes to the natural forces would make any life impossible. The "tuning" of the gravitational constants -- the "tweaking" of these constants so as to "enable" the existence of living organisms that feed, breathe, grow, and reproduce -- is one of the oddest phenomenon of the universe we observe. Astrophysicist Hugh R. Ross, Ph.D (reasons.org) lists dozens of such tunings of natural constants and physical balances, including:
magnetic field... and 151 other fundamental "tunings" with respect to life on Earth particularly. But perhaps the freakiest, and most cognitive-dissonant, of all of these "tunings" occurs in the gravitational constant, with respect to the Big Bang. See G and the Big Bangatmospheric pressure
- if stronger: electromagnetic storms would be too severe; too few cosmic ray protons would reach planet’s troposphere which would inhibit adequate cloud formation
- if weaker: ozone shield would be inadequately protected from hard stellar and solar radiation
level of supersonic turbulence in the infant universe
- if too small: liquid water will evaporate too easily and condense too infrequently; weather and climate variation would be too extreme; lungs will not function
- if too large: liquid water will not evaporate easily enough for land life; insufficient sunlight reaches planetary surface; insufficient uv radiation reaches planetary surface; insufficient climate and weather variation; lungs will not function
if too high: first stars will be of the wrong type and quantity to produce the necessary mix of elements, gas, and dust so that a future star and planetary system capable of supporting life will appear at the right time in cosmic history
- if too low: first stars will be of the wrong type and quantity to produce the necessary mix of elements, gas, and dust so that a future star and planetary system capable of supporting life will appear at the right time in cosmic history