: That someone could randomly take 3 constants of nature, admittedly the 3 most significant ones, put them together in such a way as to produce an outcome with dimensions of a length and have the result turn out to have incredible meaning in physics and cosmology. Is this really what happened?

Yes, though there is a little intuitiveness that goes into it, for instance the stronger the force the larger the distance is between its "charge" carriers at which you will see the quantum effects of scattering. G is related to the strength of the gravitational field. So as G tends to zero one expects the distance at which quantum gravity to become important to approach to zero as well. For an analogy in electromagnetic scattering in QED the probability of an emission of a photon at a vertex in a Feynmann diagram between scattering charges is given by a squared amplitude |Y|2 where Y is proportional to the square root of the fine structure constant. The fine structure constant itself is proportional to the electric constant ke so we may say Y = ake1/2. So likewise in quantum gravity we should expect the scale at which it is observable to be proportional to the square root of the gravitational constant G1/2. In hindsight the scale also makes sense because it is where the strengths of the forces of nature seem to become equal in both quantum gravity theories and in experiment as far as we have been able to observe.

• http://www.delphi.com/sciandpara

• As usual - a great answer - thanks (nt) - Kerry - February 23, 2000 - 03:21 UTC