|The impossible dream?|
Since the conception of quantum theory, it has been the dream of physicists to unify all the four basic forces into one coherent whole. These forces, in no particular/particle order, include: electromagnetism, gravity, and the strong, and weak nuclear force. In 1979 researchers working in the US and UK unified the force of electromagnetism with the weak nuclear force to form the concept of the electroweak force. For this seminal work, the three physicists involved won the Nobel prize. So far the union of the strong nuclear force remains elusive but there are sound theoretical considerations that suggest its integration to form the 'magic trio' is a sound practical proposition. To demonstrate the union experimentally will no doubt involve very high energies and physicists are currently working on this problem with apparent gusto. And when I say 'very high energies' I'm referring to the energies present immediately after the big bang. Gravity, is the weakest of all the forces, much weaker than the nuclear weak force, although it has the property to propagate over vast distances. Although the greatest scientific minds of the last century and this century (consider, Einstein and Hawking) have pondered deep and hard on how gravity might be part of this great quantum unity, however, and unfortunately, there has been little progress, apart from the development of untestable hypotheses.
The heart of the problem lies with the nature of gravity itself and our understanding of it. Until the 17th-century gravity was hardly a concept at all. It required the genius of Isaac Newton to formulate 'Gravitational Laws'. Newton's great insight was to recognise that gravity was a force dependant on mass and the equations he formulated accurately described the real world with uncanny accuracy. The greater the mass the greater the force. This force, derived from mass, decreases with distance according to the inverse square law. With regard to two interacting gravitational bodies, the greater their distance from each other, the less the gravitational attraction will be. Newton considered the force of gravity to extend unto infinity. This is a mathematical construct and gravity is unlikely to reach out that far in reality; as an analogy consider Zeno's paradox. I suspect that, in the real non-mathematical world, gravity has a finite spatial extent. This is a common mistake that folk make. When we look at the solution of a mathematical construct we often assume that it must absolutely relate to our physical reality, absolutely. This is not always the case. This does not mean the mathematics is incorrect, it means that the 'real world' is not always in tune with the underlying/ underpinning mathematics; think about it.
Although Newton was able to describe the force of gravity mathematically, he was at a loss when it came to describing the force itself. He considered his inability to describe gravitational causality to be one of his greatest failures together with his inability to turn base metals into gold; this dual insanity would vex him until the end of his days. Newton's 'Law of Universal Gravitation' explained the movement of celestial bodies in his 17th-century world extremely well. It wasn't until the 19th century that Newtonian gravity was found to be amiss. New observable phenomena and better scientific techniques and instruments alerted physicists to the uncomfortable fact that 'Great Hallowed Newton' had been wrong. So great was Newton's reputation and intellectual standing, in posterity, that it took a while for physicists to fully comprehend that Newton's gravitational postulations had been in error.
The world, and mayhap the universe, would have to await the genius and serial insights of Einstein in the second decade of the 20th century to provide scientific solace and replacement. Thus, Newtonian gravity was replaced by 'General Relativity'. This did not just represent a change, in theory, it represented a paradigm shift- this is arguably a rare occurrence in science, indeed, especially in the modern world (All hail Einstein). General relativity stated that mass warped space and time. Therefore, space and time would be forever intertwined and dance together according to mass, and not just any old disco beat. Thus, our insight has been confirmed, after all: 'fat lassies' cause greater deformation of the wooden dance floor than their less endowed/empowered sisters- ain't dat the sad truth. Arse, big fat, arse= greater gravity.
General relativity explained anomalies that Newtonian physics could not. In fact, not only was general relativity a sound theoretical postulate, but it was also quickly found to be in accord with numerous practical observations. In the 1930s there was the real and exciting expectation that gravity was about to be integrated into the quantum world to produce a single unified quantum field theory, of everything. This, was the holy grail of physics, after all. The scientist(s) endowed with the intellectual clarity and perspicacity to quantify gravity would surely claim a Nobel prize, or two. But the macro effect of gravity remained steadfast and stubborn (nay, obdurate) and refused to join the quantum world of the very small; O bitter the cud! However, there have been several theoretical attempts to incorporate gravity unto the fold, the most interesting is based on string theory. The problem is that none of these postulations have any practical observational support.
Physicists are optimistic by nature and love order and harmony in the universe of the very small and very large, so they will continue to seek and search for something which may ultimately prove to be a chimaera, albeit a beautiful delusion (ignis fatuus). Perhaps gravity is the 'rogue' force that cannot be tamed and that seeking unity is an untenable prospect. If only time will tell- but ultimately the telling of the time will depend on gravity.
Folks may have noticed that my posts have become rather sensible of late: blame it on the medication. It is certainly not due to the sunshine or the boogie. What would my readers like to see? I'm happy to knock out content on a variety of topics, within my ken, including, maths, physics, biology, history, theology, military stuff, and of course cosmology. Just let me know in the comments.