Another cornerstone of relativity theory is that any object’s inertia (resistance to change of velocity) is also the exact measure of the gravitational attraction that body exerts on another object. The fact is viewed as mysterious and profound. 7) Are the inertia of an object and its gravitational attractiveness identical because each is a measure of the object’s percentage of total mass of the universe? This question is based on the prediction that there are absolute standards of rest and motion, as proposed above. Nature may not count mass in percentages of the total. Even so, a finite amount of energy was created by the big bang, and a finite amount of matter resulted from subsequent conversion of that energy. What we know as one hundred percent of matter exists in the universe (whether or not we can identify it all): And if we can determine which of any number of bodies of mass is the greater, we can be certain that nature can, too. As an extreme example of this, an object of fifty percent or more of universal mass will attract one hundred percent of the remaining universal mass to it, and its inertia will be total. This is an extreme but perhaps not an extremely stupid example, because there seems to be an object with fifty percent of universal mass (the quantum centre of universal gravity, with its fifty percent of universal energy). At the other extreme, the smallest body of mass in the universe will be dominant in attraction over no other body, and it will have no resistance to change of velocity: So to speak. One twitch of a gnat's whisker will send it off in a new direction with a new velocity. Rates of inertia, and of gravitational attraction of all other bodies of matter, range between the two extreme examples just given. Both are based on the object's percentage of total universal mass and will therefore be of exactly the same measure. The remarkable balance between orbiting velocities of bodies of mass and their gravitational attraction to the object they orbit, is frequently noted in literature. If there was a fifty-fifty split of energy between gravity and inflationary reaction to it, could this balance be a product of the antimatter-matter equilibrium that was set by release of the big bang’s two-way energy? Perhaps there is only one point of absolute rest in the entire universe, and that is at its centre of mass, where fifty percent of universal mass has been gathered since the first fifty-fifty split of energy, when time began. We can ignore the force of gravity’s weakness at close quarters, for we are considering things on a universal scale. Perhaps it is at once the only (ultimately) irresistible force and the only immovable object in the universe. 8) All energy (and therefore matter) first appeared at the universe’s point of origin. Is the nett energy that takes a pebble to its eventual maximum distance from that point, equal exactly to the nett energy that will carry it back there? The use of ‘nett energy’ is in acknowledgement that the pebble wasn’t originally a pebble, and will not end up as a pebble. But if you measure the pebble’s mass at its farthest distance from the universe’s point of origin, and calculate the energy required to get the mass there, it seems likely that the same amount of energy will be required to reverse the sequence of events that made the pebble a pebble, and to return it to its point of origin. The nett energy of the universe is therefore zero. This fits with anti-matter and matter equilibrium, and with an equal reaction of three forces to the action of symmetry-breaking of the first (gravity). 9) Why is there so much mention of infinity in Physics? These final two questions may prompt a response from a philosopher. A response would certainly be appreciated! A very well-known account of the big bang describes a singularity that expanded. It was (says the account) an infinitesimal point with zero volume, infinite density, infinite temperature, infinite curvature, and infinite pressure. Before this singularity was a condition of space-time ‘foam’, that was preceded by a state of absolute nothingness. The account also describes how the ‘temperature’ of this singularity (the universe) cooled to less than half its initial ‘temperature’ within a short period of time. What is half an infinite temperature? Half an infinite pressure? How long is half an infinite length? Another infinite length, maybe. Since Zeno in the 5th century BC, mathematicians, philosophers, and scientists have made much of physical infinity. Achilles would not have been able to catch a tortoise, said Zeno, because he would have forever halved the remaining distance to his quarry and therefore would never have closed the gap to zero. His senses would have been fooled and he would only have thought he had caught his supper. Perhaps it is a pity that Zeno didn’t jump off a cliff to try and prove that he wouldn’t quite crash onto the rocks below. He would presumably only have thought he was dead, and his three o’clock funeral would never quite have taken place because the seconds before the hour would have kept halving. The Ancient Schoolmen debated how many angels could stand on the head of a pin. In the 20th century, budding theoretical physicists debated whether God could build a rock so heavy that he couldn’t lift it. A BBC World science programme recently asked whether God could polish off an infinite breakfast. Some dictionaries carry two meanings for ‘infinity’- one that denotes endlessness and a second that describes the very great or the very small. Thus one word is used to describe two entirely different aspects of the universe. This is disturbing to a non-academic. Just as something is either unique or it isn’t, things are either infinite or they are not. If something is nearly infinite, it is finite. That we find it beyond our ability to measure it, does not make it infinite. Malapropisms could go on for ever (to use another dodgy phrase). In the book of silly conundrums we could ask ‘Could Maths devise an equation so complex that it couldn’t solve it?’ ‘Could Mother Nature have so many children that she ran out of names for them?’ ‘Could Beauty boil an egg?’ We could ask ‘Could old Father Time lose track of his age?’... What chance do we have of attaining total knowledge if we cannot distinguish between what is physical and what is not? Of all the intricacies and complexities of mathematical infinities, do any venture outside mathematics and if they do, do any describe a physical reality? There are many ordinary people to whom nature has yet to reveal anything physical that is infinite. We would appreciate being given some examples. They would not be on the basis of what never happens, but on what always does. If two lines represent infinity because they will never meet, so do pigs because they will never fly. This question may seem trivial, but it is important because if it is not clarified, the public may think that at times theoretical physicists talk nonsense. Zeno had the excuse of not being acquainted with quantum mechanics, and was better at dividing than subtracting. Besides which, theoretical physicists are still encountering horrendous infinities when tackling quantum gravity theory, and they cannot find a consistent way of turning them into finite numbers. With seventy years of this impasse, something is clearly wrong. Scientists have encouraged us to be cynical, and many of us have come to the conclusion that nothing (physical) lasts for ever. Not diamonds. Not even space.