The Big Bang Theory Does Not Require A Singularity At T=0

Thanks for taking up the debate! I'll get right into addressing your criticisms (written as if to a third party): We see the greatest objection appear to lie in Paradigm's usage of philosophy (specifically ontology), the nature of time, space, and matter. He makes two claims: (1) That nothing can exist without a cause, and that thus it requires spacetime to have a beginning. (2) Space and time comprise something called space and are inextricably linked to one another. On both of these claims I agree, and will seek to demonstrate how they do not assist his argument for a singularity. Let me begin by addressing (1). I agree entirely that in our daily lives every material entity has a cause. This message appears on the internet because I submitted it, for example. There are countless examples of causality everywhere in nature. However, the scope of your argument can thus only fall to things within nature, and not nature itself. That is, while everything within a set obeys a certain property (causality) it does not follow that the set itself obeys that property, especially when the property is defined by the set! (causality makes no sense without time!) This is easily demonstrable by analogy: The United Nations is comprised of various nations from around the world. Does this imply that the United Nations is itself a nation? Is the set of all even numbers itself an even number? Most certainly not. Likewise, while all objects within nature existing in time are subject to causality, this certainly does not imply that time (or nature) itself is subject to causality. In fact, it is most logical to state that time could not have begun, for the very notion of a beginning implies the existence of a time with which to compare (as coming into existence is a sequential act. Time cannot have come into existence without a time before from it to have sprung!) Secondly, I come to (2). As a physics major I have no qualms with the notion of spacetime, and do not disagree with the notion that with one necessarily comes the other. However, what I fail to recognize is how this is a problem for my argument. Paradigm asks "Now, consider that there was no singularity, no point in which time began. Would time itself then become timeless? Surely not just on a philosophical level, because time outside of space means nothing, and indeed, could not exist in actuality-- never mind conceptually." I addressed the problem with the notion of beginning of time above. Now, without a beginning of time this does not negate the fact that causal events occur. It simply means that there was no beginning to time. An analogy may help: on a line of real numbers, there is an infinite number of these, stretching from negative infinity to infinity (which are not real numbers in themselves but denote the notion of being able to add a number on forever in either direction). Now, on the real number line I can always locate points, say, 1 and 2. And I can get from 1 to 2 by the addition of 1. Time likewise behaves similarly. There is always a finite distance between two points, while time itself is infinite in extent. The fact that space and time are linked does nothing to affect my argument: as long as space exists, time exists. If time is infinite, this just means the universe has always existed. Lastly I come to the empirical claim: that Hubble's redshift can be used to demonstrate that time itself had an origin. Hubble's redshift, for those who don't know, is a line relating galaxy distance to velocity. The further away a galaxy is, the faster it goes. The conclusion is that if we bring all these galaxies back together, there must be a point in time that they were all smashed together into a single point, the Big Bang singularity. There are multiple problems with deducing this: Hubble's Law (which results in this relationship) in it's simplest formulation is based off of a Newtonian metric, which, while useful for many astronomical calculations, becomes increasingly useless as both relativity and quantum mechanics come into play. Likewise, more complicated and accurate formulations take into account relativity, but leave out the play of quantum mechanics. This is for good reason, quantum effects do not mean anything until we get to a region where Hubble's Law is entirely useless. While great for galaxies, we are talking about a time when all of space was contained within a region smaller than a proton. The fundamental forces were united and behaved in a manner different than what Hubble's Law is theoretically based off of. And most importantly, gravity is quantized, which greatly affects the expansion of space (as energy density results in a gravitational tug, and energy density was quite high during the pre-Planck universe.) Extrapolation of Hubble's Law prior to (or during) the inflationary epoch is also unwarranted. This is because while the Hubble relationship took into account some basic relativity, the metric involved in Inflation is quite different and based on different parameters. We certainly do not apply the inflation metric past the point where it approximates the Hubble metric, nor should we do the opposite and apply Hubble where he's not correct. Likewise, prior to inflation gravity itself is quantized, and this means we shouldn't apply either Hubble or Inflationary metrics without great hesitation! Neither of these metrics are quantized, which means neither of these metrics are appropriate during pre-Planck era work.