Cosmology: time begins (Introduction)

by dhw, Sunday, May 25, 2014, 14:31 (3624 days ago) @ David Turell

From David:-QUOTE: "You can also use the GSL [Generalized Second Law] to show that time has to end at a singularity inside of black holes and had to have a beginning at the big bang. Otherwise, there'd be observers whose horizons wouldn't satisfy the GSL. Admittedly, no one really understands the laws of physics near singularities, so this part of my research is speculative and depends on what kinds of new physics might be relevant. It is conceivable that, even though the GSL is valid in all the situations we've been able to check so far, it is false near singularities." (David's bold)-http://blogs.scientificamerican.com/critical-opalescence/2014/05/23/time-machines-would...-No harm in speculation, but since you have put this highly controversial speculation in bold, we need to review the situation. You and I have agreed that nothing can come from nothing (see the first section of your post), in which case there must have been something before the big bang. But as George has argued, there cannot be a "before" without time. We then come to the problem of defining time. If we take it as meaning the sequence of before/now/after, or past/present/future, you and I cannot say time began with the big bang. (We don't know George's definition of time.) You have tried to define it in terms of the passage of events, and the big bang is the first event we know of (or think we know of ... the big bang remains a theory, not a fact). But we have no way of knowing whether there were or were not other events before the big bang, and so even if we accept your definition of time, we have no way of knowing whether the statement in bold is true or false. The heading: "Cosmology: time begins" therefore seems to me just as misleading in its boldness as "Innovation and Speciation: pre-planning". Far too many sensational headlines! Methinks we need a bit of moderate agnosticism on the AgnosticWeb!