'No Time for Time from No-Time' Craig Callender and Eugene Chua, UCSD - 4/14/21

Programs in quantum gravity often claim that time emerges from fundamentally timeless physics. In the semiclassical time program time arises only after approximations are taken. Here we ask what justifies taking these approximations and show that time seems to sneak in when answering this question. This raises the worry that the approach is either unjustified or circular in deriving time from no–time.

[raanjoseph]

First of all quantum phenomena do have time sequences but these sequences can be reversed without impact on the results of equations so it is incorrect to say they have "no time" but rather they have no specific temporal direction forward or backwards. At least at one point you referred to lack of time-evolution but it still does not directly address the lack of temporal directionality though that may be inferred from the term it is not implied explicitly. Secondly, emergence is not the manifestation of a new phenomenon but rather the result of cumulative phenomena. The idea of emergence arises from the mistaken notion of discrete levels of existence such as micro and macro. It is rather referring to smaller and larger or scalar phenomena on a continuum. Not addressing the philosophical aspects of emergence has you floundering with logical fallacies resulting from mistaken premises. Finally the so-called "emergence" of temporal directionality which you abbreviate as "time" would be a cumulative effect of small scale events aggregating and resulting in a given orientation. As to why this might be, it could go back to the assymmetry of matter and anti-matter the latter of which is often said to move backward in time which is an entirely different mystery to resolve. My own philosophicial take on this is that assymmetry or disorder or chaos (having little or nothing to do with chaos theory which actually purports to explain apparent chaos as orderly) is the fundamental nature of physical phenomena as order may randomly occur from and within a chaotic system (think monkeys on typewriters) but chaos could never occur in a fundamentally ordered reality, nor even the appearance thereof. With a perfectly ordered symmetry of matter and antimatter there would indeed be "no time" becasue nothing could ever even happen at all.

[websurfer]

Some say that the universe had no beginning because it began when was still non-existent!! So, counterfactually how would the universe with a beginning begin, would it have began at a point in time, or at a point before time existed??

[websurfer]

Would a universe with a beginning have began at a point in pre-existing time?? Or, would a universe with a beginning have began at a point before the existence of time?? Think about it if the universe began at a point in pre-existent time, then how could you call that the beginning of time?? I would think that a universe that began had no pre-existent time at the point when it began, otherwise it would not be a true beginning!! Right??