3 ms·
> If true, then that means the big bounce is back on the menu I don't think so. Deceleration does not imply recollapse. AFAIK none of this changes the basic fa
by pdonis 1y ago
> If true, then that means the big bounce is back on the menu
I don't think so. Deceleration does not imply recollapse. AFAIK none of this changes the basic fact that there isn't enough matter in the universe to cause it to recollapse. The expansion will just decelerate forever, never quite stopping.
- Erem 1y agoWait but decelerating forever does in fact imply recollapse doesn't it?
- deepthaw 1y agoI assume decelerating forever means asymptotically approaching not collapsing.
- pdonis 1y agoNo. The simplest example is a matter-dominated universe at exactly the critical density. It decelerates forever but never quite stops expanding--the expansion rate asymptotes to zero.
- cwillu 1y agoAn object on an escape trajectory from another mass is forever decelerating, but it still escapes.
- jimbo808 1y agoWould it not enter the viscinity of other objects which would eventually coalesce into local centers of mass (maybe like one per observable universe diameter or something)?
- ridgeguy 1y agoNope, cosmic Zeno's Paradox. Collapse never quite happens.
- xerox13ster 1y agoNope, that would be velocity changing sign, which means acceleration would increase.
- SideburnsOfDoom 1y agoNo, in much the same way that a speeding vehicle slowly decelerating towards a stop doesn't mean that it will return to where it started the journey. Actually it's worse than that, "decelerating forever" doesn't even mean that it ever even comes entirely to a stop. let alone return to where it started.