## Critical density

One consequence of general relativity is that the curvature of space depends on the ratio of rho to rho(crit). We call this ratio Ω = rho/rho(crit). For Ω less than 1, the Universe has negatively curved or hyperbolic geometry. For Ω = 1, the Universe has Euclidean or flat geometry. For Ω greater than 1, …

## Universe is flat

All measurements confirm that the universe is flat (Euclidean). To astronomers, flat means that the usual rules of geometry are observed – light not being bent by gravity travels in straight lines, not curves. But since Albert Einstein proposed that the Universe may be “curved”, the debate has been open. Scientific opinion has moved towards …

## Start debating Oldness/Flatness problem

This has been mentioned a couple of times in different threads: Anthropic Principle and Intelligent Creation (God) as opposed to Evolution. But, I’d like to put this in its own thread. So for debate. Why is the universe flat? That is, why does it have Euclidean geometry? https://debatingchristianity.com/forum/viewtopic.php?p=87677#p87677

## Cosmology summary

We’ve spent a considerable amount of time on cosmology (over 66 pages). And like other topics in the past (geology, archaeology, etc), we could go forever, but I’m going to wrap up this topic. Going by the evidence that we’re near the center of the universe and without the need to introduce multiple ad hoc …

## Gravitational time dilation

otseng wrote: ↑Tue Dec 06, 2022 8:12 am To recap the white hole model so far. We assume the entire universe started in a small volume. By definition, this would be a white/black hole. During the expansion of the universe, the event horizon would collapse as matter/energy moves apart. This would cause gravitational red-shifting. The …

## White hole model

DrNoGods wrote: ↑Mon Dec 05, 2022 2:43 pm But we don’t know if the universe is infinite in size any more than we know that it isn’t. So neither assumption is more valid than the other. It’s very reasonable to conclude the universe is finite in size since it is finite in age. How could …

## Isotropic, but not homogeneous

otseng wrote: ↑Sun Nov 27, 2022 9:07 am There is another way that things can get affected that makes it appear to us that it is uniform, but without the need for instantaneous changes at all points in the universe. The changes could occur in an isotropic manner, but not a homogeneous manner. More about …

## Universal causation

DrNoGods wrote: ↑Sun Nov 20, 2022 1:42 am If dark energy exists and is driving the expansion of spacetime, it may not require any kind of “information” to travel from one point to another to “tell it what to do” … its inherent properties enable it to act the same everywhere, like a negative gravity. …

## Speed of gravity

DrNoGods wrote: ↑Fri Nov 18, 2022 2:24 pm If it were a gravity-like “thing” then it may act identically at all points in spacetime with a result of uniform expansion throughout. I’m not so sure even gravity can act instantaneously, but is also limited by the speed of light. The speed of gravitational waves in …

## White hole

Miles wrote: ↑Wed Nov 16, 2022 3:54 pm Having stumbled across the following not too long ago, this may answer your question. Please note; this is a 2016 update. ……Is the Big Bang a black hole? The article states: The short answer is that the Big Bang gets away with it because it is expanding …