On Apr 23, 3:23 pm, RichD <r_delaney2...@yahoo.com> wrote: > Supposedly, our universe is closed and finite, although the > geometry and topology isn't precisely known. This means > a straight line (geodesic) traveler must return to his starting > poiint, yes/no? Hence, curved space. > > At the same time, astronomers claim, that space is flat, to > the precision of their measurements. Usually, this is > accompanied by the comment that the universe is balanced > between infinite expansion, or eventual collapse, we can't > tell which. > > So, space is closed, but also flat... back in my day, they > had something called a logical contradiction, which was > considered a bad thing, but I guess times change... > viva progress - > > -- > Rich
xxein: It's just a lot of proclamation of limited imagination. Not to mention the case where an outfielder does all the proscribed math in his head to catch a fly ball.
It is evident that the universe is expanding and that a local gravity has the opposite effect. Who will win?
But back to your starting point. Terms like geometry and topology are man-made. They only exist because that's the mental process by which we think. So we call that a science. In this case, physics. They are mental compilation descriptors of what we seem able to observe. Way back in the day, there was Earth, wind, water and fire. Then the Sun during the day and stars at night. An easily observed object in the night sky was the moon. We not only wondered, we invented a reason for these observations.
And that's what we still do today. It may be called a version of a formal physics but there are many versions of it. So what is the actual physic? What is really happening and why?
We only guess with more definitive man-made reasons.
We get to the point of producing electricity for many tasks. Do we ever really understand it as the physic or do we just use it because we have developed a way to do that and call it physics?
Getting back to space, it is assumed to be empty/a vacuum. If so, what is a universe? We claim energy/dark energy, matter/dark matter. Things that seem to exist in this vacuum. We exist and can measure stuff. This means that there is some sort of fluidity wrt time that we can measure at least as a change.
So now we have science claiming that space is empty vacuum within our universe? How then does space get to be curved without a medium to do it within?