The Start of Dark Energy and the limits of the Universe

Discussions ranging from space technology, near-earth and solar system missions, to efforts to understand the large-scale structure of the cosmos.

Re: The Start of Dark Energy and the limits of the Universe

Postby BurtJordaan on October 15th, 2019, 8:34 am 

bangstrom » 15 Oct 2019, 03:27 wrote:There is no barrier surrounding a galactic cluster to confine space within, like air in a bottle, to keep local space from expanding as intergalactic space expands.

Did you read what I wrote about gravitationally bound orbits? They do not increase in orbital radius. The inter-cluster voids do expand with the universal expansion and that's that - full-stop with this kind of dissident discussion here. One more round and then the thread will be closed.
User avatar
BurtJordaan
Forum Moderator
 
Posts: 2706
Joined: 17 Oct 2009
Location: South Africa
Blog: View Blog (9)


Re: The Start of Dark Energy and the limits of the Universe

Postby bangstrom on October 16th, 2019, 4:34 am 

BurtJordaan » October 15th, 2019, 7:34 am wrote:
Did you read what I wrote about gravitationally bound orbits? They do not increase in orbital radius. The inter-cluster voids do expand with the universal expansion and that's that - full-stop with this kind of dissident discussion here. One more round and then the thread will be closed.


Yes, I did read your comment about gravitationally bound orbits but you make it sound as if universal expansion does not apply within a galactic cluster but expansion applies everywhere there is spacetime like air pressure. Gravity may hold the galaxies together but spacetime changes are universal. That's why I asked about it again.

I am not questioning the standard model even though I have my doubts. I am attempting to understand your view of the same since we don’t share the same understanding and I find some of your views to be inconsistent.

For simplicity I can boil it down to one main issue related to some of the others. You say cosmological time is unchanging while the dynamic of universal expansion is “the metric expansion of space. More light years, not “longer light years”.

My question is, how can c be a constant if distance is increasing but time remains unchanged ?

Since c= d/t , the rate of time must change if distance is increasing. The ratio of d/t can remain equal to c if the changes are proportional but this is only possible if time varies proportionally to distance as it does in GR. How is this possible if, as you claim, time can not change?

Time can be made a constant in popular models where time is used as a co-moving coordinate but this makes c a variable. Space can also be made a constant the same way yielding a model of the universe that is the inverse of the other and I personally think the latter model conforms better to observations but neither model is likely to be our reality.
bangstrom
Member
 
Posts: 689
Joined: 18 Sep 2014


Re: The Start of Dark Energy and the limits of the Universe

Postby BurtJordaan on October 16th, 2019, 6:18 am 

bangstrom » 16 Oct 2019, 10:34 wrote:My question is, how can c be a constant if distance is increasing but time remains unchanged?

The point is that c is an absolute constant, but the speed of light is only equal to c in inertial reference frames. The universe is not an inertial frame and the speed of light is simply not c in such a frame.

We've been through that enough times, so this thread is now closed. If you want to continue with your interpretation, please start a new thread under "Personal Theories".
User avatar
BurtJordaan
Forum Moderator
 
Posts: 2706
Joined: 17 Oct 2009
Location: South Africa
Blog: View Blog (9)


Previous

Return to Astronomy & Cosmology

Who is online

Users browsing this forum: Google [Bot] and 10 guests