On Tuesday, December 25, 2018 at 12:35:24 AM UTC, Jason wrote:
>
>
>
> On Mon, Dec 24, 2018 at 6:28 PM <agrays...@gmail.com <javascript:>> wrote:
>
>>
>>
>> On Monday, December 24, 2018 at 9:47:52 PM UTC, Jason wrote:
>>>
>>>
>>>
>>> On Mon, Dec 24, 2018 at 4:04 PM <agrays...@gmail.com> wrote:
>>>
>>>>
>>>>
>>>> On Monday, December 24, 2018 at 8:25:11 PM UTC, agrays...@gmail.com 
>>>> wrote:
>>>>>
>>>>>
>>>>>
>>>>> On Monday, December 24, 2018 at 6:40:03 AM UTC, Brent wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 12/23/2018 8:22 PM, agrays...@gmail.com wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Monday, December 24, 2018 at 3:50:33 AM UTC, Brent wrote: 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 12/23/2018 4:47 PM, agrays...@gmail.com wrote:
>>>>>>>
>>>>>>> *If by "flat", you mean mathematically flat, like a plane extending 
>>>>>>> infinitely in all directions, as opposed to asymptotically flat like a 
>>>>>>> huge 
>>>>>>> and expanding sphere,  you have to reconcile an infinitesimally tiny 
>>>>>>> universe at the time of the BB, and simultaneously an infinitely large 
>>>>>>> universe extending infinitely in all directions. AG*
>>>>>>>
>>>>>>>
>>>>>>> All that's "infinitesimally tiny" is the visible universe.  You must 
>>>>>>> know that the Friedmann equation just defines the dynamics of a scale 
>>>>>>> factor, not a size.
>>>>>>>
>>>>>>
>>>>>> *Are you claiming the visible universe at the BB was infinitesimally 
>>>>>> tiny, but the non visible part was infinitely large (mathematically 
>>>>>> flat), 
>>>>>> or huge (asymptotically flat)? AG *
>>>>>>
>>>>>>
>>>>>> Right.  Although we can't be sure whether it is actually flat or just 
>>>>>> very big.
>>>>>>
>>>>>> Brent
>>>>>>
>>>>>
>>>>> *OK. Agreed. We seemed to disagree on this in the past, but maybe we 
>>>>> miscommunicated. AG*
>>>>>
>>>>
>>>> Here's what Ned Wright wrote. 
>>>>
>>>> Is the Universe really infinite or just really big?
>>>>
>>>> We have observations that say that the radius of curvature of the 
>>>> Universe is bigger than 70 billion light years. But the observations allow 
>>>> for either a positive or negative curvature, and this range includes the 
>>>> flat Universe with infinite radius of curvature. The negatively curved 
>>>> space is also infinite in volume even though it is curved. So we know 
>>>> empirically that the volume of the Universe is more than 20 times bigger 
>>>> than volume of the observable Universe. Since we can only look at small 
>>>> piece of an object that has a large radius of curvature, it looks flat. 
>>>> The 
>>>> simplest mathematical model for computing the observed properties of the 
>>>> Universe is then flat Euclidean space. This model is infinite, but what we 
>>>> know about the Universe is that it is really big 
>>>> <http://www.astro.ucla.edu/~wright/HGTTG.html>.
>>>>
>>>>
>>>> <http://www.astro.ucla.edu/~wright/cosmology_faq.html#top>
>>>>
>>>> *It is misleading. He's referring to the VISIBLE universe and concludes 
>>>> it might be infinite in spatial extent. Impossible due to its finite age. 
>>>> I 
>>>> wrote him about this, but never received a reply.  AG*
>>>>
>>>>
>>>>
>>> It's only impossible if you believe the believe the big bang occurred 
>>> only at a point, rather than everywhere.
>>>
>>> Consider that every point in space sees everything else around it flying 
>>> away from it, such that if you rewound time, everything would return to a 
>>> single point centered at that location. But this is true for every point in 
>>> space, so the implication is that the BigBang didn't happen at one 
>>> particular location long in the past, but at every point, including the 
>>> period at the end of this sentence.
>>>
>>
>> *You seem inclined to extreme hypotheses for which there is no data. AG *
>>
>>>
>>>
> This is the default "standard" model used used by cosmologists, it's 
> called the concordance model, or the Lambda-CDM model. There is significant 
> data for it.
>

*I don't believe it. AG *

>
> Jason
>

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