Article <vs3mhm$b8hj$1@dont-email.me>

Deutsch English Français Italiano
<vs3mhm$b8hj$1@dont-email.me>

View for Bookmarking (what is this?)
Look up another Usenet article
Path: ...!3.eu.feeder.erje.net!2.eu.feeder.erje.net!feeder.erje.net!feeds.news.ox.ac.uk!news.ox.ac.uk!nntp-feed.chiark.greenend.org.uk!ewrotcd!news.xcski.com!beagle.ediacara.org!.POSTED.beagle.ediacara.org!not-for-mail
From: Kestrel Clayton <richZIG.e.clayZIGton@gmail.com>
Newsgroups: talk.origins
Subject: Re: Big Crunch
Date: Thu, 27 Mar 2025 10:15:19 -0400
Organization: A noiseless patient Spider
Lines: 83
Sender: to%beagle.ediacara.org
Approved: moderator@beagle.ediacara.org
Message-ID: <vs3mhm$b8hj$1@dont-email.me>
References: <9fb74340-c55d-4751-a27b-34bddc88f945@gmail.com>
 <vs1gtb$2b87e$1@dont-email.me> <nmr9ujdbvv6ctkbr2500lvgmjmf0718l37@4ax.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Info: beagle.ediacara.org; posting-host="beagle.ediacara.org:3.132.105.89";
	logging-data="66638"; mail-complaints-to="usenet@beagle.ediacara.org"
User-Agent: Mozilla Thunderbird
To: talk-origins@moderators.isc.org
Cancel-Lock: sha1:qO32r0o8pSJl9tPtitLhqFQMCK8=
In-Reply-To: <nmr9ujdbvv6ctkbr2500lvgmjmf0718l37@4ax.com>
Content-Language: en-US
	DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,HEADER_FROM_DIFFERENT_DOMAINS,
	NML_ADSP_CUSTOM_MED,RCVD_IN_DNSWL_BLOCKED,
	RCVD_IN_VALIDITY_RPBL_BLOCKED,RCVD_IN_VALIDITY_SAFE_BLOCKED,
	RCVD_IN_ZEN_BLOCKED_OPENDNS,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,
	URIBL_DBL_BLOCKED_OPENDNS,URIBL_ZEN_BLOCKED_OPENDNS,
	USER_IN_WELCOMELIST,USER_IN_WHITELIST autolearn=ham autolearn_force=no
	version=3.4.6
	smtp.eternal-september.org
Bytes: 7175

On 27-Mar-25 03:34, jillery wrote:
> On Wed, 26 Mar 2025 13:26:51 -0500, RonO <rokimoto557@gmail.com>
> wrote:
> 
>> On 3/26/2025 9:41 AM, erik simpson wrote:
>>> Sorry, a senior moment in my previous reply. I wrote about something I
>>> was thinking about while "replying" to something else.  The new
>>> information about the possible evolution of dark energy is a work in
>>> progress.  This website is probably the best source of information at
>>> present.
>>>
>>> https://www.desi.lbl.gov/2025/03/19/desi-dr2-results-march-19-guide/
>>>
>>> My degree is in astrophysics, but concentrating on stellar evolution,
>>> not cosmology, and decades ago.  I am reasonably competent with general
>>> relativity, no expert. The results of further research in dark energy
>>> will probably be published in the Astrophysical Journal, Monthly Reviews
>>> of the Royal Astronomical Society or Physical Reviews.  They will be
>>> pretty hard sledding for the lay reader.
>>>
>> So far I have found estimates that our observable universe (only a
>> fraction of the whole universe) is 93 billion light years in diameter.
>> The estimate is that when the initial inflation ended, 380,000 years
>> after the Big Bang, the current visible part of the universe was only
>> around 85 million light years in diameter after the initial inflation.
>> The rate of expansion slowed down, and the acceleration of the rate of
>> expansion due to dark energy didn't start until 7.7 billion years ago.
>> Before this time the rate of expansion was slowing down.  I can't find
>> an estimate for the size of the universe when the dark energy
>> acceleration started.  In over 13 billion years the visible portion of
>> the universe has expanded from a diameter of only 85 million light years
>> to a diameter of 93 billion light years.  Over a thousand fold increase
>> in diameter after the initial inflation and the volume is increasing at r^3.
>>
>> Why was it ever assumed that dark energy would maintain a constant
>> density in an expanding universe?  Dark energy would need to increase at
>> the same rate as the expansion of space, or they would have had to
>> believe that dark energy effects were independent of the volume of space
>> with a specific amount of dark energy. Originally the density of dark
>> energy in space would have been something like 1:1.  The effect of dark
>> energy on increasing the volume of space would have to be the same when
>> the ratio increased to 1:2.
> 
> 
> My understanding is the phenomena collectively referred to as dark
> energy appears to be intrinsic to spacetime itself.  If so, as the
> volume of spacetime increases, so too does the amount of dark energy
> within that volume by the same amount aka a constant proportional to
> volume.
> 
> 
>> Is the milky way galaxy expanding at the same rate as the space between
>> galaxies?  We can see galaxies from 8 billion years ago with the Webb
>> telescope, but the images would be of galaxies 8 billion years in the
>> past.  Today how large would they be?  They believe that our galaxy is
>> 13.6 billion years old.  How large was it 13 billion years ago?
>>
>> Ron Okimoto
> 
> 
> Dark energy density is very low.  Objects which are currently
> gravitationally bound don't have enough spacetime among them to
> overcome their mutual gravity.  This includes not just galaxies, but
> even clusters of galaxies.

Quite true! Although if the scale factor of the universe continues to 
accelerate, eventually galaxy clusters, galaxies, and even solar systems 
are spread so far apart they are no longer gravitationally bound. 
Eventually the stretching of space will overwhelm even the strong 
nuclear force, and rip atoms apart.

The good news is about a dozen OTHER things will have happened by then 
to make the universe utterly inhospitable to life as we know it, so 
worrying about the Big Rip (as they call it) is somewhat like trying to 
figure out what you'll wear for your ten thousandth birthday party, when 
you are presently 22 and suffering a heart attack, while while falling 
from an airplane without a parachute, into a volcano.

-- 
[The address listed is a spam trap. To reply, take off every zig.]
Kestrel Clayton
"Every normal woman must be tempted, at times, to stoke the fire,
host the black mass, and begin eating hearts." — Rose Bailey