How Old Is The Universe?

KeyserXSoze

Gone But Not Forgotten
(ACCOUNT RETIRED)
Joined
Jun 2, 2002
Messages
946
Reaction score
15
Points
49
http://www.spaceref.com/news/viewpr.html?pid=14524
Glimpse at Early Universe Reveals Surprisingly Mature Galaxies
Observations challenge standing view of how and when galaxies formed

A rare glimpse back in time into the universe's early evolution has revealed something startling: mature, fully formed galaxies where scientists expected to discover little more than infants.

"Up until now, we assumed that galaxies were just beginning to form between 8 and 11 billion years ago, but what we found suggests that that is not the case," said Karl Glazebrook, associate professor of physics and astronomy in the Krieger School of Arts and Sciences at The Johns Hopkins University in Baltimore and co-principal author of a paper in the July 8 issue of Nature. "It seems that an unexpectedly large fraction of stars in big galaxies were already in place early in the universe's formation, and that challenges what we've believed. We thought massive galaxies came much later."

Using the Frederick C. Gillett Gemini North Telescope in Mauna Kea, Hawaii, Glazebrook and a multinational team of researchers called the Gemini Deep Deep Survey (GDDS) employed a special technique called the "Nod and Shuffle" to peer into what had traditionally been a cosmological blind spot. Called "the Redshift Desert," this era - 8 billion to 11 billion years ago, when the universe was only 3 billion to 6 billion years old - has remained relatively unexplored until now, mainly because of the challenges inherent in collecting data from the faintest galactic light ever to be dissected into the rainbow of colors called a spectrum. In all, the team collected and analyzed spectra from 300 galaxies, making it the most complete sample ever taken from the Redshift Desert.

"This was the most comprehensive survey ever done covering the bulk of the galaxies that represent conditions in the early universe," Glazebrook said. "We expected to find basically zero massive galaxies beyond about 9 billion years ago, because theoretical models predict that massive galaxies form last. Instead, we found highly developed galaxies that just shouldn't have been there, but are."

These findings challenge the dominant theory of galactic evolution, which posits that at this early stage, galaxies should have formed from the bottom up, with small pieces crashing together to build small and then ever larger galaxies. Called the "hierarchical model," this scenario predicts that normal-to-large galaxies such as those studied by GDDS would not yet exist.

"There are obviously some aspects of the early lives of galaxies that we don't yet completely understand, Glazebrook said. "We do find fewer massive galaxies in the past, but there are still more than we expected. This result is giving us a big clue as to how stars form from invisible gas in the hierarchical model, which is something not well understood under current theories. Some new ingredient is required to make more stars form earlier in the big galaxies. But what that ingredient is, we don't yet know."

The GDDS team, which included Nature paper co-authors Roberto Abraham from the University of Toronto, Patrick McCarthy from the Observatories of the Carnegie Institution of Washington and David Crampton of the National Research Council of Canada's Herzberg Institute of Astrophysics, was supported by a grant from the Packard Foundation and by institutional support from the National Science Foundation, Canada's National Research Council, the Natural Sciences and Engineering Research Council of Canada and the United Kingdom's Particle Physics and Research Council, among others.

Related Web site:

Karl Glazebrook: http://www.pha.jhu.edu/people/faculty/kgb.html
 

sunsplash1

Gone But Not Forgotten
(ACCOUNT RETIRED)
Joined
Jan 9, 2004
Messages
1,306
Reaction score
19
Points
54
I'd say middle aged (it's starting to bulge a bit...)
:(
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
25,430
Reaction score
39,178
Points
314
Location
Out of Bounds
Here's a new item which illustrates how the issue of the universe's age is still open and subject to further refinement.

A well-known star known as "Methuselah" was once estimated to be older than the estimated age of the overall universe. Subsequent refinements in data and interpretations have closed the distance between these two estimated ages at the stellar and the cosmological levels, but claiming them to be consistent still requires relying on margins of error.

One conclusion is that there needs to be more effort put into re-evaluating the universe's estimated age just as was done for the specific example of Methuselah.
How Can a Star Be Older Than the Universe?

For more than 100 years, astronomers have been observing a curious star located some 190 light years away from Earth in the constellation Libra. It rapidly journeys across the sky at 800,000 mph (1.3 million kilometers per hour). But more interesting than that, HD 140283 — or Methuselah as it's commonly known — is also one of the universe's oldest known stars.

In 2000, scientists sought to date the star using observations via the European Space Agency's (ESA) Hipparcos satellite, which estimated an age of 16 billion years old. Such a figure was rather mind-blowing and also pretty baffling. As astronomer Howard Bond of Pennsylvania State University pointed out, the age of the universe — determined from observations of the cosmic microwave background — is 13.8 billion years old. "It was a serious discrepancy," he said. ...

Taken at face value, the star's predicted age raised a major problem. How could a star be older than the universe? Or, conversely, how could the universe be younger? It was certainly clear that Methuselah — named in reference to a biblical patriarch who is said to have died aged 969, making him the longest lived of all the figures in the Bible — was old, since the metal-poor subgiant is predominantly made of hydrogen and helium and contains very little iron. It's composition meant the star must have come into being before iron became commonplace.

But more than two billion years older than its environment? Surely that is just not possible. ...
SOURCE: https://www.livescience.com/how-can-a-star-be-older-than-the-universe.html
 
Last edited:

Mythopoeika

I am a meat popsicle
Joined
Sep 18, 2001
Messages
47,167
Reaction score
42,884
Points
334
Location
Inside a starship, watching puny humans from afar
Here's a new item which illustrates how the issue of the universe's age is still open and subject to further refinement.

A well-known star known as "Methuselah" was once estimated to be older than the estimated age of the overall universe. Subsequent refinements in data and interpretations have closed the distance between these two estimated ages at the stellar and the cosmological levels, but claiming them to be consistent still requires relying on margins of error.

One conclusion is that there needs to be more effort put into re-evaluating the universe's estimated age just as was done for the specific example of Methuselah.

SOURCE: https://www.sciencealert.com/the-sc...esn-t-make-you-more-likely-to-be-narcissistic
That link seems to be irrelevant to this topic...
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
25,430
Reaction score
39,178
Points
314
Location
Out of Bounds
One approach to resolving the age of the universe conundrum is to consider that it may not have had any beginning.

What if the universe had no beginning?

In the beginning, there was … well, maybe there was no beginning. Perhaps our universe has always existed — and a new theory of quantum gravity reveals how that could work.

"Reality has so many things that most people would associate with sci-fi or even fantasy," said Bruno Bento, a physicist who studies the nature of time at the University of Liverpool in the U.K.

In his work, he employed a new theory of quantum gravity, called causal set theory, in which space and time are broken down into discrete chunks of space-time. At some level, there's a fundamental unit of space-time, according to this theory.

Bento and his collaborators used this causal-set approach to explore the beginning of the universe. They found that it's possible that the universe had no beginning — that it has always existed into the infinite past and only recently evolved into what we call the Big Bang. ...

The causal set approach neatly removes the problem of the Big Bang singularity because, in the theory, singularities can't exist. It's impossible for matter to compress down to infinitely tiny points — they can get no smaller than the size of a space-time atom.

So without a Big Bang singularity, what does the beginning of our universe look like? That's where Bento and his collaborator, Stav Zalel, a graduate student at Imperial College London, picked up the thread, exploring what causal set theory has to say about the initial moments of the universe. Their work appears in a paper published Sept. 24 to the preprint database arXiv. (The paper has yet to be published in a peer-reviewed scientific journal.) ...
FULL STORY: https://www.livescience.com/universe-had-no-beginning-time


RESEARCH REPORT (Not Yet Peer Reviewed):
If time had no beginning
Bruno Valeixo Bento, Stav Zalel

General Relativity traces the evolution of our Universe back to a Big Bang singularity. To probe physics before the singularity -- if indeed there is a ``before'' -- we must turn to quantum gravity. The Causal Set approach to quantum gravity provides us with a causal structure in the absence of the continuum, thus allowing us to go beyond the Big Bang and consider cosmologies in which time has no beginning. But is a time with no beginning in contradiction with a passage of time? In the Causal Set approach, the passage of time is captured by a process of spacetime growth. We describe how to adapt this process for causal sets in which time has no beginning and discuss the consequences for the nature of time.
https://arxiv.org/abs/2109.11953

FULL PAPER: https://arxiv.org/pdf/2109.11953.pdf
 

Lb8535

Justified & Ancient
Joined
Sep 2, 2015
Messages
2,036
Reaction score
3,979
Points
164
One approach to resolving the age of the universe conundrum is to consider that it may not have had any beginning.


FULL STORY: https://www.livescience.com/universe-had-no-beginning-time


RESEARCH REPORT (Not Yet Peer Reviewed):

https://arxiv.org/abs/2109.11953

FULL PAPER: https://arxiv.org/pdf/2109.11953.pdf
I think this is an approach to a cosmological mathematical problem - they're defining a calculation by taking out a beginning limit. People who work on this level just make my head spin - when I was in college my dorm advisor was a PhD candidate in extreme mathematics (or something like that) who was happily analysing calculations in which time ran backward.
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
25,430
Reaction score
39,178
Points
314
Location
Out of Bounds
I think this is an approach to a cosmological mathematical problem - they're defining a calculation by taking out a beginning limit. ...
They're also embracing a theoretical framework that eliminates (evades?) problems by assuming space-time is essentially quantized into discrete units. The mania for interpreting everything in terms of discrete 'building block' units is a 20th century conceit that (IMHO) has already proven itself of limited utility.
 

Victory

Justified & Ancient
Joined
Jan 15, 2017
Messages
1,496
Reaction score
3,538
Points
159
Location
London
I think there are four phases of existence.

And a fifth parallel concept.

Not entirely original thoughts, but based on reading I have done over the years.

1.) Before the universe was created.

A concept impossible for the human mind to fully grasp.

2.) From the Big Bang onwards, but before the sun, moon and stars were set in their current patterns to give us 24 hours days, seven day weeks etc. There was a reference point to work forwards from.

Hard for the human mind to grasp, but a lot of work goes into understanding it, and we can understand it to an extent.

3.) The current state of affairs, where the Sun, Moon and Stars give us a framework of time.

4.) After the planet earth ends, or the sun burns out.

Time will have to change by definition, humans may be living on other planets by then, though a concept of "Earth Time"might continue electronically.

Hard for us to grasp.

5.) The parallel concept where usual constraints of time and space are not applicable i.e. miracles, possible quantum effects, astral projection, dreams, religious soul ascents to heaven and back, near death experiences etc.

We spend a lot of time on here trying to understand these.
 
Last edited:

charliebrown

Justified & Ancient
Joined
Nov 2, 2020
Messages
1,716
Reaction score
2,615
Points
154
Location
Earth
Are they multiple universes, why does it just have to be one universe ?

Is our universe a living entity ?
 
Top