<p>Answering the title question: you can see the measurement by <a href="https://en.wikipedia.org/wiki/Planck_(spacecraft)#2018_final_data_release" rel="noreferrer">Planck</a>, which is the definitive modern measurement of the age of the universe.</p>
<p><a href="https://i.sstatic.net/OaYFh.png" rel="noreferrer"><img src="https://i.sstatic.net/OaYFh.png" alt="enter image description here" /></a></p>
<p>So, 13.8 billion years, plus/minus 20 million years.</p>
<p>If this does not answer your question (the text of your question is rather confusing, going into many unrelated topics), then you'd have to be clearer on what exactly it is that you want to know.</p>

CC BY-SA 4.0
2023-05-15T01:33:29.823Z
2023-05-15T01:33:29.823Z
Allure
<p>One major difference between a hypothesis and a theory is the amount of conjecture.</p>
<p>A hypothesis is a sketch. A theory is a complete model.</p>
<p>Today's standard narrative would have us believe that the Universe is about 13 billion years old, give or take. The number has recently been altered slightly for everyone's convenience (by subtracting a couple of billion years, I believe, to fit some newly discovered &quot;facts&quot; concerning the background radiation).</p>
<p>According to the same narrative, the age of the Universe is the amount of time that has elapsed since the Big Bang.</p>
<p>And, there's the rub.</p>
<p>The rate of expansion (recently found to be accelerating) is said to have been, in some instances, superluminal (i.e. faster than light).</p>
<p>Even though the Universe consists of mostly &quot;empty&quot; space, or &quot;spacetime,&quot; if you will, there are still trillions upon trillions of stars in it: that's a lot of mass traveling at neck-breaking speeds all over the place, forming tons upon tons of inertial frames of reference and, therefore, tons upon tons of occurrences of the Twin Paradox overlapping one another. A split-second here is a few billion years over there, and vice versa (whether overlapping instances of the Paradox cancel each other out or, conversely, become intensified, is anybody's guess). What happens when something is moving at superluminal velocity relative to its neighbors? Does its local time begin to move <em>backwards</em>?</p>
<p><em>Why not?</em></p>
<p>The idea of &quot;the age of the Universe&quot;, when you think about it, sounds suspiciously Newtonian: a relic from a period in the history of astrophysics when pondering on such matters was far more local. And, I hasten to add, classical, i.e. Einsteinian, relativity, though seemingly more advanced, <em>still</em> assumes that the laws of physics are exactly the same everywhere: a hypothesis we have no hope of ever turning into a theory because experiments yielding any kind of evidence, favorable or otherwise, are not even possible.</p>
<p>Equally impossible, it seems to me, is the task of taking into account all the variables when we estimate the Age of the Universe. Is 13 billion years really a sufficiently well-calculated guess to merit the title of theory rather than just a hypothesis? Is the age of some stars a great deal less - or a lot greater - than we assume?</p>
<p>Is the age of the fabric of space (or spacetime) exactly the same everywhere?</p>

CC BY-SA 4.0
2023-05-15T05:21:31.297Z
Related: [Age of the universe and time dilation](https://astronomy.stackexchange.com/q/6525/16685). In cosmology, it's convenient to use the comoving frame of the CMB, I have some info on that here: https://physics.stackexchange.com/a/411082/123208 Also see https://en.wikipedia.org/wiki/Distance_measure & https://en.wikipedia.org/wiki/Comoving_and_proper_distances
PM 2Ring
CC BY-SA 4.0
2023-05-16T11:07:04.967Z
This question is hard to follow, and reads more like a rant, IMHO. There's also multiple questions in it. Your very last sentence which would be an interesting question of its own.
DarkDust
CC BY-SA 4.0
2023-05-17T08:07:51.890Z
You seem to think a lot of assumptions are being made about e.g. the ages of stars.  They're not assumptions, they're based on a combination of observation and theoretical modelling.  There is overlap and cross-checking of models and predictions to make sure they're consistent.
StephenG - Help Ukraine
<universe>
How accurate are the calculations of the age of the Universe?
Ricky
# How accurate are the calculations of the age of the Universe?

(Asked by: username_0 on 2023-05-14)

One major difference between a hypothesis and a theory is the amount of conjecture.

A hypothesis is a sketch. A theory is a complete model.

Today's standard narrative would have us believe that the Universe is about 13 billion years old, give or take. The number has recently been altered slightly for everyone's convenience (by subtracting a couple of billion years, I believe, to fit some newly discovered "facts" concerning the background radiation).

According to the same narrative, the age of the Universe is the amount of time that has elapsed since the Big Bang.

And, there's the rub.

The rate of expansion (recently found to be accelerating) is said to have been, in some instances, superluminal (i.e. faster than light).

Even though the Universe consists of mostly "empty" space, or "spacetime," if you will, there are still trillions upon trillions of stars in it: that's a lot of mass traveling at neck-breaking speeds all over the place, forming tons upon tons of inertial frames of reference and, therefore, tons upon tons of occurrences of the Twin Paradox overlapping one another. A split-second here is a few billion years over there, and vice versa (whether overlapping instances of the Paradox cancel each other out or, conversely, become intensified, is anybody's guess). What happens when something is moving at superluminal velocity relative to its neighbors? Does its local time begin to move *backwards*?

*Why not?*

The idea of "the age of the Universe", when you think about it, sounds suspiciously Newtonian: a relic from a period in the history of astrophysics when pondering on such matters was far more local. And, I hasten to add, classical, i.e. Einsteinian, relativity, though seemingly more advanced, *still* assumes that the laws of physics are exactly the same everywhere: a hypothesis we have no hope of ever turning into a theory because experiments yielding any kind of evidence, favorable or otherwise, are not even possible.

Equally impossible, it seems to me, is the task of taking into account all the variables when we estimate the Age of the Universe. Is 13 billion years really a sufficiently well-calculated guess to merit the title of theory rather than just a hypothesis? Is the age of some stars a great deal less - or a lot greater - than we assume?

Is the age of the fabric of space (or spacetime) exactly the same everywhere?

**Tags:** universe
> **Comments:**
> **username_1**: Related: [Age of the universe and time dilation](https://astronomy.stackexchange.com/q/6525/16685). In cosmology, it's convenient to use the comoving frame of the CMB, I have some info on that here: https://physics.stackexchange.com/a/411082/123208 Also see https://en.wikipedia.org/wiki/Distance_measure & https://en.wikipedia.org/wiki/Comoving_and_proper_distances  
> **username_2**: This question is hard to follow, and reads more like a rant, IMHO. There's also multiple questions in it. Your very last sentence which would be an interesting question of its own.  
> **username_3**: You seem to think a lot of assumptions are being made about e.g. the ages of stars.  They're not assumptions, they're based on a combination of observation and theoretical modelling.  There is overlap and cross-checking of models and predictions to make sure they're consistent.  

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## 1 answers

### Answer by username_4 on 2023-05-15. Score: 7

Answering the title question: you can see the measurement by [Planck](https://en.wikipedia.org/wiki/Planck_(spacecraft)#2018_final_data_release), which is the definitive modern measurement of the age of the universe.

[![enter image description here](https://i.sstatic.net/OaYFh.png)](https://i.sstatic.net/OaYFh.png)

So, 13.8 billion years, plus/minus 20 million years.

If this does not answer your question (the text of your question is rather confusing, going into many unrelated topics), then you'd have to be clearer on what exactly it is that you want to know.


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