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Posted

So if I am reading this right they discovers that the universe can be either 9 billion or 19 billion years old so this changes it from the current thoughts of 14.9 billion 

“ When the Hubble Space Telescope was launched, the uncertainly over the universe’s expansion rate was off by a factor of two. This meant that the universe could be as young as 9.7 billion years or as old as 19.5 billion years. The younger value presented a huge problem; it would mean the universe was younger than the oldest known stars

https://hubblesite.org/hubble-30th-anniversary/hubbles-exciting-universe/measuring-the-universes-expansion-rate

Posted (edited)
38 minutes ago, Bmpbmp1975 said:

So if I am reading this right they discovers that the universe can be either 9 billion or 19 billion years old so this changes it from the current thoughts of 14.9 billion 

Bold by me

38 minutes ago, Bmpbmp1975 said:

When the Hubble Space Telescope was launched, the uncertainly over the universe’s expansion rate was off by a factor of two.

The Hubble Space Telescope was launched into low Earth orbit in 1990 and remains in operation. Maybe progress have been made during the 30 years?

I'll try to get some time to read the article and see what else you have misunderstood. edit
I think you misinterpreted most of the article, I suggest you give it another try.

Edited by Ghideon
Quickly read the linked article.
Posted (edited)
13 minutes ago, Ghideon said:

Bold by me

The Hubble Space Telescope was launched into low Earth orbit in 1990 and remains in operation. Maybe progress have been made during the 30 years?

I'll try to get some time to read the article and see what else you have misunderstood. 

So the age is still 13.9 billion then 

 

it started out saying factor of 2 then said 10 then went back down to 2. So I am not sure what that means exactly. Last I thought age of universe was like 13.8 or 13.9

Edited by Bmpbmp1975
Posted (edited)
3 minutes ago, Bmpbmp1975 said:

Ok thank you so that article is wrong then. 

The article is correct*.

 

*) It's a pop-sci article describing a historical situation regarding consensus at the time they launched Hubble. I've not crosschecked against peer review papers and I do not consider that necessary 

Edited by Ghideon
Disclaimer added
Posted
8 minutes ago, Ghideon said:

The article is correct*.

 

*) It's a pop-sci article describing a historical situation regarding consensus at the time they launched Hubble. I've not crosschecked against peer review papers and I do not consider that necessary 

How is it correct if it states 9 or 19b and you stated 13.8 am I missing something 

Posted
15 minutes ago, Bmpbmp1975 said:

How is it correct if it states 9 or 19b and you stated 13.8 am I missing something 

The article is correct. The ages were wrong.

The article is correct in that it correctly states what the "incorrect" (i.e. inaccurate) value was at that time.

Posted (edited)
17 minutes ago, Bmpbmp1975 said:

How is it correct if it states 9 or 19b and you stated 13.8 am I missing something

Yes, you missed to read and understand my first post in this thread.

A: 13.8 is the current number.
B: 9.7 billion years or as old as 19.5 billion years a 30 years old estimate.

The article describes a historical situation regarding consensus at the time they launched Hubble. Due to scientific progress age of the universe estimates have improved. The article can still correctly describe the consensus at the time Hubble was launched. 

Edited by Ghideon
Posted

I'm sure you've had error bars explained to you before, but that seems to be what you're missing.

Simplified:

Say someone guesses your age as 15 plus or minus 2 years.

That means they think your age is from 13 to 17 years old. (15 -2 to 15 + 2).

That does NOT mean they think you are either 13 or 17 years old. The error gives a RANGE not two options.

Later they might be more accurate for some reason and figure you are 15 plus or minus 1 year.

So they are more accurate, with 14 to 16 years old. It's still a range.

 

Your article says "could be as young as 9.7 billion years or as old as 19.5 billion years". That's a RANGE not two options. The current known age is within that range.

Posted
1 hour ago, Bmpbmp1975 said:

Thank you all, so if I understand now 13.8 is the current age  and the numbers given in the article was what the formula was 30 years ago and that formula has been updated to a better formula which gives us a more accurate age.

Posted

In general:

More/better measurements can improve certainty, reducing error bars.

That's not the same as updating a formula.

Posted
18 minutes ago, pzkpfw said:

In general:

More/better measurements can improve certainty, reducing error bars.

That's not the same as updating a formula.

Oh so you saying that since this 30 years ago they improved measurements which gave us the proper age.

the thing I also notice is none of the articles have dates on them so I am assuming this was an older article that I thought way new.

Posted
10 minutes ago, Bmpbmp1975 said:

the thing I also notice is none of the articles have dates on them so I am assuming this was an older article that I thought way new.

Tha article in your opening post refer to data from 2019. That seems pretty recent.

Posted (edited)
8 minutes ago, Ghideon said:

Tha article in your opening post refer to data from 2019. That seems pretty recent.

I see so if I am understanding what has been said. When Hubble came out 30 years ago and was new the calculation and measurements stated between 9 and 19 billions. Over the years after more measurements , calculations and study they narrowed it down to 13.8 billions years old which is what we know now.

i think I got it

thank you all. 

Edited by Bmpbmp1975
Posted
24 minutes ago, Bmpbmp1975 said:

I see so if I am understanding what has been said. When Hubble came out 30 years ago and was new the calculation and measurements stated between 9 and 19 billions. Over the years after more measurements , calculations and study they narrowed it down to 13.8 billions years old which is what we know now.

i think I got it

thank you all. 

Almost.

It's not correct to characterise this as have gone from a range to a single value.

It's still a range, just a smaller range.

Go read the wikipedia page on age of the universe. It's in the first couple of paragraphs.

 

Posted
8 minutes ago, pzkpfw said:

Almost.

It's not correct to characterise this as have gone from a range to a single value.

It's still a range, just a smaller range.

Go read the wikipedia page on age of the universe. It's in the first couple of paragraphs.

 

So 13.799 billion years give or take 20 million years? Right 

Posted (edited)

Yep. The wiki page provides a few of the different estimates as at different times.

And note those are not hard limits; it's about levels of certainty. Probabilities.

 

Edited by pzkpfw
Posted
28 minutes ago, pzkpfw said:

Yep. The wiki page provides a few of the different estimates as at different times.

And note those are not hard limits; it's about levels of certainty. Probabilities.

 

Ok but on average we are looking at 13.8 billion

Posted
11 hours ago, pzkpfw said:

And note those are not hard limits; it's about levels of certainty. Probabilities.

And now that we are nitpicking anyway: error bars are about confidence levels, rather than probabilities.

Posted
15 minutes ago, taeto said:

And now that we are nitpicking anyway: error bars are about confidence levels, rather than probabilities.

It’s both, isn’t it? If you have a normal distribution, you are indicating a probability the true value is within the error bars because your error bar represents some number of standard deviations

Posted
Just now, swansont said:

It’s both, isn’t it? If you have a normal distribution, you are indicating a probability the true value is within the error bars because your error bar represents some number of standard deviations

That has a way of sounding right. The problem is that the true value does not get picked from a random distribution. It is still an entirely reasonable possibility that the true value is very close to 13.820 billion years. And if so, then the probability that the true value lies within the error bars is exactly 0%. 

Posted
2 hours ago, taeto said:

That has a way of sounding right. The problem is that the true value does not get picked from a random distribution. It is still an entirely reasonable possibility that the true value is very close to 13.820 billion years. And if so, then the probability that the true value lies within the error bars is exactly 0%. 

You mean 100%, right?
The number you arrive at is the most likely correct value, based on the information you have. But the problem is that all you can do is make more measurements - there’s no way to peek inside the black box and see what “truth” is.

Posted
14 hours ago, pzkpfw said:

Yep. The wiki page provides a few of the different estimates as at different times.

And note those are not hard limits; it's about levels of certainty. Probabilities.

 

But on average still around the 13.8 billion right?

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