The Age of the Universe

[Doveaman]

Why do scientists maintain that the universe is only 13.8 billion years old even though objects can be observed to be 46 billion light years away?

You will notice that I did not ask why objects can be observed to be 46 billion light years away.

I am asking why scientists maintain that the universe is only 13.8 billion years old.

 

[Goonie]

Why do scientists maintain that the universe is only 13.8 billion years old even though objects can be observed to be 46 billion light years away?

You will notice that I did not ask why objects can be observed to be 46 billion light years away.

I am asking why scientists maintain that the universe is only 13.8 billion years old.

I recommend you read this.
http://www.quora.com/How-can-it-be-...rs-across-and-yet-only-13-8-billion-years-old

 

[Doveaman]

I recommend you read this.
http://www.quora.com/How-can-it-be-...rs-across-and-yet-only-13-8-billion-years-old

It's too complicated.

Can you summarize please in your own words?

 

[Goonie]

i unfortunately am not a physicist, but Here goes, the furthest we can observe is 13.8 billion light years, but remember the universe has continued expanding in that period, and the number you refer to is the theoretical radius of the universe.

 

[Michael]

It's too complicated.

Can you summarize please in your own words?

Mind you that I don't believe the universe is only 13.7 billion years old, but the 'claim' is that "space" does magical expansion tricks somewhere very inconvenient for humans to reach, and in spite of the fact that space expansion never occur on Earth, thus allowing mass/energy to expand faster than light speed. It's pure bunk of course, but that's the claim.

 

[Goonie]

Mind you that I don't believe the universe is only 13.7 billion years old, but the 'claim' is that "space" does magical expansion tricks somewhere very inconvenient for humans to reach, and in spite of the fact that space expansion never occur on Earth, thus allowing mass/energy to expand faster than light speed. It's pure bunk of course, but that's the claim.

Ah, the argument from incredulity, and if I have never seen it, it never happened.

 

[Michael]

More like an argument from pure logic. There are "simpler" ways to explain photon redshift which do *not* require *multiple* "acts of faith". The space expansion claim simply isn't the 'simplest' explanation of photon redshift.

 

[Goonie]

I get the feeling I am going to need to go and get a degree in astrophysics to answer this. all I can say is that the majority of physicists are in agreement on this figure, which is nothing more than an argument from authority.

 

[Michael]

I get the feeling I am going to need to go and get a degree in astrophysics to answer this. all I can say is that the majority of physicists are in agreement on this figure, which is nothing more than an argument from authority.

True. As you point out however, it's an argument from authority, not an observed fact. Only "photon redshift" is actually observed.

 

[[serious]]

Why do scientists maintain that the universe is only 13.8 billion years old even though objects can be observed to be 46 billion light years away?

You will notice that I did not ask why objects can be observed to be 46 billion light years away.

I am asking why scientists maintain that the universe is only 13.8 billion years old.

the the 46 billion is a calculated distance, not an observed distance.

We get that 46 billion by looking at the distance of the object, then adding expansion as calculated from redshift.

It's easier to understand by way of analogy. Let's say you have a friend going on a road trip. And lets say this friend is a luddite who doesn't have a cell phone. He instead gives you a copy of his planned route and promises to send a post card from every major city.

Day 0: Your friend leaves from Boston.
Day 2: post card from Syracuse dated day 1
Day 4: post card from Cleveland dated day 2

At this point, you figure he must be in Des Moines, and expect to get a postcard from chicago in 2 days.

Same thing here. Since the last time we observed the most distant objects, 13.6 billion years ago, we calculate the expansion of the universe has taken them out to 46 billion light years.

 

[Goonie]

the the 46 billion is a calculated distance, not an observed distance.

We get that 46 billion by looking at the distance of the object, then adding expansion as calculated from redshift.

It's easier to understand by way of analogy. Let's say you have a friend going on a road trip. And lets say this friend is a luddite who doesn't have a cell phone. He instead gives you a copy of his planned route and promises to send a post card from every major city.

Day 0: Your friend leaves from Boston.
Day 2: post card from Syracuse dated day 1
Day 4: post card from Cleveland dated day 2

At this point, you figure he must be in Des Moines, and expect to get a postcard from chicago in 2 days.

Same thing here. Since the last time we observed the most distant objects, 13.6 billion years ago, we calculate the expansion of the universe has taken them out to 46 billion light years.

Thank you.

 

[pshun2404]

i unfortunately am not a physicist, but Here goes, the furthest we can observe is 13.8 billion light years, but remember the universe has continued expanding in that period, and the number you refer to is the theoretical radius of the universe.

The problem with this perspective (and every perspective has its issues) is that it is based on an assumption that taking the Milky Way galaxy as our point of reference (which we almost cannot avoid) it measures all things in relation to this focal point....it is kind of like (similar to but more sophisticated) the old idea of we being the center of the Universe. Red shifting (one of the measures of how fast the Universe is expanding) is somewhat deceptive because the measure does not usually include the actual speed (only relative) at which we are moving AWAY FROM the object...

Now though the YECs would conjecture that IF there is a Creator that such a being COULD HAVE created the Universe with the light (appearing to have traveled) already in place (which IF there is a God is entirely a logical possibility), there is another perspective you each should read given us by an MIT physicist and mathematician Gerald Schroeder called The Age of the Universe at

http://www.geraldschroeder.com/AgeUniverse.aspx

Schroeder also being an Orthodox Jew found inspiration to explore the role of What chronological time is as a function of space from somethings postulated by the Philosopher Maimonides...

Just also good reading on this interesting subject matter....

Paul

 

[Doveaman]

the 46 billion is a calculated distance, not an observed distance.

Isn't the 13.8 billion a calculated distance as well?

Doesn't all measurements of distance require calculation?

We get that 46 billion by looking at the distance of the object then adding expansion as calculated from redshift.

And how exactly do you calculate the distance of the object before adding the expansion calculated from redshift?

 

[[serious]]

Isn't the 13.8 billion a calculated distance as well?

No. 13.6 billion is a calculated AGE. I don't know of any special relevance of 13.6 as a distance.

Doesn't all measurements of distance require calculation?

Yes. Sometime other values are calculated from that measurement. For example, a radar gun measures a change in emitted frequency due to the doppler effect. From that, it calculates speed. You would have a hard time challenging that calculation and the resultant conclusions in court by the way.

And how exactly do you calculate the distance of the object before adding the expansion calculated from redshift?

Lots of ways. You would have to be more specific.

A quick partial list of methods for calculating astronomical distances:
1. Parallax
2. Spectroscopic analysis
3. Cephied Variable stars
4. supernova standard candles

 

[Doveaman]

No. 13.6 billion is a calculated AGE. I don't know of any special relevance of 13.6 as a distance.

So how exactly did you arrive at 13.8 billion years of age for the universe?

Lots of ways. You would have to be more specific.

What exactly do you measure to determine that objects in space are 13.8 billions light years away?

And isn't the age of the universe determined by the distance of those objects?

 

[joshua 1 9]

So how exactly did you arrive at 13.8 billion years of age for the universe?

They got that by using the Hubble.

 

[[serious]]

So how exactly did you arrive at 13.8 billion years of age for the universe?

Calculations based on the hubble constant were the first indication. There have been minor revisions since, but those really just add accuracy, not fundamentally alter the calculation.

What exactly do you measure to determine that objects in space are 13.8 billions light years away?

Cite such an object or event and we can go from there.

And isn't the age of the universe determined by the distance of those objects?

Nope, it's based off the hubble constant as I mentioned earlier. This was confirmed by checking the frequency of the CMB which was predicted to be what it was based on that calculation of the age of the universe.

 

[morse86]

How is billions of billions of billions of miles of distance calculated?

What is the reference point? Using trignometry, the angle would be so small, any results would be inaccurate.

 

[dgiharris]

Why do scientists maintain that the universe is only 13.8 billion years old even though objects can be observed to be 46 billion light years away?

You will notice that I did not ask why objects can be observed to be 46 billion light years away.

I am asking why scientists maintain that the universe is only 13.8 billion years old.

I would like to take a generic stab at answering related questions to this question.

In 276 BC Eratosthenes calculated the circumference of the Earth to within 1.6%. I know that may not seem impressive to modern day man, but take a step back and really look at what he accomplished. Did he do this by circling the world, by using a satellite, by using extensive maps... No. He did it with math.

In 1786 Edmond Haley predicted the elliptical path of a comet he noticed appeared in two instances of recorded history and predicted it's coming arrival and was right. Again, he did this before satellites and computers, etc.

My point is to show how phenomenal feats of mathematics and science have long been accomplished by man before the technology we take for granted today came into play. The way we have always done it is simple.

You figure out basic mathematical and scientific truths that you have verified via experimentation to the point where you are virtually 100% confident in their validity and then you simply apply those same truths to something else, something bigger or something small or something different... Doesn't really matter because the truth will usually apply.

In the case of figuring out the age and size of the universe, we apply the knowledge we have gained concerning energy, force, electromagnetism, gravity, time, and space and mathematics and we apply that to the things we can observe such as background radiation and related measurements from deep space.

As our understanding of the above subjects improve, we will become more accurate and precise in our predictions and extrapolations.

I think that laymen do not understand or appreciate just how complex upper level science and mathematics has become over the past couple of hundred years and especially within the last 50 years. With the advent of computers and explosion of Moore's law, every scientist and researcher today is essentially equivalent to a team of one thousand 19th century scientists... Today, a scientist can do a complex calculation in seconds in what a century ago would have taken months or even years to do. He can then amend, augment, change, refine, or discount his calculations and start anew...

So in general, the way we figure out the seemingly impossible is just by applying our hard earned knowledge on a grander scale. When it comes to things like the size or age of the universe, we aren't trying to solve that question using protractors and trigonometry. We've moved well passed that and are applying Relativity, Gravitation, Conservation of Energy, and Electromagnetism in a complex equation that involves pretty much every force within the entire umbrella of known physics as well as theories of unproven (unverified) forces and sources of energy and matter.

If I were to hazard a guess, I'd guess we're probably on the right track but a few equations may have a few holes in them that will be shored up as physics progresses. but the methodology and science is sound...

 

[[serious]]

How is billions of billions of billions of miles of distance calculated?

What is the reference point? Using trignometry, the angle would be so small, any results would be inaccurate.

We already covered that:

A quick partial list of methods for calculating astronomical distances:
1. Parallax
2. Spectroscopic analysis
3. Cephied Variable stars
4. supernova standard candles