How do we know how old the universe is, again?

[basslover1]

...I may not be a genius astrophysicist here, but I would think it seems clear that I'm talking about scientific theory based on empirical evidence.*

I'm not wondering if Jesus was running around giggling and planting dinosaur bones.

*Or more specifically, theory based on SOME empirical evidence, but seeming to have large holes filled by assumptions. While they may be the 'best' explanations in accordance with Occam's razor, they don't seem to be complete and concretely proven explanations, despite the fact that they are usually discussed as if they were solid facts. And they may very well be solid facts; I'm simply wondering if anyone can fill in the mentioned 'holes' with understandable explanations.

FILL MY HOLES, ATOT.

Well, if you insist. Bend over and take it like a man.


Seriously, no one caught that yet? ATOT, you are slacking.

 

[Jeff7]

See, the thing about background radiation predictions, though, is that they kind of seem like...hm, I don't want to say 'self-fulfilling prophecy,' or even 'confirmation bias'...but something along those lines.

'We think that the universe was like this when it started. And after a long time, you would end up like that.'

Okay, that's all well and good...but if they predicted that, then they would have also have to have correctly predicted the age of the universe...which they did not...they figured it out by correlation of 'this' and 'that'...which seemed to need a time measurement to truly prove. It's a lot more complicated than how I'm putting it, obviously, but I think it portrays the general idea of my complaint (or possibly just 'confusion').

Same thing with redshifting. We know how fast light travels...we know how to judge the movement of an object based on its measured redshift (or blueshift)...but...oh god, trying to put this into words turns my brain into a pretzel, nevermind.

I GOT A PRETZEL IN MY HEAD

Kind of like an equation that is partly a function of itself. Plug in your variables, get an answer. The answer changes one of the variables on the other side. Plug in again.
Solve by iteration and eventually get something close to what you're after.

Astronomy was interesting to me as a kid. You know, awesome pictures of stars, planets, nebulae, asteroids, rockets, and space probes. Good stuff.

As a job...nope. I seem to have hit a limit as far as math goes, somewhere a little bit after calculus. :\
Algebra/2: Easy.
Geometry: Easy
Trig: Easy
Calc: BRICK WALL! Bam! Solid A's in math up until then. Calc got me some of the lowest grades I ever got in high school. (A few C's on tests and quizzes, but still - not what I was accustomed to.)
College: Calc 2: The homework let me maintain my grade at a tolerable B.
Differential equations: My only C in college, at a damn solid 75%. Inception: Calculus.


I think they're doing math in astrophysics that goes a good bit beyond that. I guess that's why you've got Masters degrees and Ph.Ds scattered here and there - they do know what they're doing.

Was that a 'what is he smoking right now' whoa? Cause Nemesis gave me one of those.

Yeah, that happens.

I think the inherent problem is that whenever I learn about something, I want to understand EVERYTHING. 'Holistic' learning, if you will.

When it's just 'I want to figure out how this device works,' I can spend a little while tinkering until I fully grasp what's going on.

...it's...not-so-easy with astronomy. Heh. Even the 'basics' simply lead to more questions that, as a layman, you're right (both of you), are hard to discern the answers to, even if they're fed directly to you.

I know the feeling.
If I work on a design for something, I try to keep as many of the design requirements in mind as I can. Due to memory limitations, I can't do it. (It has to fit in the shipping box, has to be easy to paint, easy to assemble, has to be able to use X, Y, or Z fasteners, has to fit into the chopsaw, needs to be easily grounded, Marketing wants it to not look boring, the front needs to be easily replaced, and so on.) And satisfying one requirement invariably will screw with another one.

The other approach is iterations or evolutionary attrition: Just design a little bit at a time, build it. If it doesn't work right, try again. And again. And again. Then accidentally revert back to a problem that was on the original. Then try again.
I find that method to be rather inefficient. I prefer to get it right the first time. I'd really love to have a short-term memory upgrade though, among other things. Maybe reformat my brain for more efficient information storage and processing, and use some kind of parity data for storage, and implement lossless compression capability. Godammit, why isn't it the future yet?? :awe:

 

[phucheneh]

You do sound a lot like me. I breezed through math up until calculus. The way I generally saw it was that I never had to to 'try' to be good at the earlier math- I could simply find solutions. But when it got to the point where I HAD to use memorized rules and formulas to solve problems (...I'm not fuckin' Rainman over here), I was boned.

I'm assuming you're in engineering of some sort?

Ever taken an MBTI or similar test? Unsurprisingly to me, I'm INTP, or according to Keirsey's slightly refined model, the 'Architect.'

Also unsurprisingly, when I became interested in personality typing and psychology in general, I read as much about it as I possibly could, trying to absorb what I liked, and shrugging off what I thought was irrational. Now THAT'S self-fulfilling prophecy.

 

[Jeff7]

Yup, engineering. B.S. in Mechanical Engineering Technology, though I also have some skill in electronic design, and a bit of programming.

MBTI test....not recently. On the introspective side, that much is certain.

An online test, for what it's worth, says: ISTJ.
And it looks like the second-best match is INFP

 

[amdhunter]

According to Conservapedia:

Bishop James Ussher calculated the universe was created on October 23, 4004 BC.

 

[Gintaras]

Humans are funny creatures - spieces...They created a measurment - they call TIME...and humans want to measure EVERYTHING by they own created measurment...Kinda stupid...

If you're in NYC, try to call to Tokyo...if at the other end someone answers your call right away - without "time zone" difference, it means, we all live AT THE VERY SAME MOMENT(or "time")

Why wonder about Universe? Would you wonder, why mosquitos live 3 "human days"?
Maybe our "50 or 100 years" of our life is like a flash in someone else view - if there some aliens exist. Maybe they view us same way we look at mosquitos...

TIME - is something we all tend agree about...Without wondering...

Friday night and this is what I'm thinking about...

I've been reading/watching more about astronomy, cosmology and whatnot lately. This was spurred by the realization that, despite the History Channel's best efforts at convincing me otherwise, this stuff is not boring as shit.

Seriously...the History stuff...yeah, I know, that Raiden-looking Asian guy is really smart. Yeah, Morgan Freeman is good at narrating. But dudes...your shit is boring.

Anyhow, I've known about 'red shift,' the Hubble constant, and the stuff that's used to date astronomical events, the distance of stars, and whatnot. Doesn't seem like there's much room for argument in this area.

But I can't grasp how we can attempt to date the universe, or even provide evidence of the Big Bang. I mean, aren't there stars that can't be seen from Earth? If GRB 090423 is almost as old as the universe, purely figuring from how long its light takes to reach us...why do we not assume that there are things that are much further away? Even if we know the direction in which things are expanding (do we?), how can we have any idea of where the 'edge of the universe' is?

Not to mention...we don't know how fast the expansion of the universe is accelerating or when it started accelerating, no? There's also no known 'center' to the universe (or rather, prevailing theory is that it does not exist), despite the fact presumption that the universe began from a singular point...

Basically, there are a bunch of really smart people thinking about this kinda stuff, and most of the concepts boggle my mind...but it sure seems like we base an awful lot of things off of what are, at best, assumptions.

Also, general relativity, you are a bitch to understand. Perhaps that's my problem.

I will continue reading while someone from the ATOT Geniuses Club tries to figure out a way to explain the 'age of the universe' idea in fourth-grader terms.

I feel like even Wikipedia is being condescending.

 

[nerp]

And a t-shirt shop w/ expresso bar.

Espresso. Expresso is a version of the Dodge Neon.

 

[phucheneh]

Here's a good illustration of why this type of research is hard for me to understand.

http://en.wikipedia.org/wiki/File:Hubble_Ultra_Deep_Field_diagram.jpg

I get the concept (I think). The universe is 13.7 billion years old. We've looked out and found things close to that age; which is to say, we've looked over 13 billion years into the past by observing the light currently reaching us from things 13+ billion lightyears away. That's the easy part to understand (again, accepting the age thing on 'scientific faith').

But that image implies we can look further out, and will see nothing except the earliest remnants of the Big Bang. I'm starting to get this...that area is actually, in fact, ALSO full of galaxies; but because of the distance, human life is never going to be able to observe them, as they formed less than 13 billion years ago yet are more than 13 billion lightyears away.

To them thar aliens in those unobservable galaxies, we also appear only as the earliest remants of the Big Bang; even if their optics are a thousand times stronger than ours. And this is true of anyone, anywhere in the universe; you can't see further than 13.7 billion lightyears away in any direction; but within the 12-13 billion lightyear range (or closer), galaxies are evenly distributed in all directions.

This still kind of uses some circular logic, though, as far as estimating the actual distance in our expanding universe. But I'm just gonna trust some dude has it figured out. I think part of my problem is that while I inherently trust someone like Einstein, who came up with aruably the most brilliant shit ever devised (and still had the smarts to think he was probably wrong)...large discoveries and advances in theory made in more recent years; often with my own lifetime...are just inherently harder to accept without evidence that I can personally understand on a fundamental level.

I think too much. It's not as fun as it may seem.

 

[phucheneh]

Oh, also...the whole 'infinitiveness' thing (shuttup, that could be a word)...still can't grasp that. I understand the context of 'expanding' better, but the idea of the Big Bang starting at a singular point and expelling energy in every direction...how can there not be an end?

There is a limited amount of energy in the universe, occupying spacetime that the bang itself created. Although all the stuff about the universe yielding similar observations from ANY point in it REQUIRES infinity, it doesn't prove it...it's just conjecture based one what seems illogical.

edit: did the Big Bang move faster than the speed of light, btw? I know that's 'not possible,' but it seems like in the thought of creation of everything from nothing, we throw 'possible' out the window.

 

[PlasmaBomb]

Personally I'd just ask oldsmoboat.

 

[silverpig]

Oh, also...the whole 'infinitiveness' thing (shuttup, that could be a word)...still can't grasp that. I understand the context of 'expanding' better, but the idea of the Big Bang starting at a singular point and expelling energy in every direction...how can there not be an end?

There is a limited amount of energy in the universe, occupying spacetime that the bang itself created. Although all the stuff about the universe yielding similar observations from ANY point in it REQUIRES infinity, it doesn't prove it...it's just conjecture based one what seems illogical.

edit: did the Big Bang move faster than the speed of light, btw? I know that's 'not possible,' but it seems like in the thought of creation of everything from nothing, we throw 'possible' out the window.

A few points for you to think about that may help answer your questions:

1. The universe is infinite. At the time of the big bang it was infinite too. It's just that the distance between all points in space was zero.

2. When you look 13+ billion lightyears away, you are also looking back 13+ billion years in time. At that time, the universe was much smaller. There is stuff farther, but not much.

3. Just after the big bang, a scalar inflating potential decayed. This is fancy-talk for saying that a lot of space was created in a short amount of time. So much space was created in such a small amount of time that the space between objects grew faster than light could traverse the new space. So while you and I may remain motionless in our own local environments, it would appear to both of us that we moved away from each other faster than light.

 

[Silver Prime]

But theres also the Multi an Omni Verse.

It would be better to start comparing Marvels universe then to compare the jesus christ God creator who made everything from nothing, in such atleast the Marvel gods have more intresting ways of explaining things, as of Jesus father the only explaination a noob an life long expert can say reasons why is, well...he just is.

 

[Silver Prime]

For instance...

 

[phucheneh]

A few points for you to think about that may help answer your questions:

1. The universe is infinite. At the time of the big bang it was infinite too. It's just that the distance between all points in space was zero.

2. When you look 13+ billion lightyears away, you are also looking back 13+ billion years in time. At that time, the universe was much smaller. There is stuff farther, but not much.

3. Just after the big bang, a scalar inflating potential decayed. This is fancy-talk for saying that a lot of space was created in a short amount of time. So much space was created in such a small amount of time that the space between objects grew faster than light could traverse the new space. So while you and I may remain motionless in our own local environments, it would appear to both of us that we moved away from each other faster than light.

1) I think I understand this conceptually; I'm just still struggling to grasp the implications of it. We hear about billions and billions of galaxies...but never 'infinite' galaxies. This plus the concept that the universe will 'end,' with all matter eventually becoming radiation, and that radiation decaying...it just seems to fly in the face of 'infinite.' It seems more like the concept is that since the universe contains all spacetime, it must therefore be infinite; but that seems like a paradox. Both space and time as individual concepts seem to be defined at 'finite.' Time will keep going...but nothing will be there; without physical change, there is no concept of time.

2) I talked about this in the post before the one you quoted:

I get the concept (I think). The universe is 13.7 billion years old. We've looked out and found things close to that age; which is to say, we've looked over 13 billion years into the past by observing the light currently reaching us from things 13+ billion lightyears away. That's the easy part to understand (again, accepting the age thing on 'scientific faith').

But that image implies we can look further out, and will see nothing except the earliest remnants of the Big Bang. I'm starting to get this...[but] that area is actually, in fact, ALSO full of galaxies; but because of the distance, human life is never going to be able to observe them, as they formed less than 13 billion years ago yet are more than 13 billion lightyears away.

To them thar aliens in those unobservable galaxies, we also appear only as the earliest remants of the Big Bang; even if their optics are a thousand times stronger than ours. And this [supposedly, if I'm understanding correctly] is true of anyone, anywhere in the universe; you can't see further than 13.7 billion lightyears away in any direction; but within the 12-13 billion lightyear range (or closer), galaxies are evenly distributed in all directions.

Emphasis and a couple [bracketed] clarifications added. Does this thinking have some fundamental flaw that I'm missing? This was kind of an epiphany of understanding for me.

3) Duly noted.

 

[Silver Prime]

We havent even habited other planets or even documented a solid connectional conversation with Extra terristrials yet, other than hypothticals.

So until we travel atleast the size of a few solar systems let alone galaxys.. for now it will have to remain as infinite, but comparing the amount of stars there is to the amount of sand there is on earth is still a duzzy...for a hand full of sand is like a few million XD XD XD

 

[phucheneh]

We havent even habited other planets or even documented a solid connectional conversation with Extra terristrials yet, other than hypothticals.

So until we travel atleast the size of a few solar systems let alone galaxys.. for now it will have to remain as infinite, but comparing the amount of stars there is to the amount of sand there is on earth is still a duzzy...for a hand full of sand is like a few million XD XD XD

The distances I'm talking about with regards to cosmology are something that neither we nor any other beings will ever traverse even a tiny fraction of. Even if we could travel anywhere within our solar system (or hell, our galaxy), our perspective in the grand scheme of things would be practically unchanged.

So this can all only ever, to some extent, be speculative. I'm simply doing a combination of questioning and gaining clarification of our current scientifically-based speculations.

Some may find this utterly uninteresting. I find it fascinating, and want to able to wrap my head around some of these concepts. With regard to the concept of infinity, I don't know if it will ever be anything other than opinion and semantics. You can always attempt to learn; the worst that can come of it is zero net gain in knowledge. But in most cases, at least you'll learn something. But without a broad understanding of a topic, these bits of knowledge are easily corrupted or misunderstood.

Hence the seeking of a 'broad understanding.'

 

[Silver Prime]

The distances I'm talking about with regards to cosmology are something that neither we nor any other beings will ever traverse even a tiny fraction of. Even if we could travel anywhere within our solar system (or hell, our galaxy), our perspective in the grand scheme of things would be practically unchanged.

So this can all only ever, to some extent, be speculative. I'm simply doing a combination of questioning and gaining clarification of our current scientifically-based speculations.

Some may find this utterly uninteresting. I find it fascinating, and want to able to wrap my head around some of these concepts. With regard to the concept of infinity, I don't know if it will ever be anything other than opinion and semantics. You can always attempt to learn; the worst that can come of it is zero net gain in knowledge. But in most cases, at least you'll learn something. But without a broad understanding of a topic, these bits of knowledge are easily corrupted or misunderstood.

Hence the seeking of a 'broad understanding.'

Well all in all I guess it dosent really mater we arent in some type of major break threw era where we can have distance and time warping machinery, besides that its theorically possible of course...whos to really patent the concept? Its a re-acurring event that happens from time to time to have break threws in future an past, if its not documented or passed on, it means nothing had ever happened because it is no longer in exsistance but documentations of astronomy and cosmology are cool to review...

My fravorite right now is the James webb telescope...

The James Webb Space Telescope (sometimes called JWST) is a large, infrared-optimized space telescope. The project is working to a 2018 launch date. Webb will find the first galaxies that formed in the early Universe, connecting the Big Bang to our own Milky Way Galaxy. Webb will peer through dusty clouds to see stars forming planetary systems, connecting the Milky Way to our own Solar System. Webb's instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range.

Webb will have a large mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade won't fit onto a rocket fully open, so both will fold up and open once Webbis in outer space. Webb will reside in an orbit about 1.5 million km (1 million miles) from the Earth.

The James Webb Space Telescope was named after the NASA Administrator who crafted the Apollo program, and who was a staunch supporter of space science.

http://www.space.com/17569-super-hu...scope-will-see-invisible-phenomena-video.html

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It would seem we are in the next steps of finding other planets that possibly have life like us, with the right combination of the Goldy-locks theory I think we'll find life out there in the next 10-20 years with the help of James webb mixed in with the Keplar and Hubble. Getting there would be the hardest problem as well, and communication is just as hard because disifering an understanding a dialect of alien for of communication would be astronomically harder than understanding something as simple as life of things on earth (which we havent even mastered that yet) but technology is evolving so fast in this era so patening its propertys are growing more solid.

But mixing solar energy storage-ing would be the next step in traveling the solar system in our or the next era, if they can graph a strong enough solar panel on a space shuttle ( like the ones they went to the moon on) that allows the shuttle to consume solar energy instead of gas, then we can travel atleast the solar system for now, because Via vegatational growing has made a break threw in a certain light fixture that grows in door food, the only trouble would then be water for our main source of life support on long journeys from planet to planet. But understanding everything there is to know about the Universe will be as you said not much of a matter in terms comparing someone who thought of the entire universe concept to a furtureistic actual travel to another galaxy capability in terms of our human limits it would still mean nothing in the end when trying to explain propertys of the universal meaning of limitless via=Infinite.