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

[SsupernovaE]

This may help a bit

www.filedropper.com/cosmo46cosmochronology

 

[cave_dweller]

The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us

 

[randomrogue]

The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us

 

[cave_dweller]

Yeah its an old saying

http://www.amazon.com/exec/obidos/ASIN/0740748475/guillaumedarg-20

 

[Greenman]

If you believe in religion and a god, you can claim the earth is 5000, 6000 or 50 billion. It doesn't matter. That is because if you believe in a god who created a universe, you must also beleive that its within his relm to created dated material. Perhaps he wanted to give a 6000 year old planet a tree with a decay rate showing 10 billion years old? You can apply any theory you want when you deal with religion.

It occurred to me that the scientific explanations aren't all that much different than the religious ones. They both require a certain amount of "faith".

 

[GoPackGo]

Age is irrelevant. It is which iteration are we in?

 

[IronWing]

It occurred to me that the scientific explanations aren't all that much different than the religious ones. They both require a certain amount of "faith".

Only to the extent that one scientist might not have access to the same methods (super-toys) or objects of study (moon rocks, for example) that another scientist used in gathering evidence to formulate or substantiate ideas.

 

[JulesMaximus]

You were fapping to the National Geographic again instead of paying attention...weren't you?

:biggrin: 1000, 6000, what's the difference? Morons made that up so why should I be bothered to get their fairy tales right?

 

[Markbnj]

I think there's a superdupermassive black hole somewhere that marks the starting point of the Big Bang.

Black holes are formed when stars burn out and their mass collapses in on itself, correct? If so, I would expect to find an area of relatively low density at the center point of the universe's expansion (assuming such a place exists), not a black hole.

 

[IronWing]

Black holes are formed when stars burn out and their mass collapses in on itself, correct? If so, I would expect to find an area of relatively low density at the center point of the universe's expansion (assuming such a place exists), not a black hole.

And a t-shirt shop w/ expresso bar.

 

[BoomerD]

Black holes are formed when stars burn out and their mass collapses in on itself, correct? If so, I would expect to find an area of relatively low density at the center point of the universe's expansion (assuming such a place exists), not a black hole.

Wait...P&N is at the center point of the universe's expansion?

 

[IronWing]

Wait...P&N is at the center point of the universe's expansion?

It was a mighty race for the exits, a flood as it were.

 

[Jeff7]

It occurred to me that the scientific explanations aren't all that much different than the religious ones. They both require a certain amount of "faith".

Depends on what you want to call "faith." If you want to go down farther, you have to have faith that your eyes aren't just "making shit up" and sending false data to your brain. They could be intelligent life forms that are doing this intentionally. You've got corroborating evidence though - the position of the desk you may see in front of you can also be verified by touching it, unless your hands are also in on the conspiracy.
You can also get a friend to come over and verify that your desk does in fact exist, unless his senses are also in on the conspiracy.

Blind faith is believing something without any evidence to support it - it's believing something without any good reason.
But at some point, you've really got to go with it, and say that there's a pretty good chance that you senses are giving you a sufficiently accurate representation of your environment, though perhaps not a complete one. That's where our technology and tools come into play, to help us to observe what is not easily observed otherwise. (Alpha particle radiation, magnetic fields, electric fields, radio waves, etc.)

Scientific theory is dependent on someone saying, "Hey, this thing is doing something interesting, and this reason I came up with does a good job of explaining why. Can you also verify that it works like this for you as well?" If you can also make predictions based on your idea of how something works, and someone else does the same experiment or test and gets the same results, that's supporting evidence. My understanding of the COBE (cosmic background explorer) experiment, for example, was that it was predicted that if the Universe was once extremely hot, dense, and small, the EM background would look a certain way. They sent up COBE to have a look around, and it saw very nearly exactly what was predicted. So, either the Universe somehow made itself very uniformly hot while also being very large, using some unknown mechanism of energy transfer, or it was a very small object with a nearly uniform temperature.
Or it's something else entirely, something that our wee primate brains are functionally incapable of conceiving, like a salamander trying to design a supercomputer.

 

[phucheneh]

There are good answers to all of your questions, and I can give you most, but a full explanation would take too long. I'll try to make it simple so you can get the gist of it, and then you can google for further info.

There are several ways to get the age of the universe and they all agree with each other. One way is to use the cooling curves of white dwarf stars. If you ask what types of stars should be made in what proportions in the very early universe, part of your answer includes stars that are a special type of white dwarf right now. They will have lived their lives, blown off their outer shells, and have sat as super hot white balls of mostly carbon, that produce no new energy via fusion and just cool via radiation. You can identify them from their particular chemical makeup. You can also compute their cooling curves and measure their temperature. You can thus tell when they were made. If you want to read more about it, the prof who did this work is Harvey Richer. If you google his name and white dwarf cooling curves, you'll get some more material.

The main way to calculate the universe's age came from WMAP. In the early universe, everything was so hot and dense that there was no "space" as we know it today. There was "stuff" everywhere, and it was very hot, like the surface of the sun. The universe was a plasma, and plasmas aren't transparent. Everything was roughly at the same temperature and density (special caveat for later here), and thus as the universe expanded and cooled, the atoms everywhere recombined from a plasma into a hot gas at pretty much the same time. Gas is transparent to light, and so this wave of radiation started to permeate the universe. As the universe expanded, it stretched the waves of radiation out, cooling it. We know the temperature of the plasma back at the time of recombination from experiments on earth. We know the temperature of the radiation now from WMAP measurements. We can thus compute the distance/time it travelled to get the age of the universe.

We do know how fast the universe is expanding, and can measure it using redshifts. We can also tell how fast the expansion is accelerating from supernovae.

Here is a great FAQ site written by one of my old profs.

Thanks. This is quite helpful. My problem is trying to link all the abstract principles together in a way that makes sense. You did a bit of that, and it does indeed allow me to kind of know where to look and what to read to gain further understanding. I will check out that site when I get a chance.

Wait...P&N is at the center point of the universe's expansion?

He said 'low density.' It's...pretty damned dense in there.

 

[phucheneh]

My understanding of the COBE (cosmic background explorer) experiment, for example, was that it was predicted that if the Universe was once extremely hot, dense, and small, the EM background would look a certain way. They sent up COBE to have a look around, and it saw very nearly exactly what was predicted. So, either the Universe somehow made itself very uniformly hot while also being very large, using some unknown mechanism of energy transfer, or it was a very small object with a nearly uniform temperature.
Or it's something else entirely, something that our wee primate brains are functionally incapable of conceiving, like a salamander trying to design a supercomputer.

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

 

[BoomerD]

Thanks. This is quite helpful. My problem is trying to link all the abstract principles together in a way that makes sense. You did a bit of that, and it does indeed allow me to kind of know where to look and what to read to gain further understanding. I will check out that site when I get a chance.





He said 'low density.' It's...pretty damned dense in there.

I dunno...seems pretty vacuous to me.

 

[gorobei]

-stellar spectra gets us the black body gaps telling us star elemental composition.
-early stars will have no heavy metals because they come from supernovas and stellar nursery nebulae.
-really early stars will have only H or He.
-a galaxy composed of mostly really early stars will be close to post cool down part of universe. redshift measurements on the galaxy gets us ballpark idea of where/when to start looking.

-when we look further back all we get is cosmic background radiation. this gets us small, uniform temp, pre explansion universe. thats where the WMAP and other experiments get us our current best estimate. as new techniques and technologies develop we will get better estimates.


if you really want to bend your noodle, look up neil D tyson's youtube video on how we are at exactly the right time and technology to be able to know this stuff. thousands of years from now, you wont be able to see/measure the data in order to derive these theories.

 

[Tweak155]

I thought the simple explanation was that ~14.5 billion light years was about as far as we could observe, thus the age of the universe. I'm no scientist though.

 

[Silver Prime]

To a human constalation it seems logical to question it, just like the same way a ant wonders whats in the other yard.

Ants colonize an when near another empire they go to war, the same way humans do, before it was mostly standard like a black ant vs a red ant catagorie the same way humans usually back up there own race, but now places like the United states which has the most bi-racial its being confusingly adit to wage war, maybe one of main reasons the judical law implimations in the states suck, an suck bad, having more opinions from multi cultures i what is an what isint acceptable makes it a hive full of destortion.

But as for the Universe concept, comic books have taken over our era, which is inticing to the max, possibilitys are endless to the human mind, levels of universal propertys are astoundingly awesome...

Earth level concepts of control...
-Lvl 1 Bacteria
-Lvl 2 Insects
-Lvl 3 Mammalmilia
-Lvl 4 Humans

Religon and Comic book extentensions, which control more than humans from planet creations, to galaxy creations an universe creations...
-Lvl 5 Heralds
-Lvl 6 Gods
-Lvl 7 Sky fathers
-Lvl 8 Entities
-Lvl 9 Celestials
-Lvl 10 The one above all

 

[phucheneh]

-stellar spectra gets us the black body gaps telling us star elemental composition.
-early stars will have no heavy metals because they come from supernovas and stellar nursery nebulae.
-really early stars will have only H or He.
-a galaxy composed of mostly really early stars will be close to post cool down part of universe. redshift measurements on the galaxy gets us ballpark idea of where/when to start looking.

-when we look further back all we get is cosmic background radiation. this gets us small, uniform temp, pre explansion universe. thats where the WMAP and other experiments get us our current best estimate. as new techniques and technologies develop we will get better estimates.


if you really want to bend your noodle, look up neil D tyson's youtube video on how we are at exactly the right time and technology to be able to know this stuff. thousands of years from now, you wont be able to see/measure the data in order to derive these theories.

...starting to make more sense now.

Also, I know while watching the BBC's 'Wonders the Universe/Solar System' series, Brian Cox says something similar about our current time. Only he goes even further by saying the time that life even CAN exist is some infinitesimally small percentage of a percentage point of the lifespan of the universe. Granted, its not quite as impressive if you don't include the enormous amount of time it will take all the leftover dwarf stars to burn out.

I highly recommend the BBC stuff. Though it's not on a terribly high level, it's just nice to watch, and some of the things I didn't quite understand were explained in brilliantly simple ways. Certainly inspires further thinking/research.

Will check out the NDT video (damn long conjoined names).

 

[Nemesis 1]

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.

Well actually there is a good simple measure of time. You may not like it bur if you read it as coprrectly wriiten in the hebrew or greek . Greak the word Aeon is used for a day . Who changed the mmeaning doesn't matter to me . its enough to know it was purposelly changed. an Aeon = 1 Billion years. or an age. If you look at the days of creation as being 1 billion years . Than the story told has realism to it . Day was added to create law. Threw Religion. Those who have power keep it. Problem is there Day thing couldn't stand the test of time . From that time to now.The whole religious lie is unraveling and when all the lies are removed. Genesis is actually pretty good record keeping if you expand a day to aeon =1billion years . We have proof of a world wide flood . No! Whats written was at one time accurate and truthful but power has corrupted the word. Why ? TO bring about the present.WHY? You likely will not like the hebrew god our creator when IT returns much like that comet thats arriving in november. Everyone is going to say that cool. Until we go threw its tail particles. History channel is neat . But it only leads. Look back in history to when pledges wiped the majority people off of earth . Find the years than cross referance those years with astrogolocal events of that period . You be surprised at what you find, Comets are a BAD THING very bad . One this big getting this close is only going to bring plegde. and metors. So much of the truth is right in front of us covered up with complete BS started by the first I have the biggest club in the cave idealism. But really genesis is pretty accurate if you view a day as 1billion years . It also changes ones view on god. I believe in GOD . But he hasn't talked to any man ever. what happened on earth in semaria in the garden of eden . I have know clue what planet those beings were from. I do know they left some trash on this wonderful world.

 

[Farang]

I think the scope of your questions is a bit beyond answering as a forum post. Really you need to read a lot of books and/or take some courses.

If you're really interested in this read up a bit on wikipedia on stuff like Hubble's Law and then hit the library and your local university. The problem you're going to genuinely have though is either you have to read a layman's version of this stuff that doesn't explain much of anything or you have to build up a foundation from the bottom up and learn a lot of math, physics, and astronomy.

True enough. As a layperson, I found Bill Bryson's a Short History of Nearly Everything to be a really good overview that is readable. I'm sure it glosses over plenty of important stuff but if you want a shortcut this is it.

 

[Farang]

To a human constalation it seems logical to question it, just like the same way a ant wonders whats in the other yard.

Ants colonize an when near another empire they go to war, the same way humans do, before it was mostly standard like a black ant vs a red ant catagorie the same way humans usually back up there own race, but now places like the United states which has the most bi-racial its being confusingly adit to wage war, maybe one of main reasons the judical law implimations in the states suck, an suck bad, having more opinions from multi cultures i what is an what isint acceptable makes it a hive full of destortion.

But as for the Universe concept, comic books have taken over our era, which is inticing to the max, possibilitys are endless to the human mind, levels of universal propertys are astoundingly awesome...

Earth level concepts of control...
-Lvl 1 Bacteria
-Lvl 2 Insects
-Lvl 3 Mammalmilia
-Lvl 4 Humans

Religon and Comic book extentensions, which control more than humans from planet creations, to galaxy creations an universe creations...
-Lvl 5 Heralds
-Lvl 6 Gods
-Lvl 7 Sky fathers
-Lvl 8 Entities
-Lvl 9 Celestials
-Lvl 10 The one above all

whoa.

 

[phucheneh]

whoa.

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

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.

 

[Farang]

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

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.

more a 'back away slowly' type whoa