New Estimates for Universe's Age

Makarand writes "In a study published recently in the journal Science, a team of researchers say that they are 95% sure the universe is between 11.2 billion and 20 billion years old according to this article on Space.com. The new calculations from cosmologists at Case Western Reserve University and Dartmouth College involved new information about old star clusters in our galaxy and a better understanding of how stars evolve." Which blows my theory that the Universe is predated by Zsa Zsa Gabor, but oh well.

Comments

Is the age of the universe definable?

[Mr2cents]

I am no physics guru, but I've been asking myself this question for some time now. Since time was created with the big bang, and considering the theory of relativity, is it sensible to define the age of the universe? Did time behave as we are used to at the very beginning? If I'm right (feel free to correct me) when using the relativity theory you have to define a clock first and then you can measure time according to that clock. So what clock are they using?

Re:Is the age of the universe definable?

[BabyDave]

The "classic" way (due to Hubble) to guess at the "age of the Universe" was as follows:

1. If we observe galaxies outside the Local Group, we see their light as being red-shifted. This indicates that they're moving away from us with some speed.
2. There is a simple relation (called Hubble's law) between the recession speed v, and the distance r between us and the galaxy. This is v = Hr where H is a constant.
3. Nothing can travel faster than the speed of light. So stick v = c into the above equation, and see what r is. Call this "the radius of the Universe".
4. The "age of the Universe" is the time that a photon would take to travel a distance r

Stick all that together, and you get t = 1/H. The problem being that finding H is fairly difficult - we can't accurately find distances to far-away galaxies. Estimates range from 50 km/s/Megaparsec to 100 km/s/Mpc

So how else could we measure the "age of the Universe"? Well, we could work out the age of the oldest stars we can see, make some guesses at how long they would take to form from hot matter, and take that as our "age". After quickly RTFA-ing, I think this is what they've done, with a revised method to obtain the age of a star.

next year...

[muyuubyou]

...will be 9~26 billion.

So they know they weren't accurate last year, and I have to "believe" them now.
What happened to science? Do the word "proof" mean something anymore?

At least, they should explain more in what are those estimates based instead of going for headlines with fancy numbers.

Accuracy...?

[altgrr]

"The universe is between 11.2 and 20 billion years old" could be interpreted as meaning "The universe is 15.6bn years old +/- 4.4 billion", which is +/-28% accuracy. To be 95% sure at this accuracy level isn't actually all that bad, when you think about the normal distribution, bell curves and the like. However, it does imply that there's some considerable discrepancy between each estimate, as you may well expect for something we don't really know much about.

Contradictions

[Dusabre]

Yes you can have it both ways. Otherwise:

The Bible states that the world is flat. Can you accept its round or are you suggesting that you can either be a Christian or a heathen 'round-worldist'.

Oh and since Adam and Eve are key to religion... then what about those people who weren't descended from them, those people that Cane was worried would smite him after he killed his brother. And those people whose daughter he married and lived with in the land of Nod.

Etc, etc, ad nauseam (see (Bible Contradictions))

The Bible contradicts itself constantly. You have to be able to rationally treat those contradictions. I can call myself a Christian without treating the Bible as literal truth. Can you?