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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.
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?
"It's too bad that stupidity isn't painful." - Anton LaVey
This IS science. The only thing you can "prove" is that the universe exists NOW, and many people would doubt even that (that you can prove it, not that it exists). If you want absolute yes/no statements, try religion.
All you can say in science is "given that assumption X is true, and our model is valid in these conditions, Y +/- Z will happen."
One of the basic rules of proper science is that any measurement without errors or confidence limits is meaningless.
At least, they should explain more in what are those estimates based
I'm sure they do in the actual article. Although I agree with you that the headline sucks.
They're only 95% sure. I'm 100% sure the universe is over 1000 years old. I'm only 5% away from the top scientists!
That raises a good point. When the hell did scientists start spouting off about how sure they were of anything?...
Your dissapproval is based on misunderstanding To be fair, almost certainly the misunderstanding is not yours, but in the space.com article.
"95% sure" doesn't mean that they're really 95% sure that they have absolute revealed truth. What it means is that, given the data and an understanding of the uncertainties in the data, and given the models and the uncertainties in the models, if we reproduced the experiment many times (i.e. we had many universes each of which produced stars that we could make the same measurements on), 95% of the time our data would give an age between 11.2 and 20 billion years old.
That's what a confidence interval means. That's what 95% sure means. Unfortunately, the Space.com article makes it sound the way you've interpreted it. Obviously, yes, it means that this is under the assumption that our theories are correct-- of course, some of the theories in question are pretty well tested and well believed. But you are right that you can't prove anything, you can only disprove them.
If you've ever heard Lawrence Krauss (the physicist quoted in the article) give a popular science lecture (he lectures a lot on the conflict between science and pseudoscience), he does emphasize this point. We do *know* some things from science. Even if it's a theory, we are pretty sure that some theories are right.
But "sure" is not really "we have revealed truth". It is a misunderstanding of the term "confidence" used in scientific papers, which really means "the data are consistent with...", and quantifies how consistent the data are.
-Rob
So, last year, they had an estimate of 13-14 billion. This year, it's 11-20 billion. Yeah to scientific progress!
/. does not allow sup tags) combined with standard cosmological models (omega m = 0.3, lambda = 0.7) implies an age of 13+/-2 Gyr. I tend to believe this one more. The errors quotes are probably 1 sigma errors (ie, 68 precent confidence - double the errors for 95%).
:)
Science is not exactly a reputable astrophysical journal. I would tend to go with the estimate of 13-14 billion years. See this ppaper - the figure of H0=73+/-2(r)+/-7(s) km s-1 Mpc-1 (hmm,
However, I am possibly biased, the author is my supevisor
Hmm... That does seem a bit small.
Really? This figure has been known for at least ~30 years.
1: there must have been a few big stars go bang to make all the elements of the earth.
Yeah, I think one SN in your environment will bring the content of metals in your environment up to about 1/10^5 of the value found near the sun. Stars born in these regions are called population 3 stars, and roughly represent the first stars to be born. All they had at birth was hydrogen (75% by mass) and helium (25%). Then came pop 2 stars, then pop 1 stars (like the sun). ie, there have been roughly 2 generations before us. The first stars to be born were probably very massive, and these died very very quickly (lifetime goes down as a factor of hmmm, maybe mass squared - I can't back this up by data, and my memory is dead after all those ginger martini's, and I want to go home), subsequent generations were probably biased more towards low mass, but this is still very much subject to speculation and simulations (we know virtually nothing about star formation, and the initial mass function (the number of stars formed as a function of their birth mass - more massive stars are increasingly rare), even whether it varies with time)
If the Earth is 4.5billion years old, then the solar system must be say 5 billion years old, how quick do large stars explode? must be say 1 billion - 3 billion years tops
Far shorter. 1 billion years is the lifetime of a very low mass star - only say 2 solar masses (I can't be bothered running my program to find out the proper number). Normal SN happen about 10^6 years after birth, but depending on mass.
There is another very important point to recognize here. The HST Key project results (based upon Cepheid variable stars) is independent of the measurement/modeling of the ages of the oldest stars of Milky Way halo stars and clusters. Sure, both measurements each have significant systematic errors, but their uncertainties come from entirely different things! So the fact that they agree is quite reassuring. It also means that the measurements can be combined, at least to some degree.
With the newest generation of instruments and telescopes observing the Universe from radio waves to gamma rays, there will be new, independent methods of measuring the age and fate of the Universe. Already measurements from Type 1a supernovae are narrowing the uncertainties in some cosmological parameters. Other methods that currently yield very large error bars, but will be pivotal in the next few years are gravitational lensing (a detailed description here) and the Senyaev-Zeldovich effect (some details here).
When and if we get to the point where all methods yield the same result, we'll have our answer. In the meantime, if you just quote the formal results from just a single group, from a single type of argument/measurement, the systematic errors are going to be large, particularly when you're dealing with anything on cosmological scales!
The problem is that it's taught as more true than religion, and the atheism aspect of evolution ("man evolved from apes") isn't seperated from the observable theory ("life evolves to the survival of the fittest.")
.. biology. Evolutionary common descent happens to be part of the state of the art in biology (and has been for some time.) That's why it's taught in schools. There are millions of biologists, botanists, zoologists, etc. around the world. If biological evolution is as flawed as some people claim it is, then you would think that there would be massive scientific outcry against the theory. Instead, what we have is a small but vocal handful of "creation scientists", the majority of which are located in the U.S. and just happen to be (surprise!) Protestant fundamentalists.
If you believe that biological evolution predicts that "man evolved from apes", then it is perhaps unsurprising that you have problems with the theory. Let us cut the creationist hyperbole and consider what it really predicts: that mankind and modern apes have a distant, common ancestor. How is this the "atheism aspect" of evolution? What does this say about the existence or nonexistence of God? Be specific. Accuracy counts.
Come on, now. Be brave and say what you really mean: twin-nested common descent is not the "atheism aspect", it is the "anti-Protestant-fundamentalist aspect" of evolution. That would be an accurate statement. If you believe that the entire universe is only 6,000 years old and that the book of Genesis is the literal truth, then you're obviously going to have problems with biological evolution (and most of the rest of the natural sciences, as well.) However, you should know that you are in the minority; the vast majority of Christians have no problems reconciling their faith with obvious scientific fact.
Science education is about the presentation of the current state of the art of various fields of study. This includes chemistry, physics, and yes
What does this tell you?
Finally, to get this more on-topic, it should be noted that evolution has absolutely nothing to do with the formation or the age of the universe, the formation or the age of the Earth, the validity of the Koran, or the score of yesterday's Giants-49ers game. It is a biological theory that discusses changes in the gene pool of a population over time. That's all it is.
We're going down, in a spiral to the ground
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?