The Universe Is 13.73 Billion Years Old 755
CaptainCarrot writes "Phil Plait, aka The Bad Astronomer has summarized for his readers the new results released by NASA from the Wilkinson Microwave Anisotropy Probe (WMAP), which has been surveying the 3K microwave radiation left over from the Big Bang. Some of the most interesting results: The age of the universe is now known to unprecedented accuracy: 13.73 billion years old, +/- 120 million. Spacetime is flat to within a 2% error margin. And ordinary matter and energy account for only 4.62% of the universe's total. Plait's comment on the age result: 'Some people might say it doesn't look a day over 6000 years. They're wrong.'"
Re:Figurative or literal? (Score:0, Interesting)
Non sense. Who was measuring time and which reference frame was he using?
If he was moving close to the speed of ligth with respect to those protons and neutrons it could take several million years for neutrons and protons to form. And that scenario is very likely since at the beggining there was a big bang, with matter being thrown in opposite directions.
References on underlying postuate? (Score:4, Interesting)
If the universe were open, the brightest microwave background fluctuations (or "spots") would be about half a degree across. If the universe were flat, the spots would be about 1 degree across. While if the universe were closed, the brightest spots would be about 1.5 degrees across.
I've heard these sweeping statements before, can anyone point out a reasonably accessible proof that overcomes basic statistical counterarguments? Basic common sense here - I can infer some interesting characteristics about gravity by splashing paint on my wall and studying the results from across the room, but I don't really have enough data to overcome a host of other contributing factors...
Goldilocks and the three cosmological clocks (Score:5, Interesting)
Low-metal stars in globular clusters are thought to be the universe's oldest and from nuclear-synthesis physics thought to be 15 B.Y. The disagreement among the two clocks was so bad for a while, some astronomers thought the big-bang hypothesis was flawed.
The third and most recent clock - spatial power spectrum of the background microwave radiation- gives a percise age within the error range of the other two ages. Further observations of the other two clocks seem to be converging to this one. Astromenrs are now happy, kissing and making up.
Re:The 6000-year people may be right (Score:3, Interesting)
- Not scientific evidence. It's historical.
- Geologic evidence, including radiological dating and tectonic theory, put the age of the Earth at billions of years. Take a geology class.
- The age of the falls at Niagara may be 6000 years, but that says nothing about the age of the Earth.
- There is good evidence that what we see in the Universe did start in a hot, dense state billions of years ago. Take some astronomy classes.
- Actually, the sun was much cooler billions of years ago, as main sequence stars get hotter as they age.
- There is good evidence that the moon formed in a collision between the Earth and a Mars-sized planet billions of years ago.
I'm not going to go on. The page simply lists any evidence at all for possibly suggesting that the Earth is only thousands of years old, no matter how flimsy. It's all debunked easily by our modern scientific understanding.it's funny he mentions 6K years (Score:5, Interesting)
although we are still getting over the idea of mankind being the center of the biological world. some of us (not on slashdot, i am speaking in a broader sense of all of mankind) still grapple with evolution as contentious
but even still in cosmology, anthropocentrism colors our percetions as mortal biological creatures: we have a beginning, a middle, and an end. and we imprint this in our abrahamic religions. and we imprint this in our cosmological awareness of the universe. but must the universe have a beginning, middle and end?
i am going to sound like a crackpot here to some people, but scientific convention has been overthrown before, and i am sure it will be again: the big bang smells bad to me. i am certain its evidence is being misinterpreted. much as misinterpreting the evidence of seeing the sun rise and set means the sun is going around the earth. you can say i am showing a bias of my own here. and yes, i am: anthropocentric ideas are wrong in describing how the universe actually is, that's my bias. and i hope that bit of intellectual honesty on my part will allow some of you to admit to the anthropocentric stink about the big bang theory
the universe is endless, in time and space. there, i said it. i of course have no proof of this. but i can conjecture that time dilation effects as we backtrack towards the big bang means that there never really is a beginning. or that the big bang, as huge is it, is still a local effect, not the sum total of the universe, that there is still something going on out there beyond the microwave background radiation, perhaps other big bangs. that we see all around us hubble's outward momentum, but it is still a local effect, that somewhere out there, beyond the cosmic backgorund radiation, some being is looking around him and worrying about a cosmic crunch. that his hubble constant is reversed. like waves on the ocean on a massive scale: wave tip here, trough there
to me, the big bang has the stink of abrahamic religious myth all over it. i think the big bang will be found to be merely another vestige of our trek from superstition to real science, like the phlogiston theory [wikipedia.org] or lamarckian evolution [wikipedia.org]. taken very seriously in their times, as silly as they seem now. so i think it will be with the big bang theory someday too, that it's obvious abrahamic influence will be more accutely seen in later generations
i may be pilloried and voted as a troll by the defenders of the status quo here for saying this, but i will still say it: the big bang will be disproven. the universe is endless in time and space
Re:References on underlying postuate? (Score:3, Interesting)
Current thinking is that the universe had structure on all different scales. That is, we had some blobs where there was a little bit more matter than average (overdense regions) and some blobs where there was a little bit less matter than average (underdense regions). The "all different scales" means that these blobs (statistically) were just as likely to be 1 mm across as 1 m across. Note that this "no scale" does not apply to the amount of overdensity or underdensity -- that was pretty much fixed. The prejudice is that these over- and under-dense regions were created by fluctuations in the inflaton field, which made the universe expand really quickly early on. Why? Well, there are some issues that need to be addressed in cosomology (see the motivation section in the wikipedia article on cosmic inflation [wikipedia.org]).
(For the experts, I realise that the Harrison-Zeldovich purely scale invariant spectrum is on the edge of being ruled out by WMAP. If that is the greatest inaccuracy I make in this description then I will be happy!)
So how do these random-sized blobs (due to inflation, or even some other mechanism if you are a skeptic) tell us about gravity? Well, the answer to this is that the CMB is a snapshot of the universe when it finally cooled to the ionization temperature of hydrogen. Before that, the electrons were free because they had too much energy to be bound to hydrogen atoms, and the light scattered off all the charged particles. Only once the plasma had cooled to form neutral ions could the light travel an appreciable distance without scattering. So what we are seeing is the light after it has bounced around in the plasma for some time.
So what? Well, we don't actually *see* a scale invariant spectrum. Like the article says, we see roughly 1 degree patches on the sky. What is happening is that overdense regions collapse, and just like a collapsing gas, as it gets smaller the overdense region heats up and increases in pressure. Eventually the pressure is great enough to stop the collapse and the spot starts expanding again. Starting with a scale invariant spectrum, we actually get a characteristic "size" for spots from the interplay between number of baryons (i.e. protons and neutrons) and gravity. The strength of gravity relates to the curvature.
So it is not that the "initial random splashes of paint" tell us anything about gravity, but rather than gravity (and some ideal gas like thermodynamics) process these over and underdense regions until we get a statistical distribution of sizes. The involvement of gravity in this "processing" is where numbers like flatness come from.
Re:There is no contradiction. (Score:5, Interesting)
Re:References on underlying postuate? (Score:3, Interesting)
I can understand how initial density can place a limit on fluctuation sizes, but these results presume that the signal we're seeing is most likely the residual noise of the original bang. What I'm curious about is how other signal sources can be ruled out?
From the papers at the site it looks like WMAP had sufficient instrument resolution high enough to overcome Nyquist limits on input w/r/t desired measurement, and they feel they have a good model to subtract noise from galactic sources (synchrotron and thermal dust emissions), so we are likely looking at the multipole moment of the intergalactic background. I have no problem there. They also show a compelling fit between the measured signal and that predicted by Lambda CDM, which is interesting, and how they reach conclusions like a better Hubble estimation and the like.
What I'm curious about is what research is being done to come up with alternate explanations for the intergalactic background signal? Ever since COBE I keep seeing this presumption that this signal is Big Bang noise. I'm NOT arguing against the Big Bang here, and I'm not trying to bring back the aether
Big Bang Works Well With Theism (Score:1, Interesting)
I would also say that the Big Bang theory was resisted by atheists who saw its theistic implications.
But the earth is estimated at 4.5 bil years old... (Score:5, Interesting)
Re:Big Mistake (Score:5, Interesting)
Consider a Looney Tunes animated film as a metaphor for the universe. Such a film is 2-dimensional, its "time" (measured in frames) is totally unlike the time in the outside world, the physics is mostly consistent but unlike real-world physics, etc. Bugs Bunny wants to know: what happened before the opening credits, and who drew the animator? (It must have been an even more complicated animator!)
The answer is completely outside his understanding. The animator is vastly more complex than a cartoon character, and he wasn't drawn at all. Nothing happened before the opening credits: the animator's world is outside the film, and the nature of time there is completely different.
Similarly, questions like "what happened before the creation of the universe" and "who created God" are not really meaningful.
Re:Heh. (Score:4, Interesting)
I teach ancient Greek. Everything that author claims is founded solely on internal evidence from four texts using words in unusual contexts.
About the only claims there that are consistent with non-biblical usage are (1) that pisteuo means "to rely on, trust in", which does not support the general argument; and (2) when he cites someone else to assert that "faith" can usefully be thought of as "framed in terms of an ancient client-patron relationship". There is no necessary connection with proof or evidence, and pistis means pretty much exactly what the crazier fundamentalists think it does. (One of the few things they do get right.)
Re:Big Mistake (Score:2, Interesting)
I disagree entirely. It is very useful, both intellectually and psychologically, to ask questions that have no answers. We have to deal with that all our lives. The origin of the universe is only one of a multitude of unanswerable questions we have to reconcile ourselves with during a lifetime. Death, misfortune, what another person is really feeling, who is my dad.. oops.
I actually believe it's the other way around - we ask about the nature of the universe *because* we are wired up already to deal with an unpredictable reality of unanswerable questions. We have to be, because we started off having to ask questions in the first place to survive. They just became more complicated as time went on, but we ask them for the same reasons - to feel like we have a grasp on things.