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How Do We Know the Timeline of the Universe?
StartsWithABang writes The history of the Universe happened in a well-known order: inflation ends, matter wins out over antimatter, the electroweak symmetry breaks, antimatter annihilates away, atomic nuclei form, then neutral atoms, stars, galaxies, and eventually us. But scientists and science magazines often publish timelines of the Universe with incredibly precise times describing when these various events occur. Here's how we arrive at those values, along with the rarely-publicized uncertainties.
We pretend we do, but it was actually re-created yesterday after the reboot of God's Second Life server farm.
Think of it as a perfect sphere.
"The history of the Universe happened in a well-known order: inflation ends, matter wins out over antimatter, the electroweak symmetry breaks, antimatter annihilates away, atomic nuclei form, then neutral atoms, stars, galaxies"
This is the comic book version of what happened.
We do not know that it happened in that manner. This is the popular version of what our current guesswork is and no more.
It should not be taken as "canon" or "real" any more than 2001 The Space Odyssey intro with apes inventing the use of bones as tools.
Because "science" --- the one with hypothesis, testing, reproduction of results is different than the speculation one --- which is very often quite wrong. If you want a recent example, there were many theories about the surface of Titan before we landed a probe there. They were quite wrong. So were a great many of the prevaling theories about Mars before we send probes there.
Early Universe ideas? Not fact. Not "well-known". Guesses.
Humans have made bad models from guesswork fit perfectly in the past, there were very orderly models of the geocentric model of the universe that accounted for the movement of Venus and Jupiter, etc quite well. http://en.wikipedia.org/wiki/G...
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
On the back of a giant turtle.
on unreadable clickbait hipstersites.
Heard a radio discussion about which major piece of science would likely crack over the next fifty years. The answer came back as the Big Bang, with one of the participants saying [rather indiscreetly, IMHO] that it was Sir Martin Rees in a pers. comms. who suggested that it was full of holes and the area was ripe for a paradigm shift.
I once saw Fred Hoyle lecture on his Steady State Theory. He was awaiting the red shift results from a twin maser in some distant galaxy somewhere and we were assured that it would disprove the BBT. He was the single most beguiling speaker of my life. Came out fully believing, for the rest of the evening at least.
So, ask him your own question.
Achille Talon
Hop!
It's turtles all the way down
who where what when now?
Wrong. All the way down it's turtle shit, also known as 'dark matter'.
Heh. Belief and Unicrons. That'll add to the discussion meaningfully !
When did slashdot become populated with loud, uneducated Americans instead of 'nerds' who actually know at least a thing or two?
I couldn't figure out if this was trolling or just someone on acid. Maybe a troll on acid. Whatever the case, that's some crazy shit.
But yeah, been getting more worried about this trend towards hokum in Slashdot. Not sure if it's just a different crowd, or the world is just getting madder. If it keeps up, I'm out.
Disclaimer: I work in a cosmology department. What you've just written is total bullshit.
We make predictions, and they work. I could tear apart the nonsense you've written, but instead let me just point to the facts:
http://xkcd.com/54/
http://sci.esa.int/planck/5155...
http://www.astro.virginia.edu/...
I could go on an on posting pretty pictures and graphs matching data, but let me just say that we work incredibly hard to make predictions from our models, we test those predictions against observations and test many of our systems to over 5 sigma. To say that what we're doing is just guessing is frankly insulting to a lot of incredibly hard working people. We /predicted/ the CMB then observed it. We predicted the power spectrum then observed it. We predict the population densities of stars at certain redshifts, point telescopes and damned well count the things and find them to match. We predict galactic rotations, lensing effects, (integrated) Sachs-Wolfe effects and a hundred
other little things, and we damned well test them, lining up our models against observations. We certainly haven't got everything right yet - there's a lot of room for investigation as to what went on before inflation, say, or exactly what type of matter dark matter is (but before you say we know nothing about it, I suggest you educate yourself - we don't know what it comprises, but we have damned good bounds on certain properties like its ratio of pressure to density). We don't know why the cosmological constant takes the value it does, but a whole host of checks all come up with the same number.
So no, we don't have "Guesses". We have repeatedly tested hypotheses from which we observe consistent data and find heavy statistical significance. What you've done is insult a lot of incredibly hard working, very smart people who are very serious about their work.
Dude, relax. The Electric Universe trolls have been around Slashdot for at least a decade now. In fact, after a huge apk-esque copypasta burst in the early 2000's, they kind of faded away.
In fact, seeing an Electric Universe troll now is like spotting a baiji. Just marvel, make note of it, and move on.
Thanks man. I'm breathing a bit easier now.
This is my first sighting of one in the wild. The closest I've ever come was in my uni days, hearing someone cite Erich von Däniken in a debate on evolution.
The first piece of observed antimatter was the positron and it isn't an atom. The idiot is in the mirror.
The turtle doesn't stands on nothing, it swims.
Linux is for people who don't mind RTFM.
The thing is our knowledge of the universe is so infinitesimally small that really it would be far fairer to call it a guess than a Hypothesis.
What makes you say that? Just because there are things we don't yet know doesn't automatically mean we are wrong about the things we do know. We're perfectly capable of building models that predicatively describe the world around us. If you build a model that accurately describes something and how it will (or did) behave then that is not a guess.
The big bang theory is basically a consensus picture of what we think happened based on the evidence we currently have. Some of the evidence we are extremely confident about. Some less so. And some we know we don't know yet (see dark matter) but know something about what is missing. We are basically saying that given our current observations and physical models, the following (insert theory here) must be true. Every theory is subject to revision based on future observations - some just need more of it that others. Models of what must have happened in the past (geologic, cosmological, archaeologic, etc) often get revised as new evidence is uncovered that must be accounted for in the model.
Silly me, making the mistake of reading TFA on /. ( aside: what's the proper way to punctuate a sentence ending in /.?)
You want to know how we 'know' all of those things with such great precision? It's all about the scale of temperature fluctuations in the cosmic microwave background. The CMB is a snapshot of the universe some 30k years after the big bang, during the time of first neutralization, when the pathlength of photons quickly (on cosmic scales) went form very short in the hot plasma (think neon light tube) to mostly neutral hydrogen. The spectrum of density fluctuations there tells an incredible amount about how the small perturbations left over from inflation evolved during that early time, and is the main stick by which all of our cosmological models are tested. The incredible agreement with the standard cosmological model and the CMB using only 7 free parameters is probably the most successful accomplishment in scientific history.
Nowhere on the article's page of drivel is the CMB mentioned, nor the WMAP or Planck satellites which were responsible for bringing us that data. I didn't read much of the article, but there is simply no way to speak intelligently about early universe models without the CMB. If you actually want to learn about this stuff, take a look at some of the public stuff NASA has put together for WMAP at http://map.gsfc.nasa.gov/missi... ; some of the animations are really quite revealing, and I use them in seminars on the subject all the time. Then if you're still hungry for more and can handle the math, take a look at Dodelson's Modern Cosmology.
Bah, still too angry about this kind of crap. Not a good way to start the week.
That's pretty cleverly-worded there. You could be a sophomore year co-op student, or a janitor for all we know. You've made an appeal to authority (fallacy) on an incredibly vague claim of authority, and then supported your argument with Internet comics.
And exactly what in his argument was actually wrong? Or are you just being an argumentative dick-head because it amuses you? What about the science did he get wrong?
Weak-ass..
Pot meet kettle...
If you ask me, the paradigm shift should be that science stops trying to answer questions which it obviously can't ever answer.
You don't know what you cannot answer until you try to answer it. Science generally speaking can (theoretically) answer any question which has observable evidence and is falsifiable. What our universe looks like and how it developed are well within the bounds of being observable and falsifiable.
The study of things that happened in the past is called history and it is not a science, no matter how much circumstantial evidence is collected.
I'm sure the scientists who study geology, archaeology, paleontology, astronomy, and numerous other disciplines will be disappointed to hear what they are doing isn't considered science anymore. Oh wait, those ARE sciences. How foolish of you.
They did not establish any credibility to be undermined, and there was no substantive argument made - they only linked to external sources.
Physics is a pretty big field. You seriously expect someone to spend the time to restate a meaningful amount of here what has already been adequately stated elsewhere?
Last I checked, xkcd is not a reputable source of cosmological authority.
Did you actually read to what was linked? Do you actually understand the formula shown and why it matters? Pretty clear the answer is no.
A "scientific hypothesis" does often catch more suggestion of testable, derived predictions, but it's also frequently used in a more general sense, just as "guess" can be used in a more noble sense.
Calling theories that have been tested as much as relativity or quantum mechanics "guesses" is to deny the world in front of you. While they could be shown to be false in some manner tomorrow, the simple fact is that much of the modern world would simply not work if the words "hypothesis" and "guess" were equivalent. The computer you are typing on would not work if quantum mechanics was merely a guess. GPS could not function if relativity were merely a guess, regardless of how noble a sense you use it. We only call them theories instead of facts because we know that they could in principle be proven wrong even though we have no actual expectation that this will happen and huge volumes of evidence in support of these "theories".
Anti-science folk should be ignored.
If you ignore anti-science folks you end up living in a theocracy. Ask the folks living in big parts of the Middle East what that is like. You ignore those who are anti-science at your peril. If the anti-science people are the only ones doing the talking then their ideas will eventually carry the day no matter how absurd them might be when viewed objectively.
We don't need to scheme and manipulate to make sure our presentation of science leaves them on the poorest footing to rebut us, because, unless they are using science, their rebuttal is irrelevant.
Wrong. They don't need to be right for their argument to win the day. Science does not become policy by magic. It requires educating and persuading policy makers, sometimes against their will. Being right is important but not remotely sufficient to ensure that science becomes the basis of policy rather than mysticism and magical thinking.
Pretty much says same thing as these pictues or Degrasse's Cosmos calender, but with more snapy video.
Then why is inflation the very first "unsolved problem" on this hefty Wikipedia page?
Mr. Siegel's wonderfully know-it-all blog post is based on inflation...i.e. the assumed explanation for an unsolved problem.
I come here for the love
A spherical turtle of uniform density in a frictionless vacuum.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
In my 61 years of asking for answers this is clear; who can say what a fact is except it always leads to other question(s) Kind of like nuclear reaction, only much slower. But don't let all of that genius mentality go to waste. You could look like 'ET' in a few thousand years with huge orbs!