Banner
    The New Date For The End Of The Universe Will Be...
    By Hank Campbell | July 24th 2012 05:30 AM | 19 comments | Print | E-mail | Track Comments
    About Hank

    I'm the founder of Science 2.0® and co-author of "Science Left Behind".

    A wise man once said Darwin had the greatest idea anyone...

    View Hank's Profile
    How will the Universe end?  And when? It's been speculation in religion and philosophy since man realized he was special.  Can physics offer anything new?

    Let's go to the Dark Energy hypotheses and see.  1998 really messed us up, theoretically. Until then, we knew the Universe had to slow down - well, theoretically.  But then the Hubble showed us truly distant supernovae and we got the uncomfortable reality that the Universe was actually expanding more slowly in the past than it is now.  That meant gravity has not been slowing Universal expansion, it has been accelerating. 

    What could cause that?  No one knew but theorists were on the case and all of the explanations (Einstein's cosmological constant, ether, Einstein's theory of gravity is wrong) became a blanket dark energy hypothesis. 

    It also meant we don't even know what we don't know.  Dark energy (unknown) became 70% of existence, dark matter (unknown) another 25% and what we know as matter is about 5%.  Sounds like matter doesn't matter, right?  Maybe, though it is actually kind of cool to have space be special.  For instance, matter can't travel fast than light, not even in Italy, but space can.  That explains how the age of the Universe and the size of the Universe are not correlated - if you're limited to light years.

    Rate of expansion since the birth of the universe 15 billion years ago. The more shallow the curve, the faster the rate of expansion. At about 7.5 billion years ago, objects in the universe legally  separated and did it fast.  Why?  I don't know.  Trust issues, or maybe they met a younger universe.  Or dark energy. Credit: Ann Feild (STScI)

    So there are lots more questions now but that big one has remained constant and no one in the history of human introspection has gotten close; namely, when and how will it end?

    The Big Rip is one hypothetical possibility for our Cosmic Doomsday, proposed by a group at the the Institute of Theoretical Physics at the Chinese Academy of Sciences. Dark energy has given them the means to end the Universe the same way a Hot Big Bang and inflation began it.

    There's a tiny bit of equation-ing in this piece but I will leave the nuts and bolts ("divergence-free parametrization for dark energy w(z)=w0+wa[ln(2+z)/(1-z)-ln2]") to those who want to read their article (citation below - it's free to read).  You have to essentially accept the equation-of-state parameter w, the ratio of pressure and density of dark energy, and if w<-1 then dark energy density will grow to infinity in finite time (you like that one??) and gravitational repulsion will tear us all to smithereens. 

    Well, the Norse missed Ragnarok in 2010, Christianity did not get us last year and our cosmological Nibiru destruction has already passed.  Mayan calendars are looking shaky too.  What do Chinese theoretical physicists say? 

    These guys pants the Teutonic pretensions of Chevallier-Polarski-Linder parameterization because w will diverge when the redshift parameter approaches -1 and opt for the Asian divergence-free Ma-Zhang parameterization to foretell the Apocalypse.  After doing a Monte Carlo analysis (spare me - of you read this far there is no point in noting the flaws of doing a Monte Carlo) they came up with a
    95.4% confidence level of having the Big Rip at...16.7 billion years.

    What does that all mean? 16 billion years is a lot of time so it feels pretty safe. But it's nice to have a number and if they are wrong, no one will be able to tell them.

    Citation: LI XiaoDong, WANG Shuang, HUANG QingGuo, ZHANG Xin4, LI Miao, 'Dark energy and fate of the Universe', Sci China-Phys Mech Astron, 2012, 55(7): 1330-1334 DOI: 10.1007/s11433-012-4748-z

    Comments

    BDOA
    Yes, but w<-1 isn't very likely, because w<-1 describes matter that doesn't obey the usual weak conditions of general relativity, laws saying that for instance that matter has positive energy and more mass energy than binding energy. w<-1 is called phantom dark energy, and called such because its like unobtainium, that sort of material shouldn't exist. Mind you dark energy is weird so perphaps all bet on its behaviour are off.
    BDOA Adams, Axitronics
    I'm sure they'll get it right eventually...

    '95.4% confidence level of having the Big Rip at...16.7 billion years'
    From the above quote of the article a new question arises:
    Will there be another big bang after 16.7 billion years? Will there be a new universe?

    ... scribbles in agenda: Dec 31st 16700002011, reservations at Milliways 11:59 pm (fireworks included)
    Now who said science has no practical value?

    Hi Hank,

    I'm the guy who was discussing the epidemiology of cigar smoking with you.

    You rejected clearly proven things regarding cigars, but somehow think the daqrk matter article you are discussing is conclusive. It not only is not conclusive, but is quite poor.

    The authors discuss a quantity "w" which is the ratio of the density of the dark energy mass to the density of the regular mass. The problem is that the acceleration of the Unvirse is caused by the negative PRESURE of the supposed dark energy, not its mass.

    Here is a summary of whay General Relativity applied to the standard cosmological models tells us

    1) The deceleration/acceleration of the expansion Universe is proportional to the mass density plus 3 times the pressure densitity

    2) The square "velocity" of the expansion is relared to the mass density.

    For the first result we know that if the Universe's expansion is really accelerating, then the mass density plus 3 times the pressure density must be negative. But from the second condition we know that the mass density is positive (because no real number squared can be negative). So key to the "dark matter" scheme is the negative pressure. If dark matter had negative mass density it would affect the motion, but because the total mass density could not be negative, the effect could never be strong enough to cause acceleration.

    The article doesn't deal with the pressure over time--w is just a ratio of mass densities.

    Hank
    You rejected clearly proven things regarding cigars, but somehow think the daqrk matter article you are discussing is conclusive. It not only is not conclusive, but is quite poor.
    This shows your lack of understanding about speculative physics is equivalent to your lack of knowledge about what causes cancer.  There is nothing in this article that anyone who knows anything about physics would read as anything but dismissive.
    Hank, you were not able to respond to any of my specific pohysics arguments.

    Saying "There is nothing in this article that anyone who knows anything about physics would read as anything but dismissive. " is a pretty lane bluff. It is childish. You neither understood the paper nor what I was saying, right?

    OK, if you know General Relativity, you should be able to answer this. Suppose you had an infinite cylinder of mass with a mass per length density p. What is the g00 metric component outside the cylinder. Feel free to use a first order approximation,.

    You are a faker.

    Hank
    There's nothing fake about dismissing your thesis - that I was claiming their article was conclusive. I did nothing of the kind I also don't much care about discussing high school physics with you and your claim you can create a wormhole or go faster than light or wherever you are going next. Buy my book, then write a review telling me how stupid I am.  At least you have earned the right then.
    Now we know that if we express the time/date in a computer as a 64-bit integer we'll never have another Y2K bug type of problem because it'll count up well past the end of the universe. But if the prediction is wrong, when people ask future computer scientists why they have a Y584B problem the scientists can answer "because the people that designed it thought the universe would end by then!" and laugh at our backwardness over a dark matter latte.

    Hank
     But if the prediction is wrong, when people ask future computer scientists why they have a Y584B problem 
    I wish I had a way to steal this bit and use it, but you have created true singularity humor.
    Hank Campbell's fascinating look at the weird speedup/slowdown/speedup of (the current model of) the Universe, is both fun and... kinda weird at the end. STill, consider this. Today's model has our Big Bang cosmos first (1) expanding superluminally hyperfast in so-called "inflation"... then (2) slowing down because of intense gravity (when things were closer together... then (3) speeding up again because of dark energy. Will there come a point in "time" when we turn toward the fourth wall, give a cold stare at the audience of this funhouse simulation, and say to them: "You're kidding, right? Who writes this stuff?"

    David Brin, (author of EXISTENCE tinyurl.com/exist-trailer )

    Hank
     Will there come a point in "time" when we turn toward the fourth wall, give a cold stare at the audience of this funhouse simulation, and say to them: "You're kidding, right? Who writes this stuff?"
    Even better, I will be able to turn to myself and ask that question.

    I won't have a good answer then, either.
    Could you make one important point of clarification: did the Chinese physicists calculate the end to be 16.7 billion years from now or when the universe reaches the age of of 16.7 years (a mere 1.7 billion years from now)? When you consider that decades ago when I was in grade school we were taught the universe was 3 billion years old, this could matter more than one may think. Apparently time sometimes flies, I wouldn't be surprised if in a decade or two the universe is 20 billion years old.

    Hank
    You have 16.7 billion years from now, give or take a few billion plus the 4.6% chance they have no idea what they're talking about.
    Gerhard Adam
    Plus the fact that it won't matter one bit to any of us having this discussion.
    Mundus vult decipi
    No, there's a 4.6% that if they *do* know what they're talking about, their number is still wrong. I.e., if your article correctly described what they mean by "a 95.4% confidence level," 4.6% is *their* estimate of the chance that they're wrong about the number even if their theories and calculations are completely right.

    Hank
    Right, that is what the term outlier is.  People know how confidence intervals work in the Science 2.0 audience, this isn't USA Today.
    Hank "I also don't much care about discussing high school physics with you."

    You must have gone to a really good high school if they taught you what the metric in General Relativity is.

    But if it is a high school question, how come you could not answer it?

    I asked you a very simple question that someone who took an introductory General Relativity course and understood it well would have no trouble answering. You, as I expected, could not. It is obvious you do not understand the science at all, yet you argue about it.

    "and your claim you can create a wormhole or go faster than light or wherever you are going next"

    I made no such claim, nor implied anything remorely like that. Apparently you googled and found something that looked like that to you, but googling is no substitute for understanding what you are talkintg about.

    Indeed, your lack of scientific competance is again manifest by your wormhole claim. I asked you for a first order approximation. That is a WEAK field approximation. If any wormhole could be created it would have to be a very STRONG field. No one with scientific competence would have made your mistake.

    And you still have failed to tell me what was wrong with my actual comment about that papers. I claimed that the key characteristic of "dark energy" is negative PRESSURE. You can probably even google that it is negative PRESSURE that has to cause the supposed accelerated expansion of the Universe. But if you look at the paper they dealt solely with the supposed evolution of the MASS density.

    ."Buy my book, then write a review telling me how stupid I am. At least you have earned the right then. "

    I don't need to buy the book to see you have been making bad errors. I keep giving you specific ones.
    .

    Maybe dumb, but I always try to relate macro phenomenons to everyday ones. Now, put a pan with water on the stove and start to heat it. What do you see when it starts to boil? The bubbles start on the bottom, start to rise and they expand. Why do they expand at an accelerating rate? Hey, come on dummy, we all kow why. Maybe our universe is just a bubble in a pan of soup. Now, looking down, maybe you are boiling universes in your pan with boiling water.