Quantum Equation Suggests Universe Had No Beginning 288
cyberspittle writes: The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once. "In addition to not predicting a Big Bang singularity, the new model does not predict a "big crunch" singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again. ... In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe."
Attractive proposition (Score:4, Interesting)
Equations and theories that not only explain current observations but bundle up and deal with things our other theories say we should observe that we don't are attractive from a neatness standpoint. I'm skeptical when they make exotic and complex predictions which we haven't seen any evidence of yet, but when they tie up all the loose ends without creating more I usually take that as a sign there's something fundamentally right about that path. Only time and accumulated evidence will add certainty to it, but I like the ideas in this one.
And as far as a universe with no beginning or end is concerned, what's the problem? I was dealing with infinite open shapes (lines, planes) in grade school, unending closed shapes are trivial (a circle, a sphere), and if you assume our universe is a 4-dimensional "slice" of an n-dimensional space it's not that hard to construct an arrangement where you can travel forever in any "direction" (since the time axis counts as a direction here) inside our universe without either encountering an edge or returning to your starting point. The math's brain-bending when you start, but it's like differential equations: migraine-inducing and you hate it with the burning fire of a thousand suns right up until they describe the General Method, at which point you blink and go "Oh. That's easy. Why didn't you mention this in the FIRST PLACE?!
Re:Attractive proposition (Score:5, Insightful)
And as far as a universe with no beginning or end is concerned, what's the problem?
In a word: entropy.
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And as far as a universe with no beginning or end is concerned, what's the problem?
In a word: entropy.
I'm sure there's a quantum correction for that.
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And as far as a universe with no beginning or end is concerned, what's the problem?
In a word: entropy.
As I understand it, this new equitation only deals with the nature of the universe, not any of the stuff in the universe. So, yeah entropy will always increase inside the universe and the universe will eventually become uniform and the same temperature and density in all directions.
But, the universe itself is infinite and will stay so.
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But entropy could go asymptotically to zero as time goes to minus infinity.
So I still do not see the problem.
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In a word: entropy.
Good call! Don't see red shift explained either.
In this model, the universe is still expanding, it's not static at all. So redshift is just explained the normal way, in fact the Hubble constant is mentioned in the actual paper.
The paper [sciencedirect.com] is far above my level of understanding but, as far as I understood, when you play time backward but take quantum trajectories (whatever those are) into account, the universe doesn't come together in a single point but in some other state, much more dense than today but not a singularity. So the universe is still expanding
Re: Attractive proposition (Score:2)
Loop quantum cosmology also has a non-singular link between the end of a shrinking universe and the beginning of an expanding one. So does string theory, for that matter.
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Which makes this approach seem similar to that heavy breathing about black holes not existing due to quantum corrections. It's headline hyperbole. So mathematical singularities may not exist, and there is very likely a minimum length in the universe.
This paper seems to exchange one infinity (density) for another (time in the past). If there was no initial bang and no crunch to come what was the universe doing for that infinity in the past before it expanded?
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And as far as a universe with no beginning or end is concerned, what's the problem? I was dealing with infinite open shapes (lines, planes) in grade school, unending closed shapes are trivial (a circle, a sphere), and if you assume our universe is a 4-dimensional "slice" of an n-dimensional space it's not that hard to construct an arrangement where you can travel forever in any "direction"
Sort of like a world in Minecraft, well, at least in the XZ coordinates.
Re:Attractive proposition (Score:5, Funny)
But... (Score:5, Interesting)
Are they saying that the universe fluctuates between a not-quite-a-singularity tiny point of density and a not-quite-eternally-infinite empty void, or that it simply was a not-quite-a-singularity tiny point of density for an infinite time before it expanded?
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not sure but the bigger question would be how stoned would I have to be to even consider the ramifications of what you're suggesting?
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I was under the impression that we're living amid a second generation of stars. Early-universe stars were very large, very bright, and have all died already, giving birth to the current generation of cooler, longer living stars we see in our night sky. Granted, I'm basing that off of reading the Xeelee sequence, so who knows.
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Things moving in a space don't describe the size of the space they're contained in unless they interact with a boundary. You can't make the claim that the universe is growing or shrinking. All you can say is that some objects are moving away from each other. This could either be space expanding (the popular theory involving dark energy which is just the pet name they gave the missing force they can't explain), or space is not expanding and another force acting on the mass that hasn't been accounted for.
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OK, these guys are probably far smarter than I'll ever be, but... the universe clearly isn't staying at a finite size, and playing the universe's expansion in reverse would imply that it started at a single point. How do they account for this?
Various Quantum Gravity theories predict different things here. Some, like Loop Quantum Gravity (LQG), predict that over extremely short distances gravity is repulsive. Applied to cosmology (Loop Quantum Cosmology, LQC) this leads to a prediction of a "bounce", where a contracting phase flips into an expansion phase.
http://en.wikipedia.org/wiki/L... [wikipedia.org]
http://en.wikipedia.org/wiki/B... [wikipedia.org]
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...and playing the universe's expansion in reverse would imply that it started at a single point. How do they account for this?
They're saying that under this theory, playing it backwards does not imply that it starts at a single point. I could point to someone blowing up a balloon, and say "it must have started from an infinitely dense singularity". I'd be completely wrong.
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yeah so it first spent an infinite amount of time being 'small' but not 'big bang start of all' small?
if they're saying that the universe grows and the contracts again to a point(big bang) and grows ad infinitum then yeah why not..
but how does the whole thing fit into the models we have for matter to come into existence(I mean different atoms) and so forth?
and what's this "MAY" take into account.. it either does or doesn't.
About the structure of the universe... (Score:4, Insightful)
It's interesting, but I'm curious as to whether the model shows a universe developing with the features we observe. The density of the universe is one thing, the general structure of it is another. There seems to have been a lot of thinking around how the universe was shaped by the big bang including all sorts of models and simulations. It'll be interesting to understand if this new model also fits.
only one way you're getting me into this debate (Score:5, Funny)
and that involves a certain plant, a yard of gummed-edge pressed wood pulp and a bucket of munchies.
Toldja! (Score:5, Funny)
...it's turtles, all the way down.
How about energy conservation? (Score:4, Interesting)
One of the many, big, unanswered questions concerning the origin of the universe is - where did the energy come from? Conservation of energy - the assumption that energy cannot be either destroyed or created - is a fundamental axiom in physics, which goes against the idea that there was a point in time before which the universe didn't exist, but after, it did. Unless, of course, one can conceive of a negative energy of equal size having been created at that same moment.
A naive consideration would say that if a mass, M, is created, then there must have an 'anti-mass', -M, as well; using Newton's equations, we would expect M and -M to repulse each other, while M would attract M and -M would attract -M (yes, doesn't make sense at stated, but follow my thought here, OK?) And, if one were to ramble on along those lines anyway, it seems tempting to look at the equations for how electric charges interact and think of electric charge as a kind of imaginary (as in complex numbers) mass. No doubt better people than I have already spotted this and worked out why it doesn't make sense, but I haven't seen their work yet.
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Naively, doesn't conservation of energy also suggest that particles can't pop into existence out of nothing? But they do [wikipedia.org].
TL:DR; physics is bonkers.
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Naively, doesn't conservation of energy also suggest that particles can't pop into existence out of nothing? But they do [wikipedia.org].
Do they? Hawking Radiation has never been observed or proven. It's a theory. And in any case, the black hole would lose the same amount of energy as was in the radiation.
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A photon with gamma ray wavelength and the power to ionize atoms gets stretched by all possible observation points into a microwave that can do no such thing.
Where did that energy go?
It is different than red-shift (a directional observation bias) in that the energy simply is gone.
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A photon with gamma ray wavelength and the power to ionize atoms gets stretched by all possible observation points into a microwave that can do no such thing.
If by "observation points" you mean "reference frames," then won't there always be a reference frame where it has gamma ray (or any other) wavelength?
Where did that energy go?
Nowhere, I think. It's like running fast enough to snatch a bullet out of the air without hurting yourself. Relative to you, the bullet has very little kinetic energy.
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[...] the idea that there was a point in time before which the universe didn't exist [...]
Time is part of the universe, so there wasn't and there will never be a point in time when the universe doesn't exist. On the other hand, there could be other universes, possibly with their own times.
Re:How about energy conservation? (Score:4, Interesting)
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Conservation of energy - the assumption that energy cannot be either destroyed or created - is a fundamental axiom in physics, which goes against the idea that there was a point in time before which the universe didn't exist, but after, it did
Emi Noether showed in the first half of the last century that conservation of energy is equivalent to time invariance ("shift symmetry of time"). At the beginning of time, i. e. the beginning of the universe, there was no time invariance; time was just being "created". Hence no conservation of energy.
Need Falsifiable Observable Predictions (Score:4, Interesting)
All of these type of models about the universe have elegant math behind them.
But until they can any observable predictions which can be measured and possibly falsifiable, then we are really dealing with pure math and philosophy and not physics.
One can construct countless mathematical models which fit known observations, but very few make new falsifiable observable predictions.
This is my gripe with something like String/M-Theory, which has not made any legitimate predictions, and fails at stuff like monopoles which not been observed.
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If they're talking about a pulsating universe, there may be a way to verify some of it. I'm looking at this from a layman's perspective. If a big crunch happened before our current universe's big bang, could it be possible that this big bang happened before all of the material from the previous universe had been drawn into the singularity? Because simply put, why would the singularity wait for everything to fall into it? What if 'our' big bang annihilated that still inward falling matter while rapidly expan
Summary of the actual paper (Score:5, Interesting)
Suppose the Universe is filled by a Bose-Einstein condensate of gravitons with mass, and that the amplitude of the condensate's wavefunction spans the entire universe.
Turns out that when you derive the FRW equations from this, doing so inserts a cosmological-constant lookalike into the equation for a''
So plug the size of the Universe into the Yukawa equation and a graviton mass of 10^-32eV pops out. Plug this into the assumption that the wavefunction is a Gaussian the size of the universe (which makes d'Alembertian proportional to the wavefunction and gives you that nice constant) and you get a cosmological constant that's plausibly near to what we observe.
Inserting the universe-condensate also creates a second correction term which prevents the FRW scale factor from blowing up or collapsing either in the past or the future, which makes that nasty big bang singularity go away.
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It's worth noting that they invoke Bohmian quantum mechanics, which will immediately sketch out a lot of quantum folks...
What bugs me is that the massive graviton blows up the mass hierarchy problem. It's hard enough to come up with a non-contrived way to have particles whose measured mass ranges from 1eV to 170GeV, but to extend it by 30 orders of magnitude on the light side is just mean.
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If gravitons have non-zero rest energy, then gravity can't have infinite range...if it's 10^-32 eV, then gravity doesn't extend farther than about 10^48 meters...ok...possible... LOL
Bohmian mechanics is probably what prevents a singularity, as particle trajectories can't cross (quantum potential becomes infinite as trajectories converge)...
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Boundary conditions... (Score:3)
too bad we can't verify them. Especially since the thrown most of the assumed ones out of their model. It's nevertheless an interesting approach in describing the universe if you take the time to read about it. Who knows, maybe the existing models were over-constrained and it might not be bad to give them a fresh look.
The truth probably lays somewhere in between.
First for quantum (Score:2)
This has to be the first time any kind of science involving the word quantum has made more sense than an alternative.
Equation (Score:5, Funny)
A few years ago, a colleague proposed the idea that North-European population are tall because of an adaptation to the colder climate.
He could prove his theory but only for a perfectly spherical viking.
Time (Score:2)
Time is how we measure change, its a property of an object, not an object itself.
For time to have a begining would mean a situation when nothing changed. Which suggests zero energy. So for time to have a beggining is to suggest energy can be created created.
orsomethinglikethat
Wrong conclusion (Score:2)
If the unisverse is not expanding (which it is presently) in general then that allows not to conclude that the age of the universe is infinite. It only shows that you cannot determine the age of the universe on the basis of inflation. However, you still could determine the age by entropy. The higher the entropy the older the universe. And if I look at my work desk, the universe is pretty damn old.
Comment removed (Score:5, Insightful)
Shepard tone (Score:4, Interesting)
In music, there is something called a Shepard tone [wikipedia.org], which is a series of skillfully combined harmonics that, when listened to as a loop, appears to be constantly ascending.
Perhaps the "expanding universe" is something like that.
Forever ? (Score:2)
"The universe may have existed forever,",
Forever, yes, but how for is that ? I thought the time started ar big bang.
Sounds very Indian and Hindu... (Score:2)
big bang black hole (Score:2)
If all universe was smaller than, well, very small, how come it didn't form a black hole in the first seconds?
And then if nothing exits the black hole, how did universe manage to do it?
Half Life (Score:4, Insightful)
What does Forever even mean? (Score:2)
Isn't this... (Score:2)
Isn't this just a rehashing of the steady state theory of the universe?
But it obviously happened. (Score:2)
Or so all other evidence indicates. That said, is there any reason why what we call the "big bang" represents nothing more than an unmeasurable atemporal interval between otherwise quite mundane spatio-temporal domains? That would satisfy the condition of "eternal existence" and leave room for the big bang.
In other words, big bang, followed by big crunch some xx billion years later. Rinse, lather and repeat.
Einstein had some doubt about an infinite universe (Score:3)
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You know, what I've often asked myself is, "What was there before the Big Bang?"
Probably a big: "I love you baby... really I do..."
Some things never change...
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LOL ... "I can see paradise by the hydrogen glow" ... "Praying for the end of time, so I can end my time with you!!!"
Re:The whole idea is crazy (Score:5, Insightful)
You know, what I've often asked myself is, "What was there before the Big Bang?"
Thats a bit like asking what is south of the south pole.
Re:The whole idea is crazy (Score:5, Insightful)
Thats a bit like asking what is south of the south pole.
Maybe. But the current model could be wrong.
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Re:The whole idea is crazy (Score:4, Informative)
You know a "religionist" came up with the Big Bang Theory right?
At least credit the source (Score:2)
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At least credit the source Hawking [hawking.org.uk] (or earlier).
But for every equation or citation in my post, I lose half my audience.
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Re:The whole idea is crazy (Score:5, Funny)
But seriously, as AC has posted, the question is meaningless if time "started" at the point of the Big Bang. Hard to get your head around maybe. I know my mother has problems with it, but she also poses strange questions like "why aren't apes having human babies now." It's like a hundred years of science has just slipped past her.
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Two experimental physicists, with one shouting: "Oh God, shut if off! Shut it off!"
gah! typo. Who looks silly now?
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That's actually a funny/insightful question :D
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But seriously, as AC has posted, the question is meaningless if time "started" at the point of the Big Bang.
That's a mighty big "if". I like watching all the armchair physicists around here assume they know the answer with a religious-like fervor.
For all we know, the Big Bang had a cause. What caused it may exist in a "lower level" time that we don't knowingly experience. We might just experience our local time.
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"What was there before the Big Bang?"
There was a Big Kaboom.
As in, "Where's the kaboom? There was supposed to be an earth-shattering kaboom!"
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You know, what I've often asked myself is, "What was there before the Big Bang?"
The question does not make any sense, I mean from a purely linguistic point of view it does, but the question itself does not make sense to ask.
Anything we know, have known and are able to know takes place after the big bang, thus asking what came before it is a question we cannot really answer.
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Anything we know, have known and are able to know takes place after the big bang, thus asking what came before it is a question we cannot really answer.
But there could have been something, right? What was there is just more of a philosophical than a scientific question.
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Well, if there was no time 'before' the big bang, what does 'before' mean?
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The big bang model is an interpolation backwards in time from our current world. It shows how things must have been, but at the singularity it stops making sense. I think this interpolation is missing something important, something that we don't know about yet.
Re:The whole idea is crazy (Score:5, Insightful)
Certainly I agree with you, there is a lot we don't know. The trouble is, at the moment, in order to speculate on this, we are leaving science and entering philosophy. Science does not have an answer for us here, and maybe never will. We have some math, but nothing that really means anything to us.
I would say that these questions cannot be objectively answered - there is no way to measure what happened 'before' since there is no frame of reference that would be meaningful to us and allow us to understand what 'happens' outside our little bubble of physics and space/time. How do we measure outside of space and time? What are we measuring for that matter? What does 'before', or 'cause' or 'effect' mean in such a reality?
As a self professed religious person, I believe there are subjective and unprovable answers. Others disagree and are happier with the questions. In either case it seems wise to not give up on looking.
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I've heard it said that our our universe is definitely not the inside of a black hole but I have never heard the reasoning for that claim beyond the "maths says it's a singularity". As with a black hole, light cannot escape our visible universe and the inflationary period embedded in the BBT could be interpreted as the initial collapse into a black hole, ie: I like to speculate that it's black holes all the way down (and up, sideways, etc).
Damn, that is what I am also wondering about. Would be really nice to see a good explanation for that.
I mean there must be some relation between the singularity that a black hole is and the singularity at the big bang. In one case the mass collapses and in the other one it inflates and forms a universe. But what is the difference, or isn't there any, and it is just looking at it from outside and from inside?
Below the article here is a link to an article about a theory related to that. [phys.org]. The theory is that
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The problem is our consciousness and language are so dependent on the concept of time that we lack the language, and therefore ability to conceive of a state of being without time.
You said "could have been." The GP said "what came before it." "Been" and "before" imply a time-ordered sequence of events, but these are only possible from time t=0 on. There is no time t=-1, "before" the Big Bang, because that necessarily means a clock was ticking down to (or up to) the big kaboom. But clocks only tick from t=0
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"What's the difference between a duck's legs?"
I fail to see how that is a meaningless question. Maybe the duck is injured with one leg broken. So the difference is that one leg is functional while the other is not.
The question is only meaningless without context. The same as the question by the OP. But we have context for the question, and in this context the question is not meaningless. Maybe you view the answer as pointless, but the question is not meaningless.
Re:The whole idea is crazy (Score:5, Informative)
You know, what I've often asked myself is, "What was there before the Big Bang?"
Nothing. As accepted, currently, time began with the Big Bang, so there was no before the Big Bang.
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Time itself is part of the universe, so asking what was "before" the creation of spacetime is a meaningless question.
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The question isn't meaningless, even if it restricts us to pure speculation.
Comment removed (Score:5, Informative)
Re:The whole idea is crazy (Score:5, Insightful)
Well, let's say the question is premature. Before you can ask it, you have to determine whether the question itself is based on false assumptions. This kind of question is tricky because questions you *can* ask meaningfully have the same syntax as questions which are meaningless.
For example, you can ask "What is colder than 0 degrees C?", but you can't ask "What is colder than 0 degrees K?". One question is meaningful and the other is not.
So asking "What happened before the Big Bang?", entails two assumptions, namely (1) the Big Bang happened and (2) the scientific consensus on the Big Bang is fundamentally flawed. If the scientific consensus is correct, then it's like asking, "What's colder than 0 degrees K?" or "What's north of the North Pole?"
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--
JimFive
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No, definitely meaningless. Time itself began with the Big Bang. The instant of the Big Bang is t=0. There is no t = -1. If there could be, then there would be time, which would pass from that point leading up to the moment of the Big Bang. But time began with the Big Bang.
But, our language and consciousness are so dependent on the concept of time that we lack the language to describe a state of being without it. Which is why we erroneously say things like "before the Big Bang," but it's a meaningless state
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Photon. Time is nonexistent.
Or $TIMELESS_DEITY. Time exists, but has about as much meaning as the time index of a video. It makes more sense to watch everything in proper order, but you're free to watch the thing in reverse if you like.
But time-ordered sequences of events are only possible after t=0.
Imagine you're a CPU and your perception of time is in cloc
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No, definitely meaningless. Time itself began with the Big Bang. The instant of the Big Bang is t=0. There is no t = -1.
It's not meaningless.
The time we experience may have started with the Big Bang, but there may be a lower level time component to the greater universe. For example, one theory is that two Branes colliding caused the Big Bang we know and love. In order for two Branes to collide, they must exist in their own time, lower level than our time.
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It's meaningless. Time is part of space-time (unsurprisingly given the name). Space-time came into existence via the Big Bang (let's just pretend our theories are right for the moment, as wrong as that obviously is). Before is a reference to time. There is no time without space-time and thus there is no "before the Big Bang".
It's like asking "what is above the Universe" - which is also meaningless since above (and let's again pretend and say we a have a frame of reference here) is a reference to space. Ther
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being infinite in one direction is enough to scramble my brains
Right, We use the other infinite directions for two slices of bacon and toast.
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To "get it", consider the universe as being infinite in all directions.
There's nothing to think about. There's no such width, height, or depth as infinite. Infinite isn't a number.
The universe isn't infinite. It's nonsensical.
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It's quantum physics.. what do you expect?
Trick answer.
Very funny.
ah ah ah
ha ha ha
Question tricks.
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3) You're the first person I've ever heard to claim that the big crunch matches scripture, and frankly I don't see where you pulled that from.
Clearly it is Ragnarogk, the end of days and doom of the gods!
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Clearly it is Ragnarogk, the end of days and doom of the gods!
Too late, it's already come & gone. [io9.com]
Re:Can't disprove Hell (Score:5, Funny)
Comcast Theory
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Basic logic fail!
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Are you a JRef regular? You usually only get this kind of silliness there.
In reply to "hell is other people" you say "Most of the Universe has no people, hence Universe isn't Hell." That doesn't make any sense.
Let's give you a hand. If we accept that "hell is other people" then we need to assert that "the universe isn't other people" to conclude "the universe isn't hell". If you instead assert "Most of the Universe has no people" then all that follows is "Most of the universe has no hell".
Now go and si
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if there was no big bang, why is it that the further away from Earth we look with telescopes, the more red-shifted the light is?
It gets tired on the long journey.
Actually, I wanted to aske the same question,but.. (Score:2)
I wanted to ask the same question, but then I remembered asymptotic functions. Going back in time, entropy would decrease, but the rate this decrease could become smaller smaller as one regards points that are farther back in time.
However, this would imply that for most of the previous eternity, the universe wasn't doing all that much.
tl;dr: The second law requires
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So I guess, if this works out, we can just throw away the laws of thermodynamics? Obviously if entropy is always increasing, and the universe is of infinite age, then certainly there would be no organization today, right?
If the universe always existed, then we don't know that entropy is always increasing. Maybe the universe always existed, but there is some mechanism that causes entropy to cycle between increasing and decreasing? Who knows? OTOH, this is just a hypothesis and has yet to be accepted.
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Considering that entropy might decrease leads to some fairly strange scenarios, e.g.:
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General relativity does require a beginning to the universe. Einstein realized that a universe dominated by an attractive force had to be either shrinking or expanding. He didn't think that was realistic, so he added the cosmological constant to balance the attraction of gravity and get a static universe. That was in 1907-1915. People started doing galactic redshift surveys (with a handful of close galaxies) around 1912, but it wasn't until the late 1920s that it started to be accepted that the universe
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And if time is mentioned, it's always interesting to ask "in what frame of reference"?
If there are any photons left over from shortly after the big bang, they would state that the universe just began seconds ago.