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Shape of the Universe Determined To Be Really, Really Flat
StartsWithABang writes: You might imagine all sorts of possibilities for how the Universe could have been shaped: positively curved like a higher-dimensional sphere, negatively curved like a higher-dimensional saddle, folded back on itself like a donut/torus, or spatially flat on the largest scales, like a giant Cartesian grid. Yet only one of these possibilities matches up with our observations, something we can probe simply by using our knowledge of how light travels in both flat and curved space, and measuring the CMB, the source of the most distant light in the Universe. The result? A Universe that's so incredibly flat, it's indistinguishable from perfection. Which means it's probably even flatter than Kansas.
Not sure what OP is on about.
http://michaelsmith.id.au
Let us build dykes in the void outside the universe, and polder in some more vacuum !
Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
If its surface is flat, what good a wormhole will do?
Although there are locally flat shapes that are finite (eg torus or klein bottle), it seems likely that the universe is infinite. The observable universe is still finite though.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
The universe is a communion wafer.
No one will ever measure the universe to be perfectly flat, because that would require a perfect measurement with no margin for error, not even by the smallest number you can imagine. With either positive curvature or negative curvature, there would be margin for error but the only number neither positive nor negative is exactly zero.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
I don't mind reading blog posts on the medium, but this is really not news. You might as well have included this wikipedia article with the others you linked: http://en.wikipedia.org/wiki/S...
So, who are the lucky bastards who get the Dolly Parton universe?
Table-ized A.I.
The assumption of GR is that space/time can be described as a smooth manifold - a manifold being intuitively something like a beach ball, donut or similar. Smooth means that when you look at a piece of the manifold at a sufficiently small scale, it looks more and more flat; it really is that simple, what makes it hard is when you introduce the technical tools you need to make precise calculations. So, since we don't actually know the size of the universe, perhaps what we can measure is that we are looking at a much smaller scale than we imagined.
But, some will say, how about the speed of light? The age of the universe is known, so if it started out in the big bang as a single point, it can only be a limited number of lightyears across, right? There are several things to say, that might rock that particular boat a little. Firstly, we don't know that the universe was just a single point in size - in fact, the way QM is interpreted, it seems reasonable to think it wasn't. Secondly, if inflation happened, the universe went through a phase when it expanded a lot faster than the speed of light. And thirdly, of course, the speed of light is only known to be the limit within what we know as vacuum in the space-time we observe now, it only limits how much of the universe we can see now; we have every reason to assume that there is a lot more of it than that.
Through the law of large numbers the two options seemed to be perfectly flat or perfectly round. We should just simulate it in StarLogo and go with whatever the turtles tell us.
When you combine time cube theory with electric universe theory you get a cubic universe plus an electric clock. The cubic universe is flat (in the cosmological sense), so if the two underlying theories are correct then the universe diverges from flatness by the amount of one electric clock.
However, pedantically speaking, that's "plus one electric clock per universe". So in the case of a multiverse, the theorem only indicates the average. But with judicious application of the Central Limit Theorem, the Pauli Exclusion Principle, the Heisenberg Uncertainty Principle, and a line of reasoning left as an exercise for the reader, we can confidently conclude the universe is probably approximately flat, for definitions of "confidently", "conclude", "the universe", "is", "probably", "approximately", "flat", and "definitions" which remain to be derived from first principles.
Read more about it on my blog, Starts with a Bump on the Head, which, as you may have guessed from the title, is written in atrophic dactylic tetrameter, like all good cosmological monographs and comic books.
Sheesh, evil *and* a jerk. -- Jade
The most meaningful discussion this post generated was one regarding the flatness of the state of Kansas.
With all due respect to Ms Knightly, her lack of buxomness while exercising is about the least interesting thing to discuss at this point.
Someone flopped a steamer in the gene pool.
No, it isn't. I like flat- or small-chested women. The only US-American girlfriend I ever had, was as flat-chested as Kansas' plains, and she was smokin' hot. Morale of this tale: flat is beautiful; the universe being flat, it is beautiful.
Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
The universe is all of space and time. We have not observed/measured/etc. most of the universe yet to determine its shape. The parts of the universe we have observed are flat. Until we observe more of the universe, we will not know if the universe is flat or not.
Choosing the lesser of two evils is a choice for evil.
Here's an explanation: The universe is a hologram
How is this fitting with Big Bang? Should not a round universe be shaped?
If you spill a drop of coffee on a piece of paper, the stain will expand to form a circle. The paper is still flat or otherwise an elliptic or otherwise non-circular stain would have formed.
Since we apparently have a seriously large system that is flat what are the forces that would cause a flat universe to perpetuate itself? Rotation might offer an explanation but there is also the notion that some force pressing from the top and another force pressing from below might cause a flat universe. Let the speculation begin! If the universe is like a flat sea can the universe cascade over the edge?
Are all the turtles flat, or just the first one?
You'd think based on what we know about smaller scale explosions that the universe would be spherical, but even explosions in a vacuum aren't perfectly spherical. The shape of the shrapnel field and gasses depends on exactly how the explosion occurs. Until we know how dark matter and dark energy affect regular matter and energy with respect to accelerating it there's no obvious way to determine what the shape of the universe would be 13+ billion years after its creation. Subtle imperfections in the initial, generally spherical, shape of the universe might be amplified by their interaction with dark matter and energy, resulting in the initial sphere becoming highly irregular as it expands in size.
I think the question could be attacked from two sides. We can examine the current shape of the universe (shitty, because we can only see what is possibly just a small piece of it which may prove insufficient to extrapolate an accurate bigger picture) and ask, "If it looks like this now, what must it have looked like in the beginning," or we can attempt to understand through mathematics and theory what happened in the beginning and then extrapolate what it must look like now. Either way, I don't think we'll have a generally-agreed-upon answer anytime soon. Dark matter/energy is a giant hole in our understanding of how/why things move in the universe, so first thing first, figure that one out then worry about the size and shape of the universe.
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The universe is all of space and time. We have not observed/measured/etc. most of the universe yet to determine its shape. The parts of the universe we have observed are flat. Until we observe more of the universe, we will not know if the universe is flat or not.
Unless they say otherwise, if you hear physicists talking about the "Universe" they're probably talking about the observable universe.
What is the universe? I've already thought of universe to be the space that stars exists in.
For this discussion I will define the terms differently:
- Universe: the star field expanded from this big bang.
- Space: A place in which a universe exists.
Now if the universe generates space, than we went full circle and we decided that space is made of ether. i.e. space is something.
But what if more than one big bang happens in space, and therefor there are multiple universes.
We may not be able to see the other universes:
- because the universe-background-radiation is blocking it,
- The other universes are to far for enough photons to reach us to detect it.
- Close by universes started at about the same time as our universe, and therefor light has not reached us yet.
Who knows the tomorrow we may see another universe intersect with ours.
You fail to understand what scientists know versus what they speculate about.
Making the assumption that they are even somewhat accurate about the big bang (unlikely), the math used to get there breaks down and doesn't work as the size approaches infinitely small. Everything is just speculation from unimaginative scientists who think they know what happened 14 billion years ago at some random spot that they can't even point their finger in the general direction of.
That does not mean that space was not infinitely large while at the same time infinitely small, its all a matter of perspective. Outside looking in, its infinitely small, inside looking out its infinitely large.
Note: We can't get an accurate police report 20 minutes after the event with 20 eye witnesses, but many are dead set that we KNOW what happened during the big bang. When you think about things like this, use your head and think about the police report.
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Everything is just speculation from unimaginative scientists who think they know what happened 14 billion years ago at some random spot that they can't even point their finger in the general direction of.
Good grief, no. Where does this idea of science ultra orthodoxy come from? I haven't worked directly with any cosmologists, but every one says "This is what we think happened. "Know" is a completely different thing, and the only people who "know" how the universe was created use a reference book from the middle east, therefore around 4004 b.c.e.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
You are talking about the observable universe. The actual universe is either infinite or looping, by definition. As for the origin of the big bang, it is only a single point in the observable universe. In the actual universe, the big bang happened everywhere.
When scientists talk about the universe, they usually mean the observable universe because as you said, there is no way to know what's beyond it.
That article and many others missed the point. What they thought they'd seen was evidence for gravitational waves during inflation. There are lots of other reasons to believe inflation happened.
As for the origin of the big bang, it is only a single point in the observable universe.
No, no, no. The Big Bang was not an explosion emanating from a point. The Big Bang happened everywhere at once. It had no center.
Does that mean I cannot blame anymore the space curvature for me being overweight ?
Don't you know it is now both immoral and criminal to think beyond the next quarterly report?
The problem is, that as far as can be determined, what we have observed, is all that mankind will ever reasonably be able to observe on this matter. So unlike the glass of water above, its like observing 99% of the lake and finding no lochness monster, then concluding there is no lochness monster.
What we have observed is what we can observe, and it may be all that we can ever observe. It does not mean that there is nothing else that can affect us. A better example is of someone stuck in a little cove, observing the ocean from that viewpoint, hence seeing only a fraction of it. As far as that person is concerned there need be nothing else anywhere.
It happens when the narrative of "think" is given to science journalists and TV producers. It then becomes "know". And that's what the public hears.
http://i.imgur.com/1nSMqI4.png
I'd be very interested in reading your paper where you include the math where working through the conceptualization of 'outside looking in'.
I'd certainly be open to other interpretations but they need to be a bit more rigorous than: I fundamentally don't understand the math of modern cosmology so I came up with some new model that's about as complicated as visualizing an inflated balloon.
BTW, your analogy really ought to be 20 cameras not 20 eye witnesses. That's a closer approximation.
Breasts are just enlarged sweat glands that exude a fatty sweat. Seriously, that's all they are. They can be nice or unpleasant or anywhere in between to look at, but what makes them special for us homo sapiens are the contexts within we are watching them. On a stripper, "Good fun". On a woman we fancy, "Woohoo!". On a woman who fancies us? THAT'S where they become beautiful.
But they're otherwise just sacks of fatty sweats under a gland. Just like kissing someone is sucking one end of a tube half full of shit.
When you think about it that way, you realise it isn't the mere object you're interested in, it's the social context of personal interaction and co-dependent involvement that makes you like boobies and kissing.
Considering how uninformed journalists are, it's not surprising that the nuance of 'know' versus 'reasonably confident based on evidence to date' is lost on them.
I've always wondered...
How is a 3-D project of a 2-D universe different from an intrinsically 3-D universe? How would you tell the difference? And would you care?
...that the flat universe is being supported by 4 elephants, and that these elephants in turn are standing on the back of a giant turtle, who is cruising the quantum realm between universes looking for quantum fish and insects to eat.
"And that, My Liege, is how we know the universe to be banana shaped"
Certain phenomenon could be different, such as the ratio of a blackhole's circumference to its mass.
Which means it's probably even flatter than Kansas.
The band or the state?
It must have been something you assimilated. . . .
Native Kansan here. There are actually several states flatter including Florida, Texas, and North Dakota:
http://www.theatlantic.com/technology/archive/2014/03/science-several-us-states-led-by-florida-are-flatter-than-a-pancake/284348/
A mathematical note: Tori can be flat.
If the universe (and here we are talking about the large spacetime structure, not any of the weird tiny compactified extra string dimension stuff) is globally flat, it can still have the structure of a torus.
The torus when viewed as a 2 dimensional space in 3 dimensions, is not flat-- it has some positively curved parts (think the outer edge of the donut) and some negatively curved portions (think the saddle like regions on the inner ring of the torus.) However, the total curvature (when I sum up all contributing curvatures) on the torus is zero. This is related to a mathematical fact that the total curvature of any surface is given by a topological quantity called the genus. In simpler terms, no matter how I deform the torus, the sum of the curvature will be zero. This is very different from the sphere, whose total curvature is always 2\pi.
So, a flat universe would imply that we cannot live on a 4 sphere, because such objects must always have at least some positive curvature. However, there are examples of tori that have no curvature.
In the 2 dimensional case, it is best to see this from the ``Pac-Man'' perspective. The pacman game is played on a flat surface, and whenever you head off the top of the screen, you arrive at the bottom, and whenever you go off the left side of the screen you wind up on the right hand side. This describes a possible shape for the universe, and this shape is the torus! To see this, imagine that you took the playing field, and glue the top and bottom sides together. That would give you a cylinder. Taking the left and right sides and gluing them together would give you a torus. Now that we believe the pacman game is played on a torus, notice that the original interpretation was a flat surface. So , there is a flat representation of the torus.
To avoid some confusion and people trying to draw flat tori in 3 dimensional space, it can't be done. Every surface viewed in 3 dimensional space will necessarily have some positive curvature around its maximal value. Sorry folks!
In fact, of all the 2 dimensional (compact) surfaces, the only one that has a flat representation is the torus. So, if the universe is compact (and 2 dimensional, which seems unlikely,) there is hope for a Pacman world.
You fail to understand what scientists know versus what they speculate about.
Not really. They're very clear about that. It's a requirement of science that you enumerate all of your assumptions, and quantify uncertainties whenever possible.
Making the assumption that they are even somewhat accurate about the big bang (unlikely)
For example, that's not an assumption. The general idea behind the big bang, that the universe was once infinitely small and it expanded, can be used to make certain predictions regarding what you expect to see when you look out in all directions, what you expect to see in the CMB, etc. You can precisely measure how accurate those predictions match up with experiments, and it's really, REALLY accurate.. Check out the text that goes with that graph: "Graph of cosmic microwave background spectrum measured by the FIRAS instrument on the COBE, the most precisely measured black body spectrum in nature. The error bars are too small to be seen even in an enlarged image, and it is impossible to distinguish the observed data from the theoretical curve."
What that boils down to is that your statement about how unlikely it is that scientific theories are "even somewhat accurate about the big bang" is provably an incorrect statement, based on our best available measurements. If you want to make an argument for your case, you need to bring something more to the table than, "I personally feel like scientists are speculating and can't possibly have a high likelyhood of stumbling upon what actually happened." The people you're criticizing have data. You have a feeling. You need to bring in some data, at which point I and everybody else will be glad to accept that our previous theories were wrong. The Lumineferous Ether was accepted theory, but when Michelson and Morley couldn't detect it using their inteferometer, and Einstein showed up with special relativity as an alternative with supporting data gathered from the 1919 solar eclipse, the Ether theory was destroyed. Scientists do not fear being proven wrong. However, you do have to bring evidence with you.
Everything is just speculation from unimaginative scientists who think they know what happened 14 billion years ago at some random spot that they can't even point their finger in the general direction of.
See? You're criticizing a theory that you don't even understand. Scientists can point to you the spot the Big Bang happened, exactly. So can I. It happened where I'm standing right now. At the exact spot that I'm standing. It also happened at the exact same spot you're standing. And at the exact center of the Andromeda galaxy. And exactly at whatever spot you pick at the edges of the milky way. Or any spot at all in the universe: Every spot in the universe is the center of the universe. The Big Bang isn't matter spreading into existing space. The space in which matter exists is expanding. Check out that video, it explains it really well.
That does not mean that space was not infinitely large while at the same time infinitely small, its all a matter of perspective. Outside looking in, its infinitely small, inside looking out its infinitely large.
This right there is the difference between speculation and scientific hypothesis. "Something that looks small from one perspective can look big from another perspective, so whose to say what's infinitely small or infinitely large" is hand-waving. Scientists don't do that. They tell you what they mean by small, and when. At roughly 10^-43 s after the Big Bang, the universe was 10^-35 m. That's the end of the Planck Epock. During the Inflationary Epoch, the universe grew to about 10 cm by 10^-32 s. These numbers are, admittedly by eve
Warning: Opinions known to be heavily biased.
And don't forget the BC vs. BCE confusion.
Well, measuring CMB for the curvature of the Universe is a bit like trying to guess the shape of a really large body of water, while underwater, by measuring the vibrations caused by the fish swimming in that same water. Basically, not enough data to truly conclude. However, NASA to the rescue! We'll probably know for sure by 2034 ish http://en.wikipedia.org/wiki/L...
Everything is just speculation from unimaginative scientists who think they know what happened 14 billion years ago at some random spot that they can't even point their finger in the general direction of.
Why would any scientist do that? They would merely point right here, just like any scientist anywhere else would. There is no center of the big bang, we are the center along with every other point.
Note: We can't get an accurate police report 20 minutes after the event with 20 eye witnesses, but many are dead set that we KNOW what happened during the big bang. When you think about things like this, use your head and think about the police report.
No, I don't think we have any clue what really happened during it, or even for a significant amount of time after it. But we have pretty solid evidence that it happened. The metric expansion of space is happening, and the CMB is there just like it should have been. It comes from all directions in space, just like it should have. It's the afterglow of the big bang. Bask in its beauty.
Your skepticism seems borne of ignorance, and that's sad. Read up on it so you can at least be legitimately skeptical.
We can see almost all the observable universe, from now until just a few hundred million years after the big bang. In other words, we can see most of the universe that there will ever be to see.
Actually, they're just used by academics, everywhere, period. Regardless of their beliefs. Science, a while ago, decided not to define itself in religious terms. I wouldn't take it so personally, because it's not. It's not militant atheism.
It's called inductive reasoning. And it's the basis of all science.
Let's not think about the very moment the observable universe came to life. t=0 is a mathematical singularity and it messes things up.
Instead we should go back in time and get closer and closer to t=0. If we consider the observable universe as a bubble inside the real, infinite universe, as we go back in time the bubble shrinks, like the rest of the universe. But shrinking something infinite doesn't make it less infinite, so in the end the observable universe will become smaller and smaller while the real universe will stay infinite. As we approach t=0, the observable universe will start to resemble a single point, but this point is still the entire observable universe, not a point inside it.
Hum, I believe the problem is that most of the world is not christian, but they would still like to be able to refer to the year according to the Gregorian calendar, since it is almost universally used.
AD is kinda heavy for non-christians; it means in full "Anno Domini Nostri Iesu Christi", or in english "In the Year of Our Lord Jesus Christ", so if you are very pedantic writing 2015 AD is actually a lie for them.
What do you suggest the Chinese and Japanese to do, for example?
entropy happens
Considering how uninformed journalists are, it's not surprising that the nuance of 'know' versus 'reasonably confident based on evidence to date' is lost on them.
Have you folks ever noticed on some of the whackier science shows, that when they get to parts that you know something about, how often they are just plain wrong?
It's a pity when we have alot of the public thinking that "Ancient Aliens" is a science show.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
therefore around 4004 b.c.e.
In my limited experience with the acronyms "BCE" and "CE", they're mostly used by atheist intellectuals that arrogantly mock religious types.
Yup, your experience is pretty limited. The problem with Before/Christ, and AD (Anno Domini) is threefold, not th eleast that you have a before and after something, yet th before, is BC and the afterwards is AD, so there is a marked inconsistency. If we use BC, one might think either AC, or BD might be an appropriate reference.
Another is that christians do not own the world. There are many people of many religions - or none at all - who are scientists, and it's quite a conceit for christians to demand that they refer to your religious value in their science.
Then there is the entire idea of before Christ and after Christ. When exactly is that year and date? I can just about for certain assure you that it wasn't December 25th, and some dating puts it at around 4 B.C.E. or thereabouts. We'll assume for the sake of argument that he did exist. So there is a lot of ambiguity about the actual date, we were saddled with the stupid year 1 thing, and it just isn't at all precise.
Their arrogant, "it's time we moved past the whole BC/AD thing since we know better," attitude is annoying as hell.
Let me get this straight. I type B.C.E. and you fly into a spittle foaming rage to tell me that I am arrogant?
You calling me arrogant is so amazingly hypocritical as to be astounding.
You are so arrogant that you demand to force other people to bow to a religious construct that isn't consistent, or even has an actual verifiable Date. Kinda nice to have a date. And your arrogance has gone so far that you are not even capable of seeing it. You see arrogance in me, because that is your worldview. When you invent something, you can tell people how to use it. C.E. and therefore B.C.E., was coined a long time ago,, as in the 1600's, by Cheristians. Deal with it.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
What do you suggest the Chinese and Japanese to do, for example?
Bow before their christian overlords.
Maybe this can be an adjunct ot Fox News' Ware on Christmas meme.
Athiests war on the God given Dating system
They don't seem to know that the earliest use of Common Era was by Johannes Kepler in 1615.
Anyone care to claim that Kepler was an arrogant atheist?
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
Humm, both did get royally fucked by christian powers. Still wasn't enough to get them to use AD, though ;p
entropy happens
Seriously I don't get it, are they saying there are more dimensions?
The article shows images of 2d things being wrapped around 3d things. So are they not saying by extension that our 3d universe is potentially wrapped in more dimensions, otherwise how could it be anything other than 3d.
And a 2d universe can't bend because it is a f**king 2d universe otherwise it wouldn't be a ruddy 2d universe it'd be a 3d universe.
This sh*t doesn't make any sense.
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all seem to understand and propagate this concept that scientists treat Science as a religion. It's like some sort of projection thing.
I think its the old adage of when your tool is a hammer, everything lookd like a nail. It's an inability to accept that everyone does not think in the same manner as they do. They cannot imagine not having a religion, so they likewise cannot imagine anyone imagining elsewise.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
"Infinite" in actualized physical terms is meaningless
Set theory is the basic logic maths is built on, it didn't change much for over 2000yrs. About a century ago people like Cantor, Godel, Russell, and many others started looking at set theory and infinities. The line of enquiry culminated with Godel's incompleteness theorem showing that any and every set of things is dependent on something else outside the set, add what is outside the set and you still have something else outside the new set. Godel's discovery that maths is "incomplete" (contains unprovable truths) destroyed what Russell and others had been trying to do with their Principia Mathematica- show that all mathematical truths can be mechanically derived from a set of fundamental axioms (Newton's "clockwork universe").
In other words Godel discovered that (maths says) the Universe (with a capital U) is "turtles all the way down" (and up).
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
No, it literally does mean that nothing else can affect us. If we are affected, we can observe these effects.
..Keira Knightley
If we are affected, we can observe these effects.
Agreed.
No, it literally does mean that nothing else can affect us.
Absolutely not. We know only what we have observed and deduced in the limited life of the human race. Other things that we have not observed or deduced yet will emerge. But until they do, we don't know that they are there.
After all, we know minecraft is smoother than a bowling ball at the scale of the earth. If you expand minecraft out to the scale of the universe, which is flatter?
Now I've heard it all. Precisely where does the third dimension .. er.. fit, then?
That in about 100 years Cosmologists will be laughing at the fact that we thought the universe was flat.