Astronomers explore 'last blank space' on map of the Universe

October 28, 2009,
Afterglow of GRB 090423. Credit: AJ Levan

( -- The most distant object ever discovered is described in this week's edition of the science journal Nature. Two international teams of astronomers report their observations of a gamma-ray burst from a star that died when the Universe was 640 million years old, or less than 5 percent of its present age.

Dubbed GRB 090423, the record-breaker is an example of the brightest and most violent explosions known to exist. The explosion is thought to accompany the catastrophic death of a very massive star as it ended its life, and is triggered by the centre of the star collapsing to form a black hole.

"This observation allows us to begin exploring the last blank space on our map of the ", said Professor Nial Tanvir of the University of Leicester, who led one of the teams.

Although the itself occurred about 630 million years after the Big Bang, it is so far away (about 13.1 billion light years) that the light from the explosion only arrived at the Earth in April of this year. "It is tremendously exciting to be looking back in time to an era when the first stars were just switching on", commented team member Dr Andrew Levan of the University of Warwick.

Much of this light was in the form of very high energy gamma-ray radiation, which triggered the detectors on a satellite called Swift. Following up on the automatic announcement from Swift several of the world's largest telescopes turned to the region of the sky within the next minutes and hours and located the faint, fading afterglow of the GRB. Detailed analysis revealed that the afterglow was seen only in and not in the normal optical. This was the clue that the burst came from very great distance.

Beyond the mere breaking of a record, the age of the newly detected object opens a window into a cosmological era that has not previously been accessible to observation. The cosmic "Dark Ages" are thought to have ended about 800-900 million years after the , when light from stars and galaxies re-ionized the previously neutral gas pervading the Universe. As more gamma-ray bursts are detected from these early times, it should be possible to trace the progress of this re-ionization, leading to the intergalactic medium we see today.

Gamma-ray bursts are the Universe's most luminous explosions. Most occur when run out of nuclear fuel. As their cores collapse into a black hole or neutron star, gas jets -- driven by processes not fully understood -- punch through the star and blast into space. There, they strike gas previously shed by the star and heat it, which generates short-lived afterglows in other wavelengths.

The previous record holder was a burst with a redshift of 6.7, which places it 180 million light-years closer than GRB 090423.

Provided by Science and Technology Facilities Council (news : web)

Explore further: New Gamma-Ray Burst Smashes Cosmic Distance Record (w/Video)

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2.8 / 5 (8) Oct 28, 2009
[q} " is so far away (about 13.1 billion light years) that the light from the explosion only arrived at the Earth in April of this year.

I have never understood just how, as we see this light arriving from such an early time after the bang, WE got here first, to be able to view it.. Can anyone please explain this to me??
1.6 / 5 (18) Oct 28, 2009
"observations of a gamma-ray burst from a star that died when the Universe was 640 million years old, or less than 5 percent of its present age"

It amazes me that scientists can say something so unprovably stupid with a straight face, as if they are talking about the height of a camel or something.
4.3 / 5 (13) Oct 28, 2009
It is important to realize that there was no space or time before the Big Bang, it was the beginning of it all. The Big Bang happened not at one point in space, but rather it happened in all of space. After the Big Bang, the universe underwent a brief period of extremely fast expansion. Matter formed from recombination and hydrogen and helium formed. Now think of this as a cloud that essentially permeates space. In particularly dense parts of the cloud, gravity pulls the atoms together and creates the first structures, and stars come to be. Some stars formed far away from where we are now, and has taken billions of light years to reach where we are. So the reason that we are here so long before the light from faraway stars can reach us is because of the universe's extremely fast expansion in its early evolution, which allowed things to form far distant from each other.
4.7 / 5 (13) Oct 28, 2009
Why is it that you view the scientific world so dubiously? Do you think that scientists conjecture things without solid evidence? That there are not people who review every bit of research publication to make sure that it is aptly justified? When talking about such cosmic timescales, we use the expansion rate of the universe to determine how long ago something happened. Each element has a distinct fingerprint in the light spectrum due to electrons needing discrete energies to change orbital levels. As the universe expands, light that is travelling through it gets 'stretched', causing wavelengths to be longer than they originally were. The amount that they are shifted is a function of how long they have been around. This redshift measurement is how scientists say such things 'with a straight face'.

Science provides the only explanation of nature that necessarily follows empirical measurements. Perhaps you should treasure it instead of berating it.
1.7 / 5 (17) Oct 28, 2009
ncanna, yeah...all the time. Black holes, dark matter, dark energy, the big bang, origins of life, planetary accretion, red shift, string theory, higgs bosons...need I go on?

There is nothing empirical about "theoretical" physics.
Oct 28, 2009
This comment has been removed by a moderator.
4.7 / 5 (13) Oct 28, 2009
Skepticism is fine, but to call scientists foolish is ignorant. On the note of a large percentage of galaxies being blueshifted, I'd like to see your source for that information. The only galaxy known to be blueshifted with respect to the Milky Way as far as I know is Andromeda. On the note of galaxies colliding despite the expansion of the universe, the inflating balloon analogy only accounts for the expansion of the universe. The model does not account for the gravity of large amounts of matter, i.e. galaxies. Whenever two galaxies form in the same general vicinity, they will obviously have gravitational effects on each other. The expansion of the universe is not noticeable compared to the more dominant effects of gravity.

4.7 / 5 (12) Oct 28, 2009
mystikchakra: Galaxies are observed to have supermassive objects at their cores which are more dense than is possible for a star. What do you propose is there if not a black hole, which is predicted by the dynamics of Einstein's relativistic equations (for which there has been STRONG empirical evidence)? As for the Big Bang, what do you propose started the universe, when we can look at light redshifted to the microwave range coming unbiased from every direction in space, which indicates homogeneity in the early universe corresponding to events described by the Big Bang? Dark matter is a proposed explanation for the discrepancy between expected rotation curves and observed rotation curves of galaxies. Some physicists are trying to reformulate gravity to find an explanation which does not rely on dark matter. Higgs bosons and string theory are proposed, not relied upon as fact. You seem to have the misconception that something being popular means that it is homogeneously accepted.
5 / 5 (10) Oct 28, 2009
As for the origins of life, what is there to wonder about? We have extremely strong evidence for evolution and know much about the conditions on the Earth from the time when life was speculated to arise. The compounds which make up organic matter were present in large amounts. This, combined with a great amount of time for these compounds to mix and stew about can cause a self replicating molecule, which is the beginnings of life. Natural selection governs the rest.

So in general, yes, you do need to go on. I have yet to hear you mention anything that casts a shadow on science. The alternative is to rely on some spirituality, which is a matter of faith, not evidence. If you're willing to put your faith in something for which there is contradictory evidence, that is your prerogative, but I'll choose that which has some basis in fact.
1.9 / 5 (10) Oct 28, 2009
How is it that in a universe approximately 14 billion years old (13.7 something), is it possible to see anything further than 7 billion light years away. Me thinks the laws of physics have been ignored.
2.4 / 5 (15) Oct 28, 2009
Imho, pauldentler & mysticshakra are pretty much accurate
in their skepticism of the Big Bang hypothesis.
Unfortunately, they need to also take into consideration
what approach is needed to get any research funding and grants.

You must present a plan that fits in with their simple mindset.
Infinity is not a concept they fund. It's best to present your
objective on about an 8th grade level to get further funding.
There must also be a beginning and end to everything for funding.
Good luck trying to present a static universe made up of many
little 'Big Bangs'. It simply goes against what they want and
you'll will be looking for another job.
1.1 / 5 (8) Oct 28, 2009
I'm sorry, where is the evidence of how something unalive belcomeing alive? I mean excatly how does something like that happen? Seems like you have too have faith in a theory. By and by, there was not as much time as you suppose for this development, the eath needed time to cool before life wae even possible.
5 / 5 (11) Oct 28, 2009
Unless I am mistaken, mysticshakra seems not to be proposing an alternate explanation for cosmology, rather trying to comment on the ineptitude of modern scientists. If he were proposing an opposing theory, then I would be pleased with the enthusiasm and desire to explain.
The issue that I take is with this seeming casting-off of physics. I feel like much of the skepticism is based in a non-understanding of the actual theory and is a result of distaste with pop science.
1.6 / 5 (11) Oct 28, 2009

No what I mean is if the universe is 14 billion years old, (that is the age that scientist have put to it) and if it began as a singularity, a single point in space and time as proposed by the original big bang theory then the most we could expect to see in any direction should be seven billion light-years away. Seven billion years out and then seven billion years for the light to reach earth. This asumes we are at the center. NASA has the knowable universe as 28 billion light-years across (Approx.). The expansion theory came about as they began discovering objects outside the seven billion light year distance. Frankly I don't know how wide the universe is, only that we can only see approx. 14 billion light-years in any direction. 14 Billion being the age of the universe. Assuming a single point beginning, then we should only be able to see about seven billon light-years in any direction unless the laws of physics were violated in the beginning of the universe.
4.1 / 5 (10) Oct 29, 2009
Wow, I can't believe I live in an age where people question evolution. Regarding the article, I find it amazing how vast the universe is, it astonishes me.
4.9 / 5 (46) Oct 29, 2009
"if the universe is 14 billion years old, (that is the age that scientist have put to it) and if it began as a singularity, a single point in space and time,..." - TK1

The universe didn't begin IN space and time, as if it was embedded in an already existing background space. The distance that light travels to get to us increases as the universe expands, in other words space itself is expanding, ... it's not just that the galaxies are flying apart THROUGH space.
3.7 / 5 (6) Oct 29, 2009
For the doubters: The reason we still study these things is exactly because the theories are incomplete and because the experts doubt many parts of the theories. If we felt that we already knew it all, and that every one of our explanations was correct, then there would be no reason to study it any more. The metaphysical ideas like creationism are also still alive and kicking. Serious cosmologists often have ideological and philosophical discussions. The prevailing wisdom right now is that we are missing some big parts of the big picture. Relax and join the debate, but don't criticize the scientists for looking for answers and making an effort to explain what they see. The "big bang" has an interesting origin. The term was first used by a critic of the idea (he was making fun of it), not by people supporting the concept, and it's a bit of a misnomer actually.
1.3 / 5 (6) Oct 29, 2009
Is it possible that redshift of photons is not caused by the expansion of space, fueled by yet to be understood dark energy,

...but that the expansion of space caused by the photons travelling through it, transferring part of their energy to it, hence getting observed in a lower/redshifted energystate.

Is space like custardpudding? I surely hope so, because then when the universe approaches heat death, there won't be photons left to inflate the balloon and gravity could take over again...
4.3 / 5 (4) Oct 29, 2009
the most we could expect to see in any direction should be seven billion light-years away. Seven billion years out and then seven billion years for the light to reach earth. This asumes we are at the center.

Hmm... you seem to be imagining that there exists some point in space which you could travel to and say "I'm at the center of the universe -- this is where the Big Bang happened." But I'm afraid that's not true.

Imagine an expanding balloon, with two-dimensional life forms on the surface arguing about who is at the center. But the true center is not even on the surface. The standard model of the universe is of such a balloon, but with more dimensions, and what we call "space" exists only at the balloon's surface. Flatland is an excellent book for understanding extradimensional spaces.

Anyway, in theory, a beam of light traveling a "straight" line would circumscribe the universe right back to where it started -- if the universe weren't expanding at light speed.
2.8 / 5 (4) Oct 29, 2009
@Husky: It's fairly easy to rule that out via experiment and observation for a bunch of different reasons.

@Sonhouse: Try thinking of the universe as a balloon where not only is the balloon too big around for us to see any more than a little patch, but also the skin is too thick for us to see to the edge. Both the size of the balloon and the thickness of the skin are expanding. Not only can you see things that are 13 billion years old, but you can see them in every direction. To think of the starting point before the big bang as being in any particular direction is a little bit wrong. The starting point is all around us, in every direction at the same time. The starting point itself has expanded, and our universe IS that expanded point. We're not actually traveling away from some central point, we're part of it and it's getting bigger. The balloon analogy is a little off, but there's no way to really describe it with analogy so we use what we have. (that's the theory anyway)
1 / 5 (1) Oct 29, 2009
That's funny Damon; We cross-posted, and you beat me to it. lol, even used the same analogy.
3.4 / 5 (5) Oct 29, 2009
@ncanna et al
there are so many locked in paradigms in our observations of the natural world. All of them are just theories. And they don't fit ALL the data so something may be fishy - either the data or the theory. The problem is that human nature makes us comfortable with what we know so we tend to discount any "spurious" data.

Several examples; the big bang theory has a big hole - the superluminal expansion period early on has never been satisfactorily explained just "swept under the rug" to quote Feynman.
Halton Arp's observations that some related stellar objects have different red shifts. He's has been ostracized because he dared to publicize his observations - they have been swept under that rug too.
Dark matter and dark force are not needed if gravity's 1/d^2 attractive force diminishes to zero at some extreme distance instead of continuing on to infinity. The strong force and weak force have strange behaviors too.
Observation shows we are at center of the universe! ??
4 / 5 (4) Oct 29, 2009
Although there are holes in our theories, is it not okay to get excited and make statements about the results that a set of data supports? I accept that our ideas may not be correct, I was simply refuting the idea that scientists are making these claims on no basis and trying to help people understand where cosmology currently stands on the mentioned topics.
5 / 5 (2) Oct 29, 2009
Dark matter and dark force are not needed if gravity's 1/d^2 attractive force diminishes to zero at some extreme distance instead of continuing on to infinity.

This is very interesting to me. Can you provide a reference? As a physics simulation programmer, I have a preference for integer math (it's far more efficient) which will tend to cut off forces at extreme distances as you describe, and sometimes I'll manually force a cut-off even when using floating-point math. Such optimizations are absolutely essential if you want to simulate a very large system. It would both please and amuse me tremendously if we found that the universe itself does the same! But I'm still not sure how this would explain galactic rotations, the cobweb-like arrangement of matter at the cosmic scale, or the gravitational lensing attributed to dark matter.
not rated yet Oct 30, 2009
This news is so damn old. Like say 6 months old? I don't get it why news published in Nature is different from new published in and a dozen of other sites. People should start living in modern days and stop paying tribute to the anachronism called "article" in a Journal. We have to move on to other forms of peer-reviewing that won't require months of waiting and so much power focused in just 1 or 2 reviewers. God bless whoever came with the idea of

As for the news, GRB090423 is really a news, mostly because there's nothing to produce it at that redshift. But people somehow comfortable pass trough this fact. It is sad that astrophysics is such a mob. Very very sad...
5 / 5 (2) Oct 30, 2009
Gee... hundreds? Out of billions? Wow, that *is* a big percentage! :-P
5 / 5 (1) Oct 31, 2009
How do you know there are billions of galaxies?

The latest estimates are in the hundreds of billions, as Google can attest. And estimates increase as telescopes improve.

it has a boundary, the boundary being defined as the outermost galaxies in orbit about a "central core"

Um... are you talking about the "boundary" of our observational limits (ie 13.7B ly)? Or are you talking about some sort of physical boundary that a space ship would bounce off of...? The standard hyperspherical model of the universe allows you to travel infinitely in any (three-dimensional) direction. You never reach a boundary, but you could end up back where you started. See my earlier post about balloons and Flatland. The hypersphere has no boundary, except in the sense that it *is* a boundary.

The standard model also says the universe is homogeneous at the cosmic scale -- i.e. there's no central gravitational core. What cosmological model are you usin
not rated yet Oct 31, 2009
The balloon metaphor really is the best. Imagine a balloon where the rubber has a thickness of zero -- that is, it's a true 2-dimensional surface. 2-dimensional creatures live within (not on!) this surface. They cannot leave the surface; they cannot even conceive of the 3-dimensional space outside it. These creatures think their space is infinite, because they can travel infinitely in any direction without ever reaching a boundary. Eventually they might circle the balloon and end up back where they started, except that the balloon is expanding too rapidly for this ever to happen. They argue about which of them lives at the center of their universe, but they're all wrong: the center does not even reside within their plane (or curve, rather) of existence. Their space is finite and yet has no perceivable boundaries. It has a center yet they can't reach it, or even conceive of its location.

Standard theory says you and I reside in the 3D surface of a 4D balloon (more or less).
not rated yet Oct 31, 2009
Actually, the universe does appear to be "expanding uncontrollably" (at an accelerating rate, even!) and the distance between galactic superclusters is in fact growing quickly as a result. See http://en.wikiped...of_space

I'm still not quite understanding your picture of the universe. Are you imagining a flat space-time continuum containing a spherical universe? And if so, what would a ship encounter when leaving the boundary of that sphere? Empty space?

Does your cosmological model have a name? Can you point me to a reference so that I can understand it?

The hyperspherical shell universe I'm talking about has absolutely nothing to do with any spherical structures that you might observe such as galaxy clusters, etc. A galaxy or galaxy cluster would be like a picture painted on the surface of the hyperspherical balloon, and the sphericalness of the picture is completely unrelated to the shape of the canvas that the picture is drawn on.
5 / 5 (1) Nov 01, 2009
A hypersphere is like a sphere but it exists in more than 3 dimensions. See http://en.wikiped...ersphere for more info about them, including their technical definition. But to truly understand them, I suggest reading the excellent and entertaining classic "Flatland: A Romance of Many Dimensions". It's actually a novella, with a plot and everything, but it does such a good job of explaining dimensions that it has become a classroom text. It became extremely popular after the standard model of cosmology (the universe as a hypersphere) was developed. I'd consider it essential reading. Even if you end up rejecting the standard cosmological model, it's good to understand it first.

You can read the entire novella (with illustrations) for free here:
4 / 5 (2) Nov 01, 2009
Um... which part was fiction? Are you referring to the "Flatland" book? Or the standard cosmological model of the universe?

If you're saying that all extradimensional spaces are fiction, then there goes pretty much all of physics out the window...
5 / 5 (1) Nov 01, 2009
It may sound like sci-fi to you, Paul, but ever since Einstein set his theory of general relativity loose upon the world, you really can't learn modern cosmology without extradimensional math. Heck, if you think this stuff is hard to swallow, you should try quantum mechanics! ;-)
5 / 5 (1) Nov 02, 2009
The best you've been able to do thus far is quote fiction from Wikipedia.

I'm still unclear on exactly what it is that you're referring to as fiction. Are you calling the standard cosmological model (i.e. the universe as a hypersphere) fiction? Or is there something else?
5 / 5 (4) Nov 02, 2009
First, I googled galaxy blue-shift as you requested, and checked out the first four or five pages, all of which seemed to be in agreement with there only being ~100 blueshifted galaxies. Even if you assumed that we were wrong in assuming billions of galaxies, we have still directly observed 10,000 galaxies in the HUDF alone, meaning that there are < 1% of galaxies blueshifted.

Have you ever taken an astrophysics or cosmology course in your life? Not knowing the meaning of the term hypersphere shows that you do not have the mathematical or astrophysical maturity to even understand what is being discussed, much less make coherent points about it.

Galaxies which are 13 billion years old look the same as galaxies nearby because the state of evolution that our galaxy is currently in is expected to last about 100 billion years. We would have to look further to see the first galaxies forming, so at the furthest we look now, galaxies were the same as the galaxies nearby.
5 / 5 (5) Nov 02, 2009
Furthermore, I would like to point out that you are arguing in a very incoherent manner, changing topic or making outlandish claims whenever you are challenged by a valid point. Making a nuclear reactor is nowhere near the ultimum of quantum mechanics.
Mathematics is not fiction.
A hypersphere is a generalization of the notion of the sphere to a higher dimensional setting.
A hypersphere does NOT connotate an immensely large globe.
Atoms are not bound by the gravitational force - it is far too weak. Electrons are bound to the nucleus via electromagnetism.
Your claim that orbiting objects coalesce into spheres is wrong - generally they flatten into disks because of mutual gravitation.
The universe is finite, but not in the manner you are describing - you could never reach its 'boundary'.

In short, please be educated about something before you try to refute it.
3.3 / 5 (6) Nov 03, 2009
I would like to ask where Paul has seen a picture of a galaxy 13 billion light years away? NASA would pay hundreds of millions for a picture of a galaxy that far away. The only thing we can see that far away are gamma ray bursts because they are so much brighter than all the other light coming from the galaxy combined. Whether the galaxy actually looks like our own is still a mystery as far as I know. It is thought that the galaxy in which this 13.7 billion year old GRB happened would actually look a little different than our own though. There should be quite a bit more Hydrogen and Helium there and much less iron and other heavy elements at that point in time. Unfortunately, that galaxy is so far away that all we can see of it is the light from an immense explosion which passed through some part of its parent galaxy on the way here. That galaxy is not visible to our best telescopes, so we have no idea what it looks like. You, Paul, are clearly uninformed.
5 / 5 (4) Nov 03, 2009
He's right. Like the surface of this planet is finite but there is no boundary: You'll never find an edge to jump down from earth's surface.

Directly in front of me is a "sphere", it is a world globe of the oceans and land masses. It does not look "infinite" to me.

No one claimed it was. He said it was finite. In fact, that's the central point we keep trying to make to you: the globe is finite yet you'd never reach a boundary no matter how many miles you walk. Are you drunk?
1 / 5 (1) Nov 03, 2009
Oh, one more thing Paul. Your idea about red shift being caused by the light bumping into things was also recently discounted. There was a very recent observation of another gamma ray burst where they observed both visible and infra-red frequencies at the same time, and found that the lower frequencies are not in fact delayed. That is a rather new discovery though, so quite a few people haven't heard about that one yet. That theory of red shift is no longer possible and has been discarded by the community as far as I am aware. There was an article about it on this web site in the last couple weeks I believe. The consensus was already in favor of dropping that theory anyway, but the new evidence is so compelling that there's no argument now.
1 / 5 (1) Nov 03, 2009
sure, huge invisible gas clouds all around us I suppose? Nice.

Oh, and where is your picture of the galaxy 13 billion light years away. I'd really like to see that one. I'm still waiting.
5 / 5 (2) Nov 03, 2009
The Earth is just an analogy. As 3-dimensional creatures, we cannot hope to intuitively perceive a 4-dimensional object such as a hypersphere. The closest you can get is to imagine a 2-dimensional being living on the surface of a regular 3D sphere. This being is flat like paper; he has no thickness at all. He has no concept of up or down, so he cannot possibly perceive the boundary of the sphere he lives on. All he knows is that he can travel all he wants in any direction he can perceive (which is limited to north, south, east, west, and everything between), and never reach any boundary. This is because his universe (the sphere's surface) IS the boundary.

Likewise, we 3D beings could build spaceships and travel all we want in any direction we can perceive, and never reach any boundary. And this is because our universe IS the boundary. It is the surface of a 4D hypersphere. Standard cosmology says that our universe IS finite and IS bounded; we simply can't perceive the boundary.
5 / 5 (1) Nov 03, 2009
If you have never noticed it before, our planet Earth is a sphere, & guess what else? It has a central core just like all spheres. A sphere cannot exist by it's "skin" only, it requires supporting layers of substrate, or it will collapse inward uncontrollably.

And in fact some models predict that precisely that will happen. (It's called the "Big Crunch".) But other models predict that there won't be enough gravity to halt the universe's expansion; they say that matter is spread too thin, and the universe will expand forever. And to further confuse things, the universe's expansion seems to be governed by forces other than just gravity! In fact, the expansion seems to be accelerating -- suggesting that some repulsive "force" is overcoming the gravity. So the jury is very much still out on all this.
1 / 5 (1) Nov 04, 2009
No paul, he should not start with a course in Euclidean geometry. That is not the type of geometry that applies here, but I wasn't discussing the geometry of the universe. I'm talking about the subject of this article, and your doubts about how the new galaxy looks just like the ones nearer to us. I want to know why you think the galaxy 13.7 billion light years away looks like the ones we see near us. You see, we actually have no idea what that galaxy looks like. That is exactly what this article is about. The gama ray burst gives us a rare chance to gather a little data about what that galaxy may have been like 13.7 billion years ago, when the GRB happened. That's what the title of the article is talking about when they say "filling in a gap". We have very little info about that time in the history of the universe. The geometry of the universe is in fact still in question, so you are actually quite correct to question the geometry. The point is that they are trying to figure it out.
1 / 5 (1) Nov 04, 2009
I ran out of space, so sorry for double post. The state of that galaxy could tell us whether the big bang is a big hoax or maybe indicate that the big bang theory is on the right track. That's the point of looking at things so far away. You get a chance to see farther back in time because it took so long for the light to reach us. The farther we see back in time, the better we begin to understand how the universe did come to be, and what the shape of it is right now. You are talking about spheres but I don't think it's been settled yet whether the universe has positive curvature. It could be flat or have negative curvature. Going around the earth and ending up where you started isn't the same as going around the universe though. Going around the earth takes you on a curved path. Going around the universe takes you in a straight line in timespace. The idea of going in a straight line and ending where you started isn't Euclidian geometry, so that's what the other people are arguing about
2.3 / 5 (3) Nov 04, 2009
P.S. no Paul, I'm not an astrophysicist, or a cosmologist (the field you actually meant I think). My background is in aerospace engineering and business applications programming. I do however read a LOT of books about cosmology and very much enjoy pondering the big unanswered questions such as the shape of the universe and how it began. The big bang theory has a few big holes, so they could stumble onto a huge discovery any day that totally changes our ideas about reality. Seeing an object 14 billion years old would be interesting for sure. lol.
not rated yet Nov 04, 2009
Going around the earth and ending up where you started isn't the same as going around the universe though. Going around the earth takes you on a curved path. Going around the universe takes you in a straight line in timespace.

Well, technically, it's a geodesic, not a line. A geodesic is the closest you can get to a straight line when you're constrained to a curved space. If it were *really* a straight line, then you could never end up back where you started. :-) But you're right, the analogy is imperfect, because on the Earth we're not really constrained to the surface. We're not 2D beings.

You are talking about spheres but I don't think it's been settled yet whether the universe has positive curvature.

Agreed. The current model is of a hypersphere, as this does the best job of explaining the data, but the field of cosmology is still young. General relativity has pretty well established that space is curved locally, but the large-scale geometry is less certain.
1 / 5 (1) Nov 14, 2009
As a retired shop teacher, I don't begin to have the math to keep up with this discussion. Which is ok, because the article wasn't about math anyway. It was about various atoms in a star that exploded, a long way off, and a long time ago. And, we just saw it. Period.

I have never understood just how, as we see this light arriving from such an early time after the bang, WE got here first, to be able to view it.. Can anyone please explain this to me??

Good question Paul. Look guys, can we stick to the real world here? As the scientific community did for for relativity, before Einstein produced the starlight disappearing behind the planet thing. Nobody cares about math, unless it corresponds to the real world. Even then, most folks prefer the real world.

There may be other dimensions, dark energy, a big bang, etc. Do any of you have any evidence for any of it though? Start easy, answer Paul's question first.

Your certainty about unproven math reminds me of the ID crowd.

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