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Space is festooned with vast "hyperclusters" of galaxies, a new cosmic map suggests. It could mean that gravity or dark energy - or perhaps something completely unknown - is behaving very strangely indeed. We know that the universe was smooth just after its birth. Measurements of the cosmic microwave background radiation (CMB), the light emitted 370,000 years after the big bang, reveal only very slight variations in density from place to place. Gravity then took hold and amplified these variations into today's galaxies and galaxy clusters, which in turn are arranged into big strings and knots called superclusters, with relatively empty voids in between. On even larger scales, though, cosmological models say that the expansion of the universe should trump the clumping effect of gravity. That means there should be very little structure on scales larger than a few hundred million light years across. But the universe, it seems, did not get the memo. Shaun Thomas of University College London (UCL), and colleagues have found aggregations of galaxies stretching for more than 3 billion light years. The hyperclusters are not very sharply defined, with only a couple of per cent variation in density from place to place, but even that density contrast is twice what theory predicts. "This is a challenging result for the standard cosmological models," says Francesco Sylos Labini of the University of Rome, Italy, who was not involved in the work.

They are the biggest questions that science can possibly ask: where did everything in our universe come from? How did it all begin? For nearly a hundred years, we thought we had the answer: a big bang some 14 billion years ago.But now some scientists believe that was not really the beginning. Our universe may have had a life before this violent moment of creation.Horizon takes the ultimate trip into the unknown, to explore a dizzying world of cosmic bounces, rips and multiple universes, and finds out what happened before the big bang.Neil Turok, Director of Perimeter Institute for Theoretical Physics in Canada, working with Paul Steinhardt at Princeton, has proposed a radical new answer to cosmology's deepest question: What banged?Answer: Instead of the universe inexplicably springing into existence from a mysterious initial singularity, the Big Bang was a collision between two universes like ours existing as parallel membranes floating in a higher-dimensional space that we're not aware of.One bang is followed by another, in a potentially endless series of cosmic cycles, each one spelling the end of a universe and the beginning of a new one. Not one bang, but many.Sir Roger Penrose has changed his mind about the Big Bang. He now imagines an eternal cycle of expanding universes where matter becomes energy and back again in the birth of new universes and so on and so on.

newscientist.com - A shape-shifting fifth fundamental force could neatly explain the mystery of dark energy and some other puzzling astronomical observations

There is a strange and mysterious world that surrounds us, a world largely hidden from our senses.The quest to explain the true nature of reality is one of the great scientific detective stories.Clues have been pieced together from deep within the atom, from the event horizon of black holes, and from the far reaches of the cosmos.It may be that that we are part of a cosmic hologram, projected from the edge of the universe. Or that we exist in an infinity of parallel worlds. Your reality may never look quite the same again.

Albert Einstein's towering reputation is only enhanced by his self-styled biggest blunder. It might not have been a blunder after all. At stake is the fate of the universe. In 1915, Einstein derived the equations of general relativity that describe the workings of a gravity-dominated cosmos. He added a fudge factor called the cosmological constant to ensure that, in keeping with contemporary tastes, the universe described neither expanded nor contracted. Soon after, though, Edwin Hubble showed that distant galaxies were receding from us, blowing the static universe apart. Einstein reputedly disowned his idea. He might now want to disown the disowning. The discovery in 1998 that very distant supernovae appear to be not just receding but accelerating away from us suggests the presence of a mysterious "dark energy" that counteracts gravity's pull (The Astronomical Journal, vol 116, p 1009). And it turns out that a good way to reproduce this effect is to add the fudge back into Einstein's cosmological recipe. That is not to everyone's taste, largely because no one knows what dark energy might be. Some cosmologists favour other solutions. If Earth were at the heart of a giant cosmic void, for instance, that too would create the illusion that the distant cosmos is flying away from us. But that would involve abandoning an idea we have held dear for centuries: the "Copernican principle" which says that Earth's place in the universe is not at all special (New Scientist, 15 November 2008, p 32). Working out the true story may take some time. But if the evidence collected on these pages is anything to go by, science rarely shies away from slaughtering its sacred cows.

A theory of reality beyond Einstein's universe is taking shape - and a mysterious cosmic signal could soon fill in the blanks