Herschel looks back in time to see today's stars bursting into life.

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A UK-led international team of astronomers have presented the first conclusive evidence for a dramatic surge in star birth in a newly discovered population of massive galaxies in the early Universe. Their measurements confirm the idea that stars formed most rapidly about 11 billion years ago, or about three billion years after the Big Bang, and that the rate of star formation is much faster than was thought.

The scientists used the European Space Agency's Herschel Space Observatory, an infrared telescope carrying the largest mirror ever launched into space. They studied the distant objects in detail with the Spectral and Photometric Imaging Receiver (SPIRE) camera, obtaining solid evidence that the galaxies are forming stars at a tremendous rate and have large reservoirs of gas that will power the star formation for hundreds of millions of years. Their observations also confirm that these galaxies represent a crucial episode in the build up of large galaxies around us today, such as our own Milky Way.

Dr. Scott Chapman, from the Institute of Astronomy in Cambridge, has presented the new results in a paper in a special edition of the journal Monthly Notices of the Royal Astronomical Society focusing on results from Herschel.

Scott comments "These Herschel-SPIRE measurements have revealed the new population of galaxies to be hotter than expected, due to stars forming far much more rapidly than we previously believed."

The galaxies are so distant that the light we detect from them has been travelling for more than 11 billion years. This means that we see them as they were about three billion years after the Big Bang. The key to the new results is the recent discovery of a new type of extremely luminous galaxy in the early Universe. These galaxies are very faint in visible light, as the newly-formed stars are still cocooned in the clouds of gas and dust within which they were born. This cosmic dust, which has a temperature of around -240 degrees C, is much brighter at the longer, far infrared wavelengths observed by the Herschel satellite.

A related type of galaxy was first found in 1997 (but not well understood until 2003) using the "SCUBA" camera attached to the James Clerk Maxwell Telescope on Hawaii, which detects radiation emitted at even longer submillimeter wavelengths. But these distant "submillimeter galaxies" were thought to only represent half the picture of star formation in the early Universe. Since SCUBA preferentially detects colder objects, it was suggested that similar galaxies with slightly warmer temperatures could exist but have gone largely unnoticed.

Dr. Chapman and others measured their distances using the Keck optical telescope on Hawaii and the Plateau de Bure submillimeter observatory in France, but were unable to show that they were in the throes of rapid star formation.

The new galaxies have prodigious rates of star formation, far higher than anything seen in the present-day Universe. They probably developed through violent encounters between hitherto undisturbed galaxies, after the first stars and galaxy fragments had already formed. None the less, studying these new objects gives astronomers an insight into the earliest epochs of star formation after the Big Bang.

Team colleague Dr. Isaac Roseboom from the University of Sussex sums up the work. "It was amazing and surprising to see the Herschel-SPIRE observations uncover such a dramatic population of previously unseen galaxies". Professor Seb Oliver, also from Sussex, adds: "We are really blown away by the tremendous capability of Herschel to probe the distant universe. This work by Scott Chapman gives us a real handle on how the cosmos looked early in its life."

With the new discovery, the UK-led astronomers have provided a much more accurate census of some of the most extreme galaxies in the Universe at the peak of their activity. Future observations will investigate the details of the galaxies' power source and try to establish how they will develop once their intense bursts of activity come to an end.

Every Black Hole Contains Another Universe?

Like part of a cosmic Russian doll, our universe may be nested inside a black hole that is itself part of a larger universe.

In turn, all the black holes found so far in our universe—from the microscopic to the supermassive—may be doorways into alternate realities.

According to a mind-bending new theory, a black hole is actually a tunnel between universes—a type of wormhole. The matter the black hole attracts doesn't collapse into a single point, as has been predicted, but rather gushes out a "white hole" at the other end of the black one, the theory goes.

(Related: "New Proof Unknown 'Structures' Tug at Our Universe.")

In a recent paper published in the journal Physics Letters B, Indiana University physicist Nikodem Poplawski presents new mathematical models of the spiraling motion of matter falling into a black hole. His equations suggest such wormholes are viable alternatives to the "space-time singularities" that Albert Einstein predicted to be at the centers of black holes.

According to Einstein's equations for general relativity, singularities are created whenever matter in a given region gets too dense, as would happen at the ultradense heart of a black hole.

Einstein's theory suggests singularities take up no space, are infinitely dense, and are infinitely hot—a concept supported by numerous lines of indirect evidence but still so outlandish that many scientists find it hard to accept.

If Poplawski is correct, they may no longer have to.

According to the new equations, the matter black holes absorb and seemingly destroy is actually expelled and becomes the building blocks for galaxies, stars, and planets in another reality.

(Related: "Dark Energy's Demise? New Theory Doesn't Use the Force.")

Wormholes Solve Big Bang Mystery?

The notion of black holes as wormholes could explain certain mysteries in modern cosmology, Poplawski said.

For example, the big bang theory says the universe started as a singularity. But scientists have no satisfying explanation for how such a singularity might have formed in the first place.

If our universe was birthed by a white hole instead of a singularity, Poplawski said, "it would solve this problem of black hole singularities and also the big bang singularity."

Wormholes might also explain gamma ray bursts, the second most powerful explosions in the universe after the big bang.

Gamma ray bursts occur at the fringes of the known universe. They appear to be associated with supernovae, or star explosions, in faraway galaxies, but their exact sources are a mystery. (Related: "Gamma-Ray Burst Caused Mass Extinction?")

Poplawski proposes that the bursts may be discharges of matter from alternate universes. The matter, he says, might be escaping into our universe through supermassive black holes—wormholes—at the hearts of those galaxies, though it's not clear how that would be possible.

"It's kind of a crazy idea, but who knows?" he said. (Related: "Are Wormholes Tunnels for Time Travel?")

There is at least one way to test Poplawski's theory: Some of our universe's black holes rotate, and if our universe was born inside a similarly revolving black hole, then our universe should have inherited the parent object's rotation.

If future experiments reveal that our universe appears to rotate in a preferred direction, it would be indirect evidence supporting his wormhole theory, Poplawski said.

Wormholes Are "Exotic Matter" Makers?

The wormhole theory may also help explain why certain features of our universe deviate from what theory predicts, according to physicists.

Based on the standard model of physics, after the big bang the curvature of the universe should have increased over time so that now—13.7 billion years later—we should seem to be sitting on the surface of a closed, spherical universe.

But observations show the universe appears flat in all directions.

What's more, data on light from the very early universe show that everything just after the big bang was a fairly uniform temperature.

That would mean that the farthest objects we see on opposite horizons of the universe were once close enough to interact and come to equilibrium, like molecules of gas in a sealed chamber.

Again, observations don't match predictions, because the objects farthest from each other in the known universe are so far apart that the time it would take to travel between them at the speed of light exceeds the age of the universe.

To explain the discrepancies, astronomers devised the concept of inflation.

Inflation states that shortly after the universe was created, it experienced a rapid growth spurt during which space itself expanded at faster-than-light speeds. The expansion stretched the universe from a size smaller than an atom to astronomical proportions in a fraction of a second.

The universe therefore appears flat, because the sphere we're sitting on is extremely large from our viewpoint—just as the sphere of Earth seems flat to someone standing in a field.

Inflation also explains how objects so far away from each other might have once been close enough to interact.

But—assuming inflation is real—astronomers have always been at pains to explain what caused it. That's where the new wormhole theory comes in.

According to Poplawski, some theories of inflation say the event was caused by "exotic matter," a theoretical substance that differs from normal matter, in part because it is repelled rather than attracted by gravity.

Based on his equations, Poplawski thinks such exotic matter might have been created when some of the first massive stars collapsed and became wormholes.

"There may be some relationship between the exotic matter that forms wormholes and the exotic matter that triggered inflation," he said.

(Related: "Before the Big Bang: Light Shed on 'Previous Universe.'")

Wormhole Equations an "Actual Solution"

The new model isn't the first to propose that other universes exist inside black holes. Damien Easson, a theoretical physicist at Arizona State University, has made the speculation in previous studies.

"What is new here is an actual wormhole solution in general relativity that acts as the passage from the exterior black hole to the new interior universe," said Easson, who was not involved in the new study.

"In our paper, we just speculated that such a solution could exist, but Poplawski has found an actual solution," said Easson, referring to Poplawski's equations.

(Related: "Universe 20 Million Years Older Than Thought.")

Nevertheless, the idea is still very speculative, Easson said in an email.

"Is the idea possible? Yes. Is the scenario likely? I have no idea. But it is certainly an interesting possibility."

Future work in quantum gravity—the study of gravity at the subatomic level—could refine the equations and potentially support or disprove Poplawski's theory, Easson said.

Wormhole Theory No Breakthrough

Overall, the wormhole theory is interesting, but not a breakthrough in explaining the origins of our universe, said Andreas Albrecht, a physicist at the University of California, Davis, who was also not involved in the new study.

By saying our universe was created by a gush of matter from a parent universe, the theory simply shifts the original creation event into an alternate reality.

In other words, it doesn't explain how the parent universe came to be or why it has the properties it has—properties our universe presumably inherited.

"There're really some pressing problems we're trying to solve, and it's not clear that any of this is offering a way forward with that," he said.

Still, Albrecht doesn't find the idea of universe-bridging wormholes any stranger than the idea of black hole singularities, and he cautions against dismissing the new theory just because it sounds a little out there.

"Everything people ask in this business is pretty weird," he said. "You can't say the less weird [idea] is going to win, because that's not the way it's been, by any means."

Hubble Peers Deeply into the Eagle Nebula

Hubble Peers Deeply into the Eagle Nebula

The Hubble Space Telescope has once more turned its attention towards the magnificent Eagle Nebula (Messier 16). This picture shows the northwestern part of the region, well away from the centre, and features some very bright young stars that formed from the same cloud of material. These energetic toddlers are part of an open cluster and emit ultraviolet radiation that causes the surrounding nebula to glow.

The star cluster is very bright and was discovered in the mid-eighteenth century. The nebula, however, is much more elusive and it took almost a further two decades for it to be first noted by Charles Messier in 1764. Although it is commonly known as the Eagle Nebula, its official designation is Messier 16 and the cluster is also named NGC 6611. One spectacular area of the nebula (outside the field of view) has been nicknamed “The Pillars of Creation” ever since the Hubble Space Telescope captured an iconic image of dramatic pillars of star-forming gas and dust.

The cluster and nebula are fascinating targets for small and medium-sized telescopes, particularly from a dark site free from light pollution. Messier 16 can be found within the constellation of Serpens Cauda (the Tail of the Serpent), which is sandwiched between Aquila, Sagittarius, and Ophiuchus in the heart of one of the brightest parts of the Milky Way. Small telescopes with low power are useful for observing large, but faint, swathes of the nebula, whereas 30 cm telescopes and larger may reveal the dark pillars under good conditions. But a space telescope in orbit around the Earth, like Hubble — which boasts a 2.4-metre diameter mirror and state-of-the-art instruments — is required for an image as spectacular as this one.

This picture was created from images taken with the Wide Field Channel of Hubble’s Advanced Camera for Surveys. Images through a near-infrared filter (F775W) are coloured red and images through a blue filter (F475W) are blue. The exposures times were one hour and 54 minutes respectively and the field of view is about 3.3 arcminutes across.