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. In a recent paper published in the journal Physics Letters B, Indiana University physicist Nikodem Poplawski presents new mathematical models of the spiralling 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 centre of black holes. DIFFERENT THEORIES PROPOSED:
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 ultra dense 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. It is said that fact is sometimes stranger than fiction, and nowhere is this truer than in the case of black holes. Black holes are stranger than anything dreamt up by science fiction writers, but they are firmly matters of science fact. In fact, science fiction writers should not have been taken so much by surprise. The idea behind black holes, has been around in the scientific community for more than 200 years. In 1783, a Cambridge don, John Michell, wrote a paper in the Philosophical Transactions of the Royal Society of London, about what he called dark stars. He pointed
out that a star that was sufficiently massive and compact, would have such a strong gravitational field that light could not escape. Any light emitted from the surface of the star, would be dragged back by the star's gravitational attraction, before it could get very far. Michell suggested that there might be a large number of stars like this. Although we would not be able to see them, because the light from them would not reach us, we would still feel their gravitational attraction. Such objects are what we now call black holes, because that is what they are, black voids in space. A similar suggestion was made a few years later, by the French scientist the Marquis de La~plass, apparently independently of Michell. Interestingly enough, La~plass included it in only the first and second editions of his book, The System of the World, and left it out of later editions. 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. 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. 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. 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...