2007-11-15 John Moffat says dark matter does not exist In 1981 the inflationary universe model was proposed to solve some of these problems, in particular to explain the expansion of the universe and the existence of mysterious “negative-mass” matter. It suggested that for a fraction of a second at the beginning of the universe, it expanded at an exponentially fast rate. But even this theory left some questions unanswered.



Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies—stars, gas and dust—is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.



In the early 1990s Moffat proposed a radical alternative theory: that the speed of light was faster closer to the time of the big bang. His early calculations suggested that light travelled as much as 1,030 times faster than its present value (186,000 miles per second) just following the explosive beginning of the universe.



Last month theoretical astrophysicist Joao Maguelijo of Imperial College London published Faster than the Speed of Light, a new book describing his theories on a variable speed of light and

acknowledging Moffat’s groundbreaking work. In August 2002 the journal Nature published a paper by Paul Davies from the Australian Centre for Astrobiology, a followup on other papers based on Moffat’s theory.



“Had I not been aware of John’s work, I would not have myself made a small contribution to this field,” Davies says. “John has shown how it is possible to think outside the square when confronting some of the puzzles of cosmology. In particular, his cosmological solutions seem to be in good agreement with the remarkable new astronomical results showing that the fine structure constant seems to have varied over cosmological history.”



This work may herald a major reinterpretation of cosmological data, Davies adds, and require important changes to the conceptual scheme used as a framework for cosmology over the last half century. But Moffat has his detractors within the physics community.



Now John Moffat and colleagues suggest that there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn't exist.



In August 2007, the University of Arizona astronomer and his colleagues published a report that a collision between two clusters of galaxies, namely the Bullet Cluster, had caused huge volumes of dark matter to separate from the ordinary matter composing the galaxies. Many thought this was a proof to the existence of of dark matter.



But, John Moffat suggests now that his Modified Gravity (MOG) theory can explain the Bullet Cluster observation. MOG predicts that the force of gravity changes with distance. The study is published in the Nov. 21 issue of the Monthly Notices of the Royal Astronomical Society (2007).



"MOG gravity is stronger if you go out from the center of the galaxy than it is in Newtonian gravity," Moffat explained. "I say dark matter doesn't exist. It's the gravity that's changed." The MOG theory can explain the results of the detailed observations of the collision of galaxies and the dark matter was not necessary to explain the observations of the light bending.



Moffat thinks that the present day expectation by many that dark matter must exist is similar to the expectation by many leading scientists in the beginning of the 20th century that a "luminiferous ether" should exist. This was a hypothetical substance, in which the waves of light were supposed to propagate. Now it is commonly accepted that ether is not needed to explain know observations.



Source: University of Toronto



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In 1981 the inflationary universe model was proposed to solve some of these problems, in particular to explain the expansion of the universe and the existence of mysterious “negative-mass” matter. It suggested that for a fraction of a second at the beginning of the universe, it expanded at an exponentially fast rate. But even this theory left some questions unanswered.Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies—stars, gas and dust—is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.In the early 1990s Moffat proposed a radical alternative theory: that the speed of light was faster closer to the time of the big bang. His early calculations suggested that light travelled as much as 1,030 times faster than its present value (186,000 miles per second) just following the explosive beginning of the universe.Last month theoretical astrophysicist Joao Maguelijo of Imperial College London published Faster than the Speed of Light, a new book describing his theories on a variable speed of light andacknowledging Moffat’s groundbreaking work. In August 2002 the journal Nature published a paper by Paul Davies from the Australian Centre for Astrobiology, a followup on other papers based on Moffat’s theory.“Had I not been aware of John’s work, I would not have myself made a small contribution to this field,” Davies says. “John has shown how it is possible to think outside the square when confronting some of the puzzles of cosmology. In particular, his cosmological solutions seem to be in good agreement with the remarkable new astronomical results showing that the fine structure constant seems to have varied over cosmological history.”This work may herald a major reinterpretation of cosmological data, Davies adds, and require important changes to the conceptual scheme used as a framework for cosmology over the last half century. But Moffat has his detractors within the physics community.Now John Moffat and colleagues suggest that there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn't exist.In August 2007, the University of Arizona astronomer and his colleagues published a report that a collision between two clusters of galaxies, namely the Bullet Cluster, had caused huge volumes of dark matter to separate from the ordinary matter composing the galaxies. Many thought this was a proof to the existence of of dark matter.But, John Moffat suggests now that his Modified Gravity (MOG) theory can explain the Bullet Cluster observation. MOG predicts that the force of gravity changes with distance. The study is published in the Nov. 21 issue of the Monthly Notices of the Royal Astronomical Society (2007)."MOG gravity is stronger if you go out from the center of the galaxy than it is in Newtonian gravity," Moffat explained. "I say dark matter doesn't exist. It's the gravity that's changed." The MOG theory can explain the results of the detailed observations of the collision of galaxies and the dark matter was not necessary to explain the observations of the light bending.Moffat thinks that the present day expectation by many that dark matter must exist is similar to the expectation by many leading scientists in the beginning of the 20th century that a "luminiferous ether" should exist. This was a hypothetical substance, in which the waves of light were supposed to propagate. Now it is commonly accepted that ether is not needed to explain know observations.