The near future by looking for the subtle signatures it would leave in the cosmic The inflationary hypothesis will be tested in This force would have faded away rapidly, leavingīehind the universe as we see it. In this view, the early universe swelled enormously because of a repulsive Many modern cosmological theories propose occurred immediately after the bigīang. 'In a related vein, a universal repulsive 'force' is also postulated to haveĮxisted during the era of inflation-an episode of extremely rapid expansion that Of cosmology, although most physicists consider conventional explanations to be Such objects have been invoked to explain some puzzles Some theorists haveĬonjectured that finite pieces of such walls could exist in the real universe and Would repel all matter with a constant acceleration. A curious solution exists in which infinite 'walls' of highĭensity are postulated, existing under very high surface tension. It turns out that relativity theory allows for the existence of repulsive forces

Of gravity, which most physicists think may be formulated. Nonintuitive effects in relativity theory or the little understood quantum theory 'Third, one can try to turn gravity against itself-that is, one can look for Undiscovered forces are severely constrained by the many negative experiments. Searchesįor such a force have proved fruitless, and the properties of any such A second way would be toįind a new kind of force, unrelated to either the electromagnetic or nuclearįorces known to science, which would provide repulsion on human scales. Such forces are known-for instance, objects canīe levitated using magnetic or electrostatic repulsion. First, something can provide aįorce opposing that of gravity. 'One can imagine three ways of countering gravity. 'The antigravity devices of science fiction are wonders of the human imagination, The general feasibility of counteracting the pull of gravity: Steinn Sigurdsson of the Institute of Astronomy at Cambridge University addresses

Given the great reader interest in this controversial topic, weĪre now providing some additional information. We recently published a brief response to Crum of the Applied Physics LaboratoryĪt the University of Washington expands on the above response: I would be extremely skeptical of the latter assertion, but I would really need to have a copy of the research paper to respond in detail.' 'To evaluate this specific antigravity claim, one would have to know whether the researchers have just counterbalanced the gravitational attraction with a magnetic force, or whether the researchers think that they have somehow nullified a gravitational field in the way that, for example, an electric field would be nullified by a Faraday cage. Hence, if you have mass or energy (the equivalent of matter, according to the formula E=mc 2), then you have the space-time curvature. As such, gravity is not a force, but a change in the local geometry of space-time. One can produce an equal and opposite magnetic force to counterbalance the pull of gravity, but gravity itself is interpreted as a curvature of space and time by mass. 'Physical law as we know it precludes the shutting off of the gravitational interaction by any means, magnetic or otherwise. So the question remains, is it possible, even in principle, to build an antigravity device?Īndrew Trupin, assistant professor of physics at Vassar college, responds: Since then, there has been-surprise-no formal publication, but the buzz of speculation continues. Rumors of an experiment showing the existence of antigravity spread like wildfire in the fall of 1996 after being mentioned in the Sunday Telegraph and then picked up by Business Week and New Scientist.

Survey of the science lab 2 gravity lab