Slashdot Mirror
CERN Begins New Antimatter Gravity Experiments (phys.org)
An anonymous reader quotes a report from Phys.Org: We learn it at high school: Release two objects of different masses in the absence of friction forces and they fall down at the same rate in Earth's gravity. What we haven't learned, because it hasn't been directly measured in experiments, is whether antimatter falls down at the same rate as ordinary matter or if it might behave differently. Two new experiments at CERN, ALPHA-g and GBAR, have now started their journey towards answering this question.
After months of round-the-clock work by researchers and engineers to put together the experiments, ALPHA-g and GBAR have received the first beams of antiprotons, marking the beginning of both experiments. ALPHA-g began taking beam on October 30, after receiving the necessary safety approvals. ELENA sent its first beam to GBAR on July 20, and since then the decelerator and GBAR researchers have been trying to perfect the delivery of the beam. The ALPHA-g and GBAR teams are now racing to commission their experiments before CERN's accelerators shut down in a few weeks for a two-year period of maintenance work.
After months of round-the-clock work by researchers and engineers to put together the experiments, ALPHA-g and GBAR have received the first beams of antiprotons, marking the beginning of both experiments. ALPHA-g began taking beam on October 30, after receiving the necessary safety approvals. ELENA sent its first beam to GBAR on July 20, and since then the decelerator and GBAR researchers have been trying to perfect the delivery of the beam. The ALPHA-g and GBAR teams are now racing to commission their experiments before CERN's accelerators shut down in a few weeks for a two-year period of maintenance work.
What they measured there was the mass, which for masses that small can be measured by applying a known force while it is moving (typically through an orthogonal magnetic field) and measuring how quickly its trajectory is altered. How much inertia it has, however, does not necessarily mean that it reacts to gravity the same way as normal matter.
File under 'M' for 'Manic ranting'
Or maybe it falls up?
This experiment will check this but it is overwhelmingly likely to find that anti-matter falls just like matter. If it doesn't then things as fundamental as special relativity and quantum mechanics are in for a very significant rewrite.
It's one of those things, "You don't know until you try." I think everyone has a low expectation of finding that anti-matter behaves differently with gravity, but it's an experiment we can do, so why not do it?
We know there is something missing here (that is, why is matter so much more common than anti-matter?) so we need to keep experimenting, process of elimination, until we find the answer.
"First they came for the slanderers and i said nothing."