When in doubt about how human beings may be affected by weightless conditions in space, don’t seek answers from levitating flies. That’s because researchers at The University of Nottingham claim their magnetically levitated fruit flies can only provide information about the effects of weightlessness on particular biological mechanisms.
Quite obviously, it’s practically impossible to carry out a similar investigation on humans since there’s no existing magnet which can do the same. However, observing the effects on model organisms like the fruit fly could at least, offer an insight into the effects of weightlessness on certain biological mechanisms. A different kind of magnetism called diamagnetism in which objects are weakly repelled from the produced fields is what the majority of biological materials are affected by.
In the study, a powerful superconducting magnet was used to create a very strong magnetic field approximately 350,000 times stronger than that of the Earth’s field, or 16 Tesla, by the involved researchers. Within the superconducting solenoid magnet, the diamagnetic repulsive force on the flies was large enough to merely balance the force of gravity in order to levitate the insects. This technique was previously employed by physicist Andre Geim and colleagues at the University of Nijmegen in 1997, to levitate a live frog.
Dr Richard Hill, an EPSRC research fellow in the University’s School of Physics and Astronomy and one of the researchers involved in the project, explained, “It’s also important to remember that, in our future endeavors to explore space, setting up permanent bases on our Moon, or Mars for example, or other planets, it will be crucial to understand the effects of weightlessness on all living organisms: our long-term survival will of course require us to take with us many different biological organisms.”
“Crucially, as far as living organisms are concerned, the levitation force balances the force of gravity right down to the molecular level. This means we can compare the levitation force, which balances the force of gravity in our magnet, with the centrifugal force that balances the force of gravity on an astronaut in orbit around the Earth. In orbit, aboard the international space station for example, gravity is still present, but because an orbiting body is effectively in ‘free-fall’, the centrifugal force on the astronauts (because they’re going around the planet so quickly), is large enough to balance out the force of gravity. Here, we’re using the diamagnetic force to balance gravity instead of centrifugal force,” added Hill.
But the strong magnetic force could hardly have been expected to go unnoticed by the flies. The insects in the center of the field apparently walked more quickly, though the reason for this behavior wasn’t clear. It could be possible that the flies found moving around in weightlessness easier on their joints and muscles or maybe there was some confusion as to which way was up or down, in the absence of gravity.
The work on these magnetically levitated fruit flies was executed in collaboration with Madrid’s Centro de Investigaciones Biologicas scientists and carried out at The University of Nottingham’s superconducting magnet supplied by Oxford Instruments.