Wed Oct 24, 2012, 08:49 PM
Bosonic (2,839 posts)
Physicists demonstrate an actual tractor beam in the lab
It seems like we're getting closer to the Star Trek future by leaps and bounds these days. We recently learned that a NASA scientist has set his sights on building a warp drive, and now news has come in that a team of physicists have built their own tractor beam in the lab. Now, it's nothing to get too excited over — they used an optical beam to pull a 30 micrometer silica sphere suspended in water — but the demonstration proved that a tractor beam can actually exist.
We've known about the power of Bessel beams for some time now, including their potential to act as a kind of tractor beam. This optical phenomenon was first discovered by Friedrich Bessel over a hundred years ago, and has since been applied by microbiologists as a kind of tweezer.
But up until this point no one has been able to prove that a Bessel beam can actually function as a kind of tractor beam. So, in an effort to make it work, physicists David Ruffner and David Grier sought to harness a rather unique property of Bessel beams.
Specifically, these laser beams are capable of reconstructing themselves on the opposite side of an object. Subsequently, the theory is that these beams can pull an object back towards the stream of light — not unlike a tractor beam.
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Physicists demonstrate an actual tractor beam in the lab (Original post)
Response to Bosonic (Original post)
Wed Oct 24, 2012, 08:56 PM
lalalu (1,663 posts)
1. Nice. Back in the nineties I saw a simulation similar to this.
It was all theory but even then there was solid belief we would have a tractor beam. The guys demonstrating the theory were young then and i wonder if they were part of this.
Physics was always the hardest of the sciences for me. Then I had one professor who said just relax and realize it is such a basic part of our surroundings. It helped.