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I thought about this a lot guys, does tractor beam come from ATTRACTION or because like…
a TRACTOR pulls stuff…
Whatever, either way thanks to lasers IT'S REAL NOW.
In the Star Trek and Wars universes a standard trope for grabbing something in space, be
that a ship or a piece of junk or whatever, was the tractor beam.
In science fiction, the tractor beam is just a given, but in real life, scientists are
really working hard to make it real.
Theoretically, there are three major tractor beam technologies.
"Optical tweezers" use laserlight to heat the air, trap particles and create a sort
of conveyor belt to move them around.
That wouldn't work in space anyway, no air.
Another uses laserlight formed into a corkscrew shape to push things around, but they can't
really make that one either…
it's called an optical solenoid beam…
The "BEST" design in my opinion is the "Bessel beam."
it uses electromagnetic, gravitational, or acoustic energy, to move particles around!
Unfortunately, they can't build one because it requires infinite energy…
#Awkward...
So none of these are great.
So, let's start over.
At its most basic, a tractor beam applies attraction force or repulsion force using
only light energy.
Pushing is easy to envision,
it's sort of like a firehose, but instead of water it's spraying photons…
pulling makes me think of magnets… but we want to do this all with a single beam…
right?
FINALLY, according to a study published at the end of last year in Nature Photonics,
science can do this!
The scientists used a new design that lets a single beam pull and push gold-coated hollow
glass spheres for quote "tens of centimeters!"
PLUS, they actually BUILT ONE!
FER REALS!
This real-world tractor beam uses a doughnut-shaped beam to grab a sphere.
Then by varying the "polarization of the beam" the researchers can push a sphere, then stop
and reverse it …
The SHAPE of the laserlight is clutch, the tube surrounds the object, trapping it into
it's energy.
Think of it like the wheel of a bicycle…[b][c][d] the lasers are always moving AWAY from the
source, but when the polarization is
radial or along the spokes of the wheel, it forms this wall of energy -- and the sphere
is pushed away.
To PULL a sphere, they change to azimuthal polarization…
making the energy flow along the rim of the wheel.
This creates a corkscrew of energy that actually hits the sphere on the OPPOSITE side from
the light source.
So it's not really PULLING as much as reaching around and hitting its back.
It's genius!
Practically, it's not going to be useful for a while, but it seems like it should work
in the vacuum of space AND in the lab.
It doesn't require air, or heat, nor does it need infinite energy -- though it would
need a lot to move say, a whole ship.
Right now they're still calling this invention, optical tweezers.
Do you even want this to be a thing?
What would YOU do with a tractor beam?
Speaking of tweezers, grooming is very important!
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