Building the invisible - The chemistry of almost everything (18/31)

Uploaded by OUlearn on 03.09.2009

The point of this story?
Chemistry happens in your head.
You'll never see a real molecule.
You can't pick one up and see what fits where.
It's an imagined world.
But we don't need to see molecules.
We knew the Earth was round long before astronauts went up into space
to see it for themselves.
But maybe we're getting to the stage now
where we can sort of visualise atoms.
The thing that looks like a psychedelic egg box
floating in mid-air
is a representation of the surface of a matrix
of just 50 carbon atoms of graphite.
It's an image produced by a scanning tunnelling electron microscope
or STM.
The STM basically is kind of like a Braille microscope.
It doesn't present you with an image,
it presents you rather with a series of points that are scanned by a tip
as it moves back and forth across the surface.
So you get a grid of information
that tells you the height at each point on the surface.
We then reconstruct that as a shaded image
that looks like a surface and we present to the user
who's wearing a head-mounted display
which is basically two small TV sets, one in front of each eye,
and then we change the picture according to how the user moves
so it looks to them like there's a plastic surface
floating out in space in front of them.
It isn't just any view of the invisible.
The movements of his hand are monitored by a computer.
And by moving forward he can zoom into the image to inspect detail.
Chemists will be able to go from merely passively watching the surface
into a world where they can grasp, turn and rotate the image.
The idea is to represent things in a natural way that deals with surfaces
at its most basic level
and those are very natural and understandable to humans
and so we've tried to provide an interface that lets the scientist
concentrate on the surface itself
instead of on the interface to the instrument.
We can visualise the surface of matter.
A valuable tool to a chemist.
It's getting closer to reality but it's still only a representation.
Some of the most inconspicuous elements...
Beryllium - keeping the time.
Beryllium can be found in the springs of wind-up watches.
Americium - discovered in America.
This radioactive element makes smoke alarms work.
Europium - you're looking at it right now.
It's in the phosphor that makes your TV screen glow.
Osmium - for the very best fountain pen nib you don't need gold
but a hard osmium alloy.
Selenium - its electrical properties change with light.
Very handy in photocopiers.
Antimony - listen to a church bell.
You could be listening to brass with just a little bit of antinomy added.
Six inconspicuous elements.