Science

The Harwell Campus is home to a rich cross-section of science, spanning chemistry, physics, astronomy, biology, and pretty much anything else you can thing of! Showcasing this science is a core part of RAL MaDFest, and the list of exhibits and activities you can find at the festival this year are shown below.

Please note that, due to the nature of science "occasionally going wrong" (i.e. breaking), the exhibits below are subject to change without notice.

Cloud Chamber

The Cloud Chamber is one the earliest forms of particle detector. The diffusion cloud chamber, as developed by Alexander Langsdorf Jr. in the 1930's, is basically a sealed chamber cooled at the bottom and containing a heated source of alcohol (such as isopropanol) at the top. The alcohol is very volatile, easily forming a vapour, and as it falls down into the chamber it cools, and really wants to condense back to a liquid. However, there is nothing for it to condense back on to, so it should just fall freely to the bottom as a vapour. What you will see, however, is that tiny droplets of liquid alcohol do form in the chamber, creating "clouds".

Why does this happen? Charged particles, from a radioactive source or simply those from natural background radiation, polarise the alcohol molecules and cause them to become attracted to each other, which allows them to condense. So, while you cannot see these charged particles directly, what you can see is the evidence of them passing through the chamber in front of you.

Van de Graaf Generator

The Van de Graaf generator was an early form of particle accelerator, creating very high electric potential that could be used to accelerate subatomic particles. Its operation is based on the triboelectric effect, which you may be familiar with already, since it is the same effect that is responsible for other static electricity (for instance, rubbing an inflated balloon against your hair allows you to "stick" the balloon to the ceiling).

A small Van de Graaf generator like the one shown here can generate up to one hundred thousand volts of static electricity! This is certainly enough to make your hair stand up on end, but why does this happen? As the static electric charge transfers to your body, every part of you is taking on a small charge. Since this charge is the same over your whole body (including each hair on your head) and your hair is quite light, the similar charges repel each other and cause your hair to spread out to, basically, try and get away from itself! This whole process only works if you are insulated from the ground - otherwise, the electric charge would go straight through you and into the Earth, and you hair would remain exactly where it is.

Photo credit: STFC.

Lego(TM) Beamline

Lego(TM) can be used to build pretty much anything, from recreating famous movie scenes, to actual bridges. With the Mindstorms sets its possible to now create 'interactive' models that can effectively see & sense, and be programmed to react. So, for instance, it's possible to build a model of a diffraction beamline, illustrating the principles of those at ISIS, Diamond, and elsewhere, purely out of Lego.

A laser pointer is mounted on the instrument and points at a diffraction grating - this splits the incoming beam of light into separate beams with a well-defined angular spacing (which depends on the spacing of the diffraction grating). The detector is mounted on a rotating arm, and this scans around and measures the intensity of light as a function of angle. The intensity of the measured light is then drawn ('plotted'), which gives a set of diffraction 'peaks'. So why not come along and get your souvenir "diffraction postcard"!

Rubik's Cube Solver

Everyone knows the Rubik's Cube, even if you haven't ever solved one (which includes the author of this article). It is the brainchild of a professor from Hungary, Ernõ Rubik, who wanted to find away to help his students understand problems in three dimensions.This led him to develop the first prototype of what we now know as the Rubik's Cube in 1974. Although appearing simple, there are an astonishing 43,252,003,274,489,856,000 (just over 43 quantillion) possible combinations. Despite this, people who train hard at solving the puzzle can do so incredibly quickly - the current world record is 4.22 seconds. If you don't believe it, watch this video for proof!

There are, of course, techniques and algorithms that can be used to solve the puzzle, no matter what the starting patterns on the sides of the cube are, and it has been suggested that solution is never more than twenty moves away. Give a computer the information on the starting point of the cube, and some "robotic hands" by which to manipulate it, and it can can perform the same feat as the world champion. The example we have on show solves it more slowly, yes, but this is only due to the speed and limited dexterity of the robot. With some engineering it is possible to make a robot that can do it in 0.9 seconds.

Thermal Camera

While a common camera is sensitive to light from the visible spectrum, a thermal camera detects that from the infrared spectrum. Every object emits some amount of black body radiation - this spectrum of this radiation depends only on the temperature of the object itself, obeying Planck's Law. So, a camera which is sensitive to infrared radiation can determine the temperature of objects purely "by sight".

You may have seen examples of such cameras used in diverse applications such as police helicopters (scanning for people on the ground below, typically at night) or night vision goggles. You may also be surprised to know that your mobile phone is able to detect some part of the infrared spectrum. While you can't do thermal imaging because there are filters in place to selectively capture the visible spectrum, you can see the beams of infrared light emitted from your remote control if you point it directly at your phone. Try it out!

Photo credit: STFC.

Robotic Arm

Robots can be programmed to perform complex movements with precision, making them useful in many settings from production lines in factories to mining in dangerous locations. The robot here has been developed by technicians to swap delicate samples around on the neutron beamlines, automating the process so that the humans can put their feet up for a bit. It is also clever enough to know if a helpful human tries to intervene, and move the samples around without telling it!

Diamonds

Diamonds are invested into almost every level of our lives. From the materials we use on a daily basis, to the vehicles we travel in, the telecommunication systems we use, and even technologies that are yet to be commercialised. Diamond literally is on the cutting edge of every major innovation and boundary known to man.

At Element Six, part of the De Beers Group of Companies, we design, develop and produce synthetic diamond and other supermaterials, and operate worldwide with primary manufacturing facilities in China, Germany, Ireland, South Africa, the UK and US.

Meteorites

We explore space in lots of different ways. We use our experiments to study meteorites and moonrocks to try and understand more about how our solar system evolved. We build cameras and robots that are sent into space to study comets and our neighbouring planets, and we’re helping to build the world’s largest radio telescope: the Square Kilometre Array, which will help us to test Einstein’s theory of gravity and search for alien life. Participants will have a chance to hold meteorites for themselves – the oldest things they’ll ever touch – as well as program our small robots to explore Mars, and explain how the Square Kilometre Array will work.