Here at the GDC we believe in learning by doing. The GDC offers interactive science exhibits and experiments to encourage you to get actively involved in science and technology. Our science presenters can take you on a guided tour to explain the physics behind the exhibits, and how they fit in with the grand theme of our Universe. It’s great fun and educational at the same time.
The Bernoulli Ball
This fun and interactive exhibit uses a flowing jet of air to float a ball, or more balls, in the air. Bernoulli’s Principle states that an increase in the speed of moving air or a flowing fluid is accompanied by a decrease in the air or fluid’s pressure. Aeroplanes get part of their lift by taking advantage of Bernoulli’s principle. Racing cars employ Bernoulli’s principle to keep their rear wheels on the ground while travelling at high speeds.
The Giant Slinky
NEW! Use the handle of this huge 8 meter long slinky to produce transverse and longitudinal waves. The waves will travel along the slinky and “rebound” from the far end, losing a little energy each time. A great fun interactive exhibit to educate about wave motion, interference and reflection.
Ever wondered how you stop so smoothly on “The Big Drop” amusement park ride? This braking system is created by a moving magnetic car travelling over aluminium and copper panels. The moving magnetic car creates powerful eddies of electric currents which, in turn, create a magnetic force to oppose the motion. Magnetic molasses technology is used in many ways, including in non-wearing brakes for trucks and cars.
Load up 1.4kg of vegemite onto kitchen scales, raise it up a few meters into the air, and allow it to fall. What happens? Any object in free fall becomes weightless. Gravity is the only force acting upon the object. Albert Einstein had “the happiest thought of his life” when he realised that an object in free fall was comparable to the feeling of weightlessness that an astronaut in a spaceship felt. This led to his Theory of General Relativity.
Measure the speed of a sound wave in this simple science experiment. Here, a 1km long piece of poly pipe is used for the sound wave to travel through. You’ll have plenty of time to “drum” the rubber membrane and move across to listen to your own sound, made in the past. Would the speed of your sound change depending on daily atmospheric conditions?
Are you heavier on Jupiter or Mars? How much would you “weigh” if you could stand on different planets in our Solar System? This set of nine bathroom scales has been calibrated to calculate your “weight” on different places in the Solar System. The larger the mass of the planet, the heavier you will be.
Imagine being able to “see” sound. Here you can. Mineral sand sits atop a metal plate which is attached to an ipod and speaker. The ipod produces a series of different frequencies, which causes the sand on the plate to transform into different patterns. Produce a sound wave on the Giant Slinky and listen to the Tuning Fork for more fun with sound waves.
Physics tells us that antigravity is not possible. However, we can use other forces to oppose the force of gravity. Here, an electromagnet and a copper plate are used to suspend a strong magnet in the air. Ultra high speed trains in Germany and China use this technology to “float” in the air, attaining speeds of up to 500km/h.
The Corkscrew Laser
A rotating, “A” shaped metal device with an array of mirrors, reflecting a laser beam. The light patterns appear to spiral into a curved light path, even though the light travels in a straight line. We know that light can be curved through strong gravitational attraction, but this time the curved light is simply a deception of the eye.
The 4D Cube
The shapes of objects are not only changed by the curvature of space, but they are also changed by pure speed. This strange idea was one of Einstein’s first big discoveries. If you travel fast enough, the mass, length and shape of everything you see becomes altered. Equally, fast moving objects can appear to change their shapes. In this case, the TV line scan simulates a slow light speed. The cube becomes a “corkscrew” image, and by adjusting the controls, the strobe effects appear to make it almost stationary.
The Ion Drive Lifter
Our second anti-gravity exhibit is an ion engine. Ion engines have been around in science fiction for years as a way we might send spaceships to the stars. Now they are actually being tested in space. Most rockets send out a jet of hot gas from burning fuels. An ion engine instead is an all-electric rocket with no moving parts. Our ion drive allows you to fly a small craft up into the air.
Ions are electrically charged atoms. A very high voltage strips electrons from atoms in the air, the negative charge is created along the edge of the foil. The ions are accelerated downwards, thus creating a lift force which lifts the craft upwards. Because the ions are very light, ion engines need very little fuel, but they do need electric power.