What’s going on?

The exhibit simulates Earthquake. An earthquake happens when two segments in the earth’s crust suddenly slip past one another. The surface where they slip is called the fault or fault plane. Sometimes an earthquake has foreshocks- these occur before the stronger shaking. They are smaller earthquakes that happen in the same place as the larger earthquake that follows. This is what you feel at first. The largest, main earthquake is called the mainshock. You feel this very strong shaking and also see the violent swinging of hanging lamp and tree. Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur afterwards in the same place as the mainshock.

Magnitude and Intensity measure different characteristics of earthquakes. There is one magnitude for each earthquake. Magnitude measures the energy released at the source of the earthquake. It is determined from measurements on seismographs. Intensity measures the strength of shaking produced by the earthquake at a certain location. This varies depending on where you are during the earthquake. It is a description (rather than a measurement) of effects on people, damage to man-made structures or changes in the earth’s surface.

The Richter Scale is a rating of magnitude. Modified Mercalli Intensity Scale and Phivolcs Intensity Scale (PEIS) are bases for finding the intensity of an earthquake.

What’s Going on?

Notice that when only a part of the ball is out of the air stream you can feel the ball being sucked back. If you release the ball, it will move back to the center of the air stream and stay afloat.

When the ball is pulled partly out of the air stream, the air that is moving fast along the side of the ball exerts less sideways pressure on the ball than the still air in the room. The greater pressure of the surrounding air pushes the ball back to the center. The ball stays afloat because the air from the blower exerts an upward force on the ball. The maximum capacity of the blower makes the ball stay at a certain height. In other words, when a stronger source of moving air is used, the ball will float higher.

Try these other exhibits on Body Works:

Come Race with Me, Watch Me Pedal, Momentum Machine, Pick a Cone, Pipes of Pan, Training Wheel

What’s Going on?

When you rotate the crank, electricity is produced as indicated by the movement of the voltmeter needle. When you place a finger on a brass plate then rotate the crank, you feel nothing in your finger. When you place two fingers from the same hand on the two brass plates and rotate the crank, you experience a tingling feeling or mild electric shock in your fingers. This indicates that electricity flows through your fingers as in a closed circuit.

Try these other exhibits on Electricity and Magnetism:

Body beat, Circuit, Conductors and Insulators, Electric Fleas, Van De Graaff, Hand Battery, Jacob’s Ladder, Laser harp, Magnetic Repulsion, Magnetic Suction, Pedal power, Photovoltaic Cell, Plasma Sphere, Radiometer, Steady Hand Game, Thompson Ring, Tesla Coil, Video Camera

What’s going on?

When you stand in front of the wall, you produce three colored shadows: cyan, magenta, and yellow. The color of each shadow is the complement of the color of the light source–red, green, and blue. These three primary colors make up white. The complement refers to the color needed to produce white by addition. So, when a shadow removes one color from white, it must leave the complementary color. The area of one shadow is lighted by the two remaining primary colored lights. Hence, it can be seen that the two primary colors add to produce the complement of the third. For example, red and green lights form a yellow shadow in the path of the blue light.

Try these other exhibits on Vision and Perception:

Head on Platter, Wonder House, Wall of Illusion, Symmetroscope, and Anti-Gravity Mirror