Wednesday, April 30, 2008

Wii Balance Board




"The Wii Balance Board is a pressure sensitive, wireless balance board that is placed on the floor so someone can stand on it in front of the TV while playing special video games. The Wii balance board senses weight and shift in balance in any direction, and so by simply standing on the Wii board during activities allows players to follow along to movements ensuring they have control of the on-screen activities."

Monday, April 28, 2008

D-BOX Motion Code™

" D-BOX Motion Code™ is sophisticated, groundbreaking technology that creates real-life motion perfectly synchronized to on-screen movie and gaming action.

All the motion is encoded frame by frame by a skilled D-BOX motion artist. It is NOT activated by bass sound, nor does it simply tilt and pivot.

With approximately 24 frames per second and 124 programmable movements per frame, encoding a film demands endless hours of creative input and exploration by our motion artists. They currently have a data bank of over 4000 subtle – and not so subtle – movements and are creating new ones with each new movie title..."

http://www.d-box.com/2008/mfx.html

Saturday, April 26, 2008

Jeppe Hein's "Moving Walls" (2001)

"Everything is in motion, everything is changing, everything is being transformed and yet nothing changes." Jean Baidrillard

Chris Burden's The Flying Steemroller (1996)

Cunningham's "Antic Meet" (1958)

Friday, April 25, 2008

Aesthetics of standing

Posturogram showing the trace of the center-of-pressure (COP) while standing quiet. Length unit = mm.

Thursday, April 24, 2008

Zeno's paradox: motion is an illusion




British photographer Sam Taylor-Wood explores notions of weight and gravity in elegiac, poised photographs and films such as Ascension (2003) and a series of self-portraits (Self Portrait Suspended I - VIII) that depict the artist floating in mid air without the aid of any visible support.

Monday, April 21, 2008

Edgar's Amazing Pickle Show



WHO IS EDGAR?
Behind the scenes, in a monochromatic storeroom, lives a fat and lonely man, pregnant with pickles. His dreams are the stuff of 1920's circus sideshows. His reality is a chair and a paper friend.
Filmed and Edited by enLIGHTnING Films
Choreography by Claudia de Serpa Soares and Grayson Millwood

Friday, April 18, 2008


NL Architects, Cruise City, City Cruise, 2003

Tuesday, April 15, 2008

Hiller's Flying Platform



US scientist Charles Zimmerman determined that a helicopter rotor could work just as well if put below a vehicle as above it. After a scary-looking device with uncovered blades called the De Lackner Aerocycle was flown, the Hiller Company built the VZ-1 Pawnee.

The Pawnee worked on the basis of so-called 'kinesthetic control'. In other words, the vehicle's direction and speed was controlled by the pilot shifting his body. It was thought that any soldier could learn this instinctive form of control.

Second and third versions, each with a larger, deeper rotor duct were built. The third was so large that kinesthetic control was ineffective and it had a seat and conventional helicopter controls. These designs flew well enough, but the army judged them to be too small, slow and of limited usefulness and practicality for combat service.

more

Rotorcycle

Concept from the 50s was the WASP - a jet-powered, one-man platform that could fly up to 10,000 feet.

the world's largest motion platform


the wave-induced motion


The two motion bases here represent the wave-induced motion of the decks of two different ships. The motion base on the left represents a cargo ship with a 1/32 scale crane while the right motion base represents a lighter ship used to transport the cargo.

Sunday, April 13, 2008

Vertical Oscillating Platform



The Graybiel Lab constructed a vertical oscillating platform for a specific series of motion sickness experiments. The design was conceived by Dr. Simone Bortolami who also directed the construction. The platform can move up and down ± 0.85 meters at a frequency of 0.25 Hz, one complete cycle in 5 sec. This is the key frequency produced by large ships that evoke motion sickness. With this intensity of stimulation, it has been found that 50% of subjects will vomit in one hour (O’Hanlon & McCauley, 1974).

The moving shuttle rides on linear bearing rails and is driven by a 2 meter long ball screw and high torque motor. The system was designed with a minimum safety factor of 4 on the weakest link (the ball screw to gearbox coupling) under the highest load conditions. An independent braking system is triggered by three automatic failure modes (one software and two hardware) and kill switches are accessible to the subject and experimenter. Both hardware safety loops were designed to OSHA standards.

The seat in which the subject rides is built for racing cars and cushions the subject in the unlikely event of shock. It has a five-point safety harness designed to withstand a 9g crash load. The highest g load under operational conditions will be just under 2g, at the point where the oscillator reverses from down to up motion.

Saturday, April 12, 2008

DIY: Vestibular illusions

Illusion 1 – Sensing Yaw Motion

What to Do
The volunteer sits on the chair with head upright and fists on his or her thighs in the “two thumbs up” position. Tell them to rotate their wrists so that the thumbs point in the direction of movement. If the movement changes to a different direction, the wrists should be rotated so that the thumbs point in that direction. If the volunteer does not perceive any motion, the thumbs should be pointed upwards. Cover the volunteer’s eyes with the blindfold and touching only the seatback of the chair, give the chair a spin. Push the chair hard enough to rotate it eight to ten times. If necessary, give the chair an additional gentle push to keep it rotating. Gripping the chair back, slow the chair to a rapid but smooth stop. Wait a few moments to observe thumb movements and then remove the blindfold. Tell the volunteer to stare at a fixed point on the wall.

What Happens
At first, the volunteer will point thumbs in the same direction the chair is rotating. After stopping the chair, the volunteer will reverse the direction of the thumbs, indicating a feeling of movement in the opposite direction. Upon opening his or her eyes, the volunteer will experience rapid side-to-side flicking motions of the eyes that can be observed by staring directly at the volunteer’s face.

Graphic depicting a test subject indicatings the perceived direction of movement by pointing his or her thumbs.

Why
The rotation of the chair causes the endolymph within the yaw axis semicircular canal to begin moving. At first, the inertia of the fluid causes it to lag behind the motion of the subject’s body. This causes the cupula and its hair cells to bend. Now stimulated, the hair cells send signals to the brain telling it that motion has been initiated and in what speed and direction. When the chair is stopped, the momentum of the now moving endolymph causes it to continue moving even though the volunteer’s head and semicircular canals have stopped. The hair cells are now bent in the exact opposite direction as before. This sends a false signal to the brain that the direction of motion has reversed. Nystagmus, an involuntary flicking eye movement, shows the link between the vestibular and visual systems. This reflex occurs when the brain mistakenly believes the body is still moving in this Illusion and instructs the eyes to “look ahead”. The eyes track objects that the brain believes are coming into the field of vision even though the view isn’t changing.

Above: The test subject indicates the perceived direction of movement by pointing his or her thumbs.

Safety Precautions

• The Barany Chair is not an amusement ride. Please follow the directions and exercise caution when it is being used.
• Use the safety lap belt and a spotter at all times.

• Assist students in getting in and out of the chair. A small step stool may be helpful.

• Following demonstrations, allow students to sit in a non-rotating chair until any dizziness wears off.

• Perform only one illusion at a time. Allow a few minutes for the effects of the first illusion to wear off before beginning another.

• Screen candidates for motion sickness, but keep a plastic bag or container nearby in the event of illness.

Vestibular Illusion 2 – Failure to Sense Motion

What to Do
Follow the same set-up used for Illusion 1. Put a dark blindfold on the volunteer and provide ear protection to diminish auditory clues. Rotate the chair as before and have the volunteer identify the direction of motion with their thumbs. Keep the chair spinning 10 or 15 times before very gently stopping it. As with the first illusion, the volunteer should point his or her thumbs in the direction of perceived movement or upward if the volunteer perceives that motion has stopped.

What Happens
The volunteer will perceive the start of motion by pointing his or her thumbs in the direction of rotation. After a number of rotations, the
volunteer will point the thumbs upward even though the chair is still rotating. Finally, the volunteer will point thumbs the opposite direction
from the first movement to indicate counter rotation.

Why
As with the first illusion, endolymph in the yaw semicircular canal will lag behind the initial motion. Signals sent to the brain will be interpreted as bodily rotation in a particular direction. Gradually, the endolymph in the yaw semicircular canal will catch up with the motion, and stimulation of the hair cells in this canal will stop. The brain will falsely interpret the lack of hair cell stimulation to mean that the chair has come to rest. Later, when the chair slows down or stops, the momentum of endolymph will cause it to continue to flow through the yaw canal. Stimulation in the opposite direction will be falsely interpreted as movement in the opposite direction.

Vestibular Illusion 3 – Sensing Roll Motion

What to Do
Have the volunteer grip the arm rests with both hands. After putting the blindfold in place, instruct the volunteer to drop his or her chin to the chest and close the eyes. Spin the chair at least ten times then bring it to a smooth stop. Tell the
volunteer to sit up straight and open their eyes. Safety Reminder: Be sure to use a spotter when performing this illusion.

What Happens
The volunteer will experience a powerful cartwheeling sensation to the left or right (depending upon the spin direction) upon opening his or her eyes. The volunteer will find it difficult to remain sitting straight up and will tend to lean aggressively to one side or the other.

Why
By tilting the head forward, the roll axis
semicircular canal will be brought into the same plane of rotation as the Barany Chair. By stopping the chair and tilting the head back to the vertical position, the roll axis will be repositioned while the endolymph fluid is still moving in the roll axis canal. This will cause a strong sensation of cartwheeling movement. The volunteer will try to lean in the opposite direction to compensate for the effect.

Vestibular Illusion 4 – Sensing Pitch Motion

What to Do
Have the volunteer grip the arm rests with both hands. Instruct the subject to close their eyes, lean forward slightly, and turn their head as far to one side as possible. Spin the chair at least eight times in the direction the volunteer is facing, then bring it to a smooth stop. Tell the volunteer to sit back and raise his or her head to the upright position and open their eyes. Safety Reminder: Do not use a blindfold or ear covers when performing Illusion 4. Be sure to use a spotter when performing this illusion.

What Happens
The volunteer will sense that he or she is tumbling backwards and may have a difficult time sitting up.

Why
By leaning forward and tilting the head to the side, the pitch axis semicircular canal will be brought into the same plane of rotation as the motion of the Barany Chair. After stopping and returning to the upright position, endolymph fluid will continue to move in the pitch axis canal. This will cause a strong sensation of tumbling. The volunteer will readjust his or her body position in order to counteract the perceived movement.

Important Safety Note: While it is possible to simultaneously stimulate all three semicircular canals with the Barany Chair, it is NOT recommended. Simultaneous stimulation of the three canals can lead to total spatial disorientation sensation and illness.

Other Uses for the Barany Chair

The classroom version of the Barany Chair is ideal for a variety of other demonstrations of physics and technological challenges.

Conserving Angular Momentum – Hand the volunteer small barbells to extend at arm’s length during the initial rotation. By bringing the barbells in toward the chest, the rotation rate will increase. The rotation rate increases because the barbells are traveling in a smaller circle than before. To conserve their angular momentum, the rotation rate has to increase. Extending the barbells back outward slows the rotation rate, but angular momentum is still conserved. This demonstration gives the illusion of getting something for nothing.

Newton’s Laws of Motion – Hand the volunteer an electric leaf blower. While preventing the cord from wrapping too tightly around the pedestal, have the student turn on the blower and direct the exhaust at right angles. The chair will begin to accelerate. After a few rotations, the exhaust should be directed the other way so that the chair decelerates. The rotational movement of the chair demonstrates Newton’s First and Third Laws of Motion. The rate at which the chair accelerates or decelerates demonstrates the Second Law of Motion.

Working In Space – Firmly hold a threaded pipe joint over the head of the volunteer. Have the volunteer screw a pipe nipple tightly into the joint. The chair simulates microgravity and Newton’s Third Law of Motion comes into play. Without a fixed anchor point, the astronaut rotates in the opposite direction from the turning motion. This demonstration illustrates why space-walking astronauts require foot restraints as they work in space.

NASA learning resources