Going in Circles!

Experiment #2

Air date: 1/22/98

WHAT YOU'LL NEED:	1 centimeter graph paper pencil or marker chair
WHO YOU'LL NEED:	2 people: 1 subject 1 paper holder

WHAT YOU NEED TO KNOW:

Some of your muscles, such as your heart, work automatically. But others, called voluntary muscles, move only when you want to move them. These voluntary movements are directly controlled by the brain. Across the top of the brain are distinctive parts of the cerebral cortex called the sensory cortex and the motor cortex. The sensory cortex collects information from other parts of the brain, including your sense organs--eyes, ears, etc. Using that information, the motor cortex sends instructions to the part of the body you wish to move.

Since all human life developed under the pull of gravity, your motor skills and sense organs are pre-programmed to take gravity into account whenever you move. In space, the near weightless environment causes the brain to get confusing messages. The astronaut's muscle response may not match the visual cues or the senses of touch the astronaut is experiencing. As a result, the instructions sent back from the brain to the muscles don't always lead to effective eye-hand coordination.

Do you think disorientation on Earth would affect small motor skills?

WHAT TO DO:

1. Develop a one-sentence hypothesis.

2. Paper holder holds one sheet of one-centimeter graph paper (backed by a clipboard, book or tablet for stability) at a distance of 15 centimeters from the seated subject.

   

3. With eyes open, subject draws two circles on the graph paper, a small one about the size of a quarter, and a large one about the size of a compact disc.

4. Estimate the area of each circle by counting the square centimeters and partial centimeters. Try to be as exact as possible. Record the area in square centimeters.

5. With eyes closed, subject draws a small circle and a large circle on the reverse side of the graph paper, trying to keep the circles the same size as in step 3.

6. For each of the two circles calculate or answer the following:
   1. the estimated area of each circle in square centimeters
   2. whether the circle is opened or closed
   3. if opened, the width of the gap in cm
   4. if closed, the width of the overlap in cm

   

7. Note whether circles drawn with eyes closed are smaller, larger or the same size as circles drawn with eyes open.

8. With eyes closed, and head hung over the back of a chair in an upside down position, draw another small and large circle. Repeat step 6.

9. Repeat experiment with new participants. Record results on enclosed tally sheet and calculate averages from steps 4, 6 and 8, and the totals from step 7.

10. Record averages and return the reply card to WHAT'S IN THE NEWS, Wagner Annex, University Park, PA 16802..

To view video clip click on "Try This"
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On the video, Jim Pawelczyk demonstrates a similar experiment aboard NASA's KC-135, an aircraft capable of flying in large parabolic arc trajectories which temporarily "cancel" Earth's gravitational vector for about 35 seconds at a time.

Reply Card

Printable copy

Hypothesis:

Eyes Open