1L20.10 - Gravity Well - Black Hole

Code Number:
Demo Title:
Gravity Well - Black Hole
Warping of Space-Time by Mass
Area of Study:
Stellar Astronomy
Clothes Basket with Rubber Covering, Small Steel Ball, Large Steel Ball, Ping-Pong Ball (Painted, Red & Blue), Ball (Wooden), Ball (Wooden with Holes Through Diameter), Vortex Cone on Stand (Small), Vortex Cone on Stand (24 inch diameter or 40 inch diameter), and Video Camera with Power Supply.

See also 8B40.40 in Astronomy and 1L20.10/8B40.40 in Astronomy.

Place the camera looking straight down at the top of the basket.  Place the larger and heavier balls very gently into the basket. Replacement of the membrane is necessary when it shows undue wear.  Do not leave anything on the membrane during storage as stretching may occur.

The vortex cones need very little work.  Clean them with plastic polish and a soft cloth.  24 inch and 40 inch diameter fiberglass cones are available.  Note that a pretty fair demonstration of an event horizon occurs when the ball seems to stop its descent and rotate in one plane for several seconds just before it falls into the stand.

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Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.