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Fastest spinning artifact and star
Q: What is the fastest spinning man-made object and what is
the speed? I am writing a book and that is an important fact in the story.
(David, Woodland, California)
![The fastest spinning man-made object: Turbo Carver’s II air turbine [Cyber Woodworking Depot, © 2003, used with permission]](images/2005-02-25-carver.gif) A:
The fastest man-made spinning object is probably a carver’s drill — similar to
the hand piece that dentists use. Most dentist drills spin about 300,000
revolutions per minute (rpm) but the air turbine in the Turbo Carver II drill
(invented by Bill Vogel and made by
High Speed Carving and
Engraving Products LLC in Federal Way, Washington) whirls at 450,000
rpm. Perhaps not an exotic plot element but plenty fast!
The fastest spinning man-made object: Turbo Carver’s II air
turbine [Cyber Woodworking Depot, © 2003, used with permission]
The next fastest device is exotic. It comes from the
micro world of MEMS (microelectromechanical systems) where moving parts are
layers of polycrystalline (a material also used in making transistors). Sandia
Laboratories in Albuquerque, New Mexico developed a small polysilicon gear that
runs faster than 300,000 rpm.
Sandia and others are developing coatings which consist of "a
single molecular layer of material on the surface to greatly reduce its
friction," says
James J. Allen of Sandia’s MEMS Device Technology group.
Further Reading:
Sandia Laboratory: Multi-level, planarized polysilicon systems-on-a-chip
Cyber Woodworking Depot: Turbo Carver II
An aside: The fastest spinning stars.
Pulsars spin the fastest. Some spin at 60,000 rpm (which pales
beside a 450,000-rpm carver’s drill). But the surface of these 10-mile (16-km)
diameter extraordinary dense bodies (the corpse of an exploded star) are
traveling super fast — 17 percent of light speed.
The entire star rotates in a thousandth of a second. (Earth
takes a day to rotate.) Molecular bonds hold the star mass together so it moves
as a unit. The center doesn’t move since the star spins about its center. A
point on the surface, however, at its "equator" has to travel fast (like the
outside men in a marching pivot line) to keep up.
For a 10-mile diameter pulsar, that speed, at the equator, is
about 31,400 miles per second (50 000 km/s). The speed of light is 186,400 mi/s
(300 000 km/s). So, a surface chunk spins at almost 20 percent of light speed
(the ultimate speed limit).
"If the fastest-spinning pulsars were to spin up still
further, they would tear themselves apart," says
Robert Massey, astronomer at the Royal Observatory Greenwich, London.
"Astronomers deduced that pulsars had to be very compact objects by working out
how fast the surface moves — in exactly the way you just did."
Further Surfing:
The Royal Observatory Greenwich: Pulsars
Space Explorers: Gravitational radiation may regulate pulsar spin
(Answered Feb. 25, 2005)
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