Neutron stars steal space probe's glory
Justin Mullins

19:00 08 September 04


It has taken almost 50 years to conceive and build and has cost more
than $700 million, but now NASA's Gravity Probe B spacecraft could be
upstaged by telescopes on the ground.

The craft is designed to accurately test Einstein's general theory of
relativity. According to the theory, a gyroscope orbiting a massive object
such as the Earth should experience two forces that gradually cause it to
"precess", pushing its axis of spin out of alignment.

The stronger force, known as the geodetic effect, is caused by the
Earth warping the fabric of space-time. The other, known as the
gravitomagnetic effect, is caused by the rotating Earth dragging space and
time around with it.

Gravity Probe B, which carries ultra-sensitive gyroscopes, was
conceived in the 1950s to measure these forces, but was only launched in
April 2004. It has yet to take any measurements. Francis Everitt, the
physicist in charge of the project at Stanford University, US, says the
probe should produce results by mid-2006.

Full Text at NewScientist
http://www.newscientist.com/news/news.jsp?id=ns99996372


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Posted by
Robert Karl Stonjek

Robert Karl Stonjek wrote:

Neutron stars steal space probe's glory
Justin Mullins

19:00 08 September 04

It has taken almost 50 years to conceive and build and has cost more
than $700 million, but now NASA's Gravity Probe B spacecraft could be
upstaged by telescopes on the ground.

The craft is designed to accurately test Einstein's general theory of
relativity. According to the theory, a gyroscope orbiting a massive object
such as the Earth should experience two forces that gradually cause it to
"precess", pushing its axis of spin out of alignment.

The stronger force, known as the geodetic effect, is caused by the
Earth warping the fabric of space-time. The other, known as the
gravitomagnetic effect, is caused by the rotating Earth dragging space and
time around with it.

Gravity Probe B, which carries ultra-sensitive gyroscopes, was
conceived in the 1950s to measure these forces, but was only launched in
April 2004. It has yet to take any measurements. Francis Everitt, the
physicist in charge of the project at Stanford University, US, says the
probe should produce results by mid-2006.

Full Text at NewScientist
http://www.newscientist.com/news/news.jsp?id=ns99996372

1) Old news,
Science 303(5661) 1143;1153 (2004)
http://arXiv.org/abs/astro-ph/0401086
http://arxiv.org/abs/astro-ph/0312071
Deeply relativistic neutron star binaries

2) Bull****. Strong field measurements do not euchre weak field
measurements.

3) "New Scientist" is as reliable as the "Enquirer," and for the
same reasons.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf