Astrophysical Observations: Lensing and Eclipsing Einstein's Theories

I found the following that might be of general interest, particularly
given the large number of alternative gravity hypotheses posted here,
often by people who I fear do not understand GR.

------------------------------
Paper: astro-ph/0503315
Date: Tue, 15 Mar 2005 13:11:50 GMT (177kb)

Title: Astrophysical Observations: Lensing and Eclipsing Einstein's Theories
Authors: Charles L. Bennett
Journal-ref: Science, vol. 307, pages 879 - 884 (11 February 2005)

Albert Einstein postulated the equivalence of energy and mass,
developed the theory of special relativity, explained the
photoelectric effect, and described Brownian motion in five papers,
all published in 1905, 100 years ago. With these papers, Einstein
provided the framework for understanding modern astrophysical
phenomena. Conversely, astrophysical observations provide one of the
most effective means for testing Einstein's theories. Here, I review
astrophysical advances precipitated by Einstein's insights, including
gravitational redshifts, gravitational lensing, gravitational waves,
the Lense-Thirring effect, and modern cosmology. A complete
understanding of cosmology, from the earliest moments to the ultimate
fate of the universe, will require developments in physics beyond
Einstein, to a unified theory of gravity and quantum physics.

\\ ( http://arXiv.org/abs/astro-ph/0503315 , 177kb)

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

On 16 May 2005 10:41:18 -0400, Joseph Lazio
wrote:

I found the following that might be of general interest, particularly
given the large number of alternative gravity hypotheses posted here,
often by people who I fear do not understand GR.

------------------------------
Paper: astro-ph/0503315
Date: Tue, 15 Mar 2005 13:11:50 GMT (177kb)

Title: Astrophysical Observations: Lensing and Eclipsing Einstein's Theories
Authors: Charles L. Bennett
Journal-ref: Science, vol. 307, pages 879 - 884 (11 February 2005)

Albert Einstein postulated the equivalence of energy and mass,
developed the theory of special relativity, explained the
photoelectric effect, and described Brownian motion in five papers,
all published in 1905, 100 years ago. With these papers, Einstein
provided the framework for understanding modern astrophysical
phenomena. Conversely, astrophysical observations provide one of the
most effective means for testing Einstein's theories. Here, I review
astrophysical advances precipitated by Einstein's insights, including
gravitational redshifts, gravitational lensing, gravitational waves,
the Lense-Thirring effect, and modern cosmology. A complete
understanding of cosmology, from the earliest moments to the ultimate
fate of the universe, will require developments in physics beyond
Einstein, to a unified theory of gravity and quantum physics.

\\ ( http://arXiv.org/abs/astro-ph/0503315 , 177kb)
Bennett's paper has a crude treatment of redshift in a strong
gravitational field. He says regarding redshift:
L/L0 = sqrt(1 - 2MG/c^2r)
(with L representing the reduced lambda).
He concludes that L would become zero at the horizon radius. But with
constant c, wouldn't frequency go to infinity (which would imply
infinite energy)? He does not cite a source. Any comments?

John Polasek
http://www.dualspace.net

"JCP" == John C Polasek writes:

JCP On 16 May 2005 10:41:18 -0400, Joseph Lazio
JCP wrote:

I found the following that might be of general interest,
particularly given the large number of alternative gravity
hypotheses posted here, often by people who I fear do not
understand GR.

Paper: astro-ph/0503315

Title: Astrophysical Observations: Lensing and Eclipsing Einstein's
Theories
Authors: Charles L. Bennett
Journal-ref: Science, vol. 307, pages 879 - 884 (11 February 2005)
[...]
\\ ( http://arXiv.org/abs/astro-ph/0503315 , 177kb)

JCP Bennett's paper has a crude treatment of redshift in a strong
JCP gravitational field. He says regarding redshift: L/L0 = sqrt(1 -
JCP 2MG/c^2r) (with L representing the reduced lambda). He concludes
JCP that L would become zero at the horizon radius. But with constant
JCP c, wouldn't frequency go to infinity (which would imply infinite
JCP energy)? He does not cite a source. Any comments?

Yeah, bad editing or proofreading. The gravitational redshift is zero
at the horizon and goes to infinity for a distant observer. This
means that the change in wavelength for an emitted photon is zero at
the horizon and becomes infinite for a distant observer.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

On 16 May 2005 10:41:18 -0400, Joseph Lazio
wrote:

I found the following that might be of general interest, particularly
given the large number of alternative gravity hypotheses posted here,
often by people who I fear do not understand GR.

------------------------------
Paper: astro-ph/0503315
Date: Tue, 15 Mar 2005 13:11:50 GMT (177kb)

Title: Astrophysical Observations: Lensing and Eclipsing Einstein's Theories
Authors: Charles L. Bennett
Journal-ref: Science, vol. 307, pages 879 - 884 (11 February 2005)

Albert Einstein postulated the equivalence of energy and mass,
developed the theory of special relativity, explained the
photoelectric effect, and described Brownian motion in five papers,
all published in 1905, 100 years ago. With these papers, Einstein
provided the framework for understanding modern astrophysical
phenomena. Conversely, astrophysical observations provide one of the
most effective means for testing Einstein's theories. Here, I review
astrophysical advances precipitated by Einstein's insights, including
gravitational redshifts, gravitational lensing, gravitational waves,
the Lense-Thirring effect, and modern cosmology. A complete
understanding of cosmology, from the earliest moments to the ultimate
fate of the universe, will require developments in physics beyond
Einstein, to a unified theory of gravity and quantum physics.

\\ ( http://arXiv.org/abs/astro-ph/0503315 , 177kb)
Bennett's paper has a crude treatment of redshift in a strong
gravitational field. He says regarding redshift:
L/L0 = sqrt(1 - 2MG/c^2r)
(with L representing the reduced lambda).
He concludes that L would become zero at the horizon radius. But with
constant c, wouldn't frequency go to infinity (which would imply
infinite energy)? He does not cite a source. Any comments?
John Polasek
http://www.dualspace.net