Is the speed of gravity really being tested with this experiment?

wolram
Gold Member
Dearly Missed
Messages
4,410
Reaction score
555
Last edited by a moderator:
Physics news on Phys.org
http://Newton.ex.ac.uk/aip/physnews.620.html

Kopeiken and Fomolont interpret this slight displacement as providing an experimental handle on the speed of gravity itself, and thereby calculate the value of 1.06 times c. Other scientists disagree with this interpretation, and say that the radio lensing data can do little more than provide a measurement of the speed of light, not gravity. Two such opinions, by scientists who did not report at the AAS meeting, are as follows: Clifford Will of Washington University in the US (preprint at (www.arxiv.org/abs/astro-ph/0301145 ) and Hideki Asada of Hirosaki University in Japan
 
Last edited by a moderator:
http://www.metaresearch.org/media%20and%20links/press/SOG-Kopeikin.asp

Abstract. New findings were announced on 2003/01/08 by S. Kopeikin, claiming to have measured the "speed of gravity" and finding it essentially equal to the speed of light. These findings are invalid by both experimental and theoretical standards because the quantity measured was already known to propagate at the speed of light. The hyped claims therefore do a disservice to science in general and the advancement of physics in particular because the announced findings do not represent the meaning of the actual experimental results and cannot possibly represent the physical quantity heretofore called "the speed of gravity", which has already been proved by six experiments to propagate much faster than light, perhaps billions of times faster. Several mainstream relativists have also stated their disagreement that the experiment really measured what it claimed to measure.
 
Last edited by a moderator:
http://www.nature.com/nsu/020902/020902-13.html

The accuracy needed to verify Kopeikin's calculations is challenging. The telescopes must pick up angular differences of less than a third of a billionth of a degree. But Kopeikin is confident that his techniques, developed in collaboration with Ed Fomalont of the NRAO, are sensitive to discrepancies 100 times smaller than that - just enough to confirm Einstein's predictions.
 
In this video I can see a person walking around lines of curvature on a sphere with an arrow strapped to his waist. His task is to keep the arrow pointed in the same direction How does he do this ? Does he use a reference point like the stars? (that only move very slowly) If that is how he keeps the arrow pointing in the same direction, is that equivalent to saying that he orients the arrow wrt the 3d space that the sphere is embedded in? So ,although one refers to intrinsic curvature...
ASSUMPTIONS 1. Two identical clocks A and B in the same inertial frame are stationary relative to each other a fixed distance L apart. Time passes at the same rate for both. 2. Both clocks are able to send/receive light signals and to write/read the send/receive times into signals. 3. The speed of light is anisotropic. METHOD 1. At time t[A1] and time t[B1], clock A sends a light signal to clock B. The clock B time is unknown to A. 2. Clock B receives the signal from A at time t[B2] and...
So, to calculate a proper time of a worldline in SR using an inertial frame is quite easy. But I struggled a bit using a "rotating frame metric" and now I'm not sure whether I'll do it right. Couls someone point me in the right direction? "What have you tried?" Well, trying to help truly absolute layppl with some variation of a "Circular Twin Paradox" not using an inertial frame of reference for whatevere reason. I thought it would be a bit of a challenge so I made a derivation or...
Back
Top