Nordtvedt effect

Nordtvedt effect

In theoretical astrophysics, the Nordtvedt effect refers to the relative motion between the Earth and the Moon which would be observed if the gravitational self-energy of a body contributed to its gravitational mass but not its inertial mass. If observed, the Nordtvedt effect would violate the strong equivalence principle, which shows that an object's movement in a gravitational field does not depend on its mass or composition.

The effect is named after Dr. Kenneth L. Nordtvedt, from Montana State University, who first demonstrated that some theories of gravity suggest that massive bodies should fall at different rates, depending upon their gravitational self-energy.

If gravity does in fact violate the strong equivalence principle, then the more-massive Earth should fall towards the Sun at a slightly different rate than the Moon. To test for the existence (or absence) of the Nordtvedt effect, scientists have used the Lunar Laser Ranging Experiment, which is capable of measuring the distance between the Earth and the Moon with near-millimetre accuracy. Thus far, the results have failed to find any evidence of the Nordtvedt effect, demonstrating that if it exists, the effect is exceedingly weak.

References

  • THE APACHE POINT OBSERVATORY LUNAR LASER-RANGING OPERATION, by T. W. Murphy, Jr., et. al. Available online at: [1]

Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Nordtvedt effect — noun A test of the strong equivalence principle of general relativity that relies on detecting polarization in the orbit of the moon in the direction of the sun …   Wiktionary

  • Kenneth Nordtvedt — Dr. Kenneth Leon Nordtvedt is a professor emeritus in the Physics Department at Montana State University and a senior researcher specializing in relativistic theories of gravity. He was born on April 16, 1939, in Chicago, Illinois. Nordtvedt… …   Wikipedia

  • Ken Nordtvedt — Dr. Ken Nordtvedt is a professor emeritus in the Physics Department at Montana State University and a senior researcher specializing in relativistic theories of gravity. A board member scientific advisor in overseeing the joint NASA ESA Space… …   Wikipedia

  • Tests of general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts …   Wikipedia

  • Параметризованный постньютоновский формализм —     Общая теория относительности …   Википедия

  • Scientific phenomena named after people — This is a list of scientific phenomena and concepts named after people (eponymous phenomena). For other lists of eponyms, see eponym. NOTOC A* Abderhalden ninhydrin reaction Emil Abderhalden * Abney effect, Abney s law of additivity William de… …   Wikipedia

  • Parameterized post-Newtonian formalism — Post Newtonian formalism is a calculational tool that expresses Einstein s (nonlinear) equations of gravity in terms of the lowest order deviations from Newton s theory. This allows approximations to Einstein s equations to be made in the case of …   Wikipedia

  • Contributors to general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts …   Wikipedia

  • Известные учёные-релятивисты —       Служебный список статей, созданный для координации работ по развитию темы.   Данное предупреждение не устанавл …   Википедия

  • List of effects — This is a list of names for observable phenonema that contain the word effect, amplified by reference(s) to their respective fields of study. #*3D audio effect (audio effects)A*Accelerator effect (economics) *Accordion effect (physics) (waves)… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”