X-Nico

unusual facts about gravitational



Acceleration due to gravity

Gravity of Earth, the acceleration caused by the gravitational attraction of the Earth

Gravitational acceleration, the acceleration caused by the gravitational attraction of massive bodies in general

Standard gravity, or g, the standard value of gravitational acceleration at sea level on Earth

Anna Maria Nobili

She authored a number of papers on satellite dynamics and co-authored a book with Andrea Milani and P. Farinella on the orbital perturbations induced by non-gravitational forces.

Barnaba Oriani

In 1789, Oriani improved his calculations by accounting for the gravitational effects of Jupiter and Saturn.

Bernard F. Schutz

He is principal investigator in charge of data analysis for the GEO600 collaboration (which, in turn, is part of the LIGO Scientific Collaboration, the largest concerted effort to directly detect gravitational waves).

C. V. Vishveshwara

"Black Holes, Gravitational Radiation and the Universe: Essays in Honour of C.V.Vishveshwara,- Bala R. Iyer and Biplab Bhawal(eds)", (Kluwer Academic Publishers (1999)) was published in his honor for one of his birthdays to which leading personalities in the field like Roger Penrose, Jacob Bekenstein, Abhay Ashtekar, Ashoke Sen etc., have contributed essays.

Colonization of the outer Solar System

---by who?---> Nuclear power is believed by some to be the only suitable power source for the colonies, although there have been proposals to use concentrated starlight/sunlight and the gravitational potential energy of planets or dwarf planets with moons.

Elisa

Evolved Laser Interferometer Space Antenna (eLISA), a proposed configuration for a space based gravitational wave detector

European Gravitational Observatory

The European Gravitational Observatory or EGO is located in the countryside near Pisa in the Comune of Cascina.

Exploration geophysics

Exploration geophysics is the practical application of physical methods (such as seismic, gravitational, magnetic, electrical and electromagnetic) to measure the physical properties of rocks, and in particular, to detect the measurable physical differences between rocks that contain ore deposits or hydrocarbons and those without.

Extragalactic planet

A team of scientists has used gravitational microlensing to come up with a tentative detection of an extragalactic exoplanet in Andromeda, our nearest large galactic neighbour.

George Johnstone Stoney

Previous to this mandate, Hermann Weyl made a notable attempt to construct a unified theory by associating a gravitational unit of charge with the Stoney length.

Gilbert School

Joan M. Centrella '71, astrophysicist; head of the Gravitational Astrophysics Laboratory at NASA's Goddard Space Flight Center.

Gravitational keyhole

Secondary gravitational keyholes are searched for by importance sampling: Virtual asteroid trajectories (or rather their ‘initial’ values at the time of the first encounter) are sampled according to their likelihood given the observations of the asteroid.

Gravitational lens

A research published Sep 30, 2013 in the online edition of Physical Review Letters, led by McGill University in Montreal, Canada, has discovered the B-modes, that are formed due to gravitational lensing effect, using National Science Foundation's South Pole Telescope and with help from the Herschel space observatory.

Astronomers from the Max Planck Institute for Astronomy in Heidelberg, Germany, the results of which are accepted for publication on Oct 21, 2013 in the Astrophysical Journal Letters (arXiv.org), have discovered the most distant gravitational lens termed as J1000+0221 using NASA’s Hubble Space Telescope.

Gravitational lensing formalism

While gravitational lensing preserves surface brightness, as dictated by Liouville's theorem, lensing does change the apparent solid angle of a source.

Hanford Site

LIGO's Hanford Observatory, an interferometer searching for gravitational waves

Instituto de Astronomía Teórica y Experimental

The project intend to construct a dedicated optical follow-up instrument for Advanced LIGO (aLIGO)and Advanced Virgo (AdVirgo) in order to surveying the sky for even very dim afterglows of gravitational waves events.

Interferometric gravitational wave detector

Current interferometric gravitational wave detectors include GEO600 near Sarstedt, Germany, and LIGO, with detector facilities in Hanford, Washington, and Livingston, Louisiana, in the United States.

Johann Georg von Soldner

Other prescient work that became unpopular and largely forgotten for similar reasons possibly Henry Cavendish's light-bending calculations, John Michell's 1783 study of gravitational horizons and the spectral shifting of light by gravity, and even Isaac Newton's study in "Principia" of the gravitational bending of the paths of "corpuscles", and his description of light-bending in "Opticks".

Laser Interferometer Space Antenna

Previous searches for gravitational waves in space were conducted for short periods by planetary missions that had other primary science objectives (such as Cassini–Huygens), using microwave Doppler tracking to monitor fluctuations in the Earth-spacecraft distance.

Leonard Parker

Specifically, by applying the technique of Bogoliubov transformations to quantum field theory with a changing gravitational field, he discovered the physical mechanism now known as gravitational particle production.

Local reference frame

When constructing his general theory of relativity, Einstein made the following observation: a freely falling object in a gravitational field will not be able to detect the existence of the field by making local measurements ("a falling man feels no gravity").

Mountain peaks of the Wicklow Mountains

Topographic elevation is defined as the vertical distance above the reference geoid, a precise mathematical model of the Earth's sea level as an equipotential gravitational surface.

Oleg D. Jefimenko

In his opinion, there is no objective reason for abandoning Newton's force-field gravitational theory (in favor of a metric gravitational theory).

Olympic-Wallowa Lineament

The Imnaha Fault (striking towards Riggins, Idaho) is more nearly in line with the rest of the OWL, and in line with the previously mentioned gravitational anomalies that run into the continent.

Planetesimal

It is generally believed that about 3.8 billion years ago, after a period known as the Late Heavy Bombardment, most of the planetesimals within the Solar System had either been ejected from the Solar System entirely, into distant eccentric orbits such as the Oort cloud, or had collided with larger objects due to the regular gravitational nudges from the giant planets (particularly Jupiter and Neptune).

Polar motion

This polar motion should not be confused with the changing direction of the Earth's spin axis relative to the stars with different periods, caused mostly by the torques on the Geoid due to the gravitational attraction of the Moon and Sun.

Rudolf Mössbauer

His fame grew immensely in 1960 when Robert Pound and Glen Rebka used this effect to prove the red shift of gamma radiation in the gravitational field of the Earth; this Pound–Rebka experiment was one of the first experimental precision tests of Albert Einstein's general theory of relativity.

Scalar theories of gravitation

Scalar theories of gravitation are field theories of gravitation in which the gravitational field is described using a scalar field, which is required to satisfy some field equation.

Shah Guido G.

When he learns that the stations that power the Sky-Island's anti-gravitational beams are close to critical, Plat convinces Shah Guido G. to order in a division of Waves (female shock-troops whose name derives from the WAVES of the United States Navy) to put down a supposed rebellion by the technicians.

Shiva Hypothesis

The hypothesis, created by Michael Rampino of New York University, says that gravitational disturbances caused by the Solar System crossing the plane of the Milky Way galaxy are enough to disturb comets in the Oort cloud surrounding the Solar System.

Shortt-Synchronome clock

This clock was purchased in 1929 and used in physicist Paul R. Heyl's measurement of the gravitational constant.

Thibault Damour

He contributed greatly to the understanding of gravitational waves from compact binary systems, and with Alessandra Buonanno, he invented the "effective one-body" approach to solving the orbital trajectories of binary black holes.

Vacuum energy

In 1973, Edward Tryon proposed the zero-energy universe hypothesis: that the Universe may be a large-scale quantum-mechanical vacuum fluctuation where positive mass-energy is balanced by negative gravitational potential energy.

William B. Bonnor

During this period he published a paper on the Bonnor Beam which models the gravitational field of a beam of light.


see also