*  Weblogs Forum - Deterministic Software Development
... so the bodies need to be big enough for gravitation to have an effect in order for it to be a true 3-body problem. I think this ...
The theory of Einstein which generalizes special relativity to noninertial frames of reference and incorporates gravitation ... Find out information about EINSTEINS THEORY OF GRAVITATION. See relativity, general theory. ... redirected from EINSTEINS THEORY OF GRAVITATION). Also found in: Dictionary, Thesaurus.. Related to EINSTEINS THEORY OF ... The theory of Einstein which generalizes special relativity to noninertial frames of reference and incorporates gravitation, ...
*  SparkNotes: Gravitation: Orbits: Orbits
... s Gravitation: Orbits. Learn exactly what happened in this chapter, scene, or section of Gravitation: Orbits and what it means ...
*  Gravitation
Discover more about Gravitation. One of thousands of articles selected and checked for the Wikipedia for Schools by SOS ... gravitation in Wiktionary, the free dictionary.. Gravitation is a natural phenomenon by which all objects with mass attract ... Newton's law of gravitation simplifies to F = mg, where m is the mass of the body and g is a constant vector with an average ... Gravitation is also the reason for the very existence of the Earth, the Sun, and most macroscopic objects in the universe; ...
*  NetLogo Models Library: Gravitation
Gravitation. If you download the NetLogo application, this model is included. (You can also run this model in your browser, but ... Wilensky, U. (1998). NetLogo Gravitation model. http://ccl.northwestern.edu/netlogo/models/Gravitation. Center for Connected ...
*  Gift, a gravitation fanfic | FanFiction
I turned in this fanfiction at http/ a site naughtily dedicated to Gravitation by Maki Murakami. I was under the pen name of ...
*  Dirac's large numbers hypothesis in Einstein's theory of gravitation | SpringerLink
Newton's law of universal gravitation is formulated relativistically in terms of these two times and the proper distance ...
*  Newton's Theory of Universal Gravitation--Lesson Plan #30
Terms: Gravitation (or gravity), inverse-square law, solar constant.. Stories: The Story of Newton's apple is traced to its ... 20) Newton's Theory of Universal Gravitation This lesson re-derives Newton's result, that if the force of gravity decreases ... Newton's 'universal' gravitation led to a principle which today is all too easily taken for granted: that the same physical ... That is why he named his idea the theory of universal gravitation.. Was the inverse squares law just a lucky guess? It was more ...
*  Download Gravitation Cosmology And Cosmic Ray Physics
The download gravitation cosmology and cosmic ray may make on 90 phones. The download gravitation cosmology and cosmic ray ... When download gravitation appears, it too consists no tumors. questions and rules no necessitate as the download gravitation ... France dreamed download gravitation into The age. Paris to be Offices to the concentrations at the history. With download ... download gravitation of the Manuscripts of the Most Hon. England if they came to Move against Historians of patient. ...
*  Photon energy and gravitation | Physics Forums - The Fusion of Science and Community
You say 'but not still poven' and then say 'If it's red but with high intensity, it will bend spacetime more than if it's blue but with low intensity'. Is that a yes and a no? Can we say some think the math shows that Photons can bend spacetime but it has never been observed? There are many theories that deserve attention but until observations support the math, shouldn't we be careful not to present it as fact? I am new here and what to learn and would just like to have the facts straight ...
*  Gravitation and Orbiting Satellites | Physics Forums - The Fusion of Science and Community
Similar Discussions: Gravitation and Orbiting Satellites * Gravitation - Satellite in circular orbit (Replies: 3) ... Newton's Law of Universal Gravitation, Satellites & Orbits, Kepler's Law of Planetary (Replies: 3) ...
*  Gravitation, Quantum Mechanics and the Least Action Electromagnetic Equilibrium States
... Michaud A*. Senior Researcher, Canada. ... It must be emphasized here that Einstein himself had become convinced toward the end of his life that gravitation follows the ... Since all matter in existence is made of massive atoms, gravitation logically must be emergent from the properties of these ... The relation between these least action electromagnetic resonance states and the wave function as well as with gravitation will ...
*  Gravitation (book) - Wikipedia
Gravitation is a physics book on Einstein's theory of gravity, written by Charles W. Misner, Kip S. Thorne, and John Archibald ... "Juryoku riron : Gravitation koten rikigaku kara sotaisei riron made jiku no kikagaku kara uchu no kozo e. (Japanese)". amazon. ... To quote Ed Ehrlich "'Gravitation' is such a prominent book on relativity that the initials of its authors MTW can be used by ... "Gravitation - Book Review". sky-watch.com. Archived from the original on 2 February 2016. Retrieved 1 January 2015. J. B. ...
*  Gravitation (film) - Wikipedia
Gravitation (Serbo-Croatian: Gravitacija ili fanstastična mladost činovnika Borisa Horvata; English: The Fantastic Youth of ...
*  Self-gravitation - Wikipedia
The equation to calculate the effects of self-gravitation were made exact by Lynden-Bell for the purpose of giving an exact ... Self-gravity (self-gravitation) has important effects in the fields of astronomy, physics, seismology, geology, and ... Lynden-Bell, D. Stellar dynamics: Exact solution of the self-gravitation equation. Monthly Notices of the Royal Astronomical ... Three-dimensional models, oceans, rotation and self-gravitation. Geophysical Journal International, (2002) 150. p. 303-318. ...
*  Demographic gravitation - Wikipedia
Reilly, W.J. "The Law of Retail Gravitation", New York, 1931. Stewart, J.Q. "Demographic Gravitation: Evidence and Application ... It has been related to W. J. Reilly's law of retail gravitation, George Kingsley Zipf's Demographic Energy, and to the theory ... Demographic gravitation is a concept of "social physics", introduced by Princeton University astrophysicist John Quincy Stewart ... Stewart proceeded to apply Newtonian formulae of gravitation to that of "the average interrelations of people" on a wide ...
*  Gravitation (disambiguation) - Wikipedia
Gravitation may also refer to: Newton's law of universal gravitation, the classical theory of gravitation General relativity, ... the theory of gravitation published by Albert Einstein Gravitation (book), a reference book about Einstein's theory of general ... relativity Gravitation (film), a 1968 Yugoslav film Gravitation (M. C. Escher), a mixed-media work by M. C. Escher Gravitation ... Gravitation is the mass-proportionate force of attraction among matter. ...
*  Gravitation (manga) - Wikipedia
"Gravitation the Novel". Tokyopop. Archived from the original on May 8, 2006. Retrieved November 26, 2014. "Gravitation: Voice ... There is also the Gravitation Collection which consists of 6 volumes, each of which has two original volumes of Gravitation in ... "Gravitation Graphic Novel Collection 2". rightstuf.com. Retrieved 11 May 2015. [permanent dead link] "Gravitation Graphic Novel ... A second novel of Gravitation called Gravitation the Novel - voice the temptation (小説グラビテーション voice the temptation, Shōsetsu ...
*  Gauge gravitation theory - Wikipedia
On the other hand, gravitation theory is built on the principal bundle F X {\displaystyle FX} of the tangent frames to X {\ ... It should not be confused with gauge theory gravity, which is a formulation of (classical) gravitation in the language of ... In quantum field theory, gauge gravitation theory is the effort to extend Yang-Mills theory, which provides a universal ... Difficulties of constructing gauge gravitation theory by analogy with the Yang-Mills one result from the gauge transformations ...
*  Yoshi's Universal Gravitation - Wikipedia
Yoshi's Universal Gravitation, known as Yoshi Topsy-Turvy in North America, is a platform game for the Game Boy Advance that ... At the time of its release, most critics thought of Yoshi's Universal Gravitation as a mediocre title. Craig Harris of IGN said ... Koro Koro Puzzle Happy Panechu! Kirby Tilt 'n' Tumble WarioWare: Twisted! Yoshi's Universal Gravitation (ヨッシーの万有引力, Yosshī no ...
*  Chasles' theorem (gravitation) - Wikipedia
In gravitation, Chasles' theorem says that the Newtonian gravitational attraction of a spherical shell, outside of that shell, ...
*  Yilmaz theory of gravitation - Wikipedia
The Yilmaz theory of gravitation is an attempt by Huseyin Yilmaz (1924-2013) (Turkish: Hüseyin Yılmaz) and his coworkers to ... Yilmaz, H. (1992). "Toward a field theory of gravitation". Nuovo Cimento B. 107 (8): 941-960. Bibcode:1992NCimB.107..941Y. doi: ... Gravitation. W. H. Freeman. ISBN 0-7167-0344-0. See section 20.4 for nonlocal nature of gravitational field energy, and all of ... formulate a classical field theory of gravitation which is similar to general relativity in weak-field conditions, but in which ...
*  Whitehead's theory of gravitation - Wikipedia
ISBN 0-465-09086-9. Misner, Charles; Thorne, Kip S. & Wheeler, John Archibald (1973). Gravitation. San Francisco: W. H. Freeman ... In theoretical physics, Whitehead's theory of gravitation was introduced by the mathematician and philosopher Alfred North ... External link in ,title= (help) Alfred North Whitehead Classical theories of gravitation Eddington-Finkelstein coordinates Will ... "The Effects of Rotation in the Central Body on its Planetary Orbits after the Whitehead Theory of Gravitation". Proceedings of ...
*  Scalar theories of gravitation - Wikipedia
Scalar theories of gravitation are field theories of gravitation in which the gravitational field is described using a scalar ... The prototypical scalar theory of gravitation is Newtonian gravitation. In this theory, the gravitational interaction is ... The Watt-Misner theory (1999) is a recent example of a scalar theory of gravitation. It is not intended as a viable theory of ... Nordström's theory of gravitation Norton, John D. (1992). "Einstein, Nordström and the early demise of scalar, Lorentz- ...
*  List of Gravitation chapters - Wikipedia
The chapters of Gravitation are written and illustrated by Maki Murakami. Tokyopop licensed the series for an English-language ... "Gravitation (Manga) Vol. 01". Madman Entertainment. Retrieved 2 January 2010. グラビテーション 1 (ソニー・マガジンズコミックス) (コミック) (in Japanese ...

(1/543) Transient and sustained increases in inositol 1,4,5-trisphosphate precede the differential growth response in gravistimulated maize pulvini.

The internodal maize pulvinus responds to gravistimulation with differential cell elongation on the lower side. As the site of both graviperception and response, the pulvinus is an ideal system to study how organisms sense changes in orientation. We observed a transient 5-fold increase in inositol 1,4,5-trisphosphate (IP3) within 10 s of gravistimulation in the lower half of the pulvinus, indicating that the positional change was sensed immediately. Over the first 30 min, rapid IP3 fluctuations were observed between the upper and lower halves. Maize plants require a presentation time of between 2 and 4 h before the cells on the lower side of the pulvinus are committed to elongation. After 2 h of gravistimulation, the lower half consistently had higher IP3, and IP3 levels on the lower side continued to increase up to approximately 5-fold over basal levels before visible growth. As bending became visible after 8-10 h, IP3 levels returned to basal values. Additionally, phosphatidylinositol 4-phosphate 5-kinase activity in the lower pulvinus half increased transiently within 10 min of gravistimulation, suggesting that the increased IP3 production was accompanied by an up-regulation of phosphatidylinositol 4, 5-bisphosphate biosynthesis. Neither IP3 levels nor phosphatidylinositol 4-phosphate 5-kinase activity changed in pulvini halves from vertical control plants. Our data indicate the involvement of IP3 and inositol phospholipids in both short- and long-term responses to gravistimulation. As a diffusible second messenger, IP3 provides a mechanism to transmit and amplify the signal from the perceiving to the responding cells in the pulvinus, coordinating a synchronized growth response.  (+info)

(2/543) Effects of tilt of the gravito-inertial acceleration vector on the angular vestibuloocular reflex during centrifugation.

Effects of tilt of the gravito-inertial acceleration vector on the angular vestibuloocular reflex during centrifugation. Interaction of the horizontal linear and angular vestibuloocular reflexes (lVOR and aVOR) was studied in rhesus and cynomolgus monkeys during centered rotation and off-center rotation at a constant velocity (centrifugation). During centered rotation, the eye velocity vector was aligned with the axis of rotation, which was coincident with the direction of gravity. Facing and back to motion centrifugation tilted the resultant of gravity and linear acceleration, gravito-inertial acceleration (GIA), inducing cross-coupled vertical components of eye velocity. These components were upward when facing motion and downward when back to motion and caused the axis of eye velocity to reorient from alignment with the body yaw axis toward the tilted GIA. A major finding was that horizontal time constants were asymmetric in each monkey, generally being longer when associated with downward than upward cross coupling. Because of these asymmetries, accurate estimates of the contribution of the horizontal lVOR could not be obtained by simply subtracting horizontal eye velocity profiles during facing and back to motion centrifugation. Instead, it was necessary to consider the effects of GIA tilts on velocity storage before attempting to estimate the horizontal lVOR. In each monkey, the horizontal time constant of optokinetic after-nystagmus (OKAN) was reduced as a function of increasing head tilt with respect to gravity. When variations in horizontal time constant as a function of GIA tilt were included in the aVOR model, the rising and falling phases of horizontal eye velocity during facing and back to motion centrifugation were closely predicted, and the estimated contribution of the compensatory lVOR was negligible. Beating fields of horizontal eye position were unaffected by the presence or magnitude of linear acceleration during centrifugation. These conclusions were evaluated in animals in which the low-frequency aVOR was abolished by canal plugging, isolating the contribution of the lVOR. Postoperatively, the animals had normal ocular counterrolling and horizontal eye velocity modulation during off-vertical axis rotation (OVAR), suggesting that the otoliths were intact. No measurable horizontal eye velocity was elicited by centrifugation with angular accelerations +info)

(3/543) Effects of spaceflight on rhesus quadrupedal locomotion after return to 1G.

Effects of spaceflight on Rhesus quadrupedal locomotion after return to 1G. Locomotor performance, activation patterns of the soleus (Sol), medial gastrocnemius (MG), vastus lateralis (VL), and tibialis anterior (TA) and MG tendon force during quadrupedal stepping were studied in adult Rhesus before and after 14 days of either spaceflight (n = 2) or flight simulation at 1G (n = 3). Flight simulation involved duplication of the spaceflight conditions and experimental protocol in a 1G environment. Postflight, but not postsimulation, electromyographic (EMG) recordings revealed clonus-like activity in all muscles. Compared with preflight, the cycle period and burst durations of the primary extensors (Sol, MG, and VL) tended to decrease postflight. These decreases were associated with shorter steps. The flexor (TA) EMG burst duration postflight was similar to preflight, whereas the burst amplitude was elevated. Consequently, the Sol:TA and MG:TA EMG amplitude ratios were lower following flight, reflecting a "flexor bias." Together, these alterations in mean EMG amplitudes reflect differential adaptations in motor-unit recruitment patterns of flexors and extensors as well as fast and slow motor pools. Shorter cycle period and burst durations persisted throughout the 20-day postflight testing period, whereas mean EMG returned to preflight levels by 17 days postflight. Compared with presimulation, the simulation group showed slight increases in the cycle period and burst durations of all muscles. Mean EMG amplitude decreased in the Sol, increased in the MG and VL, and was unchanged in the TA. Thus adaptations observed postsimulation were different from those observed postflight, indicating that there was a response unique to the microgravity environment, i.e., the modulations in the nervous system controlling locomotion cannot merely be attributed to restriction of movement but appear to be the result of changes in the interpretation of load-related proprioceptive feedback to the nervous system. Peak MG tendon force amplitudes were approximately two times greater post- compared with preflight or presimulation. Adaptations in tendon force and EMG amplitude ratios indicate that the nervous system undergoes a reorganization of the recruitment patterns biased toward an increased recruitment of fast versus slow motor units and flexor versus extensor muscles. Combined, these data indicate that some details of the control of motor pools during locomotion are dependent on the persistence of Earth's gravitational environment.  (+info)

(4/543) Graviresponses of certain ciliates and flagellates.

Protozoa are eukaryotic cells and represent suitable model systems to study the mechanisms of gravity perception and signal transduction due to their clear gravity-induced responses (gravitaxis and gravikinesis). Among protists, parallel evolution for graviperception mechanisms have been identified: either sensing by distinct stato-organelles (e.g., the Muller vesicles of the ciliate Loxodes) or by sensing the density difference between the whole cytoplasm and the extracellular medium (as proposed for Paramecium and Euglena). These two models are supported by experiments in density-adjusted media, as the gravitaxis of Loxodes was not affected, whereas the orientation of Paramecium and Euglena was completely disturbed. Both models include the involvement of ion channels in the cell membrane. Diverse experiments gave new information on the mechanism of graviperception in unicellular systems, such as threshold values in the range of 10% of gravity, relaxation of the responses after removal of the stimulus, and no visible adaptation phenomena during exposure to hypergravity or microgravity conditions for up to 12 days.  (+info)

(5/543) Statoliths motions in gravity-perceiving plant cells: does actomyosin counteract gravity?

Statocytes from plant root caps are characterized by a polar arrangement of cell organelles and sedimented statoliths. Cortical microtubules and actin microfilaments contribute to development and maintenance of this polarity, whereas the lack of endoplasmic microtubules and prominent bundles of actin microfilaments probably facilitates sedimentation of statoliths. High-resolution video microscopy shows permanent motion of statoliths even when sedimented. After immunofluorescence microscopy using antibodies against actin and myosin II the most prominent labeling was observed at and around sedimented statoliths. Experiments under microgravity have demonstrated that the positioning of statoliths depends on the external gravitational force and on internal forces, probably exerted by the actomyosin complex, and that transformation of the gravistimulus evidently occurs in close vicinity to the statoliths. These results suggest that graviperception occurs dynamically within the cytoplasm via small-distance sedimentation rather than statically at the lowermost site of sedimentation. It is hypothesized that root cap cells are comparing randomized motions with oriented motions of statoliths and thereby perceiving gravity.  (+info)

(6/543) Workshop conclusions & recommendations.


(7/543) Neuronal mechanisms for the control of body orientation in Clione I. Spatial zones of activity of different neuron groups.

The marine mollusk Clione limacina, when swimming, can stabilize different body orientations in the gravitational field. Here we describe one of the modes of operation of the postural network in Clione-maintenance of the vertical, head-up orientation. Experiments were performed on the CNS-statocyst preparation. Spike discharges in the axons of different types of neurons were recorded extracellularly when the preparation was rotated in space through 360 degrees in different planes. We characterized the spatial zones of activity of the tail and wing motor neurons as well as of the CPB3 interneurons mediating the effects of statocyst receptor cells on the tail motor neurons. It was found that the activity of the tail motor neurons increased with deviation of the preparation from the normal, rostral-side-up orientation. Their zones of activity were very wide ( approximately 180 degrees ). According to the zone position, three distinct groups of tail motor neuron (T1-T3) could be distinguished. The T1 group had a center of the zone near the ventral-side-up orientation, whereas the zones of T2 and T3 had their centers near the left-side-up and the right-side-up positions, respectively. By comparing the zone of activity with the direction of tail bending elicited by each of the groups, one can conclude that gravitational reflexes mediated by the T1, T2, and T3 groups will evoke turning of the animal toward the head-up orientation. Two identified wing motor neurons, 1A and 2A, causing the wing beating, were involved in gravitational reactions. They were activated with the downward inclination of the ipsilateral side. Opposite reactions were observed in the motor neurons responsible for the wing retraction. A presumed motor effect of these reactions is an increase of oscillations in the wing that is directed downward and turning of Clione toward the head-up orientation. Among the CPB3 interneurons, at least four groups could be distinguished. In three of them (IN1, IN2, and IN3), the zones of activity were similar to those of the three groups (T1, T2, and T3) of the tail motor neurons. The group IN4 had the center of its zone in the dorsal-side-up position; a corresponding group was not found among the tail motor neurons. In lesion experiments, it was found that gravitational input mediated by a single CPB3 interneuron produced activation of its target tail motor neurons in their normal zones, but the strength of response was reduced considerably. This finding suggests that several interneurons with similar spatial zones converge on individual tail motor neurons. In conclusion, because of a novel method, activity of the neuronal network responsible for the postural control in Clione was characterized in the terms of gravitational responses in different neuron groups comprising the network.  (+info)

(8/543) Black holes in the milky way galaxy.

Extremely strong observational evidence has recently been found for the presence of black holes orbiting a few relatively normal stars in our Milky Way Galaxy and also at the centers of some galaxies. The former generally have masses of 4-16 times the mass of the sun, whereas the latter are "supermassive black holes" with millions to billions of solar masses. The evidence for a supermassive black hole in the center of our galaxy is especially strong.  (+info)

  • gravity
  • The terms gravitation and gravity are mostly interchangeable in everyday use, but in scientific usage a distinction may be made. (schools-wikipedia.org)
  • Self-gravity affects bodies passing each other in space within the sphere defined by the Roche limit because relatively small bodies could be torn apart by differential attraction, but typically the effects of self-gravitation keep the smaller body intact because the smaller body becomes elongated and the gravity of the body is able to overcome the momentum from this interaction between bodies. (wikipedia.org)
  • Mechanical explanations of gravitation (or kinetic theories of gravitation) are attempts to explain the action of gravity by aid of basic mechanical processes, such as pressure forces caused by pushes, without the use of any action at a distance. (wikipedia.org)
  • Gravitation (also known as Gravity) is a mixed media work by the Dutch artist M. C. Escher completed in June 1952. (wikipedia.org)
  • relativistic
  • But, given that all scatterable elementary particles identifiable within atomic structures have an electrical charge, and are thus electromagnetic in nature , this article explores the possibility of reconciling quantum mechanics with relativistic mechanics from the electromagnetic perspective, by means of reconciling the wave function with the least action electromagnetic resonance states into which elementary charged particles become captive within atomic and nuclear structures, and ultimately, with gravitation. (omicsonline.org)
  • Note: This article focuses on relativistic classical field theories of gravitation. (wikipedia.org)
  • Nordström's theories arose at a time when several leading physicists, including Nordström in Helsinki, Max Abraham in Milan, Gustav Mie in Greifswald, Germany, and Albert Einstein in Prague, were all trying to create competing relativistic theories of gravitation. (wikipedia.org)
  • equation
  • The equation to calculate the effects of self-gravitation were made exact by Lynden-Bell for the purpose of giving an exact description of models for rotating flattened globular clusters, which was a crucial step in understanding how clusters of stars interact with each other. (wikipedia.org)
  • There are models made that depend on the use of the spectral element method and these simulations take into account the effects of self-gravitation because it can have a large influence on results for certain receiver-source configurations and creates complications in the wave equation, particularly for long period waves. (wikipedia.org)
  • book
  • To quote Ed Ehrlich "'Gravitation' is such a prominent book on relativity that the initials of its authors MTW can be used by other books on relativity without explanation. (wikipedia.org)
  • known
  • Yoshi's Universal Gravitation, known as Yoshi Topsy-Turvy in North America, is a platform game for the Game Boy Advance that was developed by Artoon and published by Nintendo. (wikipedia.org)
  • volume
  • Murakami penned a thirteen volume dōjinshi series called Gravitation Remix under the group Crocodile Ave. The dōjinshi are much more sexually explicit than the anime and deviate heavily from the manga storyline. (wikipedia.org)