... Free Fall . ... Legend has it that he climbed to the top of the leaning tower of Pisa and from there dropped simultaneously heavy and light balls, noting that they hit the ground at the same time. ... This is modified by the resistance of the air, which becomes important at higher speeds and usually sets an upper limit ("terminal velocity") to the fall velocity--a much smaller limit for someone using a parachute than one falling without. ... A longer string of course extends the fall time. ...

In the absence of forces, motion in a straight line and constant velocity continues indefinitely. Motion in a circle, however, requires forces to act. ... Since its velocity v equals the distance it moves in one second, one finds . ... The above result suggests that steady motion around a circle, at least for a short time span, can be viewed as the sum of a straight-line motion with fixed velocity v , plus an accelerated motion towards the center of attraction, with the above acceleration, a . ...

Method of Calculating Cometary Orbits . ... A method of constructing a numerical theory of comet motion covering large intervals of time is presented. ... Very Long Baseline Interferometry (VLBI), Near Earth Objects (NEOs), calculating cometary orbits, numerical theory of comet motion covering large intervals of time , radial component of non-gravitational acceleration , transverse component of non-gravitational acceleration , normal component of non-gravitational ...

On 6 may 2001 the azimuth was parked at az=214.4 degrees and the dome was at 19 degrees za with motors off and the brakes on. At 7:40:49 the azimuth started moving do to the wind. ... The operators began moving the dome downhill at azimuth 258 degrees. The dome was at 18 degrees by the time the azimuth stopped moving. The azimuth rail had been greased the previous week. ... The red shows the dome position during this time (the top red line is 19 degrees and the bottom one is 18 degrees). ...

are denoted by the following symbols and may be taken to have the values below Elementary charge Speed of light in vacuum Planck constant Permeability of vacuum Permittivity of vacuum Unified atomic mass constant Rest mass of proton Rest mass of electron Boltzmann constant Avogadro constant Gravitational ... Write down the expression for the gravitational field, g, at distance r from a point mass of mass m, carefully defining all the terms in your expression. ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

... Survey Telescopes . ... Astronomers using ESOтАЩs world-leading HARPS instrument have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180. ... The newly discovered system of planets around HD 10180 is unique in several respects. ... All very massive planetary systems are found around massive and metal-rich stars, while the four lowest-mass systems are found around lower-mass and metal-poor stars [5] . ... ESOcast 20: Richest planetary system discovered...

... SQL | ... Tutorial: determine H0 using SQL queries to LEDA . ... We select in the database all galaxies with known velocity and magnitude and similar to a given template for which we know the distance, the magnitude and the radial velocity. ... We simply have to choose a property which does not depend on the distance, as for example the rotation velocity ( log(vrot) ) and select the galaxies having log(vrot) in a very narrow range around the value for the template galaxy. ... leda@univ-lyon1.fr ...

... Measurements of recent changes in the expansion rate via supernovae , published by myself in 1998with the High-z Team ( Riess et al. 1998 ) and the Supernova Cosmology Project in 1999, first revealed that the expansion of the Universe is now accelerating.€а At the time , the High-z Team began (Schmidt et al. 1998) the Universe was expected to be decelerating under the gravitational braking applied by its own mass, so this finding was an enormous surprise ...

The VIRGO project is a physics experiment; its aim is the detection of gravitational waves. ... It has not yet been possible to detect directly the gravitational waves: it remains one of the major challenges of experimental physics. ... Interferometric antennas for gravitational waves Gravitational waves distort space-time: along two perpendicular directions, the distances between fixed points will increase (resp. decrease), at the arrival of a gravitational wave. ... Publications from our Group . ...

Momentum Thursday, 24 February 2011 Quick Introduction to Momentum Principle · We will come back to all of this - this is just a taster. ... Thursday, 24 February 2011 What is this (Gamma)? = 1 1- v c 2 You are probably familiar with momentum - mass times velocity - but the real equation has this extra term in it. ... Thursday, 24 February 2011 Thursday, 24 February 2011 Thursday, 24 February 2011 Don't normally need to worry about Gamma · Unless you are dealing with remarkably fast motion! ...

Blackholes2 Forum Message . ... Distant Galaxy Red Shift Caused By Time Passage Variation. ... If I were falling toward a neutron star or a black hole, a distant galaxy would seem to be accelerating toward me? ... And apparent receding distant galaxies with a red shift. ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

. $\pi_n$ is a group . $\pi_n$ is homotopy invariant . For $n \ge 2$, the group $\pi_n$ is Abelian. Feldbau lemma . Covering homotopy theorem . The homotopy sequence of a fibration is exact . Existence and universality of a simply connected covering . Classification of coverings . Fundamental group of a wedge of circles . Sphere is orientable . Euler's formula for embedded graphs . $\pi_n(S^n) = \Integer$ . How to calculate a fundamental group using cellular decomposition

Moon Games . ... But apparent angular size , or the angle covered by an object, can also be important to Moon enthusiasts . ... Of course the Sun is much larger than the Moon, 400 times larger in fact, but today the New Moon will just cover the Sun. ... A partial eclipse is visible from a broader region). Solar eclipses illustrate the happy coincidence that while the Sun is 400 times the diameter of the Moon, it is also 400 times farther away giving the Sun and Moon exactly the same angular size . ...

... 2 Time (UT) 02:05 X-ray BP behaviour Magnetic fragment behaviour A positive fragment emerges just at the side of a negative one. The negative one becomes stronger. ... These small ones become stronger and concentrated. and move away from the negative fragments toward another negative fragments pre-existed at the southeast. ... The positive fragments move closer to the southeast negative ones and cancellation begins. A few weak negative fragments move from north toward the positive fragments. ...

. E. Swedenborg (from "Heavenly City") . List of scientific publications . List of preprints in the ArXiv . Lectures etc. (*.ppt) . My CV . Photos . Old version of the HomePage . Our paper . on the cover of . A . Phone: +7 (495) 939-50-06 . Review (in Russian); Poster on CNOC3: Gould Belt; Poster for SN1604: kicks.

... A cosmic-ray source uncovered . ... HESS scientists believe the observed cosmic-ray signature could have been produced in a single supernova remnant. ... The HESS data show the cosmic-ray density in the galactic center significantly exceeds that in the solar neighborhood. ... Two possible cosmic-ray accelerators reside in the galactic center. ... More observations are needed to pinpoint which is the cosmic-ray source. ... Only registered members of Astronomy.com are allowed to comment on this...

... Here, $\lambda = {-180^{\circ}} \ldots {+180^{\circ}}$ is the longitude and $\varphi = {-90^{\circ}} \ldots {+90^{\circ}}$ the latitude in the original coordinate system. ... begin{equation*} \tan(l_{0} - l) = \frac{\cos(\delta) \sin(\alpha - \alpha_{0})}{\sin(\delta) \cos(\delta_{0}) - \cos(\delta) \sin(\delta_{0}) \cos(\alpha - \alpha_{0})} \end{equation*} . ... begin{equation*} \sin(b) = \sin(\delta) \sin(\delta_{0}) + \cos(\delta) \cos(\delta_{0}) \cos(\alpha - \alpha_{0}) \end{equation*} . ...