Equation of Time — Problem in Astronomy M
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E a S T 7 4 T H S T R E E T August 2021 Schedule
E A S T 7 4 T H S T R E E T KEY St udi o key on bac k SEPT EM BER 2021 SC H ED U LE EF F EC T IVE 09.01.21–09.30.21 Bolld New Class, Instructor, or Time ♦ Advance sign-up required M O NDA Y T UE S DA Y W E DNE S DA Y T HURS DA Y F RII DA Y S A T URDA Y S UNDA Y Atthllettiic Master of One Athletic 6:30–7:15 METCON3 6:15–7:00 Stacked! 8:00–8:45 Cycle Beats 8:30–9:30 Vinyasa Yoga 6:15–7:00 6:30–7:15 6:15–7:00 Condiittiioniing Gerard Conditioning MS ♦ Kevin Scott MS ♦ Steve Mitchell CS ♦ Mike Harris YS ♦ Esco Wilson MS ♦ MS ♦ MS ♦ Stteve Miittchellll Thelemaque Boyd Melson 7:00–7:45 Cycle Power 7:00–7:45 Pilates Fusion 8:30–9:15 Piillattes Remiix 9:00–9:45 Cardio Sculpt 6:30–7:15 Cycle Beats 7:00–7:45 Cycle Power 6:30–7:15 Cycle Power CS ♦ Candace Peterson YS ♦ Mia Wenger YS ♦ Sammiie Denham MS ♦ Cindya Davis CS ♦ Serena DiLiberto CS ♦ Shweky CS ♦ Jason Strong 7:15–8:15 Vinyasa Yoga 7:45–8:30 Firestarter + Best Firestarter + Best 9:30–10:15 Cycle Power 7:15–8:05 Athletic Yoga Off The Barre Josh Mathew- Abs Ever 9:00–9:45 CS ♦ Jason Strong 7:00–8:00 Vinyasa Yoga 7:00–7:45 YS ♦ MS ♦ MS ♦ Abs Ever YS ♦ Elitza Ivanova YS ♦ Margaret Schwarz YS ♦ Sarah Marchetti Meier Shane Blouin Luke Bernier 10:15–11:00 Off The Barre Gleim 8:00–8:45 Cycle Beats 7:30–8:15 Precision Run® 7:30–8:15 Precision Run® 8:45–9:45 Vinyasa Yoga Cycle Power YS ♦ Cindya Davis Gerard 7:15–8:00 Precision Run® TR ♦ Kevin Scott YS ♦ Colleen Murphy 9:15–10:00 CS ♦ Nikki Bucks TR ♦ CS ♦ Candace 10:30–11:15 Atletica Thelemaque TR ♦ Chaz Jackson Peterson 8:45–9:30 Pilates Fusion 8:00–8:45 -
Captain Vancouver, Longitude Errors, 1792
Context: Captain Vancouver, longitude errors, 1792 Citation: Doe N.A., Captain Vancouver’s longitudes, 1792, Journal of Navigation, 48(3), pp.374-5, September 1995. Copyright restrictions: Please refer to Journal of Navigation for reproduction permission. Errors and omissions: None. Later references: None. Date posted: September 28, 2008. Author: Nick Doe, 1787 El Verano Drive, Gabriola, BC, Canada V0R 1X6 Phone: 250-247-7858, FAX: 250-247-7859 E-mail: [email protected] Captain Vancouver's Longitudes – 1792 Nicholas A. Doe (White Rock, B.C., Canada) 1. Introduction. Captain George Vancouver's survey of the North Pacific coast of America has been characterized as being among the most distinguished work of its kind ever done. For three summers, he and his men worked from dawn to dusk, exploring the many inlets of the coastal mountains, any one of which, according to the theoretical geographers of the time, might have provided a long-sought-for passage to the Atlantic Ocean. Vancouver returned to England in poor health,1 but with the help of his brother John, he managed to complete his charts and most of the book describing his voyage before he died in 1798.2 He was not popular with the British Establishment, and after his death, all of his notes and personal papers were lost, as were the logs and journals of several of his officers. Vancouver's voyage came at an interesting time of transition in the technology for determining longitude at sea.3 Even though he had died sixteen years earlier, John Harrison's long struggle to convince the Board of Longitude that marine chronometers were the answer was not quite over. -
Capricious Suntime
[Physics in daily life] I L.J.F. (Jo) Hermans - Leiden University, e Netherlands - [email protected] - DOI: 10.1051/epn/2011202 Capricious suntime t what time of the day does the sun reach its is that the solar time will gradually deviate from the time highest point, or culmination point, when on our watch. We expect this‘eccentricity effect’ to show a its position is exactly in the South? e ans - sine-like behaviour with a period of a year. A wer to this question is not so trivial. For ere is a second, even more important complication. It is one thing, it depends on our location within our time due to the fact that the rotational axis of the earth is not zone. For Berlin, which is near the Eastern end of the perpendicular to the ecliptic, but is tilted by about 23.5 Central European time zone, it may happen around degrees. is is, aer all, the cause of our seasons. To noon, whereas in Paris it may be close to 1 p.m. (we understand this ‘tilt effect’ we must realise that what mat - ignore the daylight saving ters for the deviation in time time which adds an extra is the variation of the sun’s hour in the summer). horizontal motion against But even for a fixed loca - the stellar background tion, the time at which the during the year. In mid- sun reaches its culmination summer and mid-winter, point varies throughout the when the sun reaches its year in a surprising way. -
Solar Engineering Basics
Solar Energy Fundamentals Course No: M04-018 Credit: 4 PDH Harlan H. Bengtson, PhD, P.E. Continuing Education and Development, Inc. 22 Stonewall Court Woodcliff Lake, NJ 07677 P: (877) 322-5800 [email protected] Solar Energy Fundamentals Harlan H. Bengtson, PhD, P.E. COURSE CONTENT 1. Introduction Solar energy travels from the sun to the earth in the form of electromagnetic radiation. In this course properties of electromagnetic radiation will be discussed and basic calculations for electromagnetic radiation will be described. Several solar position parameters will be discussed along with means of calculating values for them. The major methods by which solar radiation is converted into other useable forms of energy will be discussed briefly. Extraterrestrial solar radiation (that striking the earth’s outer atmosphere) will be discussed and means of estimating its value at a given location and time will be presented. Finally there will be a presentation of how to obtain values for the average monthly rate of solar radiation striking the surface of a typical solar collector, at a specified location in the United States for a given month. Numerous examples are included to illustrate the calculations and data retrieval methods presented. Image Credit: NOAA, Earth System Research Laboratory 1 • Be able to calculate wavelength if given frequency for specified electromagnetic radiation. • Be able to calculate frequency if given wavelength for specified electromagnetic radiation. • Know the meaning of absorbance, reflectance and transmittance as applied to a surface receiving electromagnetic radiation and be able to make calculations with those parameters. • Be able to obtain or calculate values for solar declination, solar hour angle, solar altitude angle, sunrise angle, and sunset angle. -
How Long Is a Year.Pdf
How Long Is A Year? Dr. Bryan Mendez Space Sciences Laboratory UC Berkeley Keeping Time The basic unit of time is a Day. Different starting points: • Sunrise, • Noon, • Sunset, • Midnight tied to the Sun’s motion. Universal Time uses midnight as the starting point of a day. Length: sunrise to sunrise, sunset to sunset? Day Noon to noon – The seasonal motion of the Sun changes its rise and set times, so sunrise to sunrise would be a variable measure. Noon to noon is far more constant. Noon: time of the Sun’s transit of the meridian Stellarium View and measure a day Day Aday is caused by Earth’s motion: spinning on an axis and orbiting around the Sun. Earth’s spin is very regular (daily variations on the order of a few milliseconds, due to internal rearrangement of Earth’s mass and external gravitational forces primarily from the Moon and Sun). Synodic Day Noon to noon = synodic or solar day (point 1 to 3). This is not the time for one complete spin of Earth (1 to 2). Because Earth also orbits at the same time as it is spinning, it takes a little extra time for the Sun to come back to noon after one complete spin. Because the orbit is elliptical, when Earth is closest to the Sun it is moving faster, and it takes longer to bring the Sun back around to noon. When Earth is farther it moves slower and it takes less time to rotate the Sun back to noon. Mean Solar Day is an average of the amount time it takes to go from noon to noon throughout an orbit = 24 Hours Real solar day varies by up to 30 seconds depending on the time of year. -
Sidereal Time Distribution in Large-Scale of Orbits by Usingastronomical Algorithm Method
International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438 Sidereal Time Distribution in Large-Scale of Orbits by usingAstronomical Algorithm Method Kutaiba Sabah Nimma 1UniversitiTenagaNasional,Electrical Engineering Department, Selangor, Malaysia Abstract: Sidereal Time literally means star time. The time we are used to using in our everyday lives is Solar Time.Astronomy, time based upon the rotation of the earth with respect to the distant stars, the sidereal day being the unit of measurement.Traditionally, the sidereal day is described as the time it takes for the Earth to complete one rotation relative to the stars, and help astronomers to keep them telescops directions on a given star in a night sky. In other words, earth’s rate of rotation determine according to fixed stars which is controlling the time scale of sidereal time. Many reserachers are concerned about how long the earth takes to spin based on fixed stars since the earth does not actually spin around 360 degrees in one solar day.Furthermore, the computations of the sidereal time needs to take a long time to calculate the number of the Julian centuries. This paper shows a new method of calculating the Sidereal Time, which is very important to determine the stars location at any given time. In addition, this method provdes high accuracy results with short time of calculation. Keywords: Sidereal time; Orbit allocation;Geostationary Orbit;SolarDays;Sidereal Day 1. Introduction (the upper meridian) in the sky[6]. Solar time is what the time we all use where a day is defined as 24 hours, which is The word "sidereal" comes from the Latin word sider, the average time that it takes for the sun to return to its meaning star. -
Sidereal Time 1 Sidereal Time
Sidereal time 1 Sidereal time Sidereal time (pronounced /saɪˈdɪəri.əl/) is a time-keeping system astronomers use to keep track of the direction to point their telescopes to view a given star in the night sky. Just as the Sun and Moon appear to rise in the east and set in the west, so do the stars. A sidereal day is approximately 23 hours, 56 minutes, 4.091 seconds (23.93447 hours or 0.99726957 SI days), corresponding to the time it takes for the Earth to complete one rotation relative to the vernal equinox. The vernal equinox itself precesses very slowly in a westward direction relative to the fixed stars, completing one revolution every 26,000 years approximately. As a consequence, the misnamed sidereal day, as "sidereal" is derived from the Latin sidus meaning "star", is some 0.008 seconds shorter than the earth's period of rotation relative to the fixed stars. The longer true sidereal period is called a stellar day by the International Earth Rotation and Reference Systems Service (IERS). It is also referred to as the sidereal period of rotation. The direction from the Earth to the Sun is constantly changing (because the Earth revolves around the Sun over the course of a year), but the directions from the Earth to the distant stars do not change nearly as much. Therefore the cycle of the apparent motion of the stars around the Earth has a period that is not quite the same as the 24-hour average length of the solar day. Maps of the stars in the night sky usually make use of declination and right ascension as coordinates. -
Moon-Earth-Sun: the Oldest Three-Body Problem
Moon-Earth-Sun: The oldest three-body problem Martin C. Gutzwiller IBM Research Center, Yorktown Heights, New York 10598 The daily motion of the Moon through the sky has many unusual features that a careful observer can discover without the help of instruments. The three different frequencies for the three degrees of freedom have been known very accurately for 3000 years, and the geometric explanation of the Greek astronomers was basically correct. Whereas Kepler’s laws are sufficient for describing the motion of the planets around the Sun, even the most obvious facts about the lunar motion cannot be understood without the gravitational attraction of both the Earth and the Sun. Newton discussed this problem at great length, and with mixed success; it was the only testing ground for his Universal Gravitation. This background for today’s many-body theory is discussed in some detail because all the guiding principles for our understanding can be traced to the earliest developments of astronomy. They are the oldest results of scientific inquiry, and they were the first ones to be confirmed by the great physicist-mathematicians of the 18th century. By a variety of methods, Laplace was able to claim complete agreement of celestial mechanics with the astronomical observations. Lagrange initiated a new trend wherein the mathematical problems of mechanics could all be solved by the same uniform process; canonical transformations eventually won the field. They were used for the first time on a large scale by Delaunay to find the ultimate solution of the lunar problem by perturbing the solution of the two-body Earth-Moon problem. -
Research on the Precession of the Equinoxes and on the Nutation of the Earth’S Axis∗
Research on the Precession of the Equinoxes and on the Nutation of the Earth’s Axis∗ Leonhard Euler† Lemma 1 1. Supposing the earth AEBF (fig. 1) to be spherical and composed of a homogenous substance, if the mass of the earth is denoted by M and its radius CA = CE = a, the moment of inertia of the earth about an arbitrary 2 axis, which passes through its center, will be = 5 Maa. ∗Leonhard Euler, Recherches sur la pr´ecession des equinoxes et sur la nutation de l’axe de la terr,inOpera Omnia, vol. II.30, p. 92-123, originally in M´emoires de l’acad´emie des sciences de Berlin 5 (1749), 1751, p. 289-325. This article is numbered E171 in Enestr¨om’s index of Euler’s work. †Translated by Steven Jones, edited by Robert E. Bradley c 2004 1 Corollary 2. Although the earth may not be spherical, since its figure differs from that of a sphere ever so slightly, we readily understand that its moment of inertia 2 can be nonetheless expressed as 5 Maa. For this expression will not change significantly, whether we let a be its semi-axis or the radius of its equator. Remark 3. Here we should recall that the moment of inertia of an arbitrary body with respect to a given axis about which it revolves is that which results from multiplying each particle of the body by the square of its distance to the axis, and summing all these elementary products. Consequently this sum will give that which we are calling the moment of inertia of the body around this axis. -
1 the Equatorial Coordinate System
General Astronomy (29:61) Fall 2013 Lecture 3 Notes , August 30, 2013 1 The Equatorial Coordinate System We can define a coordinate system fixed with respect to the stars. Just like we can specify the latitude and longitude of a place on Earth, we can specify the coordinates of a star relative to a coordinate system fixed with respect to the stars. Look at Figure 1.5 of the textbook for a definition of this coordinate system. The Equatorial Coordinate System is similar in concept to longitude and latitude. • Right Ascension ! longitude. The symbol for Right Ascension is α. The units of Right Ascension are hours, minutes, and seconds, just like time • Declination ! latitude. The symbol for Declination is δ. Declination = 0◦ cor- responds to the Celestial Equator, δ = 90◦ corresponds to the North Celestial Pole. Let's look at the Equatorial Coordinates of some objects you should have seen last night. • Arcturus: RA= 14h16m, Dec= +19◦110 (see Appendix A) • Vega: RA= 18h37m, Dec= +38◦470 (see Appendix A) • Venus: RA= 13h02m, Dec= −6◦370 • Saturn: RA= 14h21m, Dec= −11◦410 −! Hand out SC1 charts. Find these objects on them. Now find the constellation of Orion, and read off the Right Ascension and Decli- nation of the middle star in the belt. Next week in lab, you will have the chance to use the computer program Stellar- ium to display the sky and find coordinates of objects (stars, planets). 1.1 Further Remarks on the Equatorial Coordinate System The Equatorial Coordinate System is fundamentally established by the rotation axis of the Earth. -
GSA on the Web
Vol. 6, No. 4 April 1996 1996 Annual GSA TODAY Meeting Call for A Publication of the Geological Society of America Papers Page 17 Electronic Dipping Reflectors Beneath Abstracts Submission Old Orogens: A Perspective from page 18 the British Caledonides Registration Issue June GSA Today John H. McBride,* David B. Snyder, Richard W. England, Richard W. Hobbs British Institutions Reflection Profiling Syndicate, Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, United Kingdom A B Figure 1. A: Generalized location map of the British Isles showing principal structural elements (red and black) and location of selected deep seismic reflection profiles discussed here. Major normal faults are shown between mainland Scotland and Shetland. Structural contours (green) are in kilome- ters below sea level for all known mantle reflectors north of Ireland, north of mainland Scotland, and west of Shetland (e.g., Figs. 2A and 5); contours (black) are in seconds (two-way traveltime) on the reflector I-I’ (Fig. 2B) pro- jecting up to the Iapetus suture (from Soper et al., 1992). The contour inter- val is variable. B: A Silurian-Devonian (410 Ma) reconstruction of the Caledo- nian-Appalachian orogen shows the three-way closure of Laurentia and Baltica with the leading edge of Eastern Avalonia thrust under the Laurentian margin (from Soper, 1988). Long-dash line indicates approximate outer limit of Caledonian-Appalachian orogen and/or accreted terranes. GGF is Great Glen fault; NFLD. is Newfoundland. reflectors in the upper-to-middle crust, suggesting a “thick- skinned” structural style. These reflectors project downward into a pervasive zone of diffuse reflectivity in the lower crust. -
Sun-Synchronous Satellites
Topic: Sun-synchronous Satellites Course: Remote Sensing and GIS (CC-11) M.A. Geography (Sem.-3) By Dr. Md. Nazim Professor, Department of Geography Patna College, Patna University Lecture-3 Concept: Orbits and their Types: Any object that moves around the Earth has an orbit. An orbit is the path that a satellite follows as it revolves round the Earth. The plane in which a satellite always moves is called the orbital plane and the time taken for completing one orbit is called orbital period. Orbit is defined by the following three factors: 1. Shape of the orbit, which can be either circular or elliptical depending upon the eccentricity that gives the shape of the orbit, 2. Altitude of the orbit which remains constant for a circular orbit but changes continuously for an elliptical orbit, and 3. Angle that an orbital plane makes with the equator. Depending upon the angle between the orbital plane and equator, orbits can be categorised into three types - equatorial, inclined and polar orbits. Different orbits serve different purposes. Each has its own advantages and disadvantages. There are several types of orbits: 1. Polar 2. Sunsynchronous and 3. Geosynchronous Field of View (FOV) is the total view angle of the camera, which defines the swath. When a satellite revolves around the Earth, the sensor observes a certain portion of the Earth’s surface. Swath or swath width is the area (strip of land of Earth surface) which a sensor observes during its orbital motion. Swaths vary from one sensor to another but are generally higher for space borne sensors (ranging between tens and hundreds of kilometers wide) in comparison to airborne sensors.