THE GREAT CONJUNCTION OF JUPITER AND SATURN

Joseph de Ca'th Lon and The Grandma continue enjoying together talking about science.

Joseph likes Astronomy and they have been talking about the great conjunction of the planets Jupiter and Saturn that has occurred today. 

They have visited the Garraf Astronomical Observatory to enjoy this conjunction.

A great conjunction is a conjunction of the planets Jupiter and Saturn, when the two planets appear closest together in the sky.

Great conjunctions occur approximately every 20 years when Jupiter overtakes Saturn in its orbit. They are named great for being by far the rarest of the conjunctions between naked-eye planets.

The spacing between the planets varies from conjunction to conjunction with most events being 0.5 to 1.3 degrees. Very close conjunctions happen much less frequently, though the maximum of 1.3° is still close by inner planet standards: separations of less than 10 arcminutes have only happened four times since 1200, most recently in 2020.

On average great conjunction seasons occur once every 19.859 Julian years (365.25 days). This number can be calculated by the synodic period formula 1/(1/4332.59−1/10759.22) giving c. 7253.46 days -the average frequency of Jupiter overtaking Saturn from the Sun's POV due to the net effect of their 4332.59 and 10759.22-day orbits.

In practice Earth's orbit size can cause great conjunctions to reoccur up to some months away from the average time or the time they happen on the Sun. Since the equivalent periods of other naked eye planet pairs are all under 27 months this makes great conjunctions the rarest.

More information: BBC-Sky at Night Magazine

Occasionally there is more than one great conjunction in a season when they occur close enough to opposition: this is called a triple conjunction, which is not exclusive to great conjunctions.

The most recent great conjunction occurred on 21 December 2020, and the next will occur on 4 November 2040. During the 2020 great conjunction, the two planets were separated in the sky by 6 arcminutes at their closest point, which was the closest distance between the two planets since 1623.

The closeness is the result of one of the three approximately equally spaced longitude zones where great conjunctions occur shifting into the vicinity of one of the two longitudes where the two orbits appear to intersect when viewed from the Sun, which has a point of view similar to Earth.

The great conjunction zones revolve in the same direction as the planets at the rate of approximately one-sixth of a revolution per four centuries thus creating especially close conjunctions on an approximately four-century cycle. 

 

More precisely, the location in the sky of each conjunction in a series should increase in longitude by 16.3 degrees on average, making one full cycle relative to the stars on average once every 2,634 years. If instead, we use the convention of measuring longitude eastward from the First Point of Aries we have to keep in mind that the equinox circulates once every c. 25,772 years so longitudes measured that way increase slightly faster and those numbers become 17.95 degrees and 2,390 years.

 

The longitudes of close great conjunctions are currently about 307.4 and 127.4 degrees, in the constellations of Capricornus and Cancer respectively.

Earth's orbit can make the planets appear up to about 10 degrees ahead of or behind when they are at the optimal point, which also is true for any other part of their orbits.

Saturn's orbit plane is inclined 2.485 degrees relative to Earth's, and Jupiter's is 1.303 degrees.

Interestingly, the ascending nodes of both planets are similar, 100.6 degrees for Jupiter and 113.7 degrees for Saturn, so that if Saturn is above or below Earth's orbital plane Jupiter usually is too, this is partly caused by Earth's orbit being tilted relative to all the large planets.

Because the orbit inclination directions of Jupiter and Saturn align reasonably well it would be expected that no closest approach will ever be much worse than Saturn's orbit tilt (2.485°) minus Jupiter's (1.303°). Indeed, between the year 1 and 3000, the maximum conjunction distances were 1.3 degrees in 1306 and 1940.

More information: Time and Date

Conjunctions in both years occurred when the planets were tilted most out of the plane: longitude 206 degrees (therefore above the plane) in 1306, and longitude 39 degrees (therefore below the plane) in 1940.

When studying the great conjunction of 1603, Johannes Kepler thought that the Star of Bethlehem might have been the occurrence of a great conjunction. He calculated that a triple conjunction of Jupiter and Saturn occurred in 7 BC, −6 using astronomical year numbering.

A triple conjunction is a conjunction of Jupiter and Saturn at or near their opposition to the Sun.

In this scenario, Jupiter and Saturn will occupy the same right ascension on three occasions or same ecliptic longitude on three occasions depending on which definition of conjunction one uses, this is due to apparent retrograde motion and happens within months.

The most recent triple conjunction occurred in 1980 and 1981 while the next will be in 2238 and 2239. Lights in the sky that look like especially bright stars are commonplace. Jupiter & Saturn only appear to be in the same spot for a moment, but they spend weeks approaching and departing from each other.

They are visibly separate, distinct objects for the vast majority of the same evening on which the conjunction occurs, something wise men are not likely to miss. Aside from the 7 BC conjunction occurring at the wrong time, the Star of Bethlehem as described moves west, but makes a sharp turn to the south, a movement no star or planet can actually make.

Great Conjunctions never appear to be leading southward to any particular building in Isreal. Additionally, there are other, better candidates for the Star ofBethlehem.

The astronomers from the Cracow Academy, Jan Muscenius, Stanisław Jakobejusz, Nicolaus Schadeck, Petrus Probosczowicze, and others observed the great conjunction of 1563 to compare Alfonsine Tables (based on a geocentric model) with the Prutenic Tables (based on Copernican heliocentrism).

In the Prutenic Tables the astronomers found Jupiter and Saturn so close to each other that Jupiter covered Saturn, actual angular separation was 6.8 minutes on 25 August 1563.

The Alfonsine Tables suggested that the conjunction should be observed on another day but on the day indicated by the Alfonsine tables the angular separation was a full 141 minutes.

The Cracow professors suggested following the more accurate Copernican predictions and between 1578 and 1580 Copernican heliocentrism was lectured on three times by Valentin Fontani.

More information: Space

The great conjunction of 2020 was the closest since 1623 and eighth closest of the first three millennia AD, with a minimum separation between the two planets of 6.1 arcminutes. This great conjunction was also the most easily visible close conjunction since 1226, as the previous close conjunctions in 1563 and 1623 were closer to the Sun and therefore more difficult to see. It occurred seven weeks after the heliocentric conjunction, when Jupiter and Saturn shared the same heliocentric longitude.

The closest separation occurred on 21 December at 18:22 UTC, when Jupiter was 0.1° south of Saturn and 30° east of the Sun. This meant both planets appeared together in the field of view of most small and medium sized telescopes, though they were distinguishable from each other without optical aid.

During the closest approach, both planets appeared to be a binary object to the naked eye. From mid-northern latitudes, the planets were visible one hour after sunset at less than 15° in altitude above the southwestern horizon in the constellation of Capricornus.

The conjunction attracted considerable media attention, with news sources calling it the Christmas Star due to its proximity to Christmas.

More information: Earth Sky

 We must believe then, that as from hence
we see Saturn and Jupiter;
if we were in either of the Two,
we should discover a great many Worlds
which we perceive not;
and that the Universe extends so in infinitum.

Cyrano de Bergerac

CARL EDWARD SAGAN, SCIENCE AND COMMUNICATION

Today, The Grandma continues enjoying the visit of one of her closest friends, Joseph de Ca'th Lon.

Joseph likes Astronomy, History and Archaeology and they have been talking about Carl Edward Sagan, the American astronomer and science communicator who died on a day like today in 1996.

Joseph and The Grandma think that the best way to pay homage to Carl Sagan is talking about his life and his career.

Carl Edward Sagan (November 9, 1934-December 20, 1996) was an American astronomer, cosmologist, astrophysicist, astrobiologist, author, poet, and science communicator.

His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.

Sagan assembled the first physical messages sent into space: the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the now-accepted hypothesis that the high surface temperatures of Venus can be attributed to and calculated using the greenhouse effect.

Initially an associate professor at Harvard and later at Cornell, from 1976 to his death, he was the David Duncan Professor of Astronomy and Space Sciences at the latter. Sagan published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books.

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He wrote many popular science books, such as The Dragons of Eden, Broca's Brain and Pale Blue Dot, and narrated and co-wrote the award-winning 1980 television series Cosmos: A Personal Voyage. The most widely watched series in the history of American public television, Cosmos has been seen by at least 500 million people across 60 different countries.

The book Cosmos was published to accompany the series. He also wrote the science fiction novel Contact, the basis for a 1997 film of the same name. His papers, containing 595,000 items, are archived at The Library of Congress.

Sagan advocated scientific skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI). He spent most of his career as a professor of astronomy at Cornell University, where he directed the Laboratory for Planetary Studies.

Sagan and his works received numerous awards and honors, including the NASA Distinguished Public Service Medal, the National Academy of Sciences Public Welfare Medal, the Pulitzer Prize for General Non-Fiction for his book The Dragons of Eden, and, regarding Cosmos: A Personal Voyage, two Emmy Awards, the Peabody Award, and the Hugo Award.

Carl Sagan was born in Brooklyn, New York. His father, Samuel Sagan, was an immigrant garment worker from Kamianets-Podilskyi, then in the Russian Empire, in today's Ukraine. His mother, Rachel Molly Gruber, was a housewife from New York. Carl was named in honor of Rachel's biological mother, Chaiya Clara, in Sagan's words, the mother she never knew.

Sagan had lived in Bensonhurst, where he went to David A. Boody Junior High School. He had his bar mitzvah in Bensonhurst when he turned 13. The following year, 1948, his family moved to the nearby town of Rahway, New Jersey, for his father's work, where Sagan then entered Rahway High School. He graduated in 1951. Rahway was an older industrial town, and the Sagans were among its few Jewish families.

More information: Wired

Sagan attended the University of Chicago, which was one of the few colleges he applied to that would, despite his excellent high-school grades, consider admitting a 16-year-old. Its chancellor, Robert Maynard Hutchins, had recently retooled the undergraduate College of the University of Chicago into an ideal meritocracy built on Great Books, Socratic dialogue, comprehensive examinations and early entrance to college with no age requirement. The school also employed a number of the nation's leading scientists, including Enrico Fermi and Edward Teller, along with operating the famous Yerkes Observatory.

In 1980 Sagan co-wrote and narrated the award-winning 13-part PBS television series Cosmos: A Personal Voyage, which became the most widely watched series in the history of American public television until 1990. The show has been seen by at least 500 million people across 60 countries. The book, Cosmos, written by Sagan, was published to accompany the series.

Speaking about his activities in popularizing science, Sagan said that there were at least two reasons for scientists to share the purposes of science and its contemporary state. Simple self-interest was one: much of the funding for science came from the public, and the public therefore had the right to know how the money was being spent. If scientists increased public admiration for science, there was a good chance of having more public supporters. The other reason was the excitement of communicating one's own excitement about science to others.

After suffering from myelodysplasia for two years and receiving three bone marrow transplants from his sister, Sagan died from pneumonia at the age of 62, at the Fred Hutchinson Cancer Research Center in Seattle, Washington, on December 20, 1996. His burial took place at Lake View Cemetery in Ithaca, New York.

More information: Speakola

The universe is not required to be in perfect
harmony with human ambition.

Carl Sagan

GAIA, THE ESA SPACE OBSERVATORY FOR ASTROMETRY

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon.

Joseph likes Astronomy, History and Archaeology. They have been talking about Gaia, the space observatory of the European Space Agency (ESA) launched on a day like today in 2013.

Gaia is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until c. 2022. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented precision.

The mission aims to construct by far the largest and most precise 3D space catalog ever made, totalling approximately 1 billion astronomical objects, mainly stars, but also planets, comets, asteroids and quasars among others.

The spacecraft will monitor each of its target objects about 70 times over the first five years of the mission to study the precise position and motion of each target, and will keep doing so.

The spacecraft has enough micro-propulsion fuel to operate until about November 2024. As its detectors are not degrading as fast as initially expected, the mission could therefore be extended.

The Gaia targets objects brighter than magnitude 20 in a broad photometric band that covers most of the visual range; such objects represent approximately 1% of the Milky Way population. Additionally, Gaia is expected to detect thousands to tens of thousands of Jupiter-sized exoplanets beyond the Solar System, 500,000 quasars outside our galaxy and tens of thousands of new asteroids and comets within the Solar System.

More information: ESA

The Gaia mission will create a precise three-dimensional map of astronomical objects throughout the Milky Way and map their motions, which encode the origin and subsequent evolution of the Milky Way.

The spectrophotometric measurements will provide the detailed physical properties of all stars observed, characterizing their luminosity, effective temperature, gravity and elemental composition. This massive stellar census will provide the basic observational data to analyze a wide range of important questions related to the origin, structure, and evolutionary history of our galaxy.

The successor to the Hipparcos mission (operational 1989–93), Gaia is part of ESA's Horizon 2000+ long-term scientific program.

Gaia was launched on 19 December 2013 by Arianespace using a Soyuz ST-B/Fregat-MT rocket flying from Kourou in French Guiana.

The spacecraft currently operates in a Lissajous orbit around the Sun–Earth L2 Lagrangian point.

The Gaia space telescope has its roots in ESA's Hipparcos mission (1989–1993). Its mission was proposed in October 1993 by Lennart Lindegren (Lund Observatory, Lund University, Sweden) and Michael Perryman (ESA) in response to a call for proposals for ESA's Horizon Plus long-term scientific programme.

It was adopted by ESA's Science Programme Committee as cornerstone mission number 6 on 13 October 2000, and the B2 phase of the project was authorised on 9 February 2006, with EADS Astrium taking responsibility for the hardware. The name Gaia was originally derived as an acronym for Global Astrometric Interferometer for Astrophysics.

This reflected the optical technique of interferometry that was originally planned for use on the spacecraft. While the working method evolved during studies and the acronym is no longer applicable, the name Gaia remained to provide continuity with the project.

The total cost of the mission is around €740 million (~ $1 billion), including the manufacture, launch and ground operations. Gaia was completed two years behind schedule and 16% above its initial budget, mostly due to the difficulties encountered in polishing Gaia's ten mirrors and assembling and testing the focal plane camera system.

More information: New Atlas

Gaia was launched by Arianespace, using a Soyuz ST-B rocket with a Fregat-MT upper stage, from the Ensemble de Lancement Soyouz at Kourou in French Guiana on 19 December 2013 at 09:12 UTC (06:12 local time). The satellite separated from the rocket's upper stage 43 minutes after launch at 09:54 UTC. 

The craft headed towards the Sun–Earth Lagrange point L2 located approximately 1.5 million kilometres from Earth, arriving there 8 January 2014. The L2 point provides the spacecraft with a very stable gravitational and thermal environment.

There it uses a Lissajous orbit that avoids blockage of the Sun by the Earth, which would limit the amount of solar energy the satellite could produce through its solar panels, as well as disturb the spacecraft's thermal equilibrium. After launch, a 10-metre-diameter sunshade was deployed. The sunshade always faces the Sun, thus keeping all telescope components cool and powering Gaia using solar panels on its surface.

In October 2013 ESA had to postpone Gaia's original launch date, due to a precautionary replacement of two of Gaia's transponders. These are used to generate timing signals for the downlink of science data.

A problem with an identical transponder on a satellite already in orbit motivated their replacement and reverification once incorporated into Gaia. The rescheduled launch window was from 17 December 2013 to 5 January 2014, with Gaia slated for launch on 19 December.

Gaia was successfully launched on 19 December 2013 at 09:12 UTC. About three weeks after launch, on 8 January 2014, it reached its designated orbit around the Sun-Earth L2 Lagrange point (SEL2), about 1.5 million kilometers from Earth.

More information: EO Portal Directory

 Astronomy compels the soul to look upwards
and leads us from this world to another.

Plato

RAY LIOTTA, UNFORGETTABLE MAFIOUS CHARACTERS

Today, The Grandma continues relaxing at home. She has received the wonderful visit of Tina Picotes, one of her closest friends. Tina loves cinema and theatre and they have been talking about Ray Liotta, the American actor and producer who was born on a day like today in 1954.

Raymond Allen Liotta (December 18, 1954) is an American actor and producer.

He is best known for playing Henry Hill in Goodfellas (1990). His other roles include Ray Sinclair in Something Wild (1986), for which he received a Golden Globe nomination, as well as Shoeless Joe Jackson in Field of Dreams (1989), Officer Pete Davis in Unlawful Entry (1992), Officer Gary Figgis in Cop Land (1997), Paul Krendler in Hannibal (2001), Fred Jung in Blow (2001), the voice of Tommy Vercetti in the video game Grand Theft Auto: Vice City (2002), Chief Gus Monroe in John Q (2002), Samuel Rhodes in Identity (2003), Detective Harrison in Observe and Report (2009), Markie Trattman in Killing Them Softly (2012), Peter Deluca in The Place Beyond the Pines (2012), Lieutenant Matt Wozniak in the drama series Shades of Blue (2016–2018) and Jay Marotta in Marriage Story (2019).

Raymond Allen Liotta was born in Newark, New Jersey, on December 18, 1954. Having been abandoned at an orphanage, he was adopted at the age of six months by township clerk Mary and auto-parts store owner Alfred Liotta.

Alfred, the son of Italian immigrants, was also a personnel director and president of a local Democratic Party club. His adoptive parents each unsuccessfully ran for local office; he recalls attending parades to hand out flyers for his father's run.

More information: Showbiz Cheat Sheet

He grew up in a Roman Catholic household in Union, New Jersey, although his family was not very religious. They went to church and he received first communion and was confirmed, but the family did not pray much. He occasionally uses prayer in his daily life.

He graduated from Union High School in 1973. He graduated from the University of Miami, where he studied acting and received a BFA in 1978. He performed in musicals such as Cabaret, Dames at Sea, Oklahoma, and Sound of Music during his time there.

After college, Liotta moved to New York City. He got a job as a bartender at the Shubert Organization and landed an agent within six months. One of his earliest roles was as Joey Perrini on the soap opera Another World, on which he appeared from 1978 to 1981. He quit the show so he could try his luck in the film industry and moved to Los Angeles. He made his film debut in 1983's The Lonely Lady. His first major acting role was Something Wild (1986), which earned him his first Golden Globe nomination.

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In 1989, Liotta portrayed the ghost of famed baseball player Shoeless Joe Jackson in the fantasy/drama film Field of Dreams.

In 1990, Liotta portrayed real-life mobster Henry Hill in Martin Scorsese's critically acclaimed and commercially successful film Goodfellas.

In 1992, he starred as a psychopathic cop in the thriller Unlawful Entry. He appeared in a leading role in the science-fiction/action film No Escape.

In 1996, he starred in the sci-fi/thriller Unforgettable. Liotta earned critical praise for his turn in James Mangold's 1997 film Cop Land, and he received critical praise in 1998 for his performance as a compulsive gambler in Phoenix.

In addition to his film roles, Liotta portrayed singer Frank Sinatra in the 1998 TV movie The Rat Pack for which he received a Screen Actors Guild award nomination, starred as himself in the sitcom Just Shoot Me in December 2001 & January 2002, provided the voice of Tommy Vercetti for the 2002 video game Grand Theft Auto: Vice City, and appeared in the television drama ER in 2004, playing Charlie Metcalf in the episode Time of Death. The ER role earned Liotta an Emmy for Outstanding Guest Actor in a Drama Series. 

Liotta starred in the 2006 CBS television series Smith, which was pulled from the schedule after three episodes, and in 2012 Liotta appeared as himself in a purely vocal role for the What a Croc! episode of the Disney Channel comedy series Phineas & Ferb.

Liotta played the father of drug dealer George Jung in the 2001 Johnny Depp film Blow and, in the following year, appeared as Detective Lieutenant Henry Oak in the Joe Carnahan-directed film Narc, a role that led to an Independent Spirit Award nomination and a Phoenix Film Critics Society Awards nomination for Best Supporting Male.

He then reunited with director James Mangold in 2003, alongside John Cusack and Alfred Molina, in the dark horror-thriller Identity.

In 2005, he narrated Inside the Mafia for the National Geographic Channel. He later appeared in Smokin' Aces -reuniting with Narc director Carnahan, in which he portrayed an FBI agent named Donald Carruthers in one of the lead roles.

Liotta appeared with John Travolta in the movie Wild Hogs, in Battle in Seattle as the city's mayor, and in 2008, starred in Hero Wanted as a detective alongside Cuba Gooding Jr. Also in 2008, he made a guest appearance on the SpongeBob SquarePants episode What Ever Happened to SpongeBob?; in the episode, he voices the leader of a gang called the Bubble Poppin’ Boys, who try to kill an amnesiac SpongeBob, voiced by Tom Kenny. He also appeared in Crossing Over, co-starring Harrison Ford.

More information: NPR

Liotta played Detective Harrison in the 2009 Jody Hill comedy Observe and Report as Seth Rogen's nemesis from the local police.

In 2011, he starred in The Son of No One, opposite Channing Tatum, and for the first time in his career, Al Pacino.

In 2004, Liotta made his Broadway debut opposite Frank Langella in the Stephen Belber play, Match.

In the 2010s, Liotta appeared in Date Night, with Steve Carell, Charlie St. Cloud with Zac Efron, the independent drama Snowmen, and The River Sorrow, which stars Liotta as a detective alongside Christian Slater and Ving Rhames. He starred alongside Brad Pitt and James Gandolfini in the 2012 Andrew Dominik film Killing Them Softly and the 2013 Ariel Vromen film The Iceman features Liotta as the character of Roy DeMeo. He had a supporting role in Muppets Most Wanted (2014).

In 2014, Liotta played a preacher in the faith-based film The Identical.

Liotta starred in the Western miniseries Texas Rising for The History Channel in 2015. Other projects include Kill the Messenger with Jeremy Renner, Stretch with Chris Pine and a David Guetta video.

Since June 2015, Liotta narrates the AMC docu-series The Making of the Mob.

In 2016, Liotta began starring opposite Jennifer Lopez in Shades of Blue.

In 2018, Liotta became a spokesperson for Pfizer's Chantix advertising campaign.

More information: Irish News

 I think that if you can achieve a balance,
then you appease a lot of yourself and your career
and what it takes to maintain
in this business for a while.

Ray Liotta

ÉMILIE DU CHÂTELET, PHYSICS & NATURAL PHILOSOPHY

Today, The Grandma continues relaxing at home. The COVID19 situation is not good and the best option is to stay safe and at home doing interesting things. She has decided to read about one of her favourite scientists, Émilie du Châtelet, the French natural philosopher and mathematician who is considered one of the first scientists of the modern age, who was born on a day like today in 1706.

Gabrielle Émilie Le Tonnelier de Breteuil, Marquise du Châtelet (17 December 1706-10 September 1749) was a French natural philosopher and mathematician during the early 1730s until her untimely death due to childbirth complications in 1749.

Her most recognized achievement is her translation of and commentary on Isaac Newton's 1687 book Principia containing basic laws of physics. The translation, published posthumously in 1756, is still considered the standard French translation today.

Her commentary includes a profound contribution to Newtonian mechanics -the postulate of an additional conservation law for total energy, of which kinetic energy of motion is one element. This led to her conceptualization of energy as such, and to derive its quantitative relationships to the mass and velocity of an object.

More information: Smithsonian Magazine

Her philosophical magnum opus, Institutions de Physique (Paris, 1740, first edition), or Foundations of Physics, circulated widely, generated heated debates, and was republished and translated into several other languages within two years of its original publication. She participated in the famous vis viva debate, concerning the best way to measure the force of a body and the best means of thinking about conservation principles.

Posthumously, her ideas were heavily represented in the most famous text of the French Enlightenment, the Encyclopédie of Denis Diderot and Jean le Rond d'Alembert, first published shortly after du Châtelet's death.

Numerous biographies, books and plays have been written about her life and work in the two centuries since her death. In the early 21st century, her life and ideas have generated renewed interest.

Émilie du Châtelet was born on 17 December 1706 in Paris, the only girl amongst six children. Du Châtelet's education has been the subject of much speculation, but nothing is known with certainty.

More information: Daily JSTOR

Among their acquaintances was Fontenelle, the perpetual secretary of the French Académie des Sciences. Du Châtelet's father Louis-Nicolas, recognizing her early brilliance, arranged for Fontenelle to visit and talk about astronomy with her when she was 10 years old.

Du Châtelet's mother, Gabrielle-Anne de Froulay, was brought up in a convent, at the time the predominant educational institution available to French girls and women. While some sources believe her mother did not approve of her intelligent daughter, or of her husband's encouragement of Émilie's intellectual curiosity, there are also other indications that her mother not only approved of Du Châtelet's early education, but actually encouraged her to vigorously question stated fact.

In either case, such encouragement would have been seen as unusual for parents of their time and status. When she was small, her father arranged training for her in physical activities such as fencing and riding, and as she grew older, he brought tutors to the house for her.

As a result, by the age of twelve she was fluent in Latin, Italian, Greek and German; she was later to publish translations into French of Greek and Latin plays and philosophy. She received education in mathematics, literature, and science.

Du Châtelet also liked to dance, was a passable performer on the harpsichord, sang opera, and was an amateur actress. As a teenager, short of money for books, she used her mathematical skills to devise highly successful strategies for gambling.

Du Châtelet may have met Voltaire in her childhood at one of her father's salons; Voltaire himself dates their meeting to 1729, when he returned from his exile in London. However, their friendship developed from May 1733 when she re-entered society after the birth of her third child.

Sharing a passion for science, Voltaire and Du Châtelet collaborated scientifically. They set up a laboratory in Du Châtelet's home. In a healthy competition, they both entered the 1738 Paris Academy prize contest on the nature of fire, since Du Châtelet disagreed with Voltaire's essay. Although neither of them won, both essays received honourable mention and were published. She thus became the first woman to have a scientific paper published by the Academy.

More information: Avant Bard Theatre

In May 1748, Du Châtelet began an affair with the poet Jean François de Saint-Lambert and became pregnant. In a letter to a friend she confided her fears that she would not survive her pregnancy. On the night of 4 September 1749 she gave birth to a daughter, Stanislas-Adélaïde. Du Châtelet died on 10 September 1749, at Lunéville, from a pulmonary embolism. She was 42. Her daughter died 20 months later.

In 1749, the year of Du Châtelet's death, she completed the work regarded as her outstanding achievement: her translation into French, with her commentary, of Newton's Philosophiae Naturalis Principia Mathematica, often referred to as simply the Principia, including her derivation of the notion of conservation of energy from its principles of mechanics.

Published ten years after her death, today Du Châtelet's translation of the Principia is still the standard translation of the work into French. Her translation and commentary of the Principia contributed to the completion of the scientific revolution in France and to its acceptance in Europe.

Du Châtelet made a crucial scientific contribution in making Newton's historic work more accessible in a timely, accurate and insightful French translation, augmented by her own original concept of energy conservation.

More information: FS Blog

To be happy, one must rid oneself of prejudice,
be virtuous, healthy, and have a capacity
for enjoyment and for passion.

Emilie du Chatelet

WALES & ENGLAND, THE FIRST HOME NATIONS IN 1882

Today, The Grandma has been relaxing at home. She has been reading about sports and she has paid attention about the commemoration of a great event. On a day like today in 1882, Wales and England contest the first Home Nations, now Six Nations, rugby union match.

The Six Nations Championship is an annual international men's rugby union competition between the teams of England, France, Ireland, Italy, Scotland, and Wales.

The Six Nations is the successor to the Home Nations Championship (1883-1909 and 1932-39), played between teams from England, Ireland, Scotland, and Wales, which was the first international rugby union tournament. With the addition of France, this became the Five Nations Championship (1910-31 and 1947-99), which in turn became the Six Nations Championship with the addition of Italy.

England hold the record for outright wins with 29. Since the Six Nations era started in 2000, only Italy and Scotland have failed to win the Six Nations title.

The women's tournament started as the Women's Home Nations in the 1996 season.

The tournament was first played in 1883 as the Home Nations Championship among the four Home Nations -England, Ireland, Scotland, and Wales. However, England was excluded from the 1888 and 1889 tournaments due to their refusal to join the International Rugby Football Board.

The tournament then became the Five Nations Championship in 1910 with the addition of France. The tournament was expanded in 2000 to become the Six Nations Championship with the addition of Italy.

More information: Six Nation Rugby

Following the relative success of the Tier 2 nations in the 2015 Rugby World Cup, there were calls by Octavian Morariu, the president of Rugby Europe, to let Georgia and Romania join the Six Nations due to their consistent success in the European Nations Cup and ability to compete in the Rugby World Cup.

The winners of the Six Nations are presented with the Championship Trophy. This was originally conceived by the Earl of Westmorland, and was first presented to the winners of the 1993 championship, France. It is a sterling silver trophy, designed by James Brent-Ward and made by a team of eight silversmiths from the London firm William Comyns.

It has 15 side panels representing the 15 members of the team and with three handles to represent the three officials, referee and two touch judges. The cup has a capacity of 3.75 litres -sufficient for five bottles of champagne. Within the mahogany base is a concealed drawer which contains six alternative finials, each a silver replica of one of the team emblems, which can be screwed on the detachable lid.

A new trophy was introduced for the 2015 Championship. The new trophy was designed and crafted by Thomas Lyte silversmiths and replaces the 1993 edition, which is being retired as it represented the nations that took part in the Five Nations Championship. Ireland were the last team to win the old trophy, and coincidentally, the first team to win the new one.

More information: Rugby Football History

Rugby is great.
The players don't wear helmets or padding;
they just beat the living daylights out of each other
and then go for a beer.
I love that.

Joe Theismann

VENERE 7, THE SUCCESSFUL RUSSIAN LANDING ON VENUS

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon.

Joseph likes Astronomy, History and Archaeology. They have been talking about Venera 7, the Soviet spacecraft, part of the Venera series of probes to Venus, that landed on the Venusian surface on a day like today in 1970.

Venera 7 (in Russian Венера-7 meaning Venus 7) was a Soviet spacecraft, part of the Venera series of probes to Venus. When it landed on the Venusian surface on 15 December 1970, it became the first spacecraft to soft land on another planet and the first to transmit data from there back to Earth.

The lander was designed to be able to survive pressure of up to 180 bars and temperatures of 580 °C. This was significantly greater than what was expected to be encountered but significant uncertainties as to the surface temperatures and pressure of Venus resulted in the designers' opting for a large margin of error. The degree of hardening added mass to the probe which limited the amount of mass available for scientific instruments both on the probe itself and the interplanetary bus.

The interplanetary bus carried a solar wind charged particle detector and a cosmic ray detector. On the lander there were temperature and pressure sensors as well as an accelerometer to measure atmospheric density. The probe also carried a radar altimeter.

The probe was launched from Earth on 17 August 1970, at 05:38 UTC. It consisted of an interplanetary bus, based on the 3MV system, and a lander. During the flight to Venus, two in-course corrections were made using the bus' on-board KDU-414 engine.

Venera 7 entered the atmosphere of Venus on 15 December 1970. The lander remained attached to the interplanetary bus during the initial stages of atmospheric entry, to allow the bus to cool the lander to −8 °C for as long as possible.

More information: Russian Space Web

The lander was ejected once atmospheric buffeting broke the interplanetary bus's lock-on with Earth. The parachute opened at a height of 60 km, and atmospheric testing began with results showing the atmosphere to be 97% carbon dioxide. The parachute was initially reefed down to 1.8 square meters, opening to 2.5 square meters 13 minutes later, when the reefing line melted as designed. Six minutes after the unreefing, the parachute started to fail, resulting in a descent more rapid than planned.

The parachute eventually failed completely, and the probe entered a period of freefall. As a result, the lander struck the surface of Venus at about 59 km/h at 05:37:10 UTC.

The probe appeared to go silent on impact, but recording tapes kept rolling. A few weeks later, upon a review of the tapes by the radio astronomer Oleg Rzhiga, another 23 minutes of very weak signals were found on them. The spacecraft had landed on Venus, and probably bounced onto its side, leaving the medium gain antenna not aimed correctly for strong signal transmission to Earth.

The probe transmitted information to Earth for 53 minutes, which included about 20 minutes from the surface. It was found that the temperature at the surface of Venus was 475 °C ± 20 °C. Using the temperature, and models of the atmosphere, a pressure of 9.0 MPa ± 1.5 MPa was calculated.

From the spacecraft's rapid halt, from falling to stationary inside 0.2 seconds, it was possible to conclude that the craft had hit a solid surface with low levels of dust.

The probe provided information about the surface of Venus, which could not be seen through a thick veil of atmosphere. The spacecraft definitively confirmed that humans cannot survive on the surface of Venus, and excluded the possibility that there is any liquid water on Venus.

More information: New Atlas

 There is good evidence that Venus once had
liquid water and a much thinner atmosphere,
similar to Earth billions of years ago.
But today the surface of Venus is dry as a bone,
hot enough to melt lead,
there are clouds of sulfuric acid that reach
a hundred miles high and the air is so thick
it's like being 900 meters deep in the ocean.

Bill Nye