Monday, November 13, 2017

Lasers in Space ?

Laser Weapon System aboard USS Ponce (AFSB(I)-15) in November 2014 (05).JPG
The U.S. Navy's USS Ponce amphibious transport ship with the world's first active Laser Weapons System (LaWS). Will spacecraft someday possess such a system?
(Image Sources: Wikipedia.org , By U.S. Navy photo by John F. Williams - This Image was released by the United States Navy with the ID 141115-N-PO203-057 (next).This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information.বাংলা | Deutsch | English | español | euskara | فارسی | français | italiano | 日本語 | 한국어 | македонски | മലയാളം | Plattdüütsch | Nederlands | polski | português | Türkçe | українська | 中文 | 中文(简体)‎ | +/−, Public Domain, https://commons.wikimedia.org/w/index.php?curid=37235168 )

By Glenn A. Walsh
Reporting for SpaceWatchtower

Since the first Lasers were built in the 1960s, science-fiction television programs and motion pictures, such as Star Trek and Star Wars, portrayed Lasers or Laser-type weaponry in Outer Space. In the case of Star Trek, the weapons are called Phasers, as Star Trek creator Gene Roddenberry felt that Lasers would be superseded by more advanced weaponry by the 23rd century.

Are such Laser weaponry in use today? Will Laser weapons be used in Outer Space in the near future? While American, Chinese, and Russian militaries continue developing Lasers, for terrestrial as well as Outer Space defense-related applications, advanced communication networks using Lasers are being tested by NASA for use in Outer Space.

Of course, most people are aware that the United States started a major research program into a space-based, defense shield using Lasers in the 1980s, after U.S. President Ronald Reagan announced creation of the Strategic Defense Initiative (SDI) in a speech to the American people on 1983 March 23. Most Democrats opposed the project, led by U.S. Senator Ted Kennedy, who called the project “Star Wars.”

However many people are unaware that in response to SDI, the Union of Soviet Socialist Republics (name used for Russia for most of the 20th century) tried launching the first component of an experimental, orbital, unstaffed Laser battle-station on the evening of 1987 May 15. However, upon reaching orbit, the satellite containing this component started tumbling in orbit. Then, due to a software error, instead of going into a higher orbit, the engines fired with the satellite pointed in the wrong direction—down! The satellite soon re-entered the atmosphere, over-heated, broke-apart, and fell into the Pacific Ocean. The failure of such an expensive component convinced Kremlin leaders to cancel the rest of the project.

In 2014, the U.S. Navy deployed the world's first active Laser Weapons System (LaWS) on the USS Ponce amphibious transport ship in the Persian Gulf. The LaWS cost $40 million to develop, but costs only one dollar per shot! While the LaWS is primarily designed to attack aircraft and small boats, a second-generation system is being developed to target missiles.

The USS Ponce is scheduled to be decommissioned next year. The future of this particular LaWS installation is unclear, as it is not scheduled to be moved to a new vessel.

Last week, the U.S. Air Force gave a $26.3 million contract to Lockheed Martin “for the design, development, and production of a high power fiber laser,” for use on a fighter jet aircraft by 2021.

In August, the U.S. Army's Advanced Test High Energy Asset (ATHENA, for the Greek Goddess of Wisdom) Laser weapon underwent successful testing at the White Sands Missile Range in New Mexico. And in June, the U.S. Army successfully tested a high-energy Laser weapon system on an AH-64 Apache attack helicopter.

In July, Russia announced plans to deploy powerful Laser weapons on its sixth-generation MiG-41 fighter jet aircraft, to destroy missiles. However, their Laser system is still in the concept stage and is not expected to be available until 2035.

Current American and Russian plans to deploy Lasers in Outer Space are unclear. However, reports this year indicate that China is developing first-strike Space-Lasers designed to destroy NATO satellites. These would be both ground-based Laser weapons, along with Laser weapons on a staffed, Chinese space-station (during the Cold War, the Soviet Union considered and rejected placing such weapons on a staffed Salyut Space Station). Some believe a five-ton chemical Laser could be operational by the Chinese military, possibly by 2023.

However, high-speed data communication is where Lasers are making a strong impact in Outer Space today. On Sunday morning (November 12), NASA and aerospace launch firm Orbital ATK launched new satellites which could greatly advance the speed of data networks in Space and on Earth, perhaps eventually including the Internet, using Lasers instead of radio links. It is expected that the new Laser links could create 200 megabits per second (Mbps) connections.

The two, NanoRacks CubeSats satellites are being sent to the International Space Station (ISS) during an ISS re-supply mission. The twin satellites will be deployed from the ISS using one (of two) of their NanoRacks CubeSats Deployers.

Orbital ATK's Antares rocket with the Cygnus CRS OA-8E spacecraft (titled the SS Gene Cernan for the last man to walk on the Moon, who died in January) had a flawless launch (despite a five-minute delay due to a couple boats wandering into the launch zone) from NASA's Wallops Island Flight Facility on the Eastern Shore of Virginia. The SS Gene Cernan will take two days to reach the ISS. It is the eighth mission (of ten Orbital ATK re-supply flights under the current contract with NASA) to re-supply the International Space Station. The launch had been expected on November 11, but was delayed when an aircraft inadvertently strayed into the launch zone.

Internet Links to Additional Information ---

U.S. Navy's Laser Weapons System -
Link 1 >>> https://en.wikipedia.org/wiki/Laser_Weapon_System
Link 2 >>> http://www.cnn.com/2017/07/17/politics/us-navy-drone-laser-weapon/index.html

Mackie, Thomas. "Lazer equipped NASA satellites to revolutionise your internet speed when launched TODAY."
Sunday Express, London 2017 Nov. 12.
Link >>> http://www.express.co.uk/news/world/878501/nasa-nasa-satellites-space-technology-space-agency-new-technology-tech-revolution

Hansen, Drew. "Lockheed to develop jet-mounted laser for the Air Force."
Washington Business Journal 2017 Nov. 9.
Link >>> https://www.bizjournals.com/washington/news/2017/11/09/lockheed-to-develop-jet-mounted-laser-for-the-air.html

Sicard, Sarah. "The U.S. Army's Deadly Laser Just Took a Major Step Forward." Column: The Buzz.
NationalInterest.org / Task and Purpose 2017 Oct. 5.
Link >>> http://nationalinterest.org/blog/the-buzz/the-us-armys-deadly-laser-just-took-major-step-forward-22619

Sharkov, Damien. "Russian Military Plans Missile Killing Laser for Next-Generation Warplanes."
Newsweek 2017 July 27.
Link >>> http://www.newsweek.com/russia-plans-missile-killing-laser-next-generation-warplanes-does-it-work-642906

Judson, Jen. "US Army tests laser on Apache helicopter."
DefenseNews.com 2017 June 26.
Link >>> https://www.defensenews.com/2017/06/26/us-army-tests-laser-on-apache-helicopter/ 

Oliphant, Vickie. "China’s new space lasers to take out satellites leaving west at mercy of Beijing missiles."
Sunday Express, London 2017 March 12.
Link >>> http://www.express.co.uk/news/world/778100/China-developing-lasers-destroy-enemy-satellites-futuristic-light-war-militarise-space

Day, Dwayne A. and Robert G. Kennedy III
"Soviet Star Wars, The launch that saved the world from orbiting laser battle stations."
Air & Space Smithsonian Magazine 2010 January.
Link >>> https://www.airspacemag.com/space/soviet-star-wars-8758185/?page=1

Related Blog-Posts ---

"NASA Laser Com-System Miniaturized & Improved Data Precision." 2015 Oct. 24.

Link >>> http://spacewatchtower.blogspot.com/2015/10/nasa-laser-com-system-miniaturized.html

 

"Lunar Laser Com-System Sets Data Transmission Record." 2013 Oct. 24.

Link >>> http://spacewatchtower.blogspot.com/2013/10/lunar-laser-com-system-sets-data.html

 

"Video: Laser Shoots Down Missile." 2013 May 15.

Link >>> http://spacewatchtower.blogspot.com/2013/05/video-laser-shoots-down-missile.html

 

"Laser Weapon Funding from Science Fiction Book?" 2013 Jan. 27.

Link >>> http://spacewatchtower.blogspot.com/2013/01/laser-weapon-funding-from-science.html


Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 November 13.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
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LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Friday, November 3, 2017

Centennial: Mt. Wilson Observatory's 100-inch Hooker Telescope

http://www.trbimg.com/img-59f97730/turbine/la-1509521194-r2g8p3z875-snap-image/1250/1250x703
Image of the observatory with the historic 100-inch Hooker Reflector Telescope on Mount Wilson in Los Angeles County, California.
(Image Source: Los Angeles Times, Photographer: Francine Orr)

By Glenn A. Walsh
Reporting for SpaceWatchtower

The historic, 100-Inch Hooker Reflector Telescope, at Mount Wilson Observatory in Los Angeles County, California, marks 100 years of discoveries today (November 3). It was the night / early morning of 1917 November 2 to 3 that First Light shone through the Hooker Telescope.

In fact, 100 years ago as of the hour of the posting of this blog-post, 2017 November 3 at 3:00 a.m. Pacific Standard Time (PST) / 7:00 a.m. Eastern Daylight Saving Time (EDT) / 11:00 Coordinated Universal Time (UTC), it is believed to be the time the actual First Light occurred.

[It would be another year before the first Daylight Saving Time would be established in America, due to the United States entry into World War I. Daylight Saving Time proved unpopular to many people, particularly those in the rural areas. Hence Congress repealed Daylight Saving Time shortly after the end of World War I.]

[The international time scale used by scientists, based on the time at the Royal Observatory in Greenwich, London, England, is known as Coordinated Universal Time. At the time the Hooker Telescope began scientific research, this time was known as Greenwich Mean Time (although for Greenwich Mean Time, the day began at Noon).]

Actually, there is some dispute as to the exact time of First Light, and whether it occurred on November 2 or November 3 (or even November 1). The object viewed through the telescope is also in dispute.

The first attempt at First Light seems to have occurred on the evening of November 2, when the telescope was pointed toward Jupiter. However, the image was quite poor, and the astronomers in attendance [George Ellery Hale (first Mount Wilson Observatory Director), Walter S. Adams (second Mount Wilson Observatory Director), George W. Ritchey (also telescope-maker), Francis G. Pease (also designer of the Hooker Telescope), and Ferdinand Ellerman] feared the mirror may be defective (as happened in 1990 after the orbiting of the Hubble Space Telescope).

However, the telescope dome had been open most of the day, for construction workers to finish their work. The scientists decided the observatory interior, including the mirror, was not cool enough for proper observations. So, they agreed to allow the mirror to cool and come back later.

When George Hale and Walter Adams returned at around 3:00 on the morning of November 3, they pointed the new telescope at the bright star Vega (although the star viewed is in dispute). They saw a very sharp image of this celestial object, which is considered the actual First Light.

The dispute in the date of the First Light is due to Walter Adams' later recollection that First Light was on the evening of November 1 to 2, while the diary of George Hale and the post-dated telescope log of night assistant Wendell P. Hoge stated that First Light was on the night of November 2 to 3.

However, most astronomical research did not really get underway until 1918, when the construction of the telescope was completely finished.

Mount Wilson Observatory Director George Ellery Hale was a very ambitious astronomer. By 1908, Mount Wilson Observatory already had the largest, operational telescope in the world, a 60-Inch reflector telescope. A larger 72-Inch reflector telescope, built in 1845 in Parsonstown, Ireland, remained in use until about 1890 and was partly dismantled in 1908.

However, Director Hale was not satisfied. He wanted an even larger telescope. In fact, even before the 60-Inch telescope could be tested, a 4.5-ton disk for the mirror of a 100-Inch telescope had been cast.

A good friend of Director Hale, local businessman John D. Hooker, pledged $45,000 for an 84-Inch (later increased to 100-Inch) glass mirror disk, along with the equipment and facilities to create such a large mirror. Now, Dr. Hale had to find the money (more than $500,000) to build an observatory building to house this new, giant telescope and other needed facilities.

Mr. Hooker's gift only covered 10 per-cent of the total cost of the project. And, the Carnegie Institution of Washington, which owned and operated Mount Wilson Observatory, could not help. Their endowment was needed to maintain their existing research departments.

However, Dr. Hale found an enthusiastic supporter: industrialist and philanthropist Andrew Carnegie, who had created the Carnegie Institution of Washington! Even from his early days as a steel entrepreneur, Andrew Carnegie had greatly appreciated the importance of science and technology.

Mr. Carnegie's science philanthropy had begun in 1895 with the opening of Pittsburgh's Carnegie Museum of Natural History, which he enhanced in 1907 with, what has become, one of the world's best collections of dinosaur skeletons. He had also helped astronomer and telescope-maker John A. Brashear complete a new, 3-dome Allegheny Observatory in Pittsburgh, with all of the steel donated by the Carnegie Steel Company.

Andrew Carnegie had visited Mount Wilson Observatory in 1910 [the same year he donated an 11-Inch Brashear refractor telescope to the Carnegie Institute of Technology in Pittsburgh (today's Carnegie Mellon University), so the students could see Halley's Comet] and had been quite impressed with the 60-Inch reflector telescope. In 1911, Mr. Carnegie donated another $10 million to the Carnegie Institution of Washington. The donation came with a suggestion: “I hope the work at Mount Wilson will be vigorously pushed, because I am so anxious to hear the expected results from it. I should like to be satisfied before I depart, that we are going to repay to the old land some part of the debt we owe them by revealing more clearly than ever to them the new heavens.”

Once completed, the Hooker Telescope did not disappoint. Astronomer Edwin Hubble, for whom the Hubble Space Telescope is named, used the telescope to prove that Andromeda was not just a nebulae in our galaxy as scientists had concluded, but a whole separate galaxy of stars—one of thousands of separate galaxies.

Six years later, Dr. Hubble and Milton Humason used the Hooker Telescope to discover that the Universe is expanding, and they measured the expansion and the size of the Universe. In the 1930s, Fritz Zwicky found evidence for Dark Matter and Seth Nickolson discovered two more Moons of Jupiter (numbers 10 and 11). In the 1940s, Walter Baade used the telescope to find two different types of Cepheid Variable Stars, which led to a new estimate for the size of the Universe, double the estimate Dr. Hubble had calculated.

The 100-Inch Hooker Reflector Telescope was the world's largest reflector telescope from 1917 to 1949. In 1949, the 200-Inch Hale Reflector Telescope at Palomar Observatory in San Diego County, California, named after George Ellery Hale, became the largest telescope in the world.

In the 1980s after ending Mount Wilson Observatory's research program, the institution became a public observatory operated by the Mount Wilson Institute (but still owned by the Carnegie Institution for Science). The Institute sells telescope time to private groups, as well as providing educational tours to local youth groups and to the general public.

Special Thanks: Marilyn E. Morgan, Mount Wilson Observatory.

Internet Links to Additional Information ---

Good photograph of 100-inch Hooker Reflector Telescope:
Link >>> http://spacewatchtower.blogspot.com/2017/11/astronomical-calendar-2017-november.html

100-inch Hooker Reflector Telescope  --
Link 1 >>> http://amazingspace.org/resources/explorations/groundup/lesson/scopes/mt_wilson/
Link 2 >>> https://en.wikipedia.org/wiki/Mount_Wilson_Observatory#Hooker_telescope
Building the Telescope: Link >>> https://www.mtwilson.edu/building-the-100-inch-telescope/

Mount Wilson Observatory, Los Angeles County CA --
Link 1 >>> https://www.mtwilson.edu/
Link 2 >>> https://en.wikipedia.org/wiki/Mount_Wilson_Observatory

Khan, Amina.
"At Mt. Wilson, scientists celebrate 100th birthday of the telescope that revealed the universe."
Los Angeles Times 2017 November 1.
Link >>> http://www.latimes.com/science/la-sci-sn-mt-wilson-centennial-20171101-htmlstory.html

Nicholson, Don and Bob Eklund. "First Light Doubts on Mount Wilson."
Reflections, Mount Wilson Observatory, Mount Wilson Institute. Fall Quarter / 2017 September,
Page 3.
Link >>> http://buhlplanetarium.tripod.com/MtWilson/Reflections_Sept_2017Rev_screenres.pdf

Morgan, Marilyn. "The Amazing Mister Carnegie."
Reflections, Mount Wilson Observatory Association Winter Quarter / 2005 December.
(Includes photo of Andrew Carnegie and George Ellery Hale at Mount Wilson Observatory in 1910 March)
Link >>> http://andrewcarnegie.tripod.com/astro/Reflections-Dec2005.pdf

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 November 3.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
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LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Wednesday, November 1, 2017

Astronomical Calendar: 2017 November

                            https://upload.wikimedia.org/wikipedia/commons/thumb/7/7f/100_inch_Hooker_Telescope_900_px.jpg/800px-100_inch_Hooker_Telescope_900_px.jpg                    
The night / early morning of November 2 to 3 marks the centennial of First Light for the historic 100-inch Hooker Reflector Telescope at Mount Wilson Observatory in Los Angeles County, California. This telescope was the world's largest reflector telescope from 1917 to 1949.
(Image Sources: Ken Spencer, Wikipedia.org)

Astronomical Calendar for 2017 November: 
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2017.html#nov

 Related Blog Post ---


"Astronomical Calendar: 2017 October." 2017 Oct. 1.

Link >>> https://spacewatchtower.blogspot.com/2017/10/astronomical-calendar-2017-october.html


Source: Friends of the Zeiss.
              2017 November 1.

                             Like This Post? - Please Share!

            More Astronomy & Science News - SpaceWatchtower Twitter Feed:
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                Want to receive SpaceWatchtower blog posts in your in-box ?
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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Wednesday, October 18, 2017

250th Anniversary: Astronomy Helps Create Mason-Dixon Line

                                      http://www.exploretheline.com/images/peteatcs.jpg
This photograph shows Pete Zapadka, a member of the Amateur Astronomers Association of Pittsburgh (AAAP), leaning on the Cornerstone Monument at the precise geographic location of the southwest corner of the Commonwealth of Pennsylvania--the official end of the Mason-Dixon Line. Although due to Native American territory disputes, astronomers Charles Mason and Jeremiah Dixon never saw this site; their portion of the Mason-Dixon Line Survey ended prematurely 23 miles short of this site, 250 years ago today (October 18). Philadelphia clock-maker and astronomer David Rittenhouse placed this monument and completed the Mason-Dixon Line Survey in 1784.
(Image Source: Amateur Astronomer Pete Zapadka)                            

By Glenn A. Walsh
Reporting for SpaceWatchtower

On this date 250 years ago (1767 October 18), astronomers Charles Mason and Jeremiah Dixon completed surveying most of the southern boundary of Pennsylvania [separating from the colonies of Maryland and Virginia (now the state of West Virginia)], what became the most famous boundary in U.S. history: the Mason-Dixon Line. Although contracted to survey to, what is now, the southwest corner of the Commonwealth of Pennsylvania, local Native Americans prevented the survey of the last 23 miles of the boundary line. Philadelphia clock-maker and astronomer David Rittenhouse headed a survey team which finished surveying those last 23 miles in 1784.

The whole idea behind the Mason-Dixon Line began with a colonial land dispute between two influential British families. In 1632, English King Charles I gave a grant of land, in the American Colonies, to Cecilius Calvert. The grant for what would become the colony of Maryland provided land north of Virginia and south of the 40th parallel. Today, the City of Pittsburgh is located at the 40th parallel, so this land grant included much of what is now southern Pennsylvania.

In 1681, King Charles II provided a second land grant to William Penn for what would become the Province of Pennsylvania. Although it did mention that the southern boundary of this land grant would be the 40th parallel, much of the rest of the delineation of the land grant was convoluted and confusing. Hence, the Penn Family interpreted the grant to include land north of the 39th parallel.
.
The Penn and Calvert families both claimed the land between the 39th and 40th parallels. And, since the thriving City of Philadelphia was within these two latitudes, this made the dispute even more contentious. However, such land disputes were common in the 17th and 18th centuries, as there had been little actual surveying in America and maps and land grants were often quite vague.

The Penn and Calvert families tried to convince the settlers of the disputed region that they lived in Pennsylvania or Maryland, respectively—and, they should pay taxes to the appropriate colony. Most colonists did not care which colony they lived in; but, they did not want to pay taxes to both colonies!

After several decades, the dispute actually led to war between Pennsylvania and Maryland! What became known as Cresap's War (named for Thomas Cresap, a Maryland partisan who had moved into, what is now York County, Pennsylvania, part of the disputed territory) was a series of skirmishes between the two colonies. Also known as the Conojocular War, militias from both Maryland and Pennsylvania fought for about a year or so, until King George II enacted a cease-fire in 1738.

In 1750, King George II created a formal truce between the two colonies. This truce granted most of the disputed territory to Pennsylvania. However, no one knew where the actual boundary line between the two colonies was located. So, in 1763 the Penn and Calvert families agreed to pay for a boundary survey. Well known English astronomers and surveyors Charles Mason and Jeremiah Dixon were hired to conduct this survey.

Charles Mason had been employed by the Royal Society in Greenwich, England to observe the stars and the Moon, and create lunar tables that could be used to determine longitude. Jeremiah Dixon was a surveyor, trained by a renowned maker of high-precision astronomical instruments, John Bird.

Mason and Dixon traveled through the wilderness of early Pennsylvania, Maryland, Delaware, and Virginia, using the stars to create the boundary line, now known as the Mason-Dixon Line. The boundary began 15 miles south of the southern-most tip of the City of Philadelphia.

The east-west, 233-mile line formed the southern boundary of Pennsylvania with Maryland, and for the area west of the beginning of the Potomac River, Virginia. Of course, during the American Civil War this section of Virginia seceded from the Commonwealth of Virginia and became the state of West Virginia.

They also surveyed the 83-mile western boundary of Delaware [then considered the 3 “Lower Counties on the Delaware” (New Castle, Kent, and Sussex) of the Province of Pennsylvania], separating, what would become, the second smallest state of the Union from Maryland.

At one-mile intervals, Mason and Dixon laid mile-marker stones all along the surveyed route. On the north side of the marker was chiseled the letter P for Pennsylvania; on the south side of the marker is the letter M for Maryland. As a five-mile marker, the stone included the Penn Family Coat of Arms on the north side of the stone and the Calvert Family Coat of Arms on the south side of the stone.

Each stone was a huge block of limestone, 3.5 to 5 feet long, weighing 300 to 600 pounds. These stones had come from a quarry in southern England. Mason and Dixon carried these stones with them, during the survey, using a horse and wagon.

Many of these stones survive. However, some are missing. For instance, one stone was hit by a snow-plow in January of 1996, and it was pushed down into a farmer's field. After more than 200 years, this particular stone now sits in a farmer's barn.

As the surveyors entered the Allegheny Mountains, they did not always lay stones at one-mile intervals. Instead, they created groupings of rocks or cairns as mile-markers.

Even in the 18th century, surveying was not a new science. However, it was quite an achievement to survey a new boundary line in rugged terrain, often harsh weather, and with the constant risk of attack from Native Americans.

It usually took a couple of weeks, at least, for each set of astronomical observations for a particular mile-marker. They would spend clear-sky nights (of course, they could not work during cloudy nights) taking observations of stars, sometimes in very cold weather. They would have to lie on their backs and look through a 6-foot long telescope, measuring angles between stars and a north-south meridian line.

However, they did use state-of-the-art equipment. Jeremiah Dixon's mentor, John Bird, developed the Zenith Sector they used, which was the most advanced instrument of its day for determining latitude. According to John Bird, it was accurate to within 100 feet.

Scientists and geographers remember the work of Charles Mason and Jeremiah Dixon for two particular contributions to scientific literature:

  1. They measured the first degree of latitude in the Americas;
  2. They made the first scientific gravity measurements in the Americas.

The Pennsylvania land grant had extended 5 degrees of longitude west of the Delaware River, to the location of the southwest corner of Pennsylvania. Mason and Dixon had been commissioned to survey to the southwest corner of Pennsylvania. However, they never made it that far.

The Native American guides of Mason and Dixon refused to guide them into the territory of their enemy, the Shawnee and Delaware tribes. So, on Sunday, 1767 October 18, Mason and Dixon made their final observations before turning-back to return to Philadelphia, 23 miles short of their goal.

The following entry from Mason and Dixon's Journal, written by Charles Mason, describes setting the final mile-marker of their survey:

“Note: The Sector stood on the top of a very lofty Ridge, but when the Offset was made of 3 Chains 38 Links it fell a little Eastward of the top of the Hills; we therefore extended the true Parallel 3 Chains 80 Links Westward which fell on the top of the said Ridge; there viz. at 233 Miles 17 Chains 48 Links from the Post marked West in Mr. Bryan's Field, we set up a Post marked Won the West Side and heaped around it Earth and Stone three yards and a half diameter at the Bottom and five feet High. The figure nearly conical.”

After setting the last mile-stone, Mason and Dixon remained at the site until Tuesday, 1767 October 20, when their journal reported:

“Began to open a Visto in the True Parallel Eastward.”

Philadelphia clock-maker and astronomer, David Rittenhouse (along with surveyor Andrew Ellicott) completed surveying these last 23 miles in 1784. In addition to his scientific pursuits, University of Pennsylvania Astronomy Professor David Rittenhouse served as Treasurer of Pennsylvania from 1779 to 1787, and on behalf of the Federal Government he founded the U.S. Mint in 1792.

Although Mason and Dixon never reached the southwest corner of Pennsylvania, this was their contracted goal. Hence, the entire boundary line to the southwest corner of Pennsylvania is considered the Mason-Dixon Line. Although the Mason-Dixon Line does not follow an exact line of latitude, it is geographically located at approximately 39 degrees and 43 minutes North Latitude.

Beyond the end of the Mason-Dixon Line, at the southwest corner of Pennsylvania, the line continues west to the Ohio River, forming the boundary line between Marshall and Wetzel Counties in West Virginia. However, this county boundary line was formed by the Virginia Assembly in the latter part of the 18th century and is not an official part of the Mason-Dixon Line.

In 1786, Andrew Ellicott was commissioned to survey the western boundary line of Pennsylvania (which came to be known as Ellicott's Line), from the end of the Mason-Dixon Line, north, to Lake Erie. Part of this boundary was between Pennsylvania and Virginia; the area of Virginia between Pennsylvania and the Ohio River now contains four counties (Hancock, Brooke, Ohio, and Marshall) in what is now the Northern Panhandle of West Virginia.

North of the location where the Ohio River leaves Pennsylvania, this boundary line codified the boundary between Pennsylvania and the Federal Territory known as the “Ohio Country,” part of the Northwest Territory. This boundary line was important because Pittsburgh and a small part of Western Pennsylvania had originally been considered part of the Ohio Country (an area that had been roughly defined as west of the Allegheny Mountains, north of the Ohio River, and south of Lake Erie). The vast majority of the Ohio Country was admitted to the Union as the State of Ohio on 1803 March 1.

The Mason-Dixon Line has come to be known as the dividing line between the northern United States and the southern United States. This division began as early as 1790 March 1, when the Pennsylvania General Assembly passed legislation banning slavery in the Commonwealth. As Maryland still allowed slavery (as did Delaware and Virginia), by 1804 the Mason-Dixon Line came to be seen as the dividing line between the slave states (in the South) and free states (in the North).

During the first half of the 19th century, the Mason-Dixon Line came to be known, by slaves fleeing their southern masters, as the line of freedom. The Underground Railroad consisted of abolitionists at secret way-stations who would help African-Americans from the South cross the Mason-Dixon Line on their way to freedom and a new life.

A spiritual song sung by these run-away slaves, “Follow the Drinking Gourd,” helped these mostly illiterate refugees find their way north. The song reminded them to search for the Big Dipper asterism in the night sky, which would help them find the North Star, Polaris.

The Mason-Dixon Line was mentioned during Congressional debates leading to the Missouri Compromise of 1820, which allowed Missouri to enter the Union as a slave state, while Maine entered the Union as a free-soil state. At that time, politicians considered the Mason-Dixon Line, and extending further west along the Ohio River, as the boundary line between slave and free-soil states. The Missouri Compromise legally forbade the admission of states, which had been part of the Louisiana Purchase territories, as slave states if they existed north of Latitude 36 degrees, 30 minutes North (the southern boundary of Missouri); however, the legislation also allowed one exception: Missouri.

When the American Civil War, or War Between the States, erupted in 1861, the Mason-Dixon Line was still considered a dividing line between North and South. But because Washington, DC, a southern city, had been chosen as the site of the new nation's capital (due to the Compromise of 1790, which allowed the Federal Government to pay-off Revolutionary War debts of the states, in return for locating the national capital in the South), the Federal Government refused to allow Maryland to join the Confederate States of America (CSA), even though Maryland (along with pro-Union border states Delaware, Kentucky, and Missouri) continued to allow slavery.

In the middle of the Civil War, 50 counties in western Virginia broke-away from Virginia (which included the state capital, Richmond, as the capital of the Confederacy) to form a new state, West Virginia, which was admitted to the Union on 1863 June 20. On that date, no longer did any portion of the Mason-Dixon Line touch the Commonwealth of Virginia; the section of the Mason-Dixon Line previously bordering Virginia now bordered West Virginia.

Derived from the title, Mason-Dixon Line, and the surname of Jeremiah Dixon, “Dixie” became a name generally identifying the southern United States in the early 19th century. During the Civil War, it was generally used to refer to the Confederacy.

The song, “Dixie” or “I Wish I Was in Dixie,” probably reinforced the popular notion that Dixie meant the American South. The song became the unofficial anthem of the Confederacy during the Civil War, after being played during the inauguration of Confederate President Jefferson Davis in 1861. Upon hearing of the Confederate General Robert E. Lee's surrender at Appomattox County, Virginia in 1865, U.S. President Abraham Lincoln asked the military band to play “Dixie.”

There is still some dispute regarding who wrote the song, although it seems the song may have been authored by Daniel Emmett, a Northerner from Mount Vernon, Ohio in 1859. It quickly became popular through black-face minstrel shows.

Today, the song “Dixie” is still popular in the South. And, the term Dixie is still used to represent the South. In fact, a popular grocery store chain in the South, known as Winn-Dixie (headquartered in Jacksonville), operates 495 stores in five southern states (Alabama, Florida, Georgia, Louisiana, and Mississippi).

Interestingly, a handsome, 10-story office building in a northern city is called Dixie Terminal. Built in Downtown Cincinnati in 1921, this building is located only dozens of feet from the Ohio River. It was named Dixie Terminal because it was once a streetcar terminal (later commuter bus terminal) for streetcars coming from Dixie--that is, the suburbs of Northern Kentucky.


                                        

Internet Links to Additional Information ---

Photograph of Historical Marker near end of Survey conducted by Mason and Dixon:
Link >>> http://spacewatchtower.blogspot.com/2017/10/astronomical-calendar-2017-october.html

Mason-Dixon Line Survey web-site ExploretheLine, with photos of survey markers:
Link >>> http://www.exploretheline.com/index1.html 

Charles Mason: Link >>> https://en.wikipedia.org/wiki/Charles_Mason 

Jeremiah Dixon: Link >>> https://en.wikipedia.org/wiki/Jeremiah_Dixon 

David Rittenhouse: Link >>> https://en.wikipedia.org/wiki/David_Rittenhouse 
     University of Pennsylvania Astronomy Professor David Rittenhouse inspires the field of stars on 
     the American Flag: Link >>> http://spacewatchtower.blogspot.com/2017/06/240th-anniversary-of-american-flag-why.html

Andrew Ellicott: Link >>> https://en.wikipedia.org/wiki/Andrew_Ellicott

Special Thanks: Amateur Astronomer Pete Zapadka.

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 October 18.

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Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Saturday, October 7, 2017

Physics Nobel Prize Awarded to Developers of Laser Observatory


Image result for image ligo
Photograph of the LIGO Hanford installation near Richland, Washington.
(Image Source: LIGO, California Institute of Technology)

By Glenn A. Walsh
Reporting for SpaceWatchtower

Three American physicists, who developed a Laser observatory which led to the detection of Gravitational Waves, were awarded the 2017 Nobel Prize in Physics on Tuesday (October 3). The detection of Gravitational Waves confirmed a prediction of Albert Einstein's 1916 General Theory of Relativity.

Barry C. Barish and Kip S. Thorne of the California Institute of Technology and Rainer Weiss of the Massachusetts Institute of Technology were given the annual award "for decisive contributions to the LIGO detector and the observation of gravitational waves." LIGO, the Laser observatory, is officially known as the Laser Interferometer Gravitational-Wave Observatory.

A new branch of observational Astronomy, Gravitational-Wave Astronomy obtains and studies data from highly-energetic sources of Gravitational Waves such as Black Holes and Supernovae. Although predicted by Dr. Einstein, he had doubted whether Gravitational Waves could ever actually be detected.

The first LIGO installations went on-line in 2002 and collected data through 2010, but found no Gravitational Waves. The National Science Foundation (NSF) continued funding this project in 2008, when enhancements to LIGO were added. Agencies from other nations, such as the Max Planck Society of Germany, United Kingdom Science and Technology Facilities Council, and the Australian Research Council also started providing funding for this Physics experiment.

LIGO consists of two observational facilities: LIGO Livingston Observatory in Livingston, Louisiana and LIGO Hanford Observatory near Richland, Washington, on the campus of the U.S. Department of Energy Hanford Site. The Hanford Site was originally established in 1943 as part of the Manhattan Project's development of plutonium, which was used for the second atomic bomb dropped on Nagasaki, Japan on 1945 August 9 leading to the end of the Second World War.

The first Gravitational Wave detection was publicly announced on 2016 February 11. The detection occurred on 2015 September 14, just two days after upgraded LIGO detectors had gone on-line. The signal received was designated GW150914, and it matched the predictions of the Theory of General Relativity for the merger of two Black Holes.

A few months later, on 2016 June 15, a second detection was announced. The event, a merger of two more Black Holes, had been recorded on 2015 December 26.

The fourth and most recent LIGO detection occurred in August. Announced just last week, the August 14 coalescence of two more Black Holes was also detected by a similar facility, called the Virgo Detector, near Pisa, Italy.

Internet Links to Additional Information ---

"Gravitational waves from a binary black hole merger observed by LIGO and Virgo." News Release.
AstronomyNow.com / Joint LIGO - Virgo News Release 2017 Sept. 27.
Link >>> https://astronomynow.com/2017/09/27/gravitational-waves-from-a-binary-black-hole-merger-observed-by-ligo-and-virgo/

Laser Interferometer Gravitational-Wave Observatory (LIGO):
Link >>> https://en.wikipedia.org/wiki/LIGO

Gravitational Waves: Link >>> https://en.wikipedia.org/wiki/Gravitational_wave

National Science Foundation (NSF):
Link >>> https://en.wikipedia.org/wiki/National_Science_Foundation

Nobel Prize: Link >>> https://en.wikipedia.org/wiki/Nobel_Prize

Nobel Prize in Physics: Link >>> https://en.wikipedia.org/wiki/Nobel_Prize_in_Physics

Related Blog-Post ---

Laser Observatory May Directly Detect Gravity Waves." 2015 Oct. 7.

Link >>> http://spacewatchtower.blogspot.com/2015/10/laser-observatory-may-directly-detect.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 October 7.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Sunday, October 1, 2017

Astronomical Calendar: 2017 October

http://www.exploretheline.com/images/catawba.jpg
Photo of the West Virginia Historical Marker near the end of the Mason-Dixon Line Survey, about 70 miles south of Pittsburgh. America's most famous boundary line [separating Pennsylvania from Maryland & Virginia (now West Virginia)] which was produced with the assistance of Astronomy, the 250th anniversary of the conclusion of the Mason-Dixon Line Survey will be on October 18. However, the Native American guides of Astronomers Charles Mason and Jeremiah Dixon refused to enter the territory of their Indian enemies; hence the Mason-Dixon Line Survey ended about 23 miles short of their goal: the southwest corner of Pennsylvania. In 1784, Philadelphia clock-maker and Astronomer David Rittenhouse, with surveyor Andrew Ellicott, completed surveying those last 23 miles.
A celebration of this 250th anniversary will occur at the Mason-Dixon Historical Park in Core, West Virginia, during the weekend of October 14 and 15. More information on the celebration:
Link >>> http://md250.exploretheline.com/
(Image Source: Amateur Astronomer Pete Zapadka)

Astronomical Calendar for 2017 October: 
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2017.html#oct

 Related Blog Post ---


"Astronomical Calendar: 2017 September." 2017 Sept. 1.

Link >>> https://spacewatchtower.blogspot.com/2017/09/astronomical-calendar-2017-september.html


Source: Friends of the Zeiss.
              2017 October 1.

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Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Thursday, September 21, 2017

Fall Begins at Autumnal Equinox Friday Afternoon

http://buhlplanetarium.tripod.com/pix/graphics/solsticeimage008.png
This diagram shows the position of the Earth, in relation to the Sun, at the time of the Autumnal Equinox, as well as the other solstices and equinox of the year.
©1999, Eric G. Canali, former Floor Operations Manager of Pittsburgh's original Buhl Planetarium and Institute of Popular Science and Founder of the South Hills Backyard Astronomers amateur astronomy club; permission granted for only non-profit use with credit to author.
Special Note --- The Autumnal Equinox also marks the date of a Memorial Service (at Chatham University Eden Hall Farm, Noon to 8:00 p.m. EDT) for Eric G. Canali, who passed-away at the age of 63 on August 31. Coincidentally, August 31 in 1991 was the date of the closing of Pittsburgh's original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center) as a public museum. Mr. Canali, an avid amateur astronomer, had made his career at Buhl Planetarium.
More information about Mr. Canali: Link >>> http://buhlplanetarium.tripod.com/#canalieg

By Glenn A. Walsh
Reporting for SpaceWatchtower

The Autumnal Equinox, the beginning of the season of Autumn or Fall in the Northern Hemisphere of Earth, begins Friday Afternoon, 2017 September 22 at 4:02 p.m. Eastern Daylight Saving Time (EDT) / 20:02 Coordinated Universal Time (UTC). In Earth's Southern Hemisphere, this marks the astronomical beginning of the season of Spring.

On the day of Equinox, the Sun appears directly overhead at local Noon on the Equator. At the moment of Equinox, the Northern and Southern Hemispheres of Earth are illuminated equally. And, the time of Equinox is the only time when the Earth Terminator (dividing line on Earth between daylight and darkness) is perpendicular to the Equator.

This, and the reason for seasons on Earth in the first place, is due to the fact that Earth rotates on its axis, which is tilted at an approximate 23.44-degree angle from the plane of the Earth's orbit around the Sun. As the Earth revolves around the Sun, this axial tilt causes one hemisphere of the planet to receive more direct solar radiation during that hemisphere's season of Summer and much less direct solar radiation a half-year later during that hemisphere's season of Winter. As mentioned, during an Equinox (about half-way between Summer and Winter, and about half-way between Winter and Summer) both planetary hemispheres receive an equal amount of solar radiation.

Although "Equinox" in Latin means equal-night, the day of the Equinox does not actually have an equal amount of daylight and nightfall, as it appears on the Earth's surface. If the Sun was just a pin-point of light in our sky, as all other stars appear, day and night would be equal.

But, because the Sun is a disk, part of the Sun has risen above the horizon before the center of the Sun (which would be the pin-point of light); so there are extra moments of light on the Equinox. Likewise, part of the Sun is still visible, after the center of the Sun has set.

Additionally, the refraction of sunlight by our atmosphere causes sunlight to appear above the horizon, before sunrise and after sunset.

September 25 will mark the Equilux ("equal-light"), the actual day with equal hours and minutes of the Sun above the horizon, and equal hours and minutes of the Sun below the horizon. The Equilux occurs twice each year, approximately 3-to-4 days before the Vernal Equinox and 3-to-4 days after the Autumnal Equinox.

An urban legend that has been making the rounds for decades has it that eggs can be stood on their ends only during an Equinox, whether the Vernal Equinox in the Spring or the Autumnal Equinox in the Fall. This is completely false. Depending greatly on the size and shape of the particular egg, eggs can be stood on their ends any day of the year! Astronomy has nothing to do with whether an egg can stand on its end. If an egg can stand on its end on the Equinox (and, due to the shape and size of some eggs, this is not even possible), it can stand the same way any other day of the year.

In the last few years, with the help of the Internet and Social Media, another urban legend has become prevalent. Now it is claimed that brooms can stand, on their own, on their bristles, only on an Equinox day. This is also false. Again, as with eggs, if a broom can stand on its bristles by itself (this usually only works with newer brooms, with more even bristles) on an Equinox, it can do so any day of the year!

September 22 is also designated as the annual Falls Prevention Awareness Day for this year.

Internet Links to Additional Information ---


Season of Autumn or Fall: Link >>> http://en.wikipedia.org/wiki/Autumn

Equinox: Link >>> http://en.wikipedia.org/wiki/Equinox

Earth's Seasons: Link >>> http://en.wikipedia.org/wiki/Season

Tilt of a planet's axis: Link >>> http://en.wikipedia.org/wiki/Axial_tilt

Urban legend of eggs and brooms standing on their own, only on an Equinox:
Link >>> http://www.snopes.com/science/equinox.asp

Falls Prevention Awareness Day: Link >>> http://www.ncoa.org/improve-health/center-for-healthy-aging/falls-prevention/falls-prevention-awareness.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 September 21.

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                Want to receive SpaceWatchtower blog posts in your in-box ?
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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >