Astro-Calendar: Jan. / SpaceX Crew Dragon Test Launch Jan. 11

SpaceX Crew Dragon spacecraft, which is scheduled to undergo a critical In-Flight Abort test flight on January 11. This uncrewed test flight, which will launch from the Cape Canaveral Air Force Station in Florida, will test a vital safety system to protect astronauts during an emergency soon after a launch. After the test, the spacecraft will splash-down in the Atlantic Ocean. "The demonstration of Crew Dragon's launch escape system is part of NASA's Commercial Crew Program and is one of the final major tests for the company before NASA astronauts will fly aboard the spacecraft," NASA officials wrote.
More information on the In-Flight Abort test flight:
Link >>> https://www.space.com/spacex-crew-dragon-in-flight-abort-launch-new-date.html
More on the SpaceX Crew Dragon spacecraft:
Link >>> https://en.wikipedia.org/wiki/Dragon_2 
(Image Sources: NASA, SpaceX, Wikipedia.org, By Unknown - NASA (direct url), Public Domain, https://commons.wikimedia.org/w/index.php?curid=77702696)

Astronomical Calendar for 2020 January ---
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2020.html#jan

 Related Blog Post ---

"Astronomical Calendar: 2019 Dec. / Centennial: Death of Astronomy Philanthropist H.C. Frick"

Sunday, 2019 December 1.

Link >>> https://spacewatchtower.blogspot.com/2019/12/astronomical-calendar-2019-dec.html

Source: Friends of the Zeiss.
              Thursday, 2020 January 2.

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gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

Winter Begins Late Sat. Night; Ursid Meteor Shower Sun. Night

  
This diagram shows the position of the Earth, in relation to the Sun, at the time of the Winter Solstice, as well as the other solstice and equinoxes of the year, in Earth's Northern Hemisphere.
[Graphic Source: ©1999, Eric G. Canali, former Floor Operations Manager of the original Buhl Planetarium & Institute of Popular Science / Buhl Science Center (Pittsburgh's science & technology museum 1939-1991) and Founder of the South Hills Backyard Astronomers amateur astronomy club; permission granted for only non-profit use with credit to author.]

By Glenn A. Walsh

Reporting for SpaceWatchtower

The season of Winter, in the Northern Hemisphere of Earth, begins at the moment of the Winter / December Solstice, late Saturday Evening, 2019 December 21 at 11:19 p.m. Eastern Standard Time (EST) / December 22, 4:19 Coordinated Universal Time (UTC). This moment also marks the astronomical beginning of the Summer season in the Southern Hemisphere.

Almost 24 hours later, Sunday evening / Monday morning will mark the peak time for the annual Ursid Meteor Shower. This meteor shower peaks Sunday Evening, 2019 December 22 at 10:00 p.m. EST / December 23, 3:00 UTC.

                                               Winter Solstice 2019

In etymology, the word solstice comes from the Latin terms sol (Sun) and sistere (to stand-still). In ancient times, astronomers / astrologers / priests recognized that one day of the year when the Sun would appear to reach its lowest point in the sky for the entire year. The motion of the Sun's apparent path in the sky (what is known astronomically today as the Sun's declination) would cease on this day, and the Sun would appear to stand-still, before reversing direction.

With our Gregorian Calendar, this usually occurs on, or very close to, December 21. In ancient times, when people used the Julian Calendar, the Winter Solstice was on, or very close to, December 25, what we now know as Christmas Day. Mid-Winter festivals, at the time of the Winter Solstice, were common in ancient times. Instead of competing with these traditions, the early Roman Catholic Church Christianized the Winter festivals by observing the birth of Jesus Christ on December 25 (the actual birth date of Jesus was probably in late Summer or early Autumn).

Today, we know that, while the Sun does have motions, it is actually the motion of the Earth, tilted on its axis 23.44 degrees from the plane of our Solar System while revolving around the Sun, that causes the Earth's seasons. Hence, as the Earth arrives at the point in its orbit around the Sun, where the south polar axis is most directly inclined toward the Sun (thus, the Sun appears at its lowest point for the year in the Northern Hemisphere sky) around December 21, this marks the Winter Solstice in the Northern Hemisphere (and the Summer Solstice in the Southern Hemisphere).

Alternately around June 21, the Summer Solstice marks the beginning of Summer in the Northern Hemisphere (and this date also marks the Winter Solstice, which is the beginning of Winter in the Southern Hemisphere) as the Earth reaches the point in its orbit where the north polar axis is most directly inclined toward the Sun.

The day of the December Solstice is the only time of the year when the Sun reaches the point of Local Solar Noon at the South Pole. Conversely, it is also the only time of the year when Local Solar Midnight occurs at the North Pole. And, of course, it is the reverse during the June Solstice: the only time the Sun reaches the point of Local Solar Noon at the North Pole and the only time when Local Solar Midnight occurs at the South Pole.

Although the Winter months in the Northern Hemisphere are known for the year's coldest weather, the Earth is actually at the point in its orbit closest to the Sun (astronomically known as the point of perihelion) on or very near January 2. The Earth is farthest from the Sun, each year shortly after the Northern Hemisphere's Summer Solstice, on or very near July 5 (the point of aphelion).

Solar radiation, and hence heat from the Sun, to warm an Earth hemisphere depends on the length of daylight and the angle of the Sun above the horizon. The tilt of the planet's axis toward the Sun determines the additional and more direct solar radiation received by a planet's northern or southern hemisphere, and hence, the warmer season of the respective hemisphere.

The Earth's perihelion in January, and aphelion in July, are due to the elliptical nature of the Earth's orbit around the Sun. Perihelion and aphelion would not occur if the Earth's orbit was a true circle.

Since the Earth is closest to the Sun near the beginning of the Northern Hemisphere's Winter Season, the Earth, then, moves faster in its orbit around the Sun than it moves in July, making the Northern Hemisphere's Winter a shorter season than Summer. Winter will last for only 89 days, while this past-Summer lasted nearly 93 days. This is one of the observed consequences of Johannes Kepler's Laws of Planetary Motion, which he published at the beginning of the 17^th century.

The day of the Winter Solstice is known as the “shortest day of the year” and the “longest night of the year” as the Sun shines on the Northern Hemisphere for the shortest length of time for the entire year, on this day. For this reason, Homeless Persons' Memorial Day is commemorated on December 21.

Interestingly, the climate of a locale in the Southern Hemisphere is, on average, slightly milder than a location at the same latitude in the Northern Hemisphere, because the Southern Hemisphere has significantly more ocean water and much less land. Water warms-up and cools-down more slowly than does land. The only exception is the Antarctic Continent, which is colder than the Northern Hemisphere's Arctic region, possibly because most of the Arctic region is covered with water (although, often frozen water on the surface, but liquid water beneath the ice) while Antarctica is mostly a land mass.

                                              Ursid Meteor Shower

Almost 24 hours after the Winter Solstice comes the peak of the annual Ursid Meteor Shower, which actually begins on December 17 and usually lasts about a week ending December 24, 25, or 26. The Ursids seem to comprise a narrow stream of debris originating from Comet Tuttle. Hence, it is difficult to see Ursid meteors outside of a 12-hour window before and after the peak, where possibly 12 meteors per-hour could be seen, under ideal conditions.

The Ursid Meteor Shower is so-named because most meteors appear to radiate from a point near the Star Beta Ursae Minoris (apparent meteor shower radiant) in the Constellation Ursa Minor (better known as the asterism the “Little Dipper”), which is the brightest star in the bowl of the Little Dipper. Some people call these meteors “Ursids,” in an attempt to emphasize that their apparent radiant is Ursa Minor, not Ursa Major (the asterism the “Big Dipper”).

However, you should not, necessarily, be looking only at the Little Dipper when looking for meteors in this shower. Meteors can appear in any part of the sky at any time (although a meteor's tail may tend to point back toward the radiant).

Of course meteor showers, like all celestial observations, are weather-permitting. If there are more than a few clouds in the sky, meteors will be much more difficult to find. Clear skies are not always available in the skies of late Autumn and early Winter. And, it is always best to get away from city lights, for the opportunity to see the smaller, dimmer meteors. As always, the best time to view any meteor shower is between local midnight and local dawn, when the Earth is actually rotating into the stream of meteoric debris.

Binoculars and telescopes are not very useful for finding meteors. Meteors streak across the sky in a very short period of time, far too short to aim binoculars or a telescope. So, the best way to view a meteor shower is to lie on a blanket or beach towel on the ground, or use a reclining a chair, outdoors in an area with a good view of the entire sky (with few obstructions such as buildings, trees, or hills), and keep scanning the entire sky.

So, if you go out to see the Ursid Meteor Shower, start looking for meteors around local midnight, or perhaps a little later. Make sure you have a good site where you can see most of the sky, and that sky is relatively clear. Be sure to dress properly for the early morning temperatures, now that we are at the very beginning of Winter.

And, you want to go out ahead of time, before you actually start looking for meteors, to get your eyes accustomed to the dark sky. Dark-adapting your eyes for meteor-watching could take up to a half-hour.

Internet Links to Additional Information ---

Winter Solstice:
Link 1 >>> http://scienceworld.wolfram.com/astronomy/WinterSolstice.html
Link 2 >>> http://en.wikipedia.org/wiki/Winter

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

Popular Winter Planetarium Sky Shows Shown at Pittsburgh's original Buhl Planetarium and Institute of Popular Science (1939 to 1991), including full scripts of each show:
The Star of Bethlehem >>> http://buhlplanetarium3.tripod.com/skyshow/bethlehem/
The Stars of Winter >>> http://buhlplanetarium3.tripod.com/skyshow/winter/

Calendar Formats ---
       Gregorian Calendar: Link >>> http://en.wikipedia.org/wiki/Gregorian_calendar
       Julian Calendar: Link >>> http://en.wikipedia.org/wiki/Julian_calendar

Ursid Meteor Shower: Link >>> http://en.wikipedia.org/wiki/UrsidsA

Homeless Persons' Memorial Day:
Link >>> http://nationalhomeless.org/about-us/projects/memorial-day/

Related Blog Post ---

"2019 Summer Begins at Moment of Solstice, Mid-Day." Fri., 2019 June 21.

Link >>> https://spacewatchtower.blogspot.com/2019/06/2019-summer-begins-at-moment-of.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              Friday, 2019 December 20.

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           More Astronomy & Science News - SpaceWatchtower Twitter Feed:
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                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

Laser Space Probe Finds the Unexpected

Artist's rendering of the LISA Pathfinder space probe approaching solar orbit.
(Image Source: European Space Agency / C. Carreau)

By Glenn A. Walsh

Reporting for SpaceWatchtower

A laser space probe, designed as a space-based, proof-of-concept mission for finding gravitational-waves, has now been used to map microscopic dust shed by comets and asteroids. This is a clear demonstration that 'empty space' between stars and planetary bodies is not really all that empty!

Due to the space probe's extreme sensitivity, a requirement for the detection of gravitational-waves, NASA scientists have used data from the European Space Agency's (ESA) LISA Pathfinder spacecraft to detect 54 micrometeroid impacts on the spacecraft during the 2015 to 2017 time-frame. The micrometeroids detected are extremely small.

Their masses are measured in micrograms and are similar in size to grains of sand. This cosmic dust was actually smaller than the dust from comets that cause most meteor showers. However, they hit the spacecraft at approximate speeds of 40,000 miles-per-hour / 64,000 kilometers-per-hour, which could injure a spacecraft if the particles had been larger.

NASA scientists, headed by Ira Thorpe of the Goddard Space Flight Center in Greenbelt, Maryland, used modeling to determine where the micrometeroids originate. Their research was published in the September issue of the Astrophysical Journal, the prestigious publication founded in 1895 by George Ellery Hale, who would become Director of the Mount Wilson Observatory, and James E. Keeler, Director of the Allegheny Observatory.

The NASA scientists found that most of the micrometeroids come from short-period comets, whose orbits are determined by Jupiter; this is consistent with current ideas regarding micrometeroids near Earth. However, LISA Pathfinder also detected dust from some long-period comets, similar to the famous Halley's Comet.

These results will help in predicting impact risks for current and future spacecraft. They may also help in the understanding of the physics of planet formation.

Launched on 2015 December 3, the LISA Pathfinder mission was to prove the feasibility of a space-based laser interferometer system for finding ripples in space-time caused by, for instance, the merger of black holes. Led by the European Space Agency, with contributions from NASA, the mission was used to test technologies necessary for a space-based observatory that would do what the ground-based LIGO (Laser Interferometer Gravitational-Wave Observatory) has done from the Earth.

LIGO is limited by seismic, thermal, and other sources of noise present on the Earth. It is hoped that a space-based system, without these limitations, would be even more sensitive and find even more gravitational-waves.

The main LISA (Laser Interferometer Space Antenna) mission, expected to be launched around 2034, would consist of a constellation of three spacecraft arranged in an equilateral triangle with sides 1.55 million statute miles / 2.5 million kilometers long, in an orbit around the Sun. By precisely monitoring the distances between each satellite, more ripples in space-time should be detected.

Internet Links to Additional Information ---

LISA Pathfinder Spacecraft: Link >>> https://en.wikipedia.org/wiki/LISA_Pathfinder

LISA Spacecraft (launch in 2034): Link >>> https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna

LIGO Ground-Based Observatory: Link >>> https://en.wikipedia.org/wiki/LIGO

Micrometeroid: Link >>> https://en.wikipedia.org/wiki/Micrometeoroid

Related Blog-Posts ---

"Physics Nobel Prize Awarded to Developers of Laser Observatory." Sat., 2017 Oct. 7.

Link >>> http://spacewatchtower.blogspot.com/2017/10/physics-nobel-prize-awarded-to.html

 

"Laser Gravitational-Wave Observatory Researchers Receive 2 Awards. Sun., 2016 June 5.

Link >>> http://spacewatchtower.blogspot.com/2016/06/laser-gravitational-wave-observatory.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              Saturday, 2019 December 7.

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           More Astronomy & Science News - SpaceWatchtower Twitter Feed:
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        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

Astronomical Calendar: 2019 Dec. / Centennial: Death of Astronomy Philanthropist H.C. Frick

                    
December 2 marks the Centennial Anniversary of the death of industrialist and education and astronomical philanthropist Henry Clay Frick. And, December 19 marks the 170th anniversary of his birth. He provided much of the funding for construction of the second, three-dome Allegheny Observatory, dedicated in 1912. He asked astronomer John A. Brashear to organize the Henry Clay Frick Educational Commission, to fund supplemental educational opportunities for public school teachers, as well as provide for free-of-charge, public tours of the Allegheny Observatory several evenings a week during the warm-weather months.
Biography of Henry Clay Frick: Link >>> http://johnbrashear.tripod.com/frick.html
(Image Sources: By Bain News Service - This image is available from the United States Library of Congress's Prints and Photographs divisionunder the digital ID ggbain.07131.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., Public Domain, https://commons.wikimedia.org/w/index.php?curid=700199)

Astronomical Calendar for 2019 December ---
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2019.html#dec

 Related Blog Post ---

"Astronomical Calendar: 2019 November / Transit of Mercury Nov. 11"

Friday, 2019 November 1.

Link >>> https://spacewatchtower.blogspot.com/2019/11/astronomical-calendar-2019-november.html

Source: Friends of the Zeiss.
              Sunday, 2019 December 1.

                             Like This Post?  Please Share!

            More Astronomy & Science News - SpaceWatchtower Twitter Feed:
            Link >>> https://twitter.com/spacewatchtower

        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

100 Years Ago: U.S. Scientist Questions Evidence Proving General Theory of Relativity

Albert Einstein proposed the General Theory of Relativity in 1915. After an experiment during a solar eclipse, scientists confirmed the theory in 1919. This 1934 photograph shows Dr. Einstein (right) visiting the exhibit booth of the Amateur Astronomers Association of Pittsburgh (AAAP) at the annual conference of the American Association for the Advancement of Science in Pittsburgh. To the front-left of Dr. Einstein is Leo J. Scanlon, AAAP Co-Founder (1929), constructor of the world's first all-aluminum, astronomical observatory dome (1930), and one of the first two Buhl Planetarium lecturers (1939).
(Sources: AAAP, Scanlon Family Collection; Photo Reproduction: © Copyright David Smith)

By Glenn A. Walsh

Reporting for SpaceWatchtower

One-hundred years ago today, on Thursday, 1919 November 13, The New York Times reported that American experimental physicist Robert A. Millikan (who won the 1923 Nobel Prize in physics) questioned the results of a solar eclipse experiment confirming the General Theory of Relativity, at a Connecticut conference of the National Academy of Sciences. Just a week earlier, on Thursday, 1919 November 6, British astronomer Sir Arthur Eddington had released the results of the eclipse experiment which confirmed the General Theory of Relativity, proposed just four years earlier by German theoretical physicist Albert Einstein.

According to The New York Times article (complete text of short article near the end of this blog-post), Dr. Millikan believed that a simpler explanation could explain the solar eclipse experiment results, which would not necessarily confirm the General Theory of Relativity.

It was at a joint meeting of the Royal Society of London and the Royal Astronomical Society, in London on Thursday, 1919 November 6, that Dr. Eddington publicly presented the results of an experiment conducted during the Total Solar Eclipse of Thursday, 1919 May 29. This experiment was conducted to confirm the General Theory of Relativity, and according to Dr. Eddington the experiment did, indeed, confirm Dr. Einstein's new theory.

Over the next few days, following the public presentation of the eclipse experiment results, the world's major newspapers exclaimed how revolutionary the new theory was in providing a new explanation of the Universe, which greatly differs from the explanation given by Sir Isaac Newton centuries earlier.

The headline in The Times of London, on Friday, 1919 November 7, announced:

“Revolution in Science – New Theory of the Universe – Newtonian Ideas Overthrown.”

On Monday, 1919 November 10, The New York Times headline proclaimed:

“LIGHTS ALL ASKEW IN THE HEAVENS

Men of Science More or Less

Agog Over Results of Eclipse

           Observations

EINSTEIN THEORY TRIUMPHS.”

Dr. Einstein became an instant celebrity. This was all the more amazing considering that British scientists had confirmed a German scientist's theory, just after the end of the First World War between the two enemy nations, when there were still bitter feelings on both sides.

On Thursday, 1915 November 25, in the fourth of a weekly series of four lectures, Dr. Einstein completed his General Theory of Relativity before the Prussian Academy of Sciences. Ten years earlier, he had proposed the Special Theory of Relativity.

In his 1905 Special Theory of Relativity, Dr. Einstein described the structure of what he called, “Space-Time,” fusing together the three dimensions of space and the one dimension of time. Dr. Einstein used the Special Theory of Relativity to illustrate the equivalence of energy and mass, thus creating his famous equation: E=mc2.

Dr. Einstein's 1915 General Theory of Relativity described gravitation, as well as matter, space, and time. In this theory, Dr. Einstein first proposed that space-time is curved near the gravitational field of a mass. Thus gravity does not exert a force on an object, as proposed by Sir Isaac Newton; rather the object follows a natural path along a curved surface of space-time, when the object nears a mass.

One consequence of the General Theory of Relativity is light deflection: rays of light bend, even if just slightly, when passing a gravitational field. A real-world test of this hypothesis would demonstrate the validity of the General Theory of Relativity. But, how to test it?

The logical test seemed to be to observe star-light from distant stars and determine whether the star-light was deflected when it passed a massive object, such as a star, planet, our Moon, or our Sun. However, the light deflection is quite minimal and nearly impossible to measure when the star-light passes distant stars, planets, or even our own Moon. And, star-light passing near our Sun could only be observed during a Total Eclipse of the Sun, due to the very bright sky-glow near the Sun.

The very first attempt to measure light deflection was going to be conducted during the Total Solar Eclipse of Friday, 1914 August 21. This attempt was a disaster, as it was planned to occur in Crimea just 20 days after Germany had declared war on Russia, during World War I.

Berlin University astronomy professor Erwin Freundlich and colleagues had left Berlin on Sunday, 1914 July 19, before the Declaration of War. They were arrested as German spies, by the Russians. Their astronomical equipment, considered military surveillance equipment by the Russians, was confiscated. A few weeks later, the Berlin University astronomers were freed during a prisoner exchange.

In a way, this episode was fortunate for Dr. Einstein. His light deflection calculation (0.85 second of arc) for the 1914 eclipse was in error.

By the time Dr. Einstein delivered his third General Theory of Relativity lecture, on Thursday, 1915 November 18, he had corrected the light deflection calculation. The correct calculation was 1.7 seconds of arc, exactly twice the original value.

The first attempt to measure light deflection, after completion of the General Theory of Relativity, came by British astronomers during the Total Solar Eclipse of Saturday, 1918 June 8. However, cloud-cover prevented observations of the stars.

For the Total Solar Eclipse of Thursday, 1919 May 29, Dr. Eddington observed from the island of Principe off of the west coast of Africa, while sending a second observing expedition to Sobral, Brazil. Successful observations (of stars in the Constellation Taurus the Bull) were made from both locations. However, due to the minute deflection of star-light that actually occurred, it took several months to make the mathematical calculations necessary to confirm the General Theory of Relativity.

Finally, Dr. Eddington did publicly announce the results of his solar eclipse experiment on Thursday, 1919 November 6.

However, not all scientists (or even newspaper editorial writers) immediately accepted Dr. Einstein's new theory. In fact, 100 years ago today, on Thursday, 1919 November 13, The New York Times reported, in a mini-editorial on the editorial page (page 12), that Dr. Einstein's theory was questioned by a noted scientist at a New Haven, Connecticut conference of the National Academy of Sciences.

The following is the complete text of this short, two-paragraph article, appearing as the last of four mini-editorials, in the newspaper's regular Topics of the Times column ---

                                             Sir Isaac Finds a Defender

As the now almost famous attack of Dr. EINSTEIN on the Newtonian law of gravitation has been declared successful by many eminent men of science, it is not for the common folk to undertake a defense of the long-revered formula. People, however, who have felt a bit resentful at being told that they couldn't possibly understand the new theory, even if it were explained to them ever so kindly and carefully, will feel a sort of satisfaction on noting that the soundness of the Einstein deduction has been questioned by R.A. MILLIKAN in a paper read before the National Academy of Sciences in session at New Haven.

His plausible suggestion is that the starlight passing the Sun in eclipse was not deflected by gravitational attraction, but was refracted in the perfectly familiar way of light when it entered and emerged from the gases that form the solar atmosphere. That is understandable as well as plausible, and it is hard not to hope that it is true.

                                              
                                                         Robert A. Millikan
(Image Sources: Wikipedia.org, By Unknown (Mondadori Publishers) - http://www.gettyimages.co.uk/search/2/image?phrase=Robert%20Andrews%20Millikan%20%20mondadori&family=editorial&sort=best&page=1&excludenudity=false, Public Domain, https://commons.wikimedia.org/w/index.php?curid=41222283)

Robert A. Millikan was an American experimental physicist who was honored with the 1923 Nobel Prize in physics, for the measurement of the elementary electric charge and for his work on the photoelectric effect. He became the first president (official title: Chairman of the Executive Council) of the California Institute of Technology (which, today, includes management of the Jet Propulsion Laboratory for NASA) in 1921, serving in that position until 1945.

Internet Links to Additional Information ---

Albert Einstein:
Link 1 >>> http://www.alberteinsteinsite.com/einsteinbiography.html
Link 2 >>> https://en.wikipedia.org/wiki/Albert_Einstein

Sir Arthur Eddington:
Link 1 >>> https://www.famousscientists.org/arthur-eddington/
Link 2 >>> https://en.wikipedia.org/wiki/Arthur_Eddington

Robert A. Millikan:
Link 1 >>> https://www.nobelprize.org/prizes/physics/1923/millikan/biographical/
Link 2 >>> https://en.wikipedia.org/wiki/Robert_Andrews_Millikan

Total Solar Eclipse of Thursday, 1919 May 29:
Link 1 >>> https://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle1901/SE1919May29Tgoogle.html
Link 2 >>> https://en.wikipedia.org/wiki/Solar_eclipse_of_May_29,_1919

Eddington 1919 Solar Eclipse Experiment:
Link >>> https://en.wikipedia.org/wiki/Eddington_experiment

General Theory of Relativity:
Link 1 >>> https://www.physicsoftheuniverse.com/topics_relativity_general.html
Link 2 >>> https://en.wikipedia.org/wiki/General_relativity

Related Blog-Posts ---

"Book: 'Einstein for Anyone: A Quick Read'." Thur., 2016 Dec. 15.

Link >>> https://spacewatchtower.blogspot.com/2016/12/book-einstein-for-anyone-quick-read.html 

 

"Centennial: Einstein's General Theory of Relativity." Wed., 2015 Nov. 25.

Link >>> https://spacewatchtower.blogspot.com/2015/11/centennial-einsteins-general-theory-of.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              Wednesday, 2019 November 13.

                             Like This Post?  Please Share!

           More Astronomy & Science News - SpaceWatchtower Twitter Feed:
            Link >>> https://twitter.com/spacewatchtower

        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

Astronomical Calendar: 2019 November / Transit of Mercury Nov. 11

     
Image of a Transit of the Planet Mercury across the disk of the Sun on 2016 May 9. The tiny black dot in the lower center of the photograph is Mercury, as it crossed the solar disk in 2016. The dark / gray spot in the upper center of the photo is a sunspot, a large magnetic storm on the surface of the Sun. The next Transit of Mercury takes place this month, on Monday, 2019 November 11.
NEVER LOOK DIRECTLY AT THE SUN UNLESS YOU HAVE THE PROPER EQUIPMENT AND PROPER TRAINING TO DO SO SAFELY!
For more information, and live, on-line coverage of the event, click on the following link ---
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2019.html#transitmercury2019

Astronomical Calendar for 2019 November ---
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2019.html#nov

 Related Blog Post ---

"Astronomical Calendar: 2019 October / Change in ISS Crew"

Tuesday, 2019 October 1.

Link >>> https://spacewatchtower.blogspot.com/2019/10/astronomical-calendar-2019-october.html

Source: Friends of the Zeiss.
              Friday, 2019 November 1.

                             Like This Post?  Please Share!

            More Astronomy & Science News - SpaceWatchtower Twitter Feed:
            Link >>> https://twitter.com/spacewatchtower

        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >

For Students: Mars 2020 Name the Rover Essay Contest By Nov. 1

(Image Sources: NASA, Wikipedia.org, By NASA/JPL-Caltech - http://photojournal.jpl.nasa.gov/jpeg/PIA19672.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=40891664)

By Glenn A. Walsh

Reporting for SpaceWatchtower

NASA is offering the Mars 2020 Name the Rover essay contest for Kindergarten to 12^th Grade students in public, religious, private, and home schools. The student with the winning essay will name the Mars 2020 Rover and will be invited to watch the launch of the mission at the Cape Canaveral Air Force Station (near the Kennedy Space Center in Florida) in July of 2020.

"This naming contest is a wonderful opportunity for our nation's youth to get involved with NASA's Moon to Mars missions," said NASA Administrator Jim Bridenstine. "It is an exciting way to engage with a rover that will likely serve as the first leg of a Mars Sample return campaign, collecting and caching core samples from the Martian surface for scientists here on Earth to study for the first time."

The deadline for this student essay contest is November 1. By the November 1 deadline, students should submit a short essay (no more than 150 words) giving their proposed name for the Mars 2020 Rover and why this name should be chosen by NASA officials.

Judging the essay contest will be divided by grade level:

• Kindergarten to 4^th Grade

• 5^th to 8^th Grade

• 9^th to 12^th Grade

Student essays will be judged on the appropriateness, significance and originality of their proposed name, and the originality and quality of their essay. There may be an interview presentation for finalists.

From each of the three grade judging groups, 52 semifinalists will be selected per group, each representing their respective state or U.S. territory. Three finalists then will be selected from each group to advance to the final round.

In January of next year, the public will have the chance to vote, on-line, on the nine finalist Rover name suggestions, from the nine finalist essays which will be posted on the NASA Mars Internet Web-Site. On 2020 February 18 (exactly one year from the 2021 date of the Mars 2020 landing on Mars), NASA plans to announce the winning name for the Mars 2020 Rover.

Go to the following Internet World Wide Web link for complete contest and prize details, and how to enter the essay contest:

Link >>> https://mars.nasa.gov/mars2020/participate/name-the-rover/

NASA is also looking for volunteers to judge the thousands of contest entries expected. U.S. residents, age 18 or older, who can offer about 5 hours of their time to judge the contest entries, should register to be a judge at the following link:

Link >>> https://www.futureengineers.org/registration/judge/nametherover

Internet Links to Additional Information ---

Mars 2020 Rover:
Link 1 >>> https://mars.jpl.nasa.gov/mars2020/
Link 2 >>> https://en.wikipedia.org/wiki/Mars_2020

Related Blog-Posts ---

"Place Your Name on Mars 2020 Rover Microchip By This Monday, Sept. 30." 2019 Sept. 26.

Link >>> https://spacewatchtower.blogspot.com/2019/09/place-your-name-on-mars-2020-rover.html

 

"Help Astronomers Name Large Kuiper Belt Asteroid." 2019 April 26.

Link >>> https://spacewatchtower.blogspot.com/2019/04/help-astronomers-name-large-kuiper-belt.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              Tuesday, 2019 October 15.

                             Like This Post?  Please Share!

           More Astronomy & Science News - SpaceWatchtower Twitter Feed:
            Link >>> https://twitter.com/spacewatchtower

        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
< http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
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 >