Wednesday, November 13, 2019

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

                              https://buhlplanetarium2.tripod.com/bio/einstein/Einstein-Leo-1934AAAS.jpg 

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 Andrews Millikan 1920s.jpg
                                                         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

Benningfield, Damond. "Critics." Daily Radio Feature: StarDate.
StarDate.org 2020 Jan. 13. First retrieved 2020 Jan. 13.
Centennial: The New York Times editorial on rocket pioneer Robert Goddard, which was retracted on 1969 July 17. Link >>> https://stardate.org/radio/program/2020-01-13 


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.

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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 >

Friday, November 1, 2019

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:
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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 >