Repeating the Experiment that Made Einstein Famous
A successful measurement of the solar deflection of stars during the August 21, 2017 total solar eclipse to the highest precision ever realized.
Commercial equipment today is better than ever!
Data Analysis of Eclipse Images
December 23, 2017
By subtracting a blurred corona from each of the 34 images (0.62 second exposures), then combining all of them with a small translation, 18 very accurate, but dim, stars are measureable. Combining the 11 shorter images (0.09 seconds) allowed me to measure the two stars that are closer to the sun, and used other stars in those images to get a good alignment. A total of 20 stars are included in my final results. The left figure shows the image with the 0.62 sec exposures, the center figure shows the star positions indicated with the white circles, and the right figure shows the image with 0.09 sec exposure. Based on the location of the two close-in stars, the exposures were just about perfect!
I was originally hoping to see 8 stars that would be bright enough to get good data (Eddington based his analysis on only 5 stars in 1919!). The data shows me many more stars, so my final results were much better. (Click here to see Mathcad program example.)
Presentations and publications:
Sky & Telescope Magazine, article published August 2016.
Sky & Telescope Magazine special Eclipse issue, August 2017.
Reference to the S&T article
Reference to the S&T article
Sky & Telescope News blog
“Using Arago’s spot to monitor optical axis shift in a Petzval refractor”, D.G. Bruns, Applied Optics Vol. 56, #8, pp. 2074-2077 (2017).
“Astrometric distortion calibration of a portable refractor”, D.G. Bruns and C.T. Bruns, Applied Optics Vol. 56, #8, pp. 6288-6292 (2017).
Discover Magazine blog, interview posted May 5, 2017
Astronomy Magazine list of cool experiments, posted May 15, 2017.
Article in Live Science blog, July 26, 2017;
Universe of Learning: A presentation from Sonoma State
Tele Vue Optics, one of my sponsors, has been posting my progress on their own web pages. Click here to read their stories about me: http://bit.ly/TVOEMNP101isRel3
Hackaday blog, August 16, 2017
Presentation at AstroCON, August 17, 2017, in Casper, WY. About 400 amateur astronomers in the audience.
Repeat presentation on August 18 at the Lion’s Camp for interested students and astronomers.
Setting up on Casper Mountain, video by Canon
SHSU Student blog
Newsweek mentions the experiment
Astronomy blog posted after the eclipse
Story in the Colorado Springs Gazette-Telegraph Newspaper about me and my brother getting ready for the eclipse, performing this experiment and one other
Final paper in draft form (with small errors to be corrected in the final published paper) is available at arxiv.org.
Just Science blog
Inside Science blog
Very nice Tele Vue blog from NEAF, with lots of photos.
NEAF talk, April 21, 2018 raw version before editing. See Day 1, third talk. About 500 amateur astronomers in the audience.
Cosmic Perspective Radio interview by Andy Poniros at NEAF on WPKN radio 89.5FM
Final eclipse report, 2018, published by Classical and Quantum Gravity, on March 6, 2018 (Vol 35, No. 7, 12 April 2018).
Follow-up article in Sky & Telescope magazine in August 2018, and on their web page at SkyandTelescope.com.
“Sky brightness and color measurements during the 21 August 2017 total solar eclipse”, D.G. Bruns and R. D. Bruns, Applied Optics Vol. 57 #16, pp. 4590-4594 (2018).
Astro-Imaging Channel on YouTube, discussion of my experiment by Bob Denny, author of one of the software packages I used. He talks about my experiment for 7 minutes.
A German astronomy web blog, with an article in the September 2018 print issue.
Physics Today had a 1-year anniversary summary of Eddington’s experiment, featuring my results.
Science News had a 1-year anniversary summary of Eddington’s experiment, a shorter version of the Physics Today blog.
Discussed in an interview by Prof. Duncan (CU-Boulder) on Colorado Public Radio.
Included in “Theory and Experiment in Gravitational Physics” (Second Edition), a book by Clifford Will, published in 2018.
Invited lecture at the American Association of Physics Teachers conference in Houston in January 2019. About 100 physics teachers in the audience.
Very nice review of the APS Denver talk on the Forbes weblog, “One Hundred Years of Gravity Bending Light,” by Chad Orzel.
Smithsonian weblog on the centennial of Eddington’s success includes details of my measurements.
Still to come:
Included in O Eclipse de Einstein [Einstein’s eclipse], a book by Prof. Nuno Crato and Prof. Luís Tirapicos, to be published in 2019 in Portugal.
Possible mention in IMAX Einstein documentary movie 2019 (release may be delayed until 2020).
Al Nagler, Tele Vue Optics, Inc., for loan of the NP101is telescope and optical raytracing.
Greg Terrance, Finger Lakes Instrumentation LLC, for loan of the ML8051 CCD camera.
Stephen Bisque, Software Bisque, Inc., for loan of the MyT Paramount tripod.
George Kaplan and John Bangert, both formerly of USNO, for astrometric advice and help with NOVAS.
Norbert Zacharias, USNO, for astrometric advice.
This research has made use of FORTRAN version of NOVAS, the Naval Observatory Vector Astrometry Software package.
This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23.
Suresh Rajgopal, for help in setting up gfortran.
Corey Bruns, for help in automating the data analysis with linear algebra advice.
Ted Pecoraro, for help in improving the Paramount field tripod feet.
Steve Lang, for help setting up in Wyoming.
Jerry Kassebaum, for suggesting locations near Casper.
Greg Kinne, for help in scripting TheSky.
Ron Bruns, for calibrating weather instruments and operating an auxiliary experiment.
Thank you for your interest in Stellar Products!
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Web page last updated May 2, 2019.