Repeating
the Experiment that Made Einstein Famous
An
attempt to measure 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!
Society
for Astronomical Sciences, Ontario, CA, USA June 2016: Presentation Abstract
In 1919, astronomers performed an experiment
during a solar eclipse, attempting to measure the deflection of stars near the
sun, in order to verify Einstein’s theory of general relativity. The experiment was very difficult and
the results were marginal, but the success made Albert Einstein famous around
the world. Astronomers last
repeated the experiment in 1973, achieving an error of 11%. In 2017, using amateur equipment and
modern technology, I plan to repeat the experiment and achieve a 1% error. The best available star catalog will be
used for star positions.
Corrections for optical distortion and atmospheric refraction are better
than 0.01 arcsec. During
totality, I expect 7 or 8 measurable stars down to magnitude 10, based on
analysis of previous eclipse measurements taken by amateurs. Reference images, taken near the sun
during totality, will be used for precise calibration. Preliminary test runs performed during
twilight in April 2016 and April 2017 can accurately simulate the sky conditions
during totality, providing an accurate estimate of the final uncertainty.
(Click
here to download the technical paper.)
Ctrl+click here to open a new window and view the video
presentation on YouTube (Note
the video was taken with an infrared camera to keep the room dark, so my visual
appearance is a little funny!)
A
feature article for Sky & Telescope
Magazine appeared in the August 2016 issue, with additional description on
their web site.
(www.skyandtelescope.com/sky-and-telescope-magazine/beyond-the-printed-page/my-do-it-yourself-relativity-test/)
Data
Analysis of Eclipse Images
September
18, 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, 21 very
accurate, but dim, stars are measureable. Those are marked with the orange disks,
where the diameter of the disk represents the SNR. Combining the 11 shorter images (0.09
seconds) allowed me to measure the two stars that are close to the sun, along
with 7 very accurate reference stars.
Those stars are identified with the blue disks.
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 I
am convinced that my final results will be much better.
Presentations
and publications:
Society
for Astronomical Sciences, paper and lecture, completed June 2016.
Sky
& Telescope Magazine, article published August 2016.
Sky
& Telescope Magazine special Eclipse issue, August 2017.
Reference
to the S&T article at
https://eclipse2017.nasa.gov/testing-general-relativity
Reference
to the S&T article at https://eclipse.aas.org/resources/citizen-science
Applied
Optics journal articles, published March 2017 and August 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;
https://www.livescience.com/59940-solar-eclipse-einstein-theory-of-general-relativity.html
Universe
of Learning: A presentation from Sonoma State: https://universe-of-learning.org/uploads/.../UoL_Eclipse_Science_Briefing_Final.pdf
Hackaday blog, August 16, 2017:
http://hackaday.com/2017/08/16/eclipse-2017-was-einstein-right/
Presentation
at AstroCON, August 17, 2017, in Casper, WY.
(astrocon2017.astroleague.org/speakers)
Repeat
presentation on August 18 at the Lion’s Camp for interested students and
astronomers.
Setting
up on Casper Mountain, video by Canon: https://www.facebook.com/CanonUSA/videos/1441774269234487/
SHSU Student blog http://cs.astronomy.com/asy/b/astronomy/archive/2017/08/23/guest-blog-bucket-list-astronomy-class-revisiting-einstein.aspx
Newsweek
mentions the experiment:
http://www.newsweek.com/total-solar-eclipse-2017-america-experiments-scientists-651578
Story about me and my brother getting ready for the eclipse, performing this experiment and one other: http://gazette.com/after-lifelong-wait-for-eclipse-colorado-springs-brothers-ready-for-big-experiment/article/1609472
Still
to come:
Final
eclipse report, 2018, to be published in an astronomical journal.
Interview
for article in Astronomy magazine or The Physics Teacher.
Follow-up
article in Sky & Telescope magazine.
Presentation
at NEAF, 2018.
Included
in IMAX Einstein documentary movie 2019.
Acknowledgements:
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!
All content is Copyright
2005-2017 by Don Bruns
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Web page last updated July 21, 2017.