1. Olbers’ Paradox Sam Migirditch (migirditchsv@email.appstate.edu)
Angie Blatchley
Summer Bridge 2013
Appalachian State University

2. What is the Paradox?
Every line of sight should end on a star if the universe is infinitely large.
The sky should be bright and getting brighter.
This suggests the universe is not static.

3. Early Theories
Johannes Kepler – 1610, proposed problem and believed stars extended only a finite distance
Heinrich Olbers – 1823, proposed that intervening matter absorbed the light from the stars
Edgar Allen Poe – 1848, published a scientific paper suggesting the solution of the universe not old enough for all the light to reach Earth
Earth:
Star:
Cloud: X:

4. Dark Energy and Redshift
Dark energy is poorly understood but observed by experiments.
It is a repulsive force over extremely large distances .
Repulsion increases over distance so objects accelerate away from each other causing redshift.
Redshift preserves the speed of light and energy by changing the wavelength of light relative to the observer.

5. Explanation Verdict Too much dust to see distant stars
The dust would absorb the heat/light and eventually radiate it.
The universe has only a finite number of stars.
Inconclusive
Distribution of stars is not uniform – some stars are hidden behind other stars
The probability of an infinite amount of stars being lined up perfectly is infinitely unlikely.
The universe is expanding so distant stars are redshifted out of visible spectrum.
Correct
The speed of light is finite and the universe has a finite age so we only see the light less than 15 billion light years away.
Partially correct

6. Cosmic Microwave Background Radiation Image from WMAP

7. Works Cited
"Geometry/Dynamics of the Universe." Geometry/Dynamics of the Universe. Univ. of Oregon, n.d. Web. 21 July 2013.
Harrison, Edward Robert. Darkness at Night: A Riddle of the Universe. Cambridge, MA: Harvard UP, Print.
Hawking, Stephen. The Illustrated A Brief History of Time. New York: Bantam, Print.
Kenyon, Scott J., and Rogier A. Windhorst. The Kuiper Belt and Olbers’ Paradox. Diss. Arizona State Univ., N.p.: American Astronomical Society, The Astrophysical Journal. The American Astronomical Society, 20 Jan Web. 21 July 2013.
"Olbers’ Paradox: Why Is the Night Sky Dark?" Olbers’ Paradox. Cornell University, n.d. Web. 21 July 2013.
"Olbers’ Paradox: Why Is The Sky Dark at Night?" Olbers’ Paradox: Why Is The Sky Dark at Night? Ed. Steven Soter and Neil DeGrasse Tyson. American Museum of Natural History, Web. 22 July 2013.
Riess, Adam G., Dr., and Et Al. "Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant." Arxiv.org. Cornell University, 17 May Web. 30 July 2013.
Sobral, David. "A Large Hα Survey at Z=2.23, 1.47, 0.84 & 0.40: The 11 Gyr Evolution of Star-forming Galaxies from HiZELS." ArXiv. Cornell University Library, 28 Sept Web. 22 July
Wesson, Paul S. Olbers’ Paradox and the Spectral Intensity of the Extragalactic Background Light. Diss. Univ. of California, Berkeley and Univ. of Waterloo, N.p.: Astrophysical Journal, The American Astronomical Society. NASA Astrophysics Data System, Feb Web. 21 July 2013.
"Wilhelm Olbers (German Astronomer)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 23 July 2013.
Wolfram Research. "Size of the Observable Universe." Wolfram Alpha. Wolfram Research, n.d. Web. 23 July 2013.
"What Is a Cosmological Constant?" WMAP- Cosmological Constant or Dark Energy. Ed. Britt Griswold. NASA, 21 Dec Web. 23 July 2013.

8. Acknowledgements We would like to extend thanks to:
Dr. Rahman Tashakkori
National Science Foundation
Professor David Sitar
Dr. Jennifer Burris
Dr. Trina Palmer
Professor Nathan Weigl
Dr. Cindy Norris
Dr. Alexander Schwab
Zach Andrews
Kristen Vroom
Noah Hughes
Michael Kelly
Our peers who also participated in this program
Our family and friends