The Significance of Gravitational Waves
Christina C Lee
History of Testing General Relativity
3 Classical Tests of General Relativity
- Extra perihelion precession of Mercury's orbit
- Bending of light around Sun
- Gravitational redshift of light
Extra Precession of Mercury
By WillowW - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=3416065
1859- Urbain Le Verrier
Mercury precession problem
56 year old problem!
| Other planets tugging | |
| Sun oblateness | |
| GR | |
| Total | |
Observed
Gravitational Lenzing of Light
edited from Creative Commons 3.0: Mysid
Gravitational lenzing of light
F. W. Dyson, A. S. Eddington, and C. Davidson, "A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919" Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character (1920): 291-333, on 332.
- 1874- (unpublished) Cavendish
- 1804- Georg von Soldner
- 1911- Einstein
Sun bends light x
- 1915- Einstein
Sun bends light 2x
Observation May 2019
Gravitational Redshift
First precision test of General Relativity
Last classical test of General Relativity
By Original image by User:Vlad2i, slightly modified by User:mapos. [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/gratim.html
1959: Pound-Rebka Experiment
Modern Tests of General Relativity
- Binary Pulsar Loosing Energy
- Lunar Laser Ranging Experiment
- Galactic Gravitational Lenzing
- Gravity Probe B
Hubble's Law- Modern?
- 2012: LARES
- 1976: Gravity Probe A
- 1971: Hafele-Keating Experiment
- Redshifted light from White Dwarfs
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/Images/Hubble1929.gif
Expansion of Universe
- 1915: Einstein includes "cosmological constant" to create static universe
- 1922: Friedmann finds non-stationary solutions
- 1927: Lemaitre shows static solutions unstable
- 1929: Hubble shows expansion of universe
- 1931: Einstein agrees
Hulse-Taylor Binary
Copyrighted free use, https://commons.wikimedia.org/w/index.php?curid=827204
By Inductiveload - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9538634
1993 Noble Prize in Physics
Lunar Laser Ranging Experiment
By NASA - NASA Apollo Archive http://www.hq.nasa.gov/office/pao/History/alsj/a11/AS11-40-5952.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=719521
- Send laser to moon and back
- Get moon distance precisely
- Rule out "Nordtvedt effect"
- Bodies fall at rates depending on composition
Galactic Gravitational Lensing
By Lensshoe_hubble.jpg: ESA/Hubble & NASA derivative work: Bulwersator (Lensshoe_hubble.jpg) [Public domain], via Wikimedia Commons
By Gravity Probe B Team, Stanford, NASA (APOD) [Public domain], via Wikimedia Commons
Gravity Probe B
Gyroscopes: Bumps::
Created Most Spherical Objects Ever!
Earth: 3m
Confirms Frame Dragging Effect
Astrophysical Sources
of Gravitational Waves
Christina Lee
What is a Gravitational Wave?
By MOBle at English Wikipedia - Transferred from en.wikipedia to Commons. Transfer was stated to be made by User:Tgr., Public Domain, https://commons.wikimedia.org/w/index.php?curid=3296271
Black Holes
Black Holes
Black Holes
Electromagnetic Transients
By ALMA (ESO/NAOJ/NRAO)/A. Angelich. Visible light image: the NASA/ESA Hubble Space Telescope. X-Ray image: The NASA Chandra X-Ray Observatory - http://www.eso.org/public/images/eso1401a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=30512379
By Daniel Perley (Own work) [Public domain], via Wikimedia Commons
Supernova 1987a
Gamma-ray light curves
Electromagnetic Transients
Palomar Transient Factor
Fermi Gamma-Ray Space Telescope
NASA
Neutrino Transients
Neutron Stars
Crab Pulsar
By Cambridge University Lucky Imaging Group - http://www.ast.cam.ac.uk/~optics/Lucky_Web_Site/, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2528398
If not perfectly spherical, will emit gravitational waves
Neutron Stars
Stochastic Big Bang Background
Random Colored Noise
Unknown?
