Gravitational Redshift
Predicts that gravity should shift the frequency of light, later called gravitational redshift.
Albert Einstein · Source topic
Astronomy
49 Einstein records classified as Astronomy in the supplied World History Database data.
Early Solar Deflection Numerical Estimate
Einstein calculated an early value for the deflection of starlight passing close to the Sun and proposed that a total solar eclipse could make the displacement observable.
Freundlich Eclipse Test Discussions
Einstein encouraged astronomer Erwin Freundlich to pursue eclipse observations capable of testing the predicted gravitational bending of starlight near the Sun.
Solar Eclipse Relativity Test Proposal
Urges astronomers to test gravitational light bending during a total solar eclipse, linking his theoretical calculation directly to a possible astronomical observation.
Solar Light Deflection Prediction
Calculates that the Sun's gravitational field should bend passing starlight, turning the emerging gravitational theory into a prediction accessible to eclipse astronomy.
Berlin Notebook Gravitational Lens Calculation
During work recorded in a 1912 notebook, Einstein calculated how a foreground mass could bend light from a background source and produce the geometry of a gravitational lens.
Double-Image Lens Geometry Derived
Einstein's notebook analysis showed that gravitational deflection could allow light from one distant source to reach an observer along two paths, producing two apparent images.
Lens Magnification Formula First Calculated
Einstein worked out a magnification relation for the gravitational-lens configuration, anticipating formulae he would publish when he returned to the subject decades later.
Eclipse Test Proposal
Encourages astronomical testing of gravitational light deflection during a solar eclipse.
Einstein-Besso Mercury Calculations
Works with Michele Besso on applying the developing gravitational theory to Mercury's orbit, creating calculations that later help solve the perihelion anomaly.
Einstein-Besso Mercury Perihelion Attempt
Einstein and Michele Besso calculated Mercury's anomalous perihelion motion with the provisional gravitational theory, creating a detailed test that the Entwurf equations failed to reproduce correctly.
Revised Solar Deflection Reaches Full Relativistic Value
With the completed geometric treatment of gravity, Einstein obtained a solar light-deflection prediction approximately twice the value produced by his earlier equivalence-principle calculation.
Revised Solar Light-Bending Value
Using the completed theory, obtains the full gravitational deflection predicted for starlight grazing the Sun, approximately twice his earlier 1911 estimate.
Mercury Anomaly Reproduced without Adjustable Parameters
The relativistic Mercury calculation matched the anomalous perihelion advance using the gravitational theory itself rather than introducing an additional planet or an adjustable correction to Newtonian gravity.
Mercury Perihelion
Explains Mercury's anomalous perihelion advance using the emerging general theory of relativity.
November 18 Mercury Advance Calculation
Einstein used the emerging general theory to account for Mercury's unexplained perihelion advance, obtaining the observed residual shift that earlier gravitational models had failed to reproduce.
Zangger Letter Revisits Gravitational Lensing
Einstein mentioned the possibility of gravitational lensing in a letter to Heinrich Zangger, revisiting the double-image effect he had calculated in his 1912 notebook.
Gravitational Waves
Predicts gravitational waves as propagating disturbances in spacetime within general relativity.
Cosmological Constant Introduced
Einstein adds the cosmological constant to his gravitational field equations to permit a static universe, creating the mathematical term later associated with dark energy.
Cosmological Term Added to Field Equations
To support a static cosmological solution, Einstein modified the gravitational field equations with an additional cosmological term that could counterbalance large-scale attraction.
Machian Motivation Shapes Einstein Cosmology
Einstein designed his early relativistic cosmology partly around the hope that inertia would be determined by the overall distribution of matter, reflecting his interpretation of Mach's ideas.
Relativistic Cosmology
Applies general relativity to the universe and introduces the cosmological constant in a static cosmological model.
Repulsive Gravity in Empty Space
Einstein interprets the cosmological constant as a repulsive contribution capable of balancing ordinary gravitational attraction on the largest cosmic scales.
Static Closed Universe Model Proposed
Einstein applied general relativity to the universe as a whole and proposed a spatially closed, homogeneous model intended to remain static on cosmic scales.
Quadrupole Formula for Gravitational Waves
Refines gravitational-wave theory and derives the quadrupole form for radiated energy.
Solar Eclipse Relativity Test
British eclipse expeditions photograph stars near the Sun to test Einstein's predicted gravitational deflection.
Total Eclipse Relativity Test
The total solar eclipse provides observations designed to test the bending of starlight predicted by Einstein's general theory of relativity.
Relativity Eclipse Results Announced
Royal Society and Royal Astronomical Society report eclipse results supporting Einstein's general relativity.
Wallal Eclipse Relativity Test
A total solar eclipse expedition at Wallal obtains measurements of gravitational light deflection that provide another observational test of Einstein's relativity prediction.
Einstein Tower Inauguration
The Einstein Tower begins operation as a solar observatory designed to test relativistic effects.
Royal Astronomical Society Gold Medal
Receives the Royal Astronomical Society Gold Medal for relativity and the theory of gravitation.
Expanding Universe Paper
Adopts an expanding cosmological model and abandons the need for his earlier static-universe construction.
Expanding-Universe Cosmology Paper
Publishes a non-static cosmological model within general relativity, accepting cosmic expansion and dispensing with the static balance that motivated his cosmological constant.
Prix Jules Janssen
Receives the Prix Jules Janssen for distinguished work in astronomy and astrophysics.
Static Universe Abandoned
Einstein abandons the need for a static cosmological model after cosmic expansion becomes established, leaving the cosmological constant without its original motivation.
Static Universe Model Abandoned
Abandons his earlier static cosmological model as expanding-universe observations and relativistic cosmology make a dynamical universe the more credible interpretation.
Mount Wilson Hubble Discussion
Visits Mount Wilson and discusses observational cosmology, confronting evidence that distant galaxies exhibit the redshift-distance relation associated with cosmic expansion.
Einstein-de Sitter Cosmological Model
With Willem de Sitter, proposes a spatially flat expanding cosmological model without a cosmological constant, providing a simple benchmark solution of general relativity.
Einstein-de Sitter Model
With Willem de Sitter, proposes a simple expanding cosmological model with zero cosmological constant.
Einstein Ring Condition Described
Einstein showed that exact alignment of source, lens and observer produces a circular image geometry, the configuration later widely known as an Einstein ring.
Gravitational Lensing
Publishes a calculation showing how a foreground star can gravitationally lens light from a background star.
Lens-Like Action of a Star Published
Einstein published a short analysis of the lens-like action of a foreground star, giving a compact treatment of image formation and magnification caused by gravitational light bending.
Mandl Prompts Einstein to Publish Gravitational Lensing
After discussions with Rudi Mandl, Einstein returned to the lensing calculation he had explored in 1912 and agreed to publish the optical effect of gravitational light bending.
Stellar Lens Magnification Relation Published
Einstein quantified the magnification produced by gravitational deflection in a simple stellar-lens geometry, linking image brightness to the angular alignment of source and lens.
Two-Image Stellar Lens Configuration Published
Einstein's lensing note described how imperfect alignment can produce two apparent images of a background star because its light reaches the observer along different curved paths.
Gravitational Lens Paper
Publishes a calculation of the lens-like action of a star's gravitational field, describing how general relativity can produce multiple or magnified images of a background source.
On Gravitational Waves Published
Einstein and Rosen publish a corrected paper showing cylindrical gravitational-wave solutions.
Spherical Cluster Relativity Analysis
Studies a stationary spherical system of gravitating particles and argues that such configurations do not naturally form the Schwarzschild-type singular surface then under discussion.
Response to Godel Rotating Universe
Comments on Kurt Godel's rotating cosmological solution, acknowledging that general relativity permits global spacetime structures with profound consequences for the concept of time.