Unifies both special relativity and gravity.
Not compatible with the Standard Model, and the 2020 unification attempts are called theory of everything.
One of the main motivations for it was likely having forces not be instantaneous, but rather mediated by field to maintain the principle of locality, just like electromagnetism did earlier.
Subtle is the Lord by Abraham Pais (1982) page 22 mentions that when Einstein saw this in 1915, he was so excited he couldn't work for three days.
- youtu.be/dX4vCNi544w?t=1866 this section about numerical simulation is quite interesting. They don't know how to solve the inverse problem, so they just simulated a bunch of different mass combinations
- youtu.be/dX4vCNi544w?t=2290 they use Ubuntu everywhere, default purple desktop. God bless. It's good enough for gravitational wave detection, just not good enough for some shitty enterprise application. Lol.
Combination of electromagnetism and general relativity. Unlike combining quantum mechanics and general relativity, this combination was easier.
TODO any experiments of interest at all?
In 2020 physics, best explained by general relativity.
Articles by others on the same topic
General relativity describes gravity through the geometry of spacetime. Its metric tensor specifies distances, proper time measured by clocks, and the causal structure that limits communication. Matter and radiation affect this geometry through the Einstein field equations; freely falling test particles follow geodesics of the resulting geometry. A planet's orbit and a falling apple therefore belong to the same geometric story. The Newtonian limit recovers familiar Newtonian gravity when fields are weak and speeds are small compared with the speed of light. See David Tong's introduction to general relativity.
The most direct way to understand spacetime curvature is to compare neighboring freely falling bodies. Even when each body feels weightless, their separation can change: this is geodesic deviation, observed as a tidal force. Curvature concerns these relative measurements, rather than the shape of a drawing in an imagined surrounding space. A second accessible measurement is gravitational time dilation: identical clocks maintained at different heights accumulate different proper times. Together, tides and clocks turn an abstract geometry into laboratory questions.
General relativity is a fundamental theory of gravitation formulated by Albert Einstein, published in 1915. It extends the principles of special relativity and provides a new understanding of gravity, not as a force in the traditional sense, but as the curvature of spacetime caused by mass and energy. Key concepts in general relativity include: 1. **Spacetime**: Instead of treating space and time as separate entities, general relativity combines them into a four-dimensional continuum known as spacetime.