Some 13.8 billion years ago, the universe began with a rapid expansion we call the Big Bang. After this initial expansion, which lasted a fraction of a second, gravity started to slow the universe down. But the cosmos wouldn't ...
Astronomy
Feb 6, 2024
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97
The general theory of relativity is based on the concept of curved space–time. To describe how the energy and momentum of fields are distributed in space–time, as well as how they interact with the gravitational field, ...
General Physics
Jan 18, 2024
7
210
A quarter century ago, physicist Juan Maldacena proposed the AdS/CFT correspondence, an intriguing holographic connection between gravity in a three-dimensional universe and quantum physics on the universe's two-dimensional ...
Astronomy
Dec 24, 2023
23
251
A radical theory that consistently unifies gravity and quantum mechanics while preserving Einstein's classical concept of spacetime has been announced in two papers published simultaneously by UCL (University College London) ...
General Physics
Dec 4, 2023
30
9786
If you, like me, have used telescopes to gaze out at the wonders of the universe, then you too may have been a little captivated by the topic of gravitational lensing. Think about it: how cool is it that the very universe ...
Astronomy
Nov 1, 2023
0
27
With his theory of General Relativity in 1915, Albert Einstein revolutionized how we think about our universe. Rather than the cosmos simply providing the room for the planets and stars to orbit each other, space and time ...
Astronomy
Oct 5, 2023
11
107
Einstein's theory of gravity—general relativity—has been very successful for more than a century. However, it has theoretical shortcomings. This is not surprising: the theory predicts its own failure at spacetime singularities ...
General Physics
Sep 25, 2023
90
1036
When black holes and other enormously massive, dense objects whirl around one another, they send out ripples in space and time called gravitational waves. These waves are one of the few ways we have to study the enigmatic ...
Astronomy
Jul 1, 2023
0
117
The cosmos is a unique laboratory for testing the laws of physics, in particular those of Euler and Einstein. Euler described the movements of celestial objects, while Einstein described the way in which celestial objects ...
Astronomy
Jun 22, 2023
43
152
The theory of general relativity (GR), proposed by Einstein over a century ago, remains one of the most well-known scientific postulates of all time. This theory, which explains how spacetime curvature is altered in the presence ...
Astronomy
Jun 16, 2023
0
119
