Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Principle of Superposition and the Gravitational Field01:17

The Principle of Superposition and the Gravitational Field

2.2K
The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a point object is the vector sum of the gravitational forces on it due to various objects. The principle helps calculate the force by listing the individual forces and then vectorially summing them up. However, it should be noted that the principle of superposition is not always apparent. In the presence of a second force, the first force could...
2.2K
The Quantum-Mechanical Model of an Atom02:45

The Quantum-Mechanical Model of an Atom

60.7K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
60.7K
Space-Time Curvature and the General Theory of Relativity01:17

Space-Time Curvature and the General Theory of Relativity

4.8K
In 1905, Albert Einstein published his special theory of relativity. According to this theory, no matter in the universe can attain a speed greater than the speed of light in a vacuum, which thus serves as the speed limit of the universe.
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
4.8K
Gravity between Spherical Bodies01:27

Gravity between Spherical Bodies

9.6K
Newton's law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, the Moon, and other planets, the law holds with an assumption that masses of spherical objects are concentrated at their respective centers.
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
9.6K
Newton's Law of Gravitation01:15

Newton's Law of Gravitation

17.3K
Our everyday observation tells us that all objects close to the Earth naturally tend to fall to the ground. Early philosophers assumed that this downward force was unique to Earth. By the 16th century, Nicolaus Copernicus (1473-1543) put forward the heliocentric theory, which suggested that Earth and other planets orbited the sun, while the Moon orbited the Earth. However, it was Isaac Newton (1642-1727) who linked these two motions together in the 17th century. He reasoned that the force of...
17.3K
Quantum Numbers02:43

Quantum Numbers

53.2K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
53.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Disentangling Boltzmann Brains, the Time-Asymmetry of Memory, and the Second Law.

Entropy (Basel, Switzerland)·2025
Same author

Why bad philosophy is stopping progress in physics.

Nature·2025
Same author

Detecting Planck-Scale Dark Matter with Quantum Interference.

Physical review letters·2024
Same author

Quantum Spacetime: Proposed experiments would search for signs that space and time obey quantum rules.

Scientific American·2024
Same author

On the consistency of relative facts.

European journal for philosophy of science·2023
Same author

Locally Mediated Entanglement in Linearized Quantum Gravity.

Physical review letters·2023
Same journal

Primordial black holes and their gravitational-wave signatures.

Living reviews in relativity·2025
Same journal

Solvable models of quantum black holes: a review on Jackiw-Teitelboim gravity.

Living reviews in relativity·2023
Same journal

Electromagnetic counterparts to massive black-hole mergers.

Living reviews in relativity·2022
Same journal

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA.

Living reviews in relativity·2020
Same journal

Kilonovae.

Living reviews in relativity·2019
Same journal

Erratum: Publisher Correction: Interferometer techniques for gravitational-wave detection.

Living reviews in relativity·2019
See all related articles

Related Experiment Video

Updated: Mar 7, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

10.4K

Loop Quantum Gravity.

Carlo Rovelli1

  • 1Centre de Physique Théorique Luminy, Case 907, F-13288 Marseille, France.

Living Reviews in Relativity
|February 10, 2017
PubMed
Summary
This summary is machine-generated.

Loop quantum gravity offers a mathematically rigorous approach to quantum gravity and quantum spacetime. It provides a physical picture of spacetime microstructure and resolves singularities, yielding predictions for Planck-scale physics.

More Related Videos

Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

9.8K
Gradient Echo Quantum Memory in Warm Atomic Vapor
10:00

Gradient Echo Quantum Memory in Warm Atomic Vapor

Published on: November 11, 2013

13.3K

Related Experiment Videos

Last Updated: Mar 7, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

10.4K
Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

9.8K
Gradient Echo Quantum Memory in Warm Atomic Vapor
10:00

Gradient Echo Quantum Memory in Warm Atomic Vapor

Published on: November 11, 2013

13.3K

Area of Science:

  • Theoretical Physics
  • Quantum Gravity
  • Cosmology

Background:

  • The quantum behavior of gravity and quantum spacetime remains an open problem.
  • Loop quantum gravity is a well-developed, background-independent quantization of general relativity.

Purpose of the Study:

  • To provide an overview of the ideas, techniques, results, and open problems in loop quantum gravity.
  • To explore loop quantum gravity as a candidate theory for quantum gravity.

Main Methods:

  • Quantization of general relativity in a background-independent manner.
  • Computation of spectra for geometrical quantities.
  • Investigation of spacetime singularities and black hole entropy.

Main Results:

  • Quantitative predictions for Planck-scale physics via spectra of area and volume.
  • A physical picture of quantum spacetime microstructure with Planck-scale discreteness.
  • Resolution of spacetime singularities (black hole interiors, cosmological singularity) and derivation of black hole entropy.

Conclusions:

  • Loop quantum gravity provides a framework for understanding quantum spacetime and resolving singularities.
  • The theory is foundational to related formalisms like spin foams and group field theory.
  • It opens avenues for investigating the early universe and regions beyond the Big Bang.