cosmology

Quantum fluctuations and their role in the universe

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Les fluctuations quantiques et leur rôle dans l'univers

IN BRIEF Quantum fluctuations: spontaneous energy variations in quantum vacuum. Influence on the formation of structures in the universe. Elementary particles: emergence and rapid annihilation. Uncertainty principles: impact on quantum theory. Primordial universe: crucial role in cosmic inflation. Quantum voids: concepts of fluctuating energy zones. Applications in cosmology and particle physics. Quantum fluctuations represent a … Read more

The big bang: the birth of the universe according to physics

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Le big bang : la naissance de l'univers selon la physique

IN BRIEF Big Bang: explosive event marking the birth of the Universe Occurred about 13.7 billion years ago Emergence of a dense and hot Universe The Big Bang theory supported by contemporary observations Universe continuously expanding since its creation Questions about the origin: what happened before? No defined time before the Big Bang Exploration of … Read more

Cosmology and the Origin of the Universe

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La cosmologie et l'origine de l'univers

IN BRIEF Big Bang: cosmic event marking the origin of the Universe according to the current cosmological model. Origins of the Universe: study of the conditions preceding and following the Big Bang. Formation Eras: the Universe evolved through the radiation era, followed by the matter era. String Theory: suggests that the Big Bang could be … Read more

The limits of the observable universe: how far can we see

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Les limites de l'univers observable : jusqu'où peut-on voir

IN BRIEF Observable universe : Visible part of the universe, limited by the cosmic horizon. Size of the universe : Estimated to be at least 96 billion light-years. Cosmic horizon : Boundary beyond which the universe remains opaque. Cosmic microwave background : Light from the Big Bang visible at about 13.8 billion light-years. Expansion of … Read more

Dark energy and dark matter: the mysteries of the universe

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L'énergie noire et la matière noire : les mystères de l'univers

IN BRIEF Dark matter: Makes up about 25% of the universe. Dark energy: Represents about 70% of the universe. Dark matter: Has an attractive virtue, promoting clumping. Dark energy: Has a repulsive virtue, pushing celestial objects away. 95% of the universe: Formed by dark matter and dark energy. Invisible: Cannot be detected by light. Persistent … Read more

Spiral galaxies: characteristics and mysteries

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Les galaxies spirales : caractéristiques et mystères

IN BRIEF Spiral galaxies: grouping of hundreds of billions of stars Structure in the shape of a disk and central bulge Formed by the collapse of hydrogen and helium clouds Spiral arms influenced by giant molecular clouds Notable examples like the Milky Way and the Andromeda Galaxy Variety of shapes: spiral, elliptical, barred, and irregular … Read more

The role of black holes in the universe

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Le rôle des trous noirs dans l'univers

IN BRIEF Definition: Celestial objects with intense gravitational fields. Composition: Very compact, high mass/size ratio. Role: Impact on the growth of galaxies. Event horizon: Limit beyond which nothing can escape. Time travel: The gravity of a black hole allows for time dilation. Environment: Influence on galactic structures and their dynamics. Scientific research: Studies conducted to … Read more