The universe is a vast and mysterious place, filled with countless stars, planets, and galaxies. It is made up of following components:
Ordinary Matter
Ordinary matter is the stuff we are most familiar with. It includes everything we can see and touch, such as stars, planets, and living things. This type of matter is made up of atoms, which are composed of protons, neutrons, and electrons. Ordinary matter makes up only about 5% of the entire universe.
Dark Matter
Dark matter is a mysterious and invisible substance that does not emit or absorb light. We cannot see dark matter directly, but we know it exists because of its gravitational effects on visible matter. For instance, dark matter helps hold galaxies together. Without it, galaxies would fly apart. Dark matter makes up about 27% of the universe.
Dark Energy
Dark energy is even more mysterious than dark matter. It is an unknown force that is causing the universe to expand at an accelerating rate. Scientists do not yet understand what dark energy is, but it makes up a whopping 68% of the universe. Its discovery has revolutionized our understanding of the cosmos.
Atoms and Elements
Atoms are the building blocks of ordinary matter. They combine in various ways to form elements like hydrogen, helium, and carbon. Hydrogen and helium are the most abundant elements in the universe. They were formed during the Big Bang, the event that created the universe about 13.8 billion years ago.
Stars and Galaxies
Stars are massive balls of burning gas, primarily hydrogen and helium. They produce light and heat through nuclear fusion. Stars group together to form galaxies. Our galaxy, the Milky Way, contains billions of stars. There are billions of galaxies in the universe, each containing countless stars.
Interstellar and Intergalactic Space
Between the stars and galaxies, there is vast space filled with a thin spread of gas and dust. This space is not empty; it contains particles and electromagnetic radiation. Interstellar space is the space within a galaxy, while intergalactic space is the space between galaxies.
Quarks and Leptons
Protons and neutrons themselves are made up of even smaller particles called quarks. Quarks come in different types, or “flavors,” but protons and neutrons are composed of just two: up quarks and down quarks. Electrons, which orbit the nucleus of an atom, belong to a different family of particles known as leptons. Both quarks and leptons are fundamental particles that, together with force-carrying particles like photons and gluons, form the basis of the Standard Model of particle physics.
