Physics is the scientific study of energy, space, and time. It seeks to explain everything through observation, experimentation, and mathematical modelling. Measurements in physics involve quantifying physical properties such as force, motion, energy, and fields using standardised units. Facts in physics are determined through empirical testing, reproducibility of results, and the predictive accuracy of theories, validated through experiments and real-world applications.
Physics is fundamental physical particles of matter, such as molecules and atoms, and the forces that bind them together while governing how all matter interacts and behaves. Technically matter particles are either Fermions or made up from Quarks; the forces comes from Bosons.
The universe has just 4 forces (although technically Gravity isn’t really a force though).
What is Gravity?
Normal physical matter distorts the fabric of space-time, causing everything in the surrounding space to fall towards it. All atoms and particles contribute to this curvature, though their individual effects are very small. On a larger scale, this curvature creates the orbits of planets and satellites.
On a cosmic scale, gravity controls the formation of stars, galaxies and blackholes, playing a key role in shaping the structure of the universe. Despite its relatively weak nature compared to other forces, gravity travels over vast distances and affects all matter and energy universally.
The Electromagnetic Force
The Electromagnetic Force, one of the four fundamental forces of nature, governs the interactions between charged particles and gives rise to electric and magnetic fields. Electric and magnetic fields are two view points of the same phenomena.
These fields are not static; they can oscillate and propagate through space as electromagnetic waves. These waves are fundamental to understanding how energy travels across the universe, enabling phenomena like light, heat transfer, and wireless communication.
What are Electromagnetic Waves?
Electromagnetic (EM) waves are a type of energy transfer that propagates through space as oscillating electric and magnetic fields, which are perpendicular to each other and the direction of wave travel. They do not require a medium, meaning they can travel through a vacuum, such as the vastness of space. EM waves are classified by their wavelength and frequency into the electromagnetic spectrum, which includes radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays, and gamma rays.
Visible light, a small part of the electromagnetic spectrum, consists of wavelengths that human eyes can detect. The human eye can detect EM waves between 380–750 nanometres wave length.
Longer wavelengths than visible light, are primarily responsible for heat transfer. Objects emit IR radiation based on their temperature; warmer objects emit more IR energy. This is how heat from the Sun or a fire can warm your skin without direct contact. Infrared technology is also used in thermal imaging cameras and remote controls.
Shorter wavelengths than visible light are responsible for effects like sunburn, as they can penetrate the skin and damage DNA. UV radiation also plays a crucial role in sterilisation, killing bacteria and viruses, and helps the human body produce vitamin D.
Very long wavelengths in the electromagnetic spectrum and are used for wireless communication, including WiFi, mobile phones, and broadcasting. They carry information by modulating their amplitude or frequency, which is decoded by receivers. WiFi, for example, operates within specific radio frequency bands (2.4 GHz or 5 GHz) to transmit data over short distances.
Strong Nuclear Force
The strong nuclear force is one of the four fundamental forces of nature and is the strongest. It governs the interactions between protons and neutrons within an atomic nucleus, holding the nucleus together. This force acts over very short distances (typically within the range of atomic nuclei) and is responsible for holding atoms together by binding quarks to form protons and neutrons, as well as keeping these particles within the nucleus itself. Without the strong force, atomic nuclei would not be stable.
Weak Nuclear Force
The weak nuclear force is a fundamental force responsible for processes such as radioactive decay and neutrino interactions in atoms. The weak force has a very very short range, responsible for transforming particles (such as turning a neutron into a proton or an electron into a neutrino) and plays a critical role in the process of nuclear fusion in stars, which produces the energy that powers them.
Further reading..