WhoAwee.com - Free Online Famous Physics Discoveries for Kids

One of the greatest scientific achievements of physics in the 20th century is the discovery of quantum mechanics. It governs the dynamics of microscopic objects such as atoms and electrons. In this tiny world, things behave differently from the macroscopic world where classical mechanics rules.

The Discovery of the Vastness of the Universe

Few people realize how much our picture of the universe has changed in 100 years. At the end of the 19th century, the universe was thought to contain only hundreds of thousands of stars arranged in no particularly interesting patterns. The most distance stars were thought to be about 100,000 light years away (meaning that it would take light 100,000 years to travel from Earth to such distant stars; 1 light-year is about 10 trillion kilometers or 6 trillion miles).

The Law of Falling Bodies (1604)

Galileo Galilei overturns nearly 2,000 years of Aristotelian belief that heavier bodies fall faster than lighter ones by proving that all bodies fall at the same rate.

Universal Gravitation

Isaac Newton comes to the conclusion that all objects in the universe, from apples to planets, exert gravitational attraction on each other.

Laws of Motion (1687)

Isaac Newton changes our understanding of the universe by formulating three laws to describe the movement of objects. 1) An object in motion remains in motion unless an external force is applied to it. 2) The relationship between an object's mass (m), its acceleration (a) and the applied force (F) is F = ma. 3) For every action there is an equal and opposite reaction.

The Second Law of Thermodynamics (1824 – 1850)

Scientists working to improve the efficiency of steam engines develop an understanding of the conversion of heat into work.

Electromagnetism (1807 – 1873)

Electromagnetism is one of the four fundamental interactions of nature, along with strong interaction, weak interaction and gravitation. It is the force that causes the interaction between electrically charged particles; the areas in which this happens are called electromagnetic fields.

Special Relativity (1905)

Albert Einstein overthrows basic assumptions about time and space by describing how clocks tick slower and distances appear to stretch as objects approach the speed of light.

E = mc^2 (1905)

Energy is equal to mass times the speed of light squared. Albert Einstein's famous formula proves that mass and energy are different expressions of the same thing, and that a very small amount of mass can be converted into a very large amount of energy.

The Quantum Leap (1900 – 1935)

In physics, a quantum leap or quantum jump is a change of an electron from one quantum state to another within an atom.

The Nature of Light (1704 – 1905)

Thought and experimentation by Isaac Newton, Thomas Young and Albert Einstein lead to an understanding of what light is, how it behaves, and how it is transmitted. Newton uses a prism to split white light into its constituent colors and another prism to mix the colors into white light, proving that colored light mixed together makes white light. Young establishes that light is a wave and that wavelength determines color. Finally, Einstein recognizes that light always travels at a constant speed.

The Neutron (1935)

James Chadwick discovers neutrons, which, together with protons and electrons comprise the atom. This finding dramatically changes the atomic model and accelerates discoveries in atomic physics.

Superconductors (1911 – 1986)

The unexpected discovery that some materials have no resistance to the flow of electricity promises to revolutionize industry and technology. Superconductivity occurs in a wide variety of materials, including simple elements like tin and aluminum, various metallic alloys and certain ceramic compounds.

Nuclear Forces (1666 – 1957)

Of the basic forces at work on the subatomic level lead to the realization that all interactions in the universe are the result of four fundamental forces of nature — the strong and weak nuclear forces, the electromagnetic force and gravitation.