13. Alexander Graham Bell

Alexander Graham Bell was born on March 3, 1847 in Edinburgh, Scotland. In 1870, Bell and his family moved to Canada.

The first telephone company, Bell Telephone Company, was founded on July 9, 1877.

Bell continued his experiments in communication. He invented the photophone-transmission of sound on a beam of light, which was a precursor of fiber-optics. He also invented techniques for teaching speech to the deaf. Bell was granted 18 patents in his name, and 12 he shared with collaborators. He became one of the founding meembers of the National Geographic Society in 1888. Bell died in Baddek, Nova Scotia, on August 2, 1922.

14.Fahrenheit: The Man and His Scale

In 1714 Daniel Gabriel Fahrenheit invented the mercury thermometer which is now familiar to most of the world. He created a scale that was adopted throughout the English speaking world, but is now only used in the United States. Fahrenheit was born in Gdansk, at the time a Polish province of Prussia. He was educated in business, but also trained in natural sciences, to which he took a great interest and liking. He worked in the fields of chemistry and engineering. After he settled in Amsterdam, Fahrenheit did quite a lot of scientific work and made many discoveries, including a method for supercooling of water, that the boiling point of water is dependent on barometric pressure, and the specific gravities of many elements. Fahrenheit died in 1736. He lived a life that proved that science and business could work hand-in-hand to improve the lives and lifestyles of the people.

17.Light - What is Light?

Light is part of the electromagnetic spectrum, which ranges from radio waves to gamma rays. Visible light is not inherently different from the other parts of the electromagnetic spectrum with the exception that the human eye has evolved to detect visible waves. A photon is the smallest quantity (quantum) of energy which can be transported and it was the realization that light travelled in discrete quanta that was the origins of Quantum Theory.

18.The Discovery of Radioactivity

In 1896 Henri Becquerel was using naturally fluorescent minerals to study the properties of x-rays, which had been discovered in 1895 by Wilhelm Roentgen. The term radioactivity was actually coined by Marie Curie, Alpha particles carry more electric charge, are more massive, and move slowly compared to beta and gamma particles, they interact much more easily with matter. Beta particles are much less massive and move faster, but are still electrically charged. A sheet of aluminum one millimeter thick or several meters of air will stop these electrons and positrons. Because gamma rays carry no electric charge, they can penetrate large distances through materials before interacting–several centimeters of lead or a meter of concrete is needed to stop most gamma rays

19. Selected papers of great American physics

American physics is second to none in the world. It was not always so. The roll call is impressive, Franklin, Henry, Gibbs, Rowland, Michelson, Millikan, Compton; Many American physicists, including all whose papers appear in this volume, studied in Europe or benefited from close personal contacts with European colleagues. In this and many other ways, American physics owes a great debt to the old countries.

BENJAMIN FRANKLIN

Letter IV: Farther Experiments and Observations in Electricitry

Letter XI

JOSEPH HENRY

On the Production of Currents and Sparks of Electricity from Magnetism

On Electro-Dynamic Induction (extract)

ALBERT ABRAHAM MICHELSON

On the Relative Motion of the Earth and the Luminiferous Ether (with Edward W. Morley)

HENRY AUGUSTUS ROWLAND

Screw

The Highest Aim of the Physicist

JOSIAH WILLARD GIBBS

Preface to Elementary Principles in Statistical Mechanics

ROBERT ANDREWS MILLIKAN

On the Elementary Electrical Charge and the Avogadro Constant (extract)

ARTHUR HOLLY COMPTON

A Quantum Theory of the Scattering of X-Rays by Light Elements