Download Timeline Activity

Timeline Activity
The first list of dates in the handout serves as the template for a time-line you will create. Some dates
have more than one statement that go with them; pay attention to the number of lines for each date. The
next list of statements is not in the correct chronological order. Read through the statements and arrange the
statements so that you have a chronologically correct list of contributions to our present light theory.
450 BC ______________________
100 AD ______________________
1000 AD ______________________
1600 AD ______________________
1650 AD ______________________
1800 AD ______________________
1850 AD ______________________
1880 AD ______________________
1900 AD ______________________
1905 AD ______________________
1925 AD ______________________
Rearrange these statements:
You may find it helpful to print out the statements below: A - V, cut them out, rearrange them in the correct
order and place them on the correct lines on the timeline. You may also rearrange the dates using this
document by cutting and pasting and then saving and printing. This will serve as your notes for this section
of the unit and will help you when you take the History of Light Quiz.
A. Huygens (Dutch mathematician, physicist, and astronomer) led the wave theory in the mid 1600's. His
theory said that "each point on a wave front may be regarded as a new source of disturbance".
B. During Newton's peak period with the particle theory, he falsely stated that the speed of particles would
increase in a denser medium.
C. In 450 BC, Plato, a philosopher, observed reflection and believed that "light emanated from the eye".
D. Nine hundred years after the Greeks' observations of refraction, Alhazen, a mathematician and
astronomer, refuted the ideas of light emanating from the eye.
E. Einstein developed a photoelectric equation in 1905.
F. Hertz experimentally confirmed Maxwell's prediction - true confirmation of the wave theory.
G. deBroglie is credited with wave mechanics, right before Rutherford's discovery, by putting together the
equations E = mc2 and E = hf - a combination of particle and wave equations.
H. Hertz discovered the photoelectric effect combined or dual wave-particle theory of light.
I. One theory which took hold in the mid 17th century was Newton's (English mathematician, physicist, and
astronomer) particle theory.
J. Credited with being the "father of the electromagnetic theory", Maxwell, a Scottish mathematician and
physicist, followed Faraday. He predicted the properties of a medium that would transmit heat, light, and
electricity. He also predicted mathematically that all three types of energy propagate at the same speed. He
defined an electromagnetic wave as one that was equally divided between an electric and magnetic field,
both perpendicular to each other and also perpendicular to the direction of propagation.
K. At the turn of the 19th century, Young demonstrated interference and diffraction, only explained by a
wave theory.
L. Alhazen predicted that the angle of incidence and the angle of refraction were related, but couldn't solve
mathematically.
M. In 100 AD, the Greeks observed refraction.
N. With his quantum theory came the equation E = hf where E is proportional to the frequency of the wave.
"h" has a value of 6.6 x 10-34 Js (Plank's constant)
O. At the turn of the 20th century, Planck, a German physicist, developed the quantum theory using the
photon, indivisible packets of light, as the basis for light being emitted or absorbed in quantities called
"quanta".
P. Six hundred years later, Snell confirmed Alhazen's predictions and developed Snell's Law - a
mathematical relationship for the angle of incidence and the angle of refraction.
Q. Foucault followed Young and agreed with the wave theory. He opposed Newton's particle theory and
said the speed of light in water is less than the speed of light in air. This began confirmation of the wave
theory.
R. A German physicist named Lenard experimentally confirmed the photoelectric effect at the turn of the
20th century.
S. At the same time as Foucault (mid 19th century), Faraday, an English physicist, started the
electromagnetic theory.
T. Newton demonstrated reflection, refraction, and rectilinear propagation using particles.
U. The 1600's were known as the "Age of Experimentation" when opposing views and ideas were previous.
V. The 20th century is known as the "Modern Physics" era.