Léon Foucault: Difference between revisions

Latest revision as of 18:32, 5 December 2015

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Biography

Born Jean Bernard Léon Foucault, Foucault was born on September 18, 1819 to a Parisian publisher. Due to his family's education and access to resources, Foucault was home schooled for the majority of his childhood, before leaving home to study medicine. He quickly discovered that due to his blood phobia, medicine was not the field for him. In order to continue academic pursuits Léon began studies in physics. Initially focusing on optics, Foucault worked on photographic processes, before becoming an assistant to Alfred Donné, working with microscopic observation.

After finishing his term with Alfred Donné, Léon partnered with Hippolyte Fizeau in order to study properties of visible light generated by the sun. In 1850 the two would conduct experiments detecting the speed of light through different mediums, effectively disproving Newton's theory of light, as well as determining the speed of light within 1% of the modern accepted value. His work with Pendulums would earn him further renown when, in 1851, he presented the Foucault pendulum, a simple experiment proving the rotation of the earth. The experiment' success and public appeal led Foucault to design a similar experiment with a device he would name the gyroscope. His work publicizing science, coupled with his work on light and optics would earn Foucault both the Royal Society's Copley award and a position at the Parisian Imperial Observatory in 1855.

At the Imperial Observatory Foucault would begin work studying magnets, eventually studying eddy currents, before returning to the field of optics. After designing a device to safely view the sun through a telescope, Foucault designed a method of testing the shape of mirrors in telescopes. IN his final years, Foucault returned to the Roman Catholic church, and later passed away due to multiple sclerosis on February 11, 1868.

Notable works

Foucault's Pendulum

Foucault's Pendulum is based on the premise that a free floating pendulum set in motion will maintain it's path in space with respect to the axis it rotates about. The design consists of a long pendulum fixed only in the z direction at the pivot, with large weight at the bottom. Once set in motion the pendulum would maintain it's plane of motion with respect to the top and bottom of the z-axis, the pivot and core of earth respectively. Tracing the path of the pendulum along the ground below it, however, will show, every except at the equator, a non linear path, indicating that the surface was rotating with respect to the plane of action of the pendulum.

Measurement of the speed of light

Working with Fizeau, Foucault designed a system to accurately measure the speed of light. Using a laser as a light source, beam was fired at a continuously rotating mirror, deflected to a second stationary mirror, back to the rotating mirror, and to the location of the laser. By measuring the distance from the projected beam from the source, and taking into account the distances involved along with the rate of rotation of the mirror, Foucault was able to predict the speed of light to be 298000 km/s, only 0.6% off from the modern accepted value for the speed of light.

Awards and Recognitions

Copley Medal
Member of the Royal Society
Member of the Bureau des Longitudes
Name Inscribed in the Eiffel Tower
Officer in the Legion of Honour
Asteroid 5668 Foucault named in his honor

References

http://www-history.mcs.st-andrews.ac.uk/Biographies/Foucault.html

http://www.famousscientists.org/leon-foucault/

https://en.wikipedia.org/wiki/File:Foucault-rotz.gif

http://www.daviddarling.info/encyclopedia/S/speedlight.html

@@ Line 5: / Line 5: @@
 ==Biography==
 [[File:Foucault.jpg|thumb|300px|Foucault]]
-Light passes through different materials, or mediums, at different speeds. In general, the denser the medium, the slower light passes through it. As light changes speed as it passes through a medium, it also bends at an angle. The <i>optical density</i> of a material is how well it can transmit light.
+Born Jean Bernard Léon Foucault, Foucault was born on September 18, 1819 to a Parisian publisher. Due to his family's education and access to resources, Foucault was home schooled for the majority of his childhood, before leaving home to study medicine. He quickly discovered that due to his blood phobia, medicine was not the field for him. In order to continue academic pursuits Léon began studies in physics. Initially focusing on optics, Foucault worked on photographic processes, before becoming an assistant to [[Alfred Donné]], working with microscopic observation.
+After finishing his term with  Alfred Donné, Léon partnered with [[Hippolyte Fizeau]] in order to study properties of visible light generated by the sun. In 1850 the two would conduct experiments detecting the speed of light through different mediums, effectively disproving Newton's theory of light, as well as determining the speed of light within 1% of the modern accepted value. His work with Pendulums would earn him further renown when, in 1851, he presented the Foucault pendulum, a simple experiment proving the rotation of the earth. The experiment' success and public appeal led Foucault to design a similar experiment with a device he would name the [[gyroscope]]. His work publicizing science, coupled with his work on light and optics would earn Foucault both the [[Royal Society]]'s Copley award and a position at the Parisian Imperial Observatory in 1855.
+At the Imperial Observatory Foucault would begin work studying magnets, eventually studying eddy currents, before returning to the field of optics. After designing a device to safely view the sun through a telescope, Foucault designed a method of testing the shape of mirrors in telescopes. IN his final years, Foucault returned to the Roman Catholic church, and later passed away due to multiple sclerosis on February 11, 1868.
 ==Notable works==
-*The Index of Refraction: the ratio of the speed of light through a vacuum to the speed of light in the medium. Written as: <math>n=\frac{c}{v}</math>, where
+=== Foucault's Pendulum ===
-**c=speed of light in a vacuum
+[[File:pendulumfree.gif|thumb|300px|Foucault's Pendulum in action]]
-**v=speed of light in medium
+Foucault's Pendulum is based on the premise that a free floating pendulum set in motion will maintain it's path in space with respect to the axis it rotates about. The design consists of a long pendulum fixed only in the z direction at the pivot, with  large weight at the bottom. Once set in motion the pendulum would maintain it's plane of motion with respect to the top and bottom of the z-axis, the pivot and core of earth respectively. Tracing the path of the pendulum along the ground below it, however, will show, every except at the equator, a non linear path, indicating that the surface was rotating with respect to the plane of action of the pendulum.
-Note that the index of refraction can never be less than one, since <math>\frac{c}{c}=1</math>.
-*Snell's Law: size of the angle of refraction, or how much the light bends. Written as:<math>n_1\sin\theta_1=n_2\sin\theta_2</math>, where
-**<math>n_1</math>=index of refraction of medium 1
-**<math>n_2</math>=index of refraction of medium 2
-**<math>\theta_1</math>=angle of incidence
-**<math>\theta_2</math>=angle of refraction.
-===A Visual Model===
+=== Measurement of the speed of light ===
+[[File:solfoucault.jpg|thumb|300px|The Fouault-Fizeau Experiment]]
+Working with Fizeau, Foucault designed a system to accurately measure the speed of light. Using a laser as a light source, beam was fired at a continuously rotating mirror, deflected to a second stationary mirror, back to the rotating mirror, and to the location of the laser. By measuring the distance from the projected beam from the source, and taking into account the distances involved along with the rate of rotation of the mirror, Foucault was able to predict the speed of light to be 298000 km/s, only 0.6% off from the modern accepted value for the speed of light.
-[[File:Refraction.png]]
+==Awards and Recognitions==
+*Copley Medal
+*Member of the Royal Society
+*Member of the [[Bureau des Longitudes]]
+*Name Inscribed in the Eiffel Tower
+*Officer in the [[Legion of Honour]]
+*Asteroid [[5668 Foucault]] named in his honor
-Here we see how the ray strikes a different medium and bends.
+== See also ==
+*Foucault's Pendulum
+**http://www.animations.physics.unsw.edu.au/jw/foucault_pendulum.html
+**http://www.geophysik.uni-muenchen.de/outreach/foucault-pendulum
+*Foucault-Fizeau Apparatus
+**http://www.speed-light.info/measurement.htm
-[[File:Light_dispersion_conceptual_waves.gif ]]
+==References==
+http://www-history.mcs.st-andrews.ac.uk/Biographies/Foucault.html
-Here we see that the index of refraction is different for different wavelengths of light, so a prism will disperse white light.
-==Examples==
-===Simple===
-Simple light from eye travels through water and bends:
-[[File:Refraction_fishbowl.jpg]]
-Can be solved very easily with Snell's Law.
-===Middling===
-Single beam refraction through a prism with a laser pointer:
-[[File:Laser1.jpg]]
-Calculations through a prism can be done as shown in the diagram below:
+http://www.famousscientists.org/leon-foucault/
-[[File:Prismcalculations.png|400px]]
+https://en.wikipedia.org/wiki/File:Foucault-rotz.gif
-===Difficult===
-[[File:Rainbow.jpg]]
-While pretty, it is very difficult to solve for all the angles and indices of refraction correctly!
-This is how it works:
-[[File:24-figure-48b.gif]]
-==Connectedness==
-One of the most common uses of refraction is, quite simply, glasses. The way that light bends around a curved lens and refracts magnifies the image and can give you better eyesight.
-On this vein, refractor telescopes, used in astronomy are quite common as well, especially among amateur astronomers.
-Fiber optics is entirely dependent upon refraction and total internal reflection. These cables can send information at speeds approaching the speed of light, since the information is carried in the light itself.
-Atmospheric refraction is also the cause of green flashes.
-==History==
-Thomas Harriot was the first person to discover that light bends when travelling through a different medium. However, it was Willebrord Snell who rediscovered it and then have the law of refraction named after him. It was initially published by Descartes in 1637, although Harriot had discovered it at least 35 years prior to that date.
-Refractive lens began to be used on telescopes by 1608 and were the first type of optical telescopes developed.
-== See also ==
-*[[Color Light Wave]]
-*[[Wave-Particle Duality]]
-===External links===
-http://www-rohan.sdsu.edu/~aty/explain/optics/refr.html
-http://ocw.mit.edu/courses/mechanical-engineering/2-71-optics-spring-2009/video-lectures/lecture-2-reflection-and-refraction-prisms-waveguides-and-dispersion/MIT2_71S09_lec02.pdf
-==References==
-https://en.wikipedia.org/wiki/Refracting_telescope
-http://www-rohan.sdsu.edu/~aty/explain/optics/refr.html
+http://www.daviddarling.info/encyclopedia/S/speedlight.html
-[[Category:Optics]]
+[[Category:Notable Scientists]]