Physics Book - User contributions [en]

Philipp Lenard

2015-12-04T20:19:44Z

Vbalayan3: /* References */

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===Meteorological Findings===

Lenard was the first person to study the separation of electric charges that accompanies the aerodynamic break up of droplets of water. This is known as "spray electrification", "the waterfall effect", or the "Lenard effect". Lenard conducted studies that explored the size and shape distributions of raindrops. To do this, he constructed a wind tunnel in which water droplets of different sizes cold be held stationary for a short period of time. This helped him recognize that large raindrops are not tear-drop shaped, but are shaped more like a burger bun.

[[File:Lenard-e.gi.jpg|thumb| A water droplet forms an electric double layer. ]]

===Awards===

Royal Society Rumford Medal- 1896
Italian Society of Sciences Matteucci Medal- 1896
French Academy of Sciences Prix La Caze- 1897
Franklin Institute Franklin Medal- 1932
Nobel Prize for Physics- 1905

=="Deutsche Physik"==

Lenard was known as a strong German nationalist. He had a strong distaste for "English Physics" because he believed that it stole its ideas from Germany. He was a strong proponent and a member of the National Social Party. Lenard served as the Chief of Aryan physics under Adolf Hilter.
Lenard's strong belief and proposition for German physics led him to looking at all other physicists and their theories with great skepticism, especially Albert Einstein. His book, ''Great Men in Science, a History of scientific progress'' clearly showed his dislike for certain scientists. He even used to refer to Einstein as the "Jewish fraud" of relativity.

[[File:Swastika4.jpg]]

==References==

1. http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html

2. http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165

3. http://www.rawstory.com/2015/06/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein/

4. hhttp://www.britannica.com/biography/Philipp-Lenard

5. http://www.nndb.com/people/441/000099144/

7. http://www.einstein-website.de/biographies/lenard_content.html

[[Category:Notable Scientists]]

Philipp Lenard

2015-12-04T20:17:46Z

Vbalayan3:

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===Meteorological Findings===

Lenard was the first person to study the separation of electric charges that accompanies the aerodynamic break up of droplets of water. This is known as "spray electrification", "the waterfall effect", or the "Lenard effect". Lenard conducted studies that explored the size and shape distributions of raindrops. To do this, he constructed a wind tunnel in which water droplets of different sizes cold be held stationary for a short period of time. This helped him recognize that large raindrops are not tear-drop shaped, but are shaped more like a burger bun.

[[File:Lenard-e.gi.jpg|thumb| A water droplet forms an electric double layer. ]]

===Awards===

Royal Society Rumford Medal- 1896
Italian Society of Sciences Matteucci Medal- 1896
French Academy of Sciences Prix La Caze- 1897
Franklin Institute Franklin Medal- 1932
Nobel Prize for Physics- 1905

=="Deutsche Physik"==

Lenard was known as a strong German nationalist. He had a strong distaste for "English Physics" because he believed that it stole its ideas from Germany. He was a strong proponent and a member of the National Social Party. Lenard served as the Chief of Aryan physics under Adolf Hilter.
Lenard's strong belief and proposition for German physics led him to looking at all other physicists and their theories with great skepticism, especially Albert Einstein. His book, ''Great Men in Science, a History of scientific progress'' clearly showed his dislike for certain scientists. He even used to refer to Einstein as the "Jewish fraud" of relativity.

[[File:Swastika4.jpg]]

==References==

1. https://en.wikipedia.org/wiki/Rings_of_Saturn#Maxwell_Gap_and_Ringlet

2. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

3. http://www.biography.com/people/james-c-maxwell-9403463#saturns-rings

4. http://rsta.royalsocietypublishing.org/content/366/1871/1717

5. http://rsta.royalsocietypublishing.org/content/366/1871/1849

7. http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html

[[Category:Notable Scientists]]

File:Swastika4.jpg

2015-12-04T20:17:01Z

Vbalayan3:

Philipp Lenard

2015-12-04T20:16:34Z

Vbalayan3:

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===Meteorological Findings===

Lenard was the first person to study the separation of electric charges that accompanies the aerodynamic break up of droplets of water. This is known as "spray electrification", "the waterfall effect", or the "Lenard effect". Lenard conducted studies that explored the size and shape distributions of raindrops. To do this, he constructed a wind tunnel in which water droplets of different sizes cold be held stationary for a short period of time. This helped him recognize that large raindrops are not tear-drop shaped, but are shaped more like a burger bun.

[[File:Lenard-e.gi.jpg|thumb| A water droplet forms an electric double layer. ]]

===Awards===

Royal Society Rumford Medal- 1896
Italian Society of Sciences Matteucci Medal- 1896
French Academy of Sciences Prix La Caze- 1897
Franklin Institute Franklin Medal- 1932
Nobel Prize for Physics- 1905

=="Deutsche Physik"==

Lenard was known as a strong German nationalist. He had a strong distaste for "English Physics" because he believed that it stole its ideas from Germany. He was a strong proponent and a member of the National Social Party. Lenard served as the Chief of Aryan physics under Adolf Hilter.
Lenard's strong belief and proposition for German physics led him to looking at all other physicists and their theories with great skepticism, especially Albert Einstein. His book, ''Great Men in Science, a History of scientific progress'' clearly showed his dislike for certain scientists. He even used to refer to Einstein as the "Jewish fraud" of relativity.

[[File:swastika4.jpg|thumb|]]

== See also ==

Other famous scientists relating to Maxwell include:

[[Michael Faraday]]

[[Andre Marie Ampere]]

[[Albert Einstein]]

[[Edwin Hall]]

==References==

1. https://en.wikipedia.org/wiki/Rings_of_Saturn#Maxwell_Gap_and_Ringlet

2. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

3. http://www.biography.com/people/james-c-maxwell-9403463#saturns-rings

4. http://rsta.royalsocietypublishing.org/content/366/1871/1717

5. http://rsta.royalsocietypublishing.org/content/366/1871/1849

7. http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html

[[Category:Notable Scientists]]

Philipp Lenard

2015-12-04T18:07:51Z

Vbalayan3:

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===Meteorological findings===

Lenard was the first person to study the separation of electric charges that accompanies the aerodynamic break up of droplets of water. This is known as "spray electrification", "the waterfall effect", or the "Lenard effect". Lenard conducted studies that explored the size and shape distributions of raindrops. To do this, he constructed a wind tunnel in which water droplets of different sizes cold be held stationary for a short period of time. This helped him recognize that large raindrops are not tear-drop shaped, but are shaped more like a burger bun.

[[File:Lenard-e.gi.jpg|thumb| A water droplet forms an electric double layer. ]]

===Equations===

In a paper titled ''A dynamical theory of the electromagnetic field'', Maxwell strove to make his theories more mathematical and less analogical. His four equations that resulted from this are as follows.

1. Gauss' law for electricity: <math> \oint \overrightarrow{E} \bullet d \overrightarrow{A} = \frac{q} {\epsilon_0}</math>

2. Gauss' law for magnetism: <math> \oint \overrightarrow{B} \bullet d \overrightarrow{A} = 0</math>

3. Faraday's law of induction: <math> \oint \overrightarrow{E} \bullet \overrightarrow{d s} = -\frac{d \Phi} {dt} </math>

4. Ampere's law: <math> \oint \overrightarrow{B} \bullet \overrightarrow{d s} = \mu_0i + \frac{1} {c^2} \frac{\partial} {\partial t} \int \overrightarrow{E} \bullet d \overrightarrow{A}</math>

==Use by Other Scientists==

Albert Einstein once said "The special theory of relativity owes its origins to Maxwell's equations of the electromagnetic field."[http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html] Einstein was said to have a picture of Maxwell on his wall in his study. [http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html]

== See also ==

Other famous scientists relating to Maxwell include:

[[Michael Faraday]]

[[Andre Marie Ampere]]

[[Albert Einstein]]

[[Edwin Hall]]

==References==

1. https://en.wikipedia.org/wiki/Rings_of_Saturn#Maxwell_Gap_and_Ringlet

2. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

3. http://www.biography.com/people/james-c-maxwell-9403463#saturns-rings

4. http://rsta.royalsocietypublishing.org/content/366/1871/1717

5. http://rsta.royalsocietypublishing.org/content/366/1871/1849

7. http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html

[[Category:Notable Scientists]]

2015-12-04T17:58:54Z

Vbalayan3:

Philipp Lenard

2015-12-04T17:58:33Z

Vbalayan3:

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===Meteorological findings===

Lenard was the first person to study the separation of electric charges that accompanies the aerodynamic break up of droplets of water. This is known as "spray electrification", "the waterfall effect", or the "Lenard effect". Lenard conducted studies that explored the size and shape distributions of raindrops. To do this, he constructed a wind tunnel in which water droplets of different sizes cold be held stationary for a short period of time. This helped him recognize that large raindrops are not tear-drop shaped, but are shaped more like a burger bun.

[[File:droplet.gif|thumb| A water droplet forms an electric double layer. ]]

===Equations===

In a paper titled ''A dynamical theory of the electromagnetic field'', Maxwell strove to make his theories more mathematical and less analogical. His four equations that resulted from this are as follows.

1. Gauss' law for electricity: <math> \oint \overrightarrow{E} \bullet d \overrightarrow{A} = \frac{q} {\epsilon_0}</math>

2. Gauss' law for magnetism: <math> \oint \overrightarrow{B} \bullet d \overrightarrow{A} = 0</math>

3. Faraday's law of induction: <math> \oint \overrightarrow{E} \bullet \overrightarrow{d s} = -\frac{d \Phi} {dt} </math>

4. Ampere's law: <math> \oint \overrightarrow{B} \bullet \overrightarrow{d s} = \mu_0i + \frac{1} {c^2} \frac{\partial} {\partial t} \int \overrightarrow{E} \bullet d \overrightarrow{A}</math>

==Use by Other Scientists==

Albert Einstein once said "The special theory of relativity owes its origins to Maxwell's equations of the electromagnetic field."[http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html] Einstein was said to have a picture of Maxwell on his wall in his study. [http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html]

== See also ==

Other famous scientists relating to Maxwell include:

[[Michael Faraday]]

[[Andre Marie Ampere]]

[[Albert Einstein]]

[[Edwin Hall]]

==References==

1. https://en.wikipedia.org/wiki/Rings_of_Saturn#Maxwell_Gap_and_Ringlet

2. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

3. http://www.biography.com/people/james-c-maxwell-9403463#saturns-rings

4. http://rsta.royalsocietypublishing.org/content/366/1871/1717

5. http://rsta.royalsocietypublishing.org/content/366/1871/1849

7. http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html

[[Category:Notable Scientists]]

Philipp Lenard

2015-12-04T17:50:36Z

Vbalayan3:

Written by Vanshika Balayan

Living from June 7th, 1862 to May 20th, 1879, Philipp Eduard Anton von Lenard was a German scientist who studied the physics behind cathode rays.[http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/lenard-bio.html]

[[File:lenard.jpg|thumb|Philipp Eduard Anton von Lenardl.]]

==Personal Life==

Lenard was a nationalist and a known ant-Semite. He was an active proponent of Nazi ideology and was an important role model for the "Deutsche Physik" movement

===Life and Education===

Philip was born in Bratislava (Hungary), on 7 June, 1862. His family originated from Tyrol and were German speakers. Philipp von Lenardis, his farther, was a wine merchant in Pressburg and his mother's name was Antonie Baumann. Philipp attended the 'A Pozsonyi királyi katholikus fögymnasium´, which really had a big effect on him and made him want to pursue the sciences during his tertiary education. He then studied physics and chemistry in Vienna and Budapest in 1880. After receiving his doctorate and working under different scientists for a good bit of time, he moved to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute. The year 1905 brought him membership to the Royal Swedish Academy of Sciences and 1907 brought him membership at the Hungarian Academy of Sciences. [http://theconversation.com/when-science-gets-ugly-the-story-of-philipp-lenard-and-albert-einstein-43165]

==Work==

===Photoelectric Findings===

In 1888, Lenard began his study of cathode rays, which is where he made his biggest contributions. Lenard devised a method that made small metallic windows in the glass tubes that had allowed him to pass the rays emitted from the cathode into the laboratory or into an evacuated chamber. These windows were named "Lenard windows".
The creation of these windows then helped him observe the absorption of the rays. He saw that the absorption of the rays was proportional to the density of the material they were made to pass through. This contradicted the previous notional that cathode rays were some type of electromagnetic radiation. Additionally, Lenard saw that the rays appeared to be scattered by air after a short period of time, thus implying that cathode rays were negatively charged energetic particles. He called these quanta. This helped all physicists realize that electrons are constituent parts of an atom and that atoms mostly consist of empty space.

Lenard's most important observation was that the energy of a cathode ray is independent of the light intensity, but was greater for shorter wavelengths of light. These observations were then further explained by Albert Einstein in what he called the quantum effect. This theory showed that the energy of a cathode ray should be directly proportional to frequency by a factor of Planck's constant, h.

Lenard actually ended up being a skeptic of Einstein's theories. However, he never went against Einstein's explanation of the photoelectric effect.

[[File:cathode.jpg|thumb|A Crooke's tube. The cathode rays travel in straight lines from the cathode (shown on the left) and strike the wall of the tube (shown on the right), which then makes it glow by fluorescence.]]

===ElectroMagnetism===

In the 19th century, the connection between electricity and magnets was studied fervently by European scientists after the work of Hans Christian Oersted, Jean-Baptiste Biot and Félix Savart highlighted this connection. All of these scientists provided support for Maxwell's work, but [[Michael Faraday]] provided the most inspiration for Maxwell in his studies. However, Maxwell differed from Faraday in that he looked at the mathematical aspect of his research in addition to the physical aspects.

Maxwell's first step towards his electromagnetic theory was in his paper ''On Faraday's lines of force'' (1864), in which he proposed the idea of an incompressible fluid, the flow lines of which could represent the electric or magnetic field or current flow [http://rsta.royalsocietypublishing.org/content/366/1871/1849]. Here he explained that, in the case of electric fields, sources of the flow lines were positive charges and sinks were negative charges. In his subsequent paper, Maxwell introduced the idea of vortices, small, elastic objects that occupy space and have a small mass. Using this idea, he was able to derive Ampère's circuital law and to provide an explanation of Faraday's law of induction. In his model, these vortices were able to move in a conductor, but not in a dielectric (insulator). However, in a dielectric, the vortices can shift slightly due to an electric field.

===Equations===

In a paper titled ''A dynamical theory of the electromagnetic field'', Maxwell strove to make his theories more mathematical and less analogical. His four equations that resulted from this are as follows.

1. Gauss' law for electricity: <math> \oint \overrightarrow{E} \bullet d \overrightarrow{A} = \frac{q} {\epsilon_0}</math>

2. Gauss' law for magnetism: <math> \oint \overrightarrow{B} \bullet d \overrightarrow{A} = 0</math>

3. Faraday's law of induction: <math> \oint \overrightarrow{E} \bullet \overrightarrow{d s} = -\frac{d \Phi} {dt} </math>

4. Ampere's law: <math> \oint \overrightarrow{B} \bullet \overrightarrow{d s} = \mu_0i + \frac{1} {c^2} \frac{\partial} {\partial t} \int \overrightarrow{E} \bullet d \overrightarrow{A}</math>

==Use by Other Scientists==

Albert Einstein once said "The special theory of relativity owes its origins to Maxwell's equations of the electromagnetic field."[http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html] Einstein was said to have a picture of Maxwell on his wall in his study. [http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html]

== See also ==

Other famous scientists relating to Maxwell include:

[[Michael Faraday]]

[[Andre Marie Ampere]]

[[Albert Einstein]]

[[Edwin Hall]]

==References==

1. https://en.wikipedia.org/wiki/Rings_of_Saturn#Maxwell_Gap_and_Ringlet

2. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

3. http://www.biography.com/people/james-c-maxwell-9403463#saturns-rings

4. http://rsta.royalsocietypublishing.org/content/366/1871/1717

5. http://rsta.royalsocietypublishing.org/content/366/1871/1849

7. http://inthemindseyedyslexicrenaissance.blogspot.com/2009/08/thinking-in-pictures-einstein-and.html

[[Category:Notable Scientists]]

2015-12-03T18:36:13Z

Vbalayan3: /* Notable Scientists */

__NOTOC__
Welcome to the Georgia Tech Wiki for Intro Physics. This resources was created so that students can contribute and curate content to help those with limited or no access to a textbook. When reading this website, please correct any errors you may come across. If you read something that isn't clear, please consider revising it!

Looking to make a contribution?
#Pick a specific topic from intro physics
#Add that topic, as a link to a new page, under the appropriate category listed below by editing this page.
#Copy and paste the default [[Template]] into your new page and start editing.

Please remember that this is not a textbook and you are not limited to expressing your ideas with only text and equations. Whenever possible embed: pictures, videos, diagrams, simulations, computational models (e.g. Glowscript), and whatever content you think makes learning physics easier for other students.

== Source Material ==
All of the content added to this resource must be in the public domain or similar free resource. If you are unsure about a source, contact the original author for permission. That said, there is a surprisingly large amount of introductory physics content scattered across the web. Here is an incomplete list of intro physics resources (please update as needed).
* A physics resource written by experts for an expert audience [https://en.wikipedia.org/wiki/Portal:Physics Physics Portal]
* A wiki book on modern physics [https://en.wikibooks.org/wiki/Modern_Physics Modern Physics Wiki]
* The MIT open courseware for intro physics [http://ocw.mit.edu/resources/res-8-002-a-wikitextbook-for-introductory-mechanics-fall-2009/index.htm MITOCW Wiki]
* An online concept map of intro physics [http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html HyperPhysics]
* Interactive physics simulations [https://phet.colorado.edu/en/simulations/category/physics PhET]
* OpenStax algebra based intro physics textbook [https://openstaxcollege.org/textbooks/college-physics College Physics]
* The Open Source Physics project is a collection of online physics resources [http://www.opensourcephysics.org/ OSP]
* A resource guide compiled by the [http://www.aapt.org/ AAPT] for educators [http://www.compadre.org/ ComPADRE]

== Organizing Categories ==
These are the broad, overarching categories, that we cover in two semester of introductory physics. You can add subcategories or make a new category as needed. A single topic should direct readers to a page in one of these catagories.

<div class="toccolours mw-collapsible mw-collapsed">
===Interactions===
<div class="mw-collapsible-content">
*[[Kinds of Matter]]
**[[Ball and Spring Model of Matter]]
*[[Detecting Interactions]]
*[[Fundamental Interactions]]
*[[Determinism]]
*[[System & Surroundings]]
*[[Newton's First Law of Motion]]
*[[Newton's Second Law of Motion]]
*[[Newton's Third Law of Motion]]
*[[Gravitational Force]]
*[[Electric Force]]
*[[Conservation of Energy]]
*[[Conservation of Charge]]
*[[Terminal Speed]]
*[[Simple Harmonic Motion]]
*[[Speed and Velocity]]
*[[Electric Polarization]]
*[[Perpetual Freefall (Orbit)]]
*[[2-Dimensional Motion]]
*[[Center of Mass]]
*[[Reaction Time]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Theory===
<div class="mw-collapsible-content">
*[[Einstein's Theory of Special Relativity]]
*[[Quantum Theory]]
*[[Big Bang Theory]]
*[[Maxwell's Electromagnetic Theory]]
*[[Atomic Theory]]
*[[String Theory]]
*[[Elementary Particles and Particle Physics Theory]]
*[[Law of Gravitation]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Notable Scientists===
<div class="mw-collapsible-content">
*[[Christian Doppler]]
*[[Albert Einstein]]
*[[Ernest Rutherford]]
*[[Joseph Henry]]
*[[Michael Faraday]]
*[[J.J. Thomson]]
*[[James Maxwell]]
*[[Robert Hooke]]
*[[Carl Friedrich Gauss]]
*[[Nikola Tesla]]
*[[Andre Marie Ampere]]
*[[Sir Isaac Newton]]
*[[J. Robert Oppenheimer]]
*[[Oliver Heaviside]]
*[[Rosalind Franklin]]
*[[Erwin Schrödinger]]
*[[Enrico Fermi]]
*[[Robert J. Van de Graaff]]
*[[Charles de Coulomb]]
*[[Hans Christian Ørsted]]
*[[Philo Farnsworth]]
*[[Niels Bohr]]
*[[Georg Ohm]]
*[[Galileo Galilei]]
*[[Gustav Kirchhoff]]
*[[Max Planck]]
*[[Heinrich Hertz]]
*[[Edwin Hall]]
*[[James Watt]]
*[[Count Alessandro Volta]]
*[[Josiah Willard Gibbs]]
*[[Richard Phillips Feynman]]
*[[Sir David Brewster]]
*[[Daniel Bernoulli]]
*[[William Thomson]]
*[[Leonhard Euler]]
*[[Robert Fox Bacher]]
*[[Stephen Hawking]]
*[[Amedeo Avogadro]]
*[[Wilhelm Conrad Roentgen]]
*[[Pierre Laplace]]
*[[Thomas Edison]]
*[[Hendrik Lorentz]]
*[[Jean-Baptiste Biot]]
*[[Lise Meitner]]
*[[Lisa Randall]]
*[[Felix Savart]]
*[[Heinrich Lenz]]
*[[Max Born]]
*[[Archimedes]]
*[[Jean Baptiste Biot]]
*[[Carl Sagan]]
*[[Eugene Wigner]]
*[[Marie Curie]]
*[[Pierre Curie]]
*[[Werner Heisenberg]]
*[[Johannes Diderik van der Waals]]
*[[Louis de Broglie]]
*[[Aristotle]]
*[[Émilie du Châtelet]]
*[[Blaise Pascal]]
*[[Benjamin Franklin]]
*[[James Chadwick]]
*[[Henry Cavendish]]
*[[Thomas Young]]
*[[James Prescott Joule]]
*[[John Bardeen]]
*[[Leo Baekeland]]
*[[Alhazen]]
*[[Willebrod Snell]]
*[[Johannes Kepler]]
*[[Johann Wilhelm Ritter]]
*[[Philipp Lenard]]

</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Properties of Matter===
<div class="mw-collapsible-content">
*[[Mass]]
*[[Velocity]]
*[[Relative Velocity]]
*[[Density]]
*[[Charge]]
*[[Spin]]
*[[SI Units]]
*[[Heat Capacity]]
*[[Specific Heat]]
*[[Wavelength]]
*[[Conductivity]]
*[[Malleability]]
*[[Weight]]
*[[Boiling Point]]
*[[Melting Point]]
*[[Inertia]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Contact Interactions===
<div class="mw-collapsible-content">
* [[Young's Modulus]]
* [[Friction]]
* [[Tension]]
* [[Hooke's Law]]
*[[Centripetal Force and Curving Motion]]
*[[Compression or Normal Force]]
* [[Length and Stiffness of an Interatomic Bond]]
* [[Speed of Sound in a Solid]]
* [[Iterative Prediction of Spring-Mass System]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Momentum===
<div class="mw-collapsible-content">
* [[Vectors]]
* [[Kinematics]]
* [[Conservation of Momentum]]
* [[Predicting Change in multiple dimensions]]
* [[Derivation of the Momentum Principle]]
* [[Momentum Principle]]
* [[Impulse Momentum]]
* [[Curving Motion]]
* [[Multi-particle Analysis of Momentum]]
* [[Iterative Prediction]]
* [[Analytical Prediction]]
* [[Newton's Laws and Linear Momentum]]
* [[Net Force]]
* [[Center of Mass]]
* [[Momentum at High Speeds]]
* [[Change in Momentum in Time for Curving Motion]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Angular Momentum===
<div class="mw-collapsible-content">
* [[The Moments of Inertia]]
* [[Moment of Inertia for a ring]]
* [[Rotation]]
* [[Torque]]
* [[Systems with Zero Torque]]
* [[Systems with Nonzero Torque]]
* [[Right Hand Rule]]
* [[Angular Velocity]]
* [[Predicting the Position of a Rotating System]]
* [[Translational Angular Momentum]]
* [[The Angular Momentum Principle]]
* [[Angular Momentum of Multiparticle Systems]]
* [[Rotational Angular Momentum]]
* [[Total Angular Momentum]]
* [[Gyroscopes]]
* [[Angular Momentum Compared to Linear Momentum]]

</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Energy===
<div class="mw-collapsible-content">
*[[The Photoelectric Effect]]
*[[Photons]]
*[[The Energy Principle]]
*[[Predicting Change]]
*[[Rest Mass Energy]]
*[[Kinetic Energy]]
*[[Potential Energy]]
**[[Potential Energy for a Magnetic Dipole]]
**[[Potential Energy of a Multiparticle System]]
*[[Work]]
*[[Thermal Energy]]
*[[Conservation of Energy]]
*[[Electric Potential]]
*[[Energy Transfer due to a Temperature Difference]]
*[[Gravitational Potential Energy]]
*[[Point Particle Systems]]
*[[Real Systems]]
*[[Spring Potential Energy]]
**[[Ball and Spring Model]]
*[[Internal Energy]]
**[[Potential Energy of a Pair of Neutral Atoms]]
*[[Translational, Rotational and Vibrational Energy]]
*[[Franck-Hertz Experiment]]
*[[Power (Mechanical)]]
*[[Transformation of Energy]]

*[[Energy Graphs]]
*[[Air Resistance]]
*[[Electronic Energy Levels]]
*[[Second Law of Thermodynamics and Entropy]]
*[[Specific Heat Capacity]]
*[[Electronic Energy Levels and Photons]]
*[[Energy Density]]
*[[Bohr Model]]
*[[Quantized energy levels]]
*[[Path Independence of Electric Potential]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Collisions===
<div class="mw-collapsible-content">
*[[Collisions]]
*[[Maximally Inelastic Collision]]
*[[Elastic Collisions]]
*[[Inelastic Collisions]]
*[[Head-on Collision of Equal Masses]]
*[[Head-on Collision of Unequal Masses]]
*[[Frame of Reference]]
*[[Rutherford Experiment and Atomic Collisions]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Fields===
<div class="mw-collapsible-content">
* [[Electric Field]] of a
** [[Point Charge]]
** [[Electric Dipole]]
** [[Capacitor]]
** [[Charged Rod]]
** [[Charged Ring]]
** [[Charged Disk]]
** [[Charged Spherical Shell]]
** [[Charged Cylinder]]
** [[Charge Density]]
**[[A Solid Sphere Charged Throughout Its Volume]]
*[[Electric Potential]]
**[[Potential Difference Path Independence]]
**[[Potential Difference in a Uniform Field]]
**[[Potential Difference of point charge in a non-Uniform Field]]
**[[Sign of Potential Difference]]
**[[Potential Difference in an Insulator]]
**[[Energy Density and Electric Field]]
** [[Systems of Charged Objects]]
*[[Electric Force]]
*[[Polarization]]
**[[Polarization of an Atom]]
*[[Charge Motion in Metals]]
*[[Charge Transfer]]
*[[Magnetic Field]]
**[[Right-Hand Rule]]
**[[Direction of Magnetic Field]]
**[[Magnetic Field of a Long Straight Wire]]
**[[Magnetic Field of a Loop]]
**[[Magnetic Field of a Solenoid]]
**[[Bar Magnet]]
**[[Magnetic Dipole Moment]]
***[[Stern-Gerlach Experiment]]
**[[Magnetic Force]]
**[[Earth's Magnetic Field]]
*[[Combining Electric and Magnetic Forces]]
**[[Magnetic Torque]]
**[[Hall Effect]]
**[[Lorentz Force]]
**[[Biot-Savart Law]]
**[[Biot-Savart Law for Currents]]
**[[Integration Techniques for Magnetic Field]]
**[[Sparks in Air]]
**[[Motional Emf]]
**[[Detecting a Magnetic Field]]
**[[Moving Point Charge]]
**[[Non-Coulomb Electric Field]]
**[[Motors and Generators]]
**[[Solenoid Applications]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Simple Circuits===
<div class="mw-collapsible-content">
*[[Components]]
*[[Steady State]]
*[[Non Steady State]]
*[[Charging and Discharging a Capacitor]]
*[[Thin and Thick Wires]]
*[[Node Rule]]
*[[Loop Rule]]
*[[Resistivity]]
*[[Power in a circuit]]
*[[Ammeters,Voltmeters,Ohmmeters]]
*[[Current]]
**[[AC]]
*[[Ohm's Law]]
*[[Series Circuits]]
*[[Parallel Circuits]]
*[[RC]]
*[[AC vs DC]]
*[[Charge in a RC Circuit]]
*[[Current in a RC circuit]]
*[[Circular Loop of Wire]]
*[[Current in a RL Circuit]]
*[[RL Circuit]]
*[[LC Circuit]]
*[[Surface Charge Distributions]]
*[[Feedback]]
*[[Transformers (Circuits)]]
*[[Resistors and Conductivity]]
*[[Semiconductor Devices]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Maxwell's Equations===
<div class="mw-collapsible-content">
*[[Gauss's Flux Theorem]]
**[[Electric Fields]]
**[[Magnetic Fields]]
*[[Ampere's Law]]
**[[Magnetic Field of Coaxial Cable Using Ampere's Law]]
**[[Magnetic Field of a Long Thick Wire Using Ampere's Law]]
**[[Magnetic Field of a Toroid Using Ampere's Law]]
*[[Faraday's Law]]
**[[Curly Electric Fields]]
**[[Inductance]]
***[[Transformers from a physics standpoint]]
***[[Energy Density]]
**[[Lenz's Law]]
***[[Lenz Effect and the Jumping Ring]]
**[[Motional Emf using Faraday's Law]]
*[[Ampere-Maxwell Law]]
*[[Superconductors]]
**[[Meissner effect]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Radiation===
<div class="mw-collapsible-content">
*[[Producing a Radiative Electric Field]]
*[[Sinusoidal Electromagnetic Radiaton]]
*[[Lenses]]
*[[Energy and Momentum Analysis in Radiation]]
**[[Poynting Vector]]
*[[Electromagnetic Propagation]]
**[[Wavelength and Frequency]]
*[[Snell's Law]]
*[[Effects of Radiation on Matter]]
*[[Light Propagation Through a Medium]]
*[[Light Scaterring: Why is the Sky Blue]]
*[[Light Refraction: Bending of light]]
*[[Cherenkov Radiation]]
</div>
</div>
<div class="toccolours mw-collapsible mw-collapsed">

===Sound===
<div class="mw-collapsible-content">
*[[Doppler Effect]]
*[[Nature, Behavior, and Properties of Sound]]
*[[Resonance]]
*[[Sound Barrier]]
</div>
</div>
<div class="toccolours mw-collapsible mw-collapsed">

===Waves===
<div class="mw-collapsible-content">
*[[Multisource Interference: Diffraction]]
*[[Standing waves]]
*[[Gravitational waves]]
*[[Wave-Particle Duality]]
*[[Electromagnetic Waves]]
*[[Electromagnetic Spectrum]]
*[[Color Light Wave]]
*[[Mechanical Waves]]
*[[Pendulum Motion]]
</div>
</div>
<div class="toccolours mw-collapsible mw-collapsed">

===Real Life Applications of Electromagnetic Principles===
<div class="mw-collapsible-content">
*[[Electromagnetic Junkyard Cranes]]
*[[Maglev Trains]]
*[[Spark Plugs]]
*[[Metal Detectors]]
*[[Speakers]]
</div>
</div>

== Resources ==
* Commonly used wiki commands [https://en.wikipedia.org/wiki/Help:Cheatsheet Wiki Cheatsheet]
* A guide to representing equations in math mode [https://en.wikipedia.org/wiki/Help:Displaying_a_formula Wiki Math Mode]
* A page to keep track of all the physics [[Constants]]
* An overview of [[VPython]], [http://www.physicsbook.gatech.edu/VPython_basics beginner guide to VPython]