The nature of …and a history of our attempt to understand it.
-
Upload
pauline-hamilton -
Category
Documents
-
view
213 -
download
0
Transcript of The nature of …and a history of our attempt to understand it.
![Page 1: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/1.jpg)
The nature of
…and a history of our attempt to understand it.
![Page 2: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/2.jpg)
Early 1600’sGalileo and the speed of light…
Image and info acquired at http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html through www.google.com.
People were saying in the early 1600’s that it took no time for light to travel any distance (speed of light = infinite). Galileo thought otherwise.
![Page 3: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/3.jpg)
Early 1600’sGalileo and the speed of light…
Image and info acquired at http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html through www.google.com.
People were saying in the early 1600’s that it took no time for light to travel any distance (speed of light = infinite). Galileo thought otherwise.
![Page 4: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/4.jpg)
Early 1600’sGalileo and the speed of light…
Image and info acquired at http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html through www.google.com.
People were saying in the early 1600’s that it took no time for light to travel any distance (speed of light = infinite). Galileo thought otherwise.
Unfortunately for Galileo, light travels a mile in about .000005 s.
![Page 5: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/5.jpg)
Images acquired at http://en.wikipedia.org/wiki/Olaus_Romer, and http://hubblesite.org/newscenter/newsdesk/archive/releases/1996/30/ through www.google.com.
1676 and Olaus Rømer…
Rømer was a Danish astronomer who spent some time observing the motion of Io, one of Jupiter’s moons. He noticed that some of Io’s eclipses appeared earlier or later than expected.
![Page 6: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/6.jpg)
Images acquired at http://en.wikipedia.org/wiki/Olaus_Romer, and http://hubblesite.org/newscenter/newsdesk/archive/releases/1996/30/ through www.google.com.
1676 and Olaus Rømer…
Rømer was a Danish astronomer who spent some time observing the motion of Io, one of Jupiter’s moons. He noticed that some of Io’s eclipses appeared earlier or later than expected. Then he realized that this was because of the Earth’s position. (see sketch)
![Page 7: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/7.jpg)
Images acquired at http://en.wikipedia.org/wiki/Olaus_Romer, and http://hubblesite.org/newscenter/newsdesk/archive/releases/1996/30/ through www.google.com.
1676 and Olaus Rømer…
Rømer was a Danish astronomer who spent some time observing the motion of Io, one of Jupiter’s moons. He noticed that some of Io’s eclipses appeared earlier or later than expected. Then he realized that this was because of the Earth’s position. (see sketch)
![Page 8: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/8.jpg)
Images acquired at http://en.wikipedia.org/wiki/Olaus_Romer, and http://hubblesite.org/newscenter/newsdesk/archive/releases/1996/30/ through www.google.com.
1676 and Olaus Rømer…
Rømer was a Danish astronomer who spent some time observing the motion of Io, one of Jupiter’s moons. He noticed that some of Io’s eclipses appeared earlier or later than expected. Then he realized that this was because of the Earth’s position. (see sketch)
Measured c to be about 220,000,000 m/s.
![Page 9: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/9.jpg)
1850 Fizeau and Foucault
Images acquired at http://laser.phys.ualberta.ca/~egerton/cðer.htm and http://geocities.yahoo.com.br/saladefisica3/ through www.google.com.
![Page 10: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/10.jpg)
1850 Fizeau and Foucault
Images acquired at http://laser.phys.ualberta.ca/~egerton/cðer.htm and http://geocities.yahoo.com.br/saladefisica3/ through www.google.com.
![Page 11: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/11.jpg)
1850 Fizeau and Foucault
Images acquired at http://laser.phys.ualberta.ca/~egerton/cðer.htm and http://geocities.yahoo.com.br/saladefisica3/ through www.google.com.
![Page 12: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/12.jpg)
1850 Fizeau and Foucault
Images acquired at http://laser.phys.ualberta.ca/~egerton/cðer.htm and http://geocities.yahoo.com.br/saladefisica3/ through www.google.com.
![Page 13: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/13.jpg)
1850 Fizeau and Foucault
Images acquired at http://laser.phys.ualberta.ca/~egerton/cðer.htm and http://geocities.yahoo.com.br/saladefisica3/ through www.google.com.
Measured c to be about 300,000,000 m/s.
![Page 14: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/14.jpg)
1704 and Isaac Newton
Image acquired at http://msp.rmit.edu.au/Article_04/02.html and http://microcosmos.uchicago.edu/microcosmos_new/newton/glassworks/ andhttp://scv.bu.edu/~aarondf/avgal.html through www.google.com.
Light is made of a bunch of little “corpuscles.” (particles)
REFRACTION
![Page 15: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/15.jpg)
1801 and Thomas Young
Images acquired at http://www.fau.edu/~jordanrg/bios/Young/Young_bio.htm and http://www.cavendishscience.org/phys/tyoung/tyoung.htm andhttp://www.museum.vic.gov.au/scidiscovery/light/index.asp and http://nobelprize.org/physics/articles/ekspong/ through www.google.com.
Light is a wave.
![Page 16: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/16.jpg)
Mid 1800’s and Michael Faraday
Experimental Researches on Electricity (1839–55)
Image and info acquired at http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0001235.html and http://dspt.club.fr/FARADAY.htm andhttp://www.cartref.demon.co.uk/eng/boe20b.jpg through www.google.com.
![Page 17: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/17.jpg)
Mid 1800’s and Michael Faraday
Experimental Researches on Electricity (1839–55)
Image and info acquired at http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0001235.html and http://dspt.club.fr/FARADAY.htm andhttp://www.cartref.demon.co.uk/eng/boe20b.jpg through www.google.com.
![Page 18: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/18.jpg)
Mid 1800’s and Michael Faraday
Experimental Researches on Electricity (1839–55)
Image and info acquired at http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0001235.html and http://dspt.club.fr/FARADAY.htm andhttp://www.cartref.demon.co.uk/eng/boe20b.jpg through www.google.com.
So, a changing magnetic field makes an electric field…
![Page 19: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/19.jpg)
Mid 1800’s and Michael Faraday
Experimental Researches on Electricity (1839–55)
Image and info acquired at http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0001235.html and http://dspt.club.fr/FARADAY.htm andhttp://www.cartref.demon.co.uk/eng/boe20b.jpg through www.google.com.
So, a changing magnetic field makes an electric field…
![Page 20: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/20.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://home.usit.net/~cmdaven/electro.htm andhttp://micro.magnet.fsu.edu/primer/java/electromagnetic/ through www.google.com.
![Page 21: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/21.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://home.usit.net/~cmdaven/electro.htm andhttp://micro.magnet.fsu.edu/primer/java/electromagnetic/ through www.google.com.
If a changing magnetic field makes an electric field (or current), wouldn’t a changing electric field make a magnetic field?
![Page 22: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/22.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://home.usit.net/~cmdaven/electro.htm andhttp://micro.magnet.fsu.edu/primer/java/electromagnetic/ through www.google.com.
If a changing magnetic field makes an electric field (or current), wouldn’t a changing electric field make a magnetic field?
![Page 23: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/23.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://home.usit.net/~cmdaven/electro.htm andhttp://micro.magnet.fsu.edu/primer/java/electromagnetic/ through www.google.com.
If a changing magnetic field makes an electric field (or current), wouldn’t a changing electric field make a magnetic field?
![Page 24: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/24.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images and quotes acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://en.wikipedia.org/wiki/Maxwell's_equations
This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to
electromagnetic laws.
![Page 25: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/25.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images and quotes acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://en.wikipedia.org/wiki/Maxwell's_equations
This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to
electromagnetic laws.
![Page 26: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/26.jpg)
James Clerk Maxwell and the 60’s (the 1860’s)
Images and quotes acquired at http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Maxwell.html and http://en.wikipedia.org/wiki/Maxwell's_equations
This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to
electromagnetic laws.
So, light must be a wave!
![Page 27: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/27.jpg)
1905--Albert Einstein and the Photoelectric Effect
Images and acquired at http://sol.sci.uop.edu/~jfalward/particlesandwaves/particlesandwaves.html
![Page 28: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/28.jpg)
1905--Albert Einstein and the Photoelectric Effect
Images and acquired at http://sol.sci.uop.edu/~jfalward/particlesandwaves/particlesandwaves.html
![Page 29: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/29.jpg)
1905--Albert Einstein and the Photoelectric Effect
Images and acquired at http://sol.sci.uop.edu/~jfalward/particlesandwaves/particlesandwaves.html
Then light is both!!! (wave and particle)
![Page 30: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/30.jpg)
1905--Albert Einstein and the Photoelectric Effect
Images and acquired at http://sol.sci.uop.edu/~jfalward/particlesandwaves/particlesandwaves.html and http://en.wikipedia.org/wiki/Albert_Einstein through www.google.com.
1921 Nobel Prize (not for Relativity!!!)
Then light is both!!! (wave and particle)
![Page 31: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/31.jpg)
In summary…
Light:• Acts like a particle• Acts like a wave• Refracts• Reflects• Diffracts• Interferes with itself• Has lots of different wavelengths (some visible)
Image acquired at http://www.mic-d.com/curriculum/lightandcolor/reflection.html through www.google.com.
![Page 32: The nature of …and a history of our attempt to understand it.](https://reader035.fdocuments.in/reader035/viewer/2022081603/56649ef15503460f94c021f7/html5/thumbnails/32.jpg)
Light Demonstrations Assignment
Your Assignment…
In your groups, prepare and perform a physics demonstration that shows the class one or more of these properties of light. Each person will write a description of the demo that contains the following:
1) A sketch of the setup with all parts labeled.
2) A list of materials required.
3) A list of steps to follow to perform the demonstration.
4) Explain which principle this demonstrates and how it demonstrates it.
Properties of light:• Acts like a particle• Acts like a wave• Refracts• Reflects• Diffracts• Interferes with itself• Has lots of different wavelengths (some visible)• Is polarized
How cool your demo is will definitely be a factor in your grade on this assignment.