Light wave or particle?

21 Aug
No. Name   of Scientist Year   Place Perspective Key   ideas
1 Democritus B.C  Ancient Greece Particle theory “atoms  swarmed into the observer’s eyes”
2 Empedocles B.C Ancient Greece Wave theory “ Objects becomes visible   when touched by light rays emitted by the object”
3 Plato B.C Ancient Greece Wave theory
4 Leonardo Da Vinci 15th century Italy Wave theory “Compared the light   reflection to echo”
5 Francesco Maria Grimaldi 1665 Italy Wave theory “ Paper  published in 1665 after his death “ worked   on diffraction supporting  La Da Vinci
6 Robert Hooke  and Boyle 1665 England Wave theory “ Compared light with   water waves” explained the colours were formed on the water due to oil film
English: Validity of several theories for peri...

English: Validity of several theories for periodic water waves, according to Le Méhauté (1976). The light-blue area is the range of validity of cnoidal wave theory; light-yellow for Airy wave theory; and the dashed blue lines demarcate the required order of Stokes’ wave theory. The light-gray shading gives the range extension by numerical approximations using fifth-order stream-function theory, for high waves (H > ¼ H breaking ). (Photo credit: Wikipedia)

Light!  Wave or particle

In the end of seventeenth century saw a fierce debate about the nature of light.  Newton compared light with a stream of particles and this was accepted for reflection and refraction could be explained using this model.  He also argued that if light were waves then it would not form the sharp image of the object. (He did not realise that the light wave were too small!)

 

No. Name   of scientist Year Place Perspective Key   ideas
7  Thomas Young 1802 England Wave   theory His   double slit experiment
8 Leon   Foucault 1853 France Wave   theory His   experimental value of speed of light gave a death blow to particle theory for   it required the light to travel faster in H2O then in N2.
9 Albert   Einstein 1905 Germany Particle   theory Photo   electric effect.

The dilemma was recreated and then it was resolved only after Louis de Broglie produced his theory of wave-particle duality. He received the Nobel Prize for the world had accepted his explanation of light as being both particle and wave!

 

This new discovery gave rise to quantum mechanics.

 

 

10 Albert   Einstein 1905 Germany Particle   theory Photo   electric effect.
11 Thomson England Particle   theory Cathode   rays
12 Max   Plank 1918 Germany Quantised Radiation Black   Body Radiation
13 Louis   De Broglie 1927 France Issue resolved Crystals do show diffraction when   illuminated by electrons as confirmed independently by Davisson and Thomson.

The dilemma was recreated and then it was resolved only after Louis de Broglie produced his theory of wave-particle duality. He received the Nobel Prize for the world had accepted his explanation of light as being both particle and wave!

 

 

This new discovery gave rise to quantum mechanics.

 

 

 

 

 

 

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Lights

Lights (Photo credit: cycloctopus)

Vectors and Scalars

8 Aug
UNIQUE PICTURE: Earth as seen from the outer S...

UNIQUE PICTURE: Earth as seen from the outer Solar System (Photo credit: Icarus Kuwait)

Weight is the force of attraction due to the Earth pulling us. This is due to gravity.  Fortunately, we do not go up.  The pull of the earth is always directed to the center of the earth.  Our mass , the total quantity of the matter in our body does not change, and there is no specific direction associated with this dimension.

Physical quantities that have both magnitude and direction are known as Vectors. Scalar quantity are those that only have magnitude and no directions.

Physics 101- Base Dimensions

6 Aug

Accordoing to Lord Kelvin, any thing we are able to measure is said to a Physical quantity.  There fore, standardistion was important.  Wempe   use the SI (System International) or the International System of Units in order to standardise our measurments. Thereby, assuring that a metre of cloth is of same lenght irrespective of time and place.

The Base dimensions in Physics are Lenght, Mass, Time and this is usually taught in grade 7 or 8, later the students learn about Current, Temperature . In chemistry they are taught about mole. Lastly, the sevent base dimension the Candela.

Hello world!

6 Aug

Welcome to WordPress.com! This is your very first post. Click the Edit link to modify or delete it, or start a new post. If you like, use this post to tell readers why you started this blog and what you plan to do with it.

Happy blogging!

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