Modern Physics Timeline

7/30/2019 Modern Physics Timeline

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Mode

Phys

Ma. Jennelyn Callope Jesusa Mae Carballo Jhetro Arthur C

A Ride Through


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Modern Physics Defin

Modern physics is the interpretatioextension of physics in light of key

which happened about 1990. The

modern physics is not synonymoucontemporary physics but rather im

viewpoint in contrast with that of pr

classical physics.


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1895

WilhelmConrad

Roentgen

discovers

X-rays


4/34

1897Joseph John

Thomsonmeasures

the charge to

mass ratio of

the electron

e/m = 1.75882 x 108

C/g


5/34

1909Robert

AndrewsMillikan

measures

electron

charge


6/34

Millikan OIL drop EXPERIM


7/34

1898Ernest

Rutherforddiscovers

alpha and

beta

radiation


8/34

1910Ernest

Rutherfordand his team

performs

alpha-

scattering

experiment


9/34

RUTHERFORD SCATTERING EXPER


10/34

1911Ernest

Rutherford

discovers the

nucleus of

the atom


11/34

1919Rutherford and

James Chadwick

observed theproton as a

particle that is

emitted by

bombardment of

certain atoms

with -particles

C

ide


12/34

1932Werner

Heisenberg

proposes thatthe nucleus of

an atom is

composed of

protons and

neutrons


13/34

1901Max Planck

makes hisquantum

hypothesis,

called

Planck's Law


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PHOTOELECTRIC EFFEC

When light of a sufficiently high energy

electrons are knocked off its surface. They

positive electrode and form a current flowing

The important observations follow.

1. Electrons can be ejected only if the ligh

short wavelength (has sufficiently high energ

long or how brightly the light shines. This different for different metals.

2. The current (the number of electrons em

increases with increasing brightness (intensit

current, however, does not depend on the co

long as the wavelength is short enough

energy).


16/34

1905Einstein

postulatesthe

equivalence

of mass and

energy

E = mc2


17/34

1905Einstein

publishes his

Special

Theory of

Relativity

Special Theory of Relativity deals with

things moving near or at the speed of

light (systems that are not

accelerating).

1. The laws of physics are the same inall inertial (=non-accelerating)

reference frames.

2. 2. The speed of light in free space is

constant.

pu

T

General Theory of Relativity deals with

observers in any state of uniform motion

including relative acceleration. Also

known as Theory of Gravitation, it

determined that massive objects cause a

distortion in space-time, which is felt as

gravity.


18/34

1912William

Bragg showsthat X-rays

scatter off

crystal

lattices


19/34

1913Neils Bohr

proposes his

quantum

theory of

atomic orbits


20/34

1923Louis Victor de

Broglieproposes the

particle-wave

duality of the

electron


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1925Max Born and

WernerHeisenberg

introduce

quantum

mechanics

Sdeme

m

1926Werner

Heisenbergdevelops matrix

mechanics, the

first quantum

mechanical

theory


22/34

1927Werner

Heisenberg

publishes his

Uncertainty

Principle

The ex

of an

withinnucleu

time co

know

certaintstat

calculat

prob


23/34

1928Paul Dirac

predicts thediscovery of

the positron

and

antimatter


24/34

1929Edwin Hubble

observes the

redshift ofdistant

galaxies and

concludes that

the Universe is

expanding

The Doppler Redshift results from t

motion of the light emitting objec

observer. If the source of light is moving

you then the wavelength of the light iout, i.e., the light is shifted towards the r

The Cosmological Redshift is a redshift

the expansion of space. The waveleng

increases as it traverses the expandinbetween its point of emission and it

detection by the same amount that

expanded during the crossing time.


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REDSHIFT


26/34

1933Astrophysicist

Fritz Zwicky

infers

existence of

dark matter

Va

th

of


27/34

1935Physicist

Subramahnyan

Chandrasekhar

predicts black

holes


28/34

1938Lise Meitner

and Otto Frischsuccessfully

diagnosed the

occurrence of

nuclear fission


29/34

1942Enrico Fermi

obtains thefirst self

sustaining

fission

reaction


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1953

Murray Gell-Mann lays

foundation

for the quark

V

mo


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NEW MILLENIUM

C

E

RN


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Nuclear Research


33/34

NEW MILLENIUM

Stephen Hawking

Higgs Boson;


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Thank

You

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