Stephen Hawking was a renowned cosmologist known for his contributions to theoretical physics and his bestselling books on cosmology. He developed motor neuron disease in his early 20s but continued his scientific work despite being wheelchair-bound. Some of his major scientific works included developing the theory of black hole evaporation and penning the popular science book A Brief History of Time. Alexander Fleming discovered the antibiotic penicillin in 1928 after accidentally observing antibacterial properties in a fungus growing in one of his culture dishes. This discovery revolutionized medicine and earned him a Nobel Prize. Both men made seminal scientific contributions despite facing significant health challenges.

1. TOPIC
CONTRIBUTIONS OF:
 STEPHEN HAWKING
 ALEXANDER FLEMING

2. He is well known for his BLACK HOLE
and BIGBANG THEORY.
He is an antheist i.e., a non believer of
GOD.

3. STEPHEN HAWKING - DISABILITY
In his third year at Oxford, He noticed that he seemed to be
getting more clumsy, and he fell over once or twice for no
apparent reason. But it was not until he was at Cambridge, in
the following year, that his father noticed, and took him to the
family doctor. He was referred to a specialist, and shortly after
his 21st birthday, he went into hospital for tests. He was in for
two weeks, during which he had a wide variety of tests.
He had motor neurone disease for practically all his adult life.
Yet it has not prevented him from having a very attractive
family, and being successful in his work. He has been lucky, that
his condition has progressed more slowly than is often the case.
But it shows that one need not lose hope.

4. GROUNDBREAKING FINDINGS FROM ANOTHER YOUNG
COSMOLOGIST, ROGER PENROSE, ABOUT THE FATE OF
STARS AND THE CREATION OF BLACK HOLES TAPPED INTO
HAWKING'S OWN FASCINATION WITH HOW THE UNIVERSE
BEGAN. THIS SET HIM ON A CAREER COURSE THAT
RESHAPED THE WAY THE WORLD T HINK ABOUT BLACK
HOLES AND THE UNIVERSE.
WHILE PHYSICAL CONTROL OVER HIS BODY
DIMINISHED (HE'D BE FORCED TO USE A WHEELCHAIR
BY 1969), THE EFFECTS OF HIS DISEASE STARTED TO
SLOW DOWN. IN 1968, A YEAR AFTER THE BIRTH OF HIS
SON ROBERT, HAWKING BECAME A MEMBER O F THE
INSTITUTE OF ASTRONOMY IN CAMBRIDGE.
RESEARCH ON BLACK HOLES

5. 15 YEARS LATER,, HE PUBLISHED HIS FIRST BOOK, THE HIGHLY TECHNICAL
THE LARGE SCALE STRUCTURE OF SPACE-TIME (1973), WITH G.F.R. ELLIS.
HE ALSO TEAMED UP WITH PENROSE TO EXPAND UPON HIS FRIEND'S
EARLIER WORK.
IN 1974, HAWKING'S RESEARCH TURNED HIM INTO A CELEBRITY WITHIN THE
SCIENTIFIC WORLD WHEN HE SHOWED THAT BLACK HOLES AREN'T THE
INFORMATION VACUUMS THAT SCIENTISTS HAD THOUGHT THEY WERE. IN
SIMPLE TERMS, HAWKING DEMONSTRATED THAT MATTER, IN THE FORM OF
RADIATION, CAN ESCAPE THE GRAVITATIONAL FORCE OF A COLLAPSED STAR.
HAWKING RADIATION WAS BORN. THE ANNOUNCEMENT SENT SHOCK WAVES OF
EXCITEMENT THROUGH THE SCIENTIFIC WORLD, AND PUT HAWKING ON A PATH
THAT'S BEEN MARKED BY AWARDS, NOTORIETY AND DISTINGUISHED TITLES.

6. AS HAWKING‘ LOST HIS ABILITY TO DO WORK. THE PREDICAMENT CAUGHT THE
ATTENTION OF A CALIFORNIA COMPUTER PROGRAMMER, WHO HAD DEVELOPED
A SPEAKING PROGRAM THAT COULD BE DIRECTED BY HEAD OR EYE MOVEMENT.
THE INVENTION ALLOWED HAWKING TO SELECT WORDS ON A COMPUTER
SCREEN THAT WERE THEN PASSED THROUGH A SPEECH SYNTHESIZER. TODAY,
HAWKING DIRECTS PROGRAM THROUGH CHEEK MUSCLE ATTACHED TO SENSOR.
THROUGH THE PROGRAM, AND THE HELP OF ASSISTANTS, STEPHEN HAWKING
HAS CONTINUED TO WRITE AT A PROLIFIC RATE. HIS WORK HAS INCLUDED
NUMEROUS SCIENTIFIC PAPERS, ALSO INFORMATION FOR THE NON-SCIENTIFIC
COMMUNITY.
IN 1988 HAWKING, A RECIPIENT OF THE COMMANDER OF THE ORDER OF THE
BRITISH EMPIRE, CATAPULTED TO INTERNATIONAL PROMINENCE WITH THE
PUBLICATION OF A BRIEF HISTORY OF TIME. THE SHORT, INFORMATIVE BOOK
BECAME AN ACCOUNT OF COSMOLOGY FOR THE MASSES. IN 2001, HAWKING
FOLLOWED UP WITH THE UNIVERSE IN A NUTSHELL, WHICH OFFERED A MORE
ILLUSTRATED GUIDE TO COSMOLOGY'S BIG THEORIES. FOUR YEARS LATER, HE
AUTHORED THE EVEN MORE ACCESSIBLE A BRIEFER HISTORY OF TIME.
A BRIEF HISTORY OF TIME

7. IN 2007, AT THE AGE OF 65, HAWKING MADE AN IMPORTANT STEP
TOWARD SPACE TRAVEL. WHILE VISITING THE KENNEDY SPACE CENTER
IN FLORIDA, HE WAS GIVEN THE OPPORTUNITY TO EXPERIENCE AN
ENVIRONMENT WITHOUT GRAVITY. PICTURES OF THE FREELY FLOATING
PHYSICIST SPLASHED ACROSS NEWSPAPERS AROUND THE GLOBE.
IN 1992, OSCAR-WINNING FILMMAKER ERROL MORRIS RELEASED A
DOCUMENTARY ABOUT HAWKING'S LIFE, APTLY TITLED A BRIEF HISTORY
OF TIME.
OF COURSE, AS IT IS WITH ANY CELEBRITY, FAME HAS BROUGHT WITH IT
AN INTEREST IN HAWKING'S PERSONAL LIFE. IN 1990, HAWKING LEFT
HIS WIFE, JANE, FOR ONE OF HIS NURSES, ELAINE MASON. IN 2003,
NURSES LOOKING AFTER HAWKING REPORTED THEIR SUSPICIONS TO
POLICE THAT ELAINE WAS PHYSICALLY ABUSING HER HUSBAND.
HAWKING DENIED THE ALLEGATIONS, AND THE POLICE INVESTIGATION
WAS CALLED OFF.
SPACE TRAVEL AND FAME

8. IN 2006, HOWEVER, HAWKING AND ELAINE FILED FOR DIVORCE.
IN THE YEARS SINCE, THE PHYSICIST HAS APPARENTLY GROWN
CLOSER WITH HIS FAMILY. HE'S RECONCILED WITH JANE, WHO HAS
REMARRIED, AND PUBLISHED A 2007 SCIENCE BOOK FOR
CHILDREN, GEORGE'S SECRET KEY TO THE UNIVERSE, WITH HIS
DAUGHTER, LUCY.
IN APRIL, HAWKING, WHO HAD ALREADY ANNOUNCED HE WAS
RETIRING AFTER 30 YEARS FROM THE POST OF LUCASIAN
PROFESSOR OF MATHEMATICS AT CAMBRIDGE, WAS RUSHED TO THE
HOSPITAL FOR BEING WHAT UNIVERSITY OFFICIALS DESCRIBED AS
"GRAVELY ILL." IT WAS LATER ANNOUNCED THAT HE WAS EXPECTED
TO MAKE A FULL RECOVERY.
THE GRAND DESIGN IS HAWKING'S FIRST MAJOR PUBLICATION IN
ALMOST A DECADE. WITHIN HIS NEW WORK, HAWKING SETS OUT
TO CHALLENGE SIR ISAAC NEWTON'S BELIEF THAT THE UNIVERSE
HAD TO HAVE BEEN DESIGNED BY GOD. HIS NEW WORK,
CONCLUDES THAT THE BIG BANG WAS THE INEVITABLE
CONSEQUENCE OF THE LAWS OF PHYSICS AND NOTHING MORE.

9. STEPHEN HAWKING – HIS WORKS
 Antimatter
 The BigBang
 Black Holes
•Do Black Holes Really
Exist?
•Can Anything Escape From
a Black Hole?
 Cosmic Background Radiation
 Cosmic Rays
 Cosmological Constant
 Dark Matter
•Hot and Cold Dark Matter
•Machos
•Neutrinos
•Wimps
 E=mc2
 Gravity
 Hubble’s Law
 Imaginary Time
 Nebulae
 Planetary Motion
 Quarks
 Quasars
 Radioactivity
 Schrödinger’s Cat
 Spectroscopy and Red shift
 Singularity
 Superstrings
 Wormholes
 The Uncertainty Principle

11. AWARDS
1975 Eddington Medal
1976 Hughes Medal of the Royal Society
1979 Albert Einstein Medal
1982 Order of the British Empire (Commander)
1985 Gold Medal of the Royal Astronomical Society
1986 Member of the Pontifical Academy of Sciences
1988 Wolf Prize in Physics
1989 Prince of Asturias Awards in Concord
1989 Companion of Honour
1999 [9] Julius Edgar Lilienfeld Prize of the American Physical
Society
2003 Michelson Morley Award of Case Western Reserve University
2006 [10] Copley Medal of the Royal Society

12. He is worldly known for the invention
of penicillin.
Penicillin is an antibiotic made from
fungus named as penicillium notatum.
Structure of penicillin-

13. DISCOVERY OF LYSOZYMES
In 1922,sir Alexander had a cold when he was
working with Petri dishes with bacteria on them.
He accidentally sneezed on one of the dishes and it
was sprayed with mucus.
He was going to remove it, but he was curious to
see what would happen.
So he left the mucus on the dish and he later
examined it. Alec discovered the mucus had dissolved
the bacteria and killed it.
Sir Alexander tried the same experiment with tears.
 He studied the human and animal samples and all
the samples had the bacteria-killing substance.
He called the substance a lysozyme.

14. In 1914 sir Alexander joined
R.A.M.C.
The Royal Army Medical
Corps (RAMC) is a specialist
corps in the British Army which
provides medical services to all
British Army personnel and
their families in war and in
peace.
DURING WORLD WAR I…

17. SERENDIPITY
It means an accidental discovery.
By 1927, Fleming was investigating the properties of
staphylococci. He was already well-known from his
earlier work, and had developed a reputation as a
brilliant researcher, but his laboratory was often
untidy.
On 3 September 1928, Fleming returned to his
laboratory having spent August on holiday with his
family .
On returning, Fleming noticed that one culture was
contaminated with a fungus, and that the colonies of
staphylococci that had immediately surrounded it had
been destroyed, whereas other colonies farther away
were normal.

18. Fleming grew the mould in a pure culture and found that
it produced a substance that killed a number of disease-
causing bacteria. He identified the mould as being from the
Penicillium genus, and, after some months of calling it
"mould juice" named the substance it released penicillin on 7
March 1929.
After further experiments, Fleming was convinced that
penicillin could not last long enough in the human body to
kill pathogenic bacteria, and stopped studying it after 1931,
but restarted some clinical trials in 1934 and continued to
try to get someone to purify it until 1940.
12 years later penicillin was used in world war II and
proved to be really helpful for humans.
Soon a large acale production of penicillin began.

19. AWARDS AND
RECOGNITION..
 Memberships in 87 Scientific
Academies and Societies .
The Nobel Prize with Howard Florey
and Ernst B. Chain for Physiology or
Medicine in 1945.
 Collected 25 Honorary Degrees
 26 Medals
 18 Prizes
 13 statues
Fleming and Florey were knighted in
1944.

20. DEATH…
He dies of a heart attack in London on March the
11th 1955.
He was 73 years, 7 months and 5 days old when he
died .

21. 1.Sir
alexander
born on 8
august 1881.
3.In 1895 he
went to London
and studied at
Regent street
polytechnic.
4.In 1897 he
left the school
and worked as
a shipping
clerk.
5.In 1901
he joined
saint Mary
school.
6.In 1914 he
joined
R.A.M.C.
8.IN 1922 HE
DISCOVERED
LYSOZYMES.
9.IN 1928 HE
DISCOVERED
PENICILLIN.
7.FLEMING
MARRIED IN
1952.
10.HE
was
knighted
in 1944.
12.He was
given the noble
prize award in
1955.
13.He
died in
1955.

22. PRESENTATION BY:--
NITIN TEOTIA
SUBMITTED TO:-
Mrs. RACHNA