Alchemy becomes Chemistry

New Tools:

Fahrenheit thermometer

Joseph Black(1728 – 1799)

* Assisted by James Watt

* As ice melts, the temperature remains the same

Fixed Air

Combinedacid and limestone

CO2

Carbon dioxide

“Soda water”

Why do Things Burn?

Terra Pinguis -- Johann Becher

Phlogiston-- Georg Stahl

Joseph Priestley(1733 – 1804)

Unitarian minister

Invented the eraser

Lived next to brewery

Priestley’s mouse

Antoine-Laurent Lavoisier(1743 – 1794)

Conservation of mass

“Oxygène”(water maker)

Death of Phlogiston

Mercury oxide + heat -> mercury metal + ??

Henry Cavendish(1731 – 1810)

Factitious Air:flammableH2

Air -> NxOy

Thus air is composed Of nitrogen & oxygen

John Dalton(1766 – 1844)

Quaker schoolmaster

Reintroduced the Atom

Dalton’s LawpT = Σpi

Dalton’s Contributions

Elements composed of atoms

Many types of atoms

Different combinations =different compounds

Atomic weight scale

Compounds

Water Hydrogen peroxideH2O H2O2

Compounds

Nitrous oxide Nitrogen Dioxide N2O NO2

Humphrey Davy(1778 – 1829)

Used electricalcurrents to act uponchemicals

DiscoveredNa, Ba, K, Ca,Mg, F

Similar Elements

Johann Dobereiner

“Triads”

Coinage Metals

Cu, Ag, Au

Mendeleev & Meyer

1868/1869Both publishedVersions of aPeriodic table

Mendeleev’s version

Left blank spaces for undiscovered elements

E.g. Germanium 1886

Modern Periodic Table

Humphrey Davy(1778 – 1829)

Used electricalcurrents to act uponchemicals

DiscoveredNa, Ba, K, Ca,Mg, F

Elektron

InvisibleFluid???

Electricity

Pieter van Musschenbroek

Leyden Jar

Benjamin Franklin

Charles Couloumb(1736 – 1806)

Inverse square law 1

Charge ≈ (distance)2

Luigi Galvani(1737 – 1798)

“Animal Electricity”

Metal + frog leg

Electricity & Life

Electricity & Life

Alessandro Volta(1745 – 1827)

Voltaic Pile First Battery

Thermodynamics

Heat <-> Mechanical Force <-> Electricity

ENERGY

Count Rumford

“Caloric”

Rumford Inventions

James Joule

Interconversionof Energy forms

Gravity Heat

Rudolf Clausius

Heat dissipates

Entropy

Herman van Helmholtz

Conservation of EnergyNo energy lost in muscle movement

Helmholtz Coils

Electromagnetic Fields

Ørsted

Electrical currentaffects compass

Ampère

Solenoid

Ammeter

Michael Faraday

Magnetism <-> Electricity

Transformerelectrical current generatesmagnetic field

Electromagnetic Radiation

James Clerk Maxwell

Waves move at the speed of light

Electromagnetic Radiation

New Worlds of Astronomy

Wilhelm Herschel

Discovered “comet” 1781

First “Modern” Planet

Observed by Galileo?

Also discovered Uranianmoons

Planet Fever

Titius-Bode Law ( n + 4)

AU = 10

planet n Titius-Bode

Actual

Mercury 0 0.4 0.39

Venus 3 0.7 0.72

Earth 6 1.0 1.0

Mars 12 1.6 1.52

24 2.8 2.8

Jupiter 48 5.2 5.2

Saturn 96 10.0 9.54

Uranus fits the pattern!

planet n Titius-Bode Actual

Mercury 0 0.4 0.39

Venus 3 0.7 0.72

Earth 6 1.0 1.0

Mars 12 1.6 1.52

24 2.8 2.8

Jupiter 48 5.2 5.2

Saturn 96 10.0 9.54

Uranus 192 19.6 19.2

Piazzi (1801)

Palermo Catalogueof Stars

Comet?

New planet: Ceres

Asteroids

1802: Pallas

1804: Juno

1807: Vesta

Asteroid Belt

Uranus’ orbit

Neptune

Leverrier/Adams

Viewed by Gallewithin 1° of prediction

Vulcan?

Leverrier 1860

Parallax

Bessel

Messier catalog

To distinguishknown nebulae

& galaxies

Messier 64

Gustav Kirchoff

Identified thecomposition of

the Sun

Discovered Helium, Neon, Argon

The Beginnings of Modern Medicine

Life expectancy 35 – 39 years

Anesthesia

Before 1800

opiumalcoholmandrake root wine

Modern Anesthesia

Humphrey Davynitrous oxideN2O aka laughing gas

Ether Frolics

Crawford Long1842diethyl ether

Horace Wells

First dentist touse general anesthesia(N2O)

addict

James Young Simpson

Chloroform

Queen Victoriachose to use itfor 1853 childbirth

Pain Killers

Opiates

Laudanum (Paracelsus)

Sydenham

Cocaine

Albert Nieman(1859) isolatedcompound fromcoca leaves

1885 Merck

Original formulation ofCoca - Cola

Synthetic painkillers

Alfred Einhorn(1899)Novocaine

Other compounds:BenzocaineLidocaine

Synthetic Painkillers

Morphine (1804)Friedrich Wilhelm Adam Sertürner

First alkaloid isolated

High addiction rate

Heroin

Diacetyl morphine(1874)

Bayer (1895):Commercial preparation

Antisepsis

Puerperal (Childbed) fever

Ignaz Semmelweis1847: wash hands!

Crimean War

Florence Nightingale1854

Mortality rate40% -> 2%

Antiseptics

Joseph Lister

Carbolic Acid(Phenol)made from coal tar

What Causes Disease?

Miasma

Girolamo Fracastrodisease “seeds”

Variolation

Deliberate administration ofsmallpox particles

Milkmaids & Cowpox

Vaccination

Edward Jenner

Germ Theory of Disease

Louis Pasteur

Disproved “spontaneousgeneration”

Pasteurization

Quick heatingkills majorityof bacteria

Robert Koch

Isolated Anthrax, Tuberculosis

bacteria

Koch’s Postulates (1879)

Biological Scientific Revolution

Paralleled the Copernican controversy

Religion and Science

Questioning long heldbeliefs

Darwin’s Background

Linnaeus

Lamarck

Malthus

“Survival of the Fittest”

Population growthwill overwhelmfood resources

Neanderthals

1856:New species

Or

Deformed human

Erasmus Darwin

Lunar Society member

Physician

Zoonomia: “all warm-blooded animals have arisen from one living filament”

HMS Beagle

1831 – 1836

Survey/mapping

Galapagos Islands

His Discoveries

Giant Armadillo

Coastal vs. Islandspecies

Finches

Similar nests, eggscalls

Different beak sizes

Dog & Pigeon Breeding

Best equipped -> breed more

Alfred Russell Wallace

1858:"Contributions to the Theory of Natural Selection”

“a deficiency in one set of organs always being compensated by an increased development of some others--powerful wings accompanying weak feet”

Based on visits to Malaysiaand South America

Origin of Species (1859)

Concerns:

• Extinction• Extraordinary

traits• Similar

embryos

Pangenesis (1868)

Blended inheritance

All cells contribute

Descent of Man (1871)

Criticism:

Religious

Blending

Time scale

Gregor Mendel(1822 – 1884)

Plant hybrids

Laws ofparticulate inheritance

Genes and alleles

Mendelian Genetics

Pea plants

Varied in seed size,shape, colorplant size,flowers

Results

Dominantvs.recessive

Reproducible3:1 ratio

No yellow-green peas

Matthias Schleiden(1804 – 1881) botanist

John Goodsir(1814 – 1867)

“A nutritive centre, anatomically considered, is merely a cell, the nucleus of which is the permanent source of successive broods of young cells, which from time to time fill the cavity of their parent, and carrying with them the cell wall of the parent, pass off in certain directions, and under various forms, according to the texture or organ of which their parent forms a part. “

Chromosomes

Walther Fleming

Factors of inheritance

August Weissman(1834 – 1914)

Germ plasm

Heredity =½ of each parent

Nettie Stevens(1861 – 1912)

Two types ofchromosomes:

X and Y

Hertwig & Fol

First observed sperm/egg

Nuclear fusionin sea urchins

Thomas Hunt Morgan(1866 – 1945)

Used fruit flies(Drosophila)to show gene crossover

1933 Nobel prize

Gene Crossover

Non reciprocaltransfer of genetic information

Miescher’s Bandages

Isolated from white blood cells

Not protein

“Nuclein”

DNA: Same within Species

Erwin Chargraff

But variations betweendifferent species

Deoxyribonucleic acid

Double Helix

Elimination of the Ether

Newton:“universal medium of propagation

Michelson-Morley Experiment Interferometer:

Experimentintended to measure ether

The Speed of Light

Michelson: 299,796 ± 4 km/s

The New Atom

JJ Thompson (*1897)

Cathode rays = electrons

The Plum Pudding model

Random assortmentof positively charged protons and negativelycharged electrons

But. . . Don’t opposite charges attract?

Rutherford’s experiment

Ernest Rutherford

Planetary Model of the Atom

Protons in the nucleus

Electrons orbiting

X-rays

Wilhelm Röntgen

Radioactivity

Henri Becquerel

Radioactive Elements

Marie Skłodowskaand Pierre Curie

Radioactive Products

Radioactive Decay

Isotope Half LifeU - 238 4.5 x 109

yearsPu - 239 24,360 yearsC - 14 5730 years

Co - 60 5.3 yearsI - 131 8 days

Po - 214 1.63 x 10-4 sec

Relativity

Albert Einstein

€

γ = 1

1 - β 2 where β =

v

c

Relativistic Effects

Length Contraction

Time Dilation

The Atomic Age

E = mc2