Happy Valentine’s Day

Aristotle's system of the world had the stationary Earth at the center. Above it, water, and above water, air. Above air was fire. An object's natural place in the

world was determined by its make-up. Natural motion involved solids falling to earth (the ground), liquids

flowing to bodies of water, gases flowing to the atmosphere, and fire seeking the heavens.

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The Bohr Atom is an early quantum model of atomic structure. In it, electrons can absorb specific amounts of energy from photons by jumping from

their ground state to higher energy ("excited") states. When they jump back down, the atom emits

a photon having a specific amount of energy.

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Anders Celsius is credited with developing the first centigrade temperature scale.

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Marie Curie coined the term "radioactivity" and created the theory to explain it. She won

Nobel Prizes in physics and chemistry.

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Charles Darwin's Natural Selection model of evolution was the biggest breakthrough in

biology in the nineteenth century.

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One element of Einstein's General Theory of Relativity is the concept that gravity is not a force but rather the

consequence of mass "warping" the geometry of spacetime. When "gravitational lensing" was confirmed,

Einstein was elevated to a stature of celebrity.

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Though he recanted his support of heliocentrism under threat of torture from The Church, Galileo was found

guilty of heresy. As he was led into the confines house arrest, he is purported to have said "E pur si

muove" (“and yet it moves”, or—with some inferring applied— “Nevertheless, the world moves”).

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Werner Heisenberg is credited with the idea that we cannot know both the position and momentum

of a particle (such as an electron) beyond a certain limit. If you know the momentum, you don't

know the position (or vice versa). This is the Heisenberg Uncertainty Principle.

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Rear Admiral Grace Hopper conceptualized machine-independent computer programming languages. She is credited with popularizing the term "debugging," which originated with the removal of an actual moth from the

circuitry of a computer.

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Happy Valentine’s Day

William Thomson, Lord Kelvin developed a temperature scale that was absolute rather than relative. Zero on the

Fahrenheit and Celsius scales is relative; negative temperatures must be used on those scales. There is no temperature colder than zero on the Kelvin scale: that

temperature is "absolute zero."

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Happy Valentine’s Day

After 30 years of work and over 900 pages of calculations, Johannes Kepler published the spoils of victory from his "War on Mars" in his monumental

book, Harmony of the Worlds. Kepler’s laws of planetary motion included the Law of Ellipses, the

Law of Equal Areas, and the Law of Harmony.

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Ohm's law relates current, voltage, and resistance: V=IR. The unit of electrical resistance is named in Ohm’s honor.

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Each electron in an atom or molecule has a set of quantum numbers. One specifies energy

level (shell), one for the subshell (s, p, d, f, etc.), one for the specific orbit in the subshell, and

one for spin. The Pauli Exclusion Principle states that no two electrons in atom or molecule will

have the same set of quantum numbers.

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Happy Valentine’s Day

Astrophysicist Carl Sagan was a prolific author and popularizer of science. His landmark PBS series,

Cosmos, continues to inspire audiences to this day.

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Happy Valentine’s Day

Alessandro Volta is credited with the invention of the electrochemical cell battery. The SI unit of electric

potential (volt) is named in his honor.

SCIENTIST VALENTINES

Happy V

alentine’s Day

The he

lioc

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mo

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ly one

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SCIEN

TIST VA

LENTIN

ES

Happy V

alentine’s Day

from M

r. Baird

Jane

Go

od

all is a

n English p

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rk, Tanza

nia.

-Wikip

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ia

SCIEN

TIST VA

LENTIN

ES

Hap

py V

alen

tine’s

Day

fr

om M

r. B

aird

Ma

ria G

oe

pp

ert

-Ma

yer w

on

a N

ob

el P

rize

in

phy

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of n

ucle

ons

form

ed

hig

hly

sta

ble

nuc

lei.

SCIE

NTI

ST V

ALE

NTI

NES

Happy V

alentine’s Day

from M

r. Baird

Rosa

lind Fra

nklin used

X-ra

y crysta

llog

rap

hy to

signific

antly a

dva

nce

the und

ersta

nding

of se

vera

l m

ole

cula

r structure

s. He

r wo

rk on D

NA

wa

s pivo

tal to

the

esta

blishm

ent o

f the d

oub

le-he

lix mo

de

l.

SCIEN

TIST VA

LENTIN

ES

Hap

py V

alen

tine’s

Day

fr

om M

r. B

aird

Mic

hae

l Fa

rad

ay

visu

aliz

ed

ele

ctr

ic a

nd m

ag

netic

fie

lds

by

dra

win

g li

nes

of f

orc

e. T

he li

nes

ind

ica

ted

the

d

irec

tion

and

str

eng

th o

f the

fie

ld. T

he p

atte

rns

of l

ine

s a

lso

ind

ica

ted

attr

ac

tion

and

rep

ulsi

on.

Suc

h fie

ld

rep

rese

nta

tions

are

stil

l use

d to

da

y.

SCIE

NTI

ST V

ALE

NTI

NES

Niko

la Te

sla w

as a

n enig

ma

tic inve

ntor

and

pro

po

nent o

f alte

rnating

curre

nt d

uring The

Wa

r of the

Curre

nts. The ic

onic

p

hoto

gra

ph he

re w

as inte

nde

d to

show

n ho

w sa

fe a

lterna

ting c

urrent w

as.

SCIEN

TIST VA

LENTIN

ES

Happy V

alentine’s Day H

appy

Val

entin

e’s

Day

Ma

x Pl

anc

k w

as

a "

foun

din

g fa

the

r" o

f qua

ntum

m

ec

hani

cs.

He

the

oriz

ed

tha

t bla

ckb

od

y ra

dia

tion

wa

s e

mitt

ed

onl

y a

s m

ultip

les

of a

sp

ec

ific

"q

uant

um"

of

ene

rgy

rath

er t

han

as

a c

ont

inuo

us s

pe

ctr

um.

SCIE

NTI

ST V

ALE

NTI

NES

Happy V

alentine’s Day

Isaa

c N

ew

ton is p

urpo

rted

to ha

ve c

onne

cte

d

his theo

ry of unive

rsal g

ravita

tion to

ap

ple

s in his fa

mily's o

rcha

rd. W

e think o

f his theo

ry as

uniting fre

e fa

ll and

orb

ital m

ec

hanic

s.

SCIEN

TIST VA

LENTIN

ES

Hap

py V

alen

tine’s

Day

Alth

oug

h Li

se M

eitn

er w

as

pa

rt o

f a te

am

tha

t d

isc

ove

red

nuc

lea

r fis

sio

n, s

he w

as

not i

nclu

de

d in

th

e N

ob

el P

rize

aw

ard

ed

to h

er c

olle

ag

ue, O

tto

Ha

hn, i

n re

co

gni

tion

for t

he d

isc

ove

ry.

SCIE

NTI

ST V

ALE

NTI

NES