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Good ideas can change the world

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Explore 150 cards about people from around the world who used courage, knowledge, advocacy, discovery, and invention to help others.

Section one Β· Access and inclusion

People who helped people with disabilities

Meet disabled leaders, advocates, teachers, doctors, and inventors who expanded access, communication, rights, choice, and belonging.

30 cards Β· Oldest newest
FranceDeaf educator

Charles-Michel de l'Γ‰pΓ©e

1712–1789Invention or contributionPublic education using sign language

Did you know? He founded a public school for deaf students in Paris and learned from signs already used by Deaf people.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

FranceBlindness education pioneer

Valentin HaΓΌy

1745–1822Invention or contributionEmbossed books and a school for blind students

Did you know? He founded one of the first schools for blind children and developed raised-print books.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

France / United StatesDeaf teacher

Laurent Clerc

1785–1869Invention or contributionDeaf education and American Sign Language

Did you know? He helped establish the first permanent school for deaf students in the United States.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesEducator

Thomas Hopkins Gallaudet

1787–1851Invention or contributionA permanent American school for deaf students

Did you know? He worked with Laurent Clerc to establish the American School for the Deaf.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesSocial reformer

Dorothea Dix

1802–1887Invention or contributionReform of mental-health care

Did you know? She documented harmful conditions and campaigned for more humane care for people with mental illness.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

FranceInventor and teacher

Louis Braille

1809–1852Invention or contributionThe Braille reading system

Did you know? Louis Braille created a reading and writing system made of raised dots when he was a teenager.

Why it mattersBraille opened more ways for blind people to read, learn, write, and share ideas.

United StatesTeacher

Anne Sullivan

1866–1936Invention or contributionHands-on accessible teaching

Did you know? Anne Sullivan used touch, objects, and fingerspelling to help Helen Keller connect words with the world around her.

Why it mattersHer patient teaching demonstrated the power of finding communication methods that fit the learner.

United StatesAuthor and advocate

Helen Keller

1880–1968Invention or contributionDisability rights and education

Did you know? Helen Keller, who was deafblind, became an author and spoke around the world about disability access, education, and equality.

Why it mattersShe showed that communication and learning should be available to everyone.

United StatesPresident and polio rehabilitation supporter

Franklin D. Roosevelt

1882–1945Invention or contributionPolio rehabilitation and the March of Dimes

Did you know? After becoming disabled by polio, he supported rehabilitation programs and efforts to prevent the disease.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

Germany / United KingdomNeurologist

Ludwig Guttmann

1899–1980Invention or contributionThe early Paralympic movement

Did you know? Ludwig Guttmann used sports as part of rehabilitation for people with spinal cord injuries and organized the Stoke Mandeville Games.

Why it mattersThose games grew into the Paralympic movement and changed ideas about disability and sport.

United StatesBlind legal scholar

Jacobus tenBroek

1911–1968Invention or contributionThe National Federation of the Blind

Did you know? He founded a national organization led by blind people and argued for equal rights and opportunity.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesDisability rights activist

Justin Dart Jr.

1930–2002Invention or contributionBuilding support for the Americans with Disabilities Act

Did you know? Justin Dart Jr. traveled across the United States gathering stories from disabled people and building support for disability civil rights.

Why it mattersHis organizing helped the Americans with Disabilities Act become law in 1990.

United StatesIndependent Living leader

Ed Roberts

1939–1995Invention or contributionThe Independent Living movement

Did you know? Ed Roberts fought to attend college and helped build services led by disabled people themselves.

Why it mattersHis work supported the idea that disabled people should direct their own lives and make their own choices.

United StatesArchitect

Ron Mace

1941–1998Invention or contributionUniversal design

Did you know? He helped define universal design: making places and products usable by as many people as possible.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesDeaf educator and university leader

I. King Jordan

born 1943Invention or contributionDeaf leadership in higher education

Did you know? He became Gallaudet University's first Deaf president after the Deaf President Now movement.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesDisability rights leader

Judith Heumann

1947–2023Invention or contributionThe disability civil rights movement

Did you know? Judith Heumann helped lead the 1977 Section 504 sit-in, a major protest for disability civil rights in the United States.

Why it mattersHer organizing helped make schools, workplaces, transportation, and public life more accessible.

United StatesCivil rights organizer

Brad Lomax

1950–1984Invention or contributionDisability and racial justice organizing

Did you know? Brad Lomax connected the disability rights movement with the Black Panther Party during the 1977 Section 504 sit-in.

Why it mattersHis coalition-building strengthened the successful fight for disability civil rights protections.

United StatesDisability rights organizer

Marca Bristo

1953–2019Invention or contributionAccessible transportation and civil rights

Did you know? She helped organize for accessible public transit and passage of the Americans with Disabilities Act.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

AustraliaCommunication rights activist

Anne McDonald

1961–2010Invention or contributionThe right to communication and community living

Did you know? She fought to leave an institution and to have her communication and intelligence recognized.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United KingdomParalympian and legislator

Tanni Grey-Thompson

born 1969Invention or contributionDisability inclusion in sport and public life

Did you know? She became a leading wheelchair racer and later advocated for access and equality in public policy.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

IrelandDisability inclusion advocate

Caroline Casey

born 1971Invention or contributionBusiness disability inclusion

Did you know? She created initiatives encouraging global companies to include disabled people in employment and leadership.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United KingdomActor and disability rights activist

Liz Carr

born 1972Invention or contributionDisability representation and independent living

Did you know? She uses performance and advocacy to challenge barriers and support disabled people's right to live independently.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

AustraliaWriter and disability activist

Stella Young

1982–2014Invention or contributionChanging how disability stories are told

Did you know? Stella Young used writing, comedy, and public speaking to challenge stereotypes and patronizing ideas about disabled people.

Why it mattersHer work encouraged people to value disabled lives without turning disability into an inspirational object lesson.

United KingdomPresenter and access advocate

Sophie Morgan

born 1985Invention or contributionAccessible travel and media representation

Did you know? She campaigns for safer air travel and stronger representation of disabled people in media.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

PakistanArtist and disability advocate

Muniba Mazari

born 1987Invention or contributionDisability inclusion and public storytelling

Did you know? She uses art and public speaking to promote inclusion, education, and opportunities for disabled women.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United StatesLawyer and advocate

Haben Girma

born 1988Invention or contributionDigital access and disability inclusion

Did you know? Haben Girma became the first deafblind graduate of Harvard Law School and advocates for accessible technology and information.

Why it mattersShe helps organizations understand that accessibility creates more ways for everyone to participate.

IrelandEducator and design advocate

SinΓ©ad Burke

born 1990Invention or contributionInclusive design and accessible fashion

Did you know? SinΓ©ad Burke works with designers, schools, and organizations to show why products and spaces should include disabled people from the beginning.

Why it mattersHer work makes inclusive design part of everyday decisions rather than an afterthought.

United StatesActor and disability advocate

R. J. Mitte

born 1992Invention or contributionAuthentic disability representation

Did you know? He has used his acting career and experience with cerebral palsy to advocate for inclusion in entertainment.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

AustraliaParalympian and advocate

Madison de Rozario

born 1993Invention or contributionDisability visibility through sport

Did you know? She became a champion wheelchair racer and speaks about access, identity, and representation.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

United KingdomParalympian and advocate

Ellie Simmonds

born 1994Invention or contributionInclusive sport and disability visibility

Did you know? She became a Paralympic swimming champion and promotes inclusion for people with dwarfism.

Why it mattersTheir work helped expand access, dignity, choice, communication, or opportunity for disabled people.

Section two Β· Courage and leadership

Famous people who changed the world

Meet people from different countries whose leadership, service, and courage made a lasting difference.

30 cards Β· Oldest newest
ChinaTeacher and philosopher

Confucius

551–479 BCEContributionEthics, education, and public service

Did you know? His teachings emphasized learning, responsibility, respect, and ethical leadership.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

IndiaEmperor and reformer

Ashoka

about 304–232 BCEContributionPublic welfare and religious tolerance

Did you know? After a devastating war, he promoted nonviolence, public works, and respect among different faiths.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

Persia / TΓΌrkiyePoet and teacher

Rumi

1207–1273ContributionPoetry about compassion and connection

Did you know? His poems explored love, humility, spiritual growth, and the shared humanity of people.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

Nigeria / United KingdomWriter and abolitionist

Olaudah Equiano

about 1745–1797ContributionAbolitionist autobiography

Did you know? His account of enslavement helped build public support for ending the transatlantic slave trade.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesPresident

Abraham Lincoln

1809–1865ContributionPreserving the Union and ending legal slavery

Did you know? He led the United States during the Civil War and issued the Emancipation Proclamation.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesAbolitionist and writer

Frederick Douglass

about 1818–1895ContributionAbolition and equal citizenship

Did you know? After escaping slavery, he became a powerful writer and speaker for freedom and voting rights.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesNurse and relief organizer

Clara Barton

1821–1912ContributionThe American Red Cross

Did you know? She cared for wounded soldiers and later founded an organization providing disaster and emergency relief.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesFreedom guide

Harriet Tubman

about 1822–1913ContributionUnderground Railroad rescue missions

Did you know? After escaping slavery, Harriet Tubman returned many times to guide other people to freedom through the Underground Railroad.

Why it mattersHer courage shows how one person can take great risks to help others be free.

IndiaIndependence leader

Mahatma Gandhi

1869–1948ContributionNonviolent civil resistance

Did you know? Mahatma Gandhi organized nonviolent campaigns against British colonial rule in India.

Why it mattersHis methods influenced later civil rights and freedom movements around the world.

United StatesDiplomat and human-rights advocate

Eleanor Roosevelt

1884–1962ContributionThe Universal Declaration of Human Rights

Did you know? She chaired the United Nations group that drafted a landmark statement of universal human rights.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesCivil rights activist

Rosa Parks

1913–2005ContributionCivil rights organizing

Did you know? Rosa Parks worked for civil rights for many years. Her arrest after refusing to give up her bus seat helped spark the Montgomery Bus Boycott.

Why it mattersHer steady courage helped move the United States toward fairer laws.

South AfricaLeader and peacemaker

Nelson Mandela

1918–2013ContributionThe struggle against apartheid

Did you know? Nelson Mandela worked to end apartheid, a system of racist laws in South Africa, and later became the country's first Black president.

Why it mattersHe encouraged reconciliation and the building of a more democratic nation.

United KingdomBroadcaster and natural historian

David Attenborough

born 1926ContributionPublic understanding of nature

Did you know? His documentaries brought wildlife and environmental issues into homes around the world.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesLabor and civil-rights leader

Cesar Chavez

1927–1993ContributionFarmworker organizing

Did you know? He helped organize farmworkers seeking safer conditions, fairer pay, and a public voice.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesCivil rights leader

Martin Luther King Jr.

1929–1968ContributionNonviolent civil rights leadership

Did you know? Martin Luther King Jr. helped lead campaigns for equal rights through speeches, marches, boycotts, and other nonviolent action.

Why it mattersHis leadership helped build support for major civil rights laws in the United States.

Germany / NetherlandsDiarist

Anne Frank

1929–1945ContributionA personal record of the Holocaust

Did you know? Her diary gave generations of readers a young person's view of persecution, fear, and hope.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

South AfricaHuman rights leader

Desmond Tutu

1931–2021ContributionPeaceful leadership against apartheid

Did you know? Desmond Tutu spoke against apartheid and supported peaceful change, human rights, and reconciliation in South Africa.

Why it mattersHis moral leadership helped bring worldwide attention to injustice and encouraged healing after apartheid.

KenyaEnvironmentalist and organizer

Wangari Maathai

1940–2011ContributionThe Green Belt Movement

Did you know? Wangari Maathai started the Green Belt Movement, which helped communities in Kenya plant millions of trees.

Why it mattersHer work connected caring for the environment with peace, jobs, and stronger communities.

BangladeshEconomist and social entrepreneur

Muhammad Yunus

born 1940ContributionMicrocredit for people excluded from banking

Did you know? He developed small-loan programs intended to help low-income borrowers start businesses.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesAthlete and humanitarian

Muhammad Ali

1942–2016ContributionCivil-rights advocacy and humanitarian service

Did you know? He paired an extraordinary boxing career with public stands on race, conscience, and humanitarian causes.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United StatesMusician and literacy supporter

Dolly Parton

born 1946ContributionThe Imagination Library

Did you know? Dolly Parton created the Imagination Library to mail free books to young children.

Why it mattersThe program has helped families around the world build home libraries and enjoy reading together.

United StatesBroadcaster and philanthropist

Oprah Winfrey

born 1954ContributionEducation and community philanthropy

Did you know? She has used media and philanthropy to support education, reading, and opportunities for young people.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

IndiaChildren's-rights activist

Kailash Satyarthi

born 1954ContributionCampaigns against child labor

Did you know? He organized efforts to rescue children from forced labor and protect their right to attend school.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

United KingdomHumanitarian

Diana, Princess of Wales

1961–1997ContributionAwareness of landmines and HIV/AIDS

Did you know? She challenged stigma around HIV/AIDS and drew attention to the harm caused by landmines.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

Spain / United StatesChef and humanitarian

JosΓ© AndrΓ©s

born 1969ContributionDisaster meal relief

Did you know? JosΓ© AndrΓ©s founded World Central Kitchen to provide meals to communities after disasters and during emergencies.

Why it mattersHis work shows how food, local knowledge, and fast teamwork can help people during a crisis.

LiberiaPeace activist

Leymah Gbowee

born 1972ContributionWomen-led peace organizing

Did you know? She helped lead a movement of women whose nonviolent action supported an end to Liberia's civil war.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

IraqHuman-rights advocate

Nadia Murad

born 1993ContributionJustice for survivors of conflict-related violence

Did you know? After surviving captivity, she became an advocate for Yazidi people and survivors of sexual violence.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

PakistanEducation advocate

Malala Yousafzai

born 1997ContributionGirls' education advocacy

Did you know? Malala Yousafzai spoke up for every girl's right to attend school and continued after surviving an attack.

Why it mattersHer advocacy supports education programs and encourages young people to use their voices.

United StatesPoet and literacy advocate

Amanda Gorman

born 1998ContributionYouth poetry and literacy

Did you know? Her public poetry and nonprofit work encourage young people to read, write, and participate in civic life.

Why it mattersTheir example continues to encourage people to serve others, challenge injustice, or strengthen their communities.

SwedenClimate activist

Greta Thunberg

born 2003ContributionYouth climate organizing

Did you know? Greta Thunberg began a school strike for climate action that inspired young people in many countries to organize.

Why it mattersHer activism helped make young people's concerns about climate change harder for world leaders to ignore.

Section three Β· Understanding the universe

Scientists who changed how we understand the world

Meet scientists from Galileo and Newton to Einstein, Katherine Johnson, Stephen Hawking, and modern computer scientists.

30 cards Β· Oldest newest
GreecePhilosopher and naturalist

Aristotle

384–322 BCEScientific contributionEarly organized study of nature

Did you know? He recorded and classified observations about animals, motion, logic, and the natural world.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

Persia / IraqMathematician and astronomer

Al-Khwarizmi

about 780–850Scientific contributionAlgebra and systematic calculation

Did you know? His mathematical writing helped establish algebra and methods that influenced the word algorithm.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

PolandAstronomer

Nicolaus Copernicus

1473–1543Scientific contributionThe heliocentric model

Did you know? He developed a mathematical model placing the Sun rather than Earth near the center of the planetary system.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

ItalyAstronomer and physicist

Galileo Galilei

1564–1642Scientific contributionTelescopic astronomy and motion studies

Did you know? Galileo improved telescopes and used them to observe moons around Jupiter, mountains on the Moon, and phases of Venus.

Why it mattersHis evidence strengthened the idea that Earth moves around the Sun and helped advance observation-based science.

GermanyAstronomer and mathematician

Johannes Kepler

1571–1630Scientific contributionLaws of planetary motion

Did you know? He showed that planets travel in elliptical orbits and described how their speeds change.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

England / United KingdomScientist and inventor

Robert Hooke

1635–1703Scientific contributionCells, elasticity, and microscopy

Did you know? He published detailed microscope observations and introduced the biological term cell.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

England / United KingdomPhysicist and mathematician

Isaac Newton

1643–1727Scientific contributionLaws of motion and universal gravitation

Did you know? Isaac Newton described laws explaining how forces affect motion and how gravity acts between objects.

Why it mattersHis mathematical ideas became foundations for physics, engineering, astronomy, and spaceflight.

SwedenBotanist

Carl Linnaeus

1707–1778Scientific contributionBinomial naming of species

Did you know? He established a widely used system for giving organisms two-part scientific names.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

United KingdomPhysicist and chemist

Michael Faraday

1791–1867Scientific contributionElectromagnetism

Did you know? His experiments connected electricity and magnetism and demonstrated electromagnetic induction.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

United KingdomNaturalist

Charles Darwin

1809–1882Scientific contributionEvolution by natural selection

Did you know? He assembled evidence explaining how populations change over generations through natural selection.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

Scotland / United KingdomPhysicist

James Clerk Maxwell

1831–1879Scientific contributionElectromagnetic field theory

Did you know? His equations showed that electricity, magnetism, and light are connected.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

RussiaChemist

Dmitri Mendeleev

1834–1907Scientific contributionThe periodic table

Did you know? He organized elements by repeating properties and predicted elements that had not yet been found.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

IndiaPhysicist and biologist

Jagadish Chandra Bose

1858–1937Scientific contributionRadio, microwave, and plant-response research

Did you know? He conducted early wireless experiments and created instruments for studying plant responses.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

New Zealand / United KingdomPhysicist

Ernest Rutherford

1871–1937Scientific contributionThe nuclear model of the atom

Did you know? His experiments showed that atoms contain a small, dense, positively charged nucleus.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

Austria / SwedenPhysicist

Lise Meitner

1878–1968Scientific contributionExplanation of nuclear fission

Did you know? She and Otto Frisch explained the physics behind the splitting of atomic nuclei.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

Germany / United StatesTheoretical physicist

Albert Einstein

1879–1955Scientific contributionRelativity and the photoelectric effect

Did you know? Albert Einstein developed theories of relativity and explained how light can release electrons from certain materials.

Why it mattersHis work reshaped modern physics and contributed to technologies including solar cells, satellites, and GPS corrections.

DenmarkPhysicist

Niels Bohr

1885–1962Scientific contributionQuantum model of the atom

Did you know? He proposed a model using quantized energy levels to explain atomic spectra.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

IndiaPhysicist

C. V. Raman

1888–1970Scientific contributionThe Raman effect

Did you know? C. V. Raman discovered that a small part of light changes wavelength when it passes through a material.

Why it mattersRaman spectroscopy now helps scientists identify materials in medicine, chemistry, art, and industry.

IndiaPhysicist

Satyendra Nath Bose

1894–1974Scientific contributionBose-Einstein statistics

Did you know? His work with quantum particles led to a new type of statistics and the term boson.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

China / United StatesExperimental physicist

Chien-Shiung Wu

1912–1997Scientific contributionThe Wu experiment

Did you know? Chien-Shiung Wu designed a precise experiment showing that a rule called parity is not always conserved in nuclear physics.

Why it mattersHer experiment changed physicists' understanding of fundamental particles and forces.

United StatesMathematician

Katherine Johnson

1918–2020Scientific contributionSpaceflight trajectory calculations

Did you know? Katherine Johnson calculated flight paths for NASA missions, including John Glenn's orbit around Earth and later Moon missions.

Why it mattersHer accuracy helped astronauts travel safely and opened doors for women and Black mathematicians in science.

United KingdomChemist and crystallographer

Rosalind Franklin

1920–1958Scientific contributionX-ray evidence about DNA structure

Did you know? Her precise X-ray images provided crucial evidence for understanding DNA's double-helix structure.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

Pakistan / United KingdomTheoretical physicist

Abdus Salam

1926–1996Scientific contributionElectroweak theory

Did you know? He helped unify the electromagnetic and weak nuclear forces in a single theory.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

United StatesAstronomer

Vera Rubin

1928–2016Scientific contributionEvidence for dark matter

Did you know? Vera Rubin measured how stars move around galaxies and found strong evidence that unseen matter affects their motion.

Why it mattersHer observations helped make dark matter one of the central questions in modern astronomy.

United StatesAstronomer and science communicator

Carl Sagan

1934–1996Scientific contributionPlanetary science and public science

Did you know? He researched planetary atmospheres and helped millions of people explore science through books and television.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

United KingdomTheoretical physicist

Stephen Hawking

1942–2018Scientific contributionBlack-hole and cosmology research

Did you know? Stephen Hawking showed that black holes can release energy, now called Hawking radiation.

Why it mattersHis research connected gravity, quantum physics, and the study of the universe, while his books brought science to wider audiences.

Northern Ireland / United KingdomAstrophysicist

Jocelyn Bell Burnell

born 1943Scientific contributionDiscovery of pulsars

Did you know? As a graduate student, she identified the repeating radio signals now known to come from pulsars.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

United StatesDoctor, engineer, and astronaut

Mae Jemison

born 1956Scientific contributionSpace science and STEM education

Did you know? Mae Jemison became the first Black woman to travel in space and conducted scientific experiments aboard the Space Shuttle Endeavour.

Why it mattersShe continues to encourage young people to connect science, technology, creativity, and social responsibility.

United StatesAstrophysicist and educator

Neil deGrasse Tyson

born 1958Scientific contributionPublic science education

Did you know? He directs a planetarium and uses books, broadcasts, and talks to make space science accessible.

Why it mattersTheir scientific work helped later researchers ask better questions and build new knowledge.

China / United StatesComputer scientist

Fei-Fei Li

born 1976Scientific contributionImageNet and human-centered AI

Did you know? Fei-Fei Li led the creation of ImageNet, a large image dataset that helped advance computer vision research.

Why it mattersHer work also promotes artificial intelligence designed around human needs, dignity, and responsibility.

Section four Β· Finding new answers

Important discoveries

Explore scientific and medical discoveries that changed what people understand about health, nature, light, and the world.

30 cards Β· Oldest newest
GreeceMathematician and inventor

Archimedes

about 287–212 BCEDiscoveryPrinciples of buoyancy and levers

Did you know? He described how fluids push upward on objects and developed mathematical approaches to mechanics.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

Iraq / EgyptScientist

Ibn al-Haytham

about 965–1040DiscoveryExperiments in optics and vision

Did you know? Ibn al-Haytham used experiments to study light, reflection, and how people see.

Why it mattersHis work helped shape the scientific study of optics and the use of evidence to test ideas.

ChinaScientist and statesman

Shen Kuo

1031–1095DiscoveryMagnetic declination and geological observations

Did you know? He recorded evidence about compass direction, fossils, erosion, and long-term changes to landscapes.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

NetherlandsMicroscopist

Antonie van Leeuwenhoek

1632–1723DiscoveryObservation of microorganisms

Did you know? Using powerful handmade microscopes, he described bacteria, protozoa, and other microscopic life.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United KingdomPhysician

Edward Jenner

1749–1823DiscoverySmallpox vaccination

Did you know? He demonstrated that exposure to cowpox could protect people from deadly smallpox.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United KingdomFossil collector and paleontologist

Mary Anning

1799–1847DiscoveryMajor marine-reptile fossils

Did you know? Her careful fossil discoveries helped scientists understand prehistoric life and extinction.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United KingdomNurse and statistician

Florence Nightingale

1820–1910DiscoveryModern nursing and health statistics

Did you know? Florence Nightingale used careful records and charts to show how cleaner hospitals could save lives.

Why it mattersHer ideas improved nursing education, sanitation, and patient care.

FranceChemist and microbiologist

Louis Pasteur

1822–1895DiscoveryGerm theory, pasteurization, and vaccines

Did you know? His experiments showed that microorganisms cause fermentation and can contribute to disease.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

Austria / CzechiaGenetics pioneer

Gregor Mendel

1822–1884DiscoveryBasic laws of inheritance

Did you know? His pea-plant experiments revealed predictable patterns in how traits pass between generations.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

GermanyPhysician and microbiologist

Robert Koch

1843–1910DiscoveryDisease-causing bacteria

Did you know? He developed methods connecting particular microorganisms with particular diseases.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

GermanyPhysicist

Wilhelm RΓΆntgen

1845–1923DiscoveryX-rays

Did you know? He discovered an invisible form of radiation that could create images of structures inside the body.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United StatesPlant scientist and teacher

George Washington Carver

about 1864–1943DiscoverySoil-saving farming methods

Did you know? George Washington Carver taught farmers ways to care for tired soil by changing which crops they planted.

Why it mattersHe shared practical ideas that helped farming families and protected the land.

Poland / FranceScientist

Marie Curie

1867–1934DiscoveryRadioactivity research and mobile X-rays

Did you know? Marie Curie studied radioactivity and helped bring mobile X-ray machines to battlefield hospitals during World War I.

Why it mattersHer discoveries opened new doors for medicine and science, and her mobile units helped doctors care for wounded soldiers.

United StatesAstronomer

Henrietta Swan Leavitt

1868–1921DiscoveryA method for measuring cosmic distances

Did you know? She found a relationship in variable stars that allowed astronomers to calculate great distances.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

Scotland / United KingdomPhysician and scientist

Alexander Fleming

1881–1955DiscoveryThe discovery of penicillin

Did you know? Alexander Fleming noticed that a mold had stopped bacteria from growing and identified the substance now called penicillin.

Why it mattersPenicillin helped begin the modern age of antibiotics and made many bacterial infections treatable.

DenmarkSeismologist

Inge Lehmann

1888–1993DiscoveryEarth's solid inner core

Did you know? She used earthquake waves to show that Earth has a solid inner core inside its liquid outer core.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United Kingdom / United StatesAstronomer

Cecilia Payne-Gaposchkin

1900–1979DiscoveryThe composition of stars

Did you know? She demonstrated that stars are made mostly of hydrogen and helium.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United StatesGeneticist

Barbara McClintock

1902–1992DiscoveryJumping genes

Did you know? Her maize research revealed that some genetic elements can move to different places in DNA.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United KingdomChemist

Dorothy Crowfoot Hodgkin

1910–1994DiscoveryMolecular structures using X-rays

Did you know? She determined the three-dimensional structures of medicines including penicillin and vitamin B12.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United StatesPharmacologist

Gertrude Elion

1918–1999DiscoveryTargeted drug development

Did you know? She helped create medicines for leukemia, infections, immune conditions, and organ transplants.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United StatesMedical physicist

Rosalyn Yalow

1921–2011DiscoveryRadioimmunoassay

Did you know? She co-developed a highly sensitive method for measuring tiny amounts of substances such as hormones in blood.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

ChinaPharmaceutical scientist

Tu Youyou

born 1930DiscoveryArtemisinin malaria treatment

Did you know? Tu Youyou and her team discovered artemisinin, a medicine based on research into traditional Chinese medical knowledge.

Why it mattersArtemisinin-based treatments have helped save millions of people from malaria.

United StatesPhysicist

Mildred Dresselhaus

1930–2017DiscoveryCarbon-materials research

Did you know? Her work revealed important properties of graphite, nanotubes, and other carbon-based materials.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United Kingdom / TanzaniaPrimatologist

Jane Goodall

born 1934DiscoveryChimpanzee behavior research

Did you know? Jane Goodall observed chimpanzees making and using tools, changing how scientists understood animal behavior.

Why it mattersHer research and conservation work deepened respect for animals, habitats, and the natural world.

United StatesGeneticist

Mary-Claire King

born 1946DiscoveryThe BRCA1 breast-cancer gene location

Did you know? She demonstrated that inherited mutations could strongly affect breast-cancer risk and mapped BRCA1.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

Hungary / United StatesBiochemist

Katalin KarikΓ³

born 1955DiscoveryModified mRNA for medicine

Did you know? Katalin KarikΓ³ helped discover how to modify messenger RNA so it could work safely and effectively in the body.

Why it mattersHer research became an important foundation for mRNA vaccines and other possible treatments.

Sweden / GermanyGeneticist

Svante PÀÀbo

born 1955DiscoveryAncient human DNA

Did you know? He developed methods for studying ancient DNA and helped identify the Denisovan group of ancient humans.

Why it mattersThis discovery continues to influence research, medicine, technology, or how people understand the world.

United StatesPhysician-scientist

Drew Weissman

born 1959DiscoveryNucleoside-modified mRNA

Did you know? Drew Weissman worked with Katalin KarikΓ³ to develop modified mRNA methods that reduced harmful immune reactions.

Why it mattersTheir shared discovery helped make effective mRNA vaccines possible.

United StatesBiochemist

Jennifer Doudna

born 1964DiscoveryCRISPR-Cas9 gene editing

Did you know? Jennifer Doudna and Emmanuelle Charpentier showed how CRISPR-Cas9 could be directed to cut DNA at a chosen location.

Why it mattersThe discovery gave researchers a powerful tool for studying genes and developing possible treatments.

FranceMicrobiologist

Emmanuelle Charpentier

born 1968DiscoveryCRISPR-Cas9 gene editing

Did you know? Emmanuelle Charpentier studied a bacterial defense system and worked with Jennifer Doudna to turn it into a precise gene-editing tool.

Why it mattersTheir work transformed biological research and opened new possibilities in medicine.

Section five Β· Ideas made real

Inventions that changed daily life

Discover inventors and practical ideas that improved communication, safety, technology, and everyday life.

30 cards Β· Oldest newest
ChinaOfficial and papermaking innovator

Cai Lun

about 50–121InventionImproved papermaking process

Did you know? He is traditionally credited with documenting and improving a practical process for making paper from fibers.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

ChinaInventor

Bi Sheng

about 972–1051InventionMovable ceramic type

Did you know? He developed an early movable-type printing system using reusable ceramic characters.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

Upper Mesopotamia / TΓΌrkiyeEngineer and inventor

Al-Jazari

1136–1206InventionWater pumps, clocks, and automata

Did you know? He documented ingenious mechanical devices using gears, valves, floats, and crank mechanisms.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

GermanyPrinter and inventor

Johannes Gutenberg

about 1400–1468InventionEuropean movable-type printing press

Did you know? Johannes Gutenberg developed a practical movable-type printing system in Europe that could reproduce books more quickly.

Why it mattersHis printing method helped written knowledge reach many more people across Europe.

FranceMathematician and inventor

Blaise Pascal

1623–1662InventionA mechanical calculator

Did you know? He designed the Pascaline to help perform addition and subtraction mechanically.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United StatesInventor and statesman

Benjamin Franklin

1706–1790InventionLightning rod and bifocals

Did you know? He designed practical devices and demonstrated the electrical nature of lightning.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

Scotland / United KingdomEngineer and inventor

James Watt

1736–1819InventionEfficient steam-engine improvements

Did you know? His separate condenser greatly improved the efficiency and usefulness of steam engines.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

ItalyPhysicist and inventor

Alessandro Volta

1745–1827InventionThe electric battery

Did you know? He created the voltaic pile, an early device that produced a steady electric current.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

FranceInventor

NicΓ©phore NiΓ©pce

1765–1833InventionPermanent photography

Did you know? He created the earliest surviving photograph made with a camera using a light-sensitive surface.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United StatesInventor and artist

Samuel Morse

1791–1872InventionTelegraph system and Morse code

Did you know? He helped develop a practical electrical telegraph and a code for transmitting text.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United KingdomMathematician

Ada Lovelace

1815–1852InventionAn early computer algorithm

Did you know? Ada Lovelace wrote a detailed plan for how Charles Babbage's proposed Analytical Engine could calculate a sequence of numbers.

Why it mattersHer notes helped people imagine that computing machines could do more than basic arithmetic.

United StatesInventor

Elias Howe

1819–1867InventionLockstitch sewing machine

Did you know? He patented an important lockstitch mechanism used in practical sewing machines.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United StatesInventor and entrepreneur

Thomas Edison

1847–1931InventionPhonograph and practical electric-light systems

Did you know? Thomas Edison and the teams in his laboratories developed the phonograph and improved practical systems for electric lighting.

Why it mattersHis laboratories helped turn experimental ideas into technologies that could be produced and used widely.

Scotland / Canada / United StatesInventor and teacher

Alexander Graham Bell

1847–1922InventionThe telephone

Did you know? He received an early telephone patent and transmitted understandable speech electrically.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

Croatia / United StatesInventor and engineer

Nikola Tesla

1856–1943InventionAlternating-current electrical systems

Did you know? Nikola Tesla developed motors and electrical systems that helped make alternating-current power practical over long distances.

Why it mattersHis work became part of the electrical systems that power homes, schools, hospitals, and cities.

United StatesManufacturing innovator

Henry Ford

1863–1947InventionThe moving automobile assembly line

Did you know? Henry Ford did not invent the car. His company developed a moving assembly line that made automobiles faster and less expensive to produce.

Why it mattersThe production system changed manufacturing around the world, while also raising important questions about repetitive factory work.

United StatesInventor

Mary Anderson

1866–1953InventionWindshield wiper

Did you know? She patented a driver-operated device for clearing rain and snow from a vehicle window.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United StatesAviation pioneers

Wilbur and Orville Wright

1867–1948 / 1871–1912InventionControlled powered flight

Did you know? They built and flew the first successful powered airplane with reliable three-axis control.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

Italy / United KingdomInventor and engineer

Guglielmo Marconi

1874–1937InventionLong-distance radio communication

Did you know? He developed and demonstrated practical wireless telegraph systems over increasing distances.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

United StatesInventor

Garrett Morgan

1877–1963InventionSafety hood and traffic signal

Did you know? Garrett Morgan invented a safety hood for breathing in smoky places and patented a three-position traffic signal.

Why it mattersHis practical inventions were designed to protect people and make busy streets safer.

United StatesComputer scientist and naval officer

Grace Hopper

1906–1992InventionEarly compilers and accessible programming

Did you know? She helped create early compiler technology that translated written instructions into machine code.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

SwitzerlandEngineer and inventor

George de Mestral

1907–1990InventionHook-and-loop fastener

Did you know? Inspired by burrs sticking to fabric and fur, he invented the fastener later sold as Velcro.

Why it mattersThis invention helped shape later technology and changed how people work, communicate, travel, or live.

Austria / United StatesInventor and actor

Hedy Lamarr

1914–2000InventionFrequency-hopping communication

Did you know? Hedy Lamarr co-invented a frequency-hopping system designed to make radio-guided signals harder to block.

Why it mattersThe idea became an important early step toward later wireless communication technologies.

United StatesChemist and inventor

Stephanie Kwolek

1923–2014InventionKevlar fiber

Did you know? Stephanie Kwolek discovered the strong, lightweight synthetic fiber that became known as Kevlar.

Why it mattersKevlar is used in protective equipment and many products that need strength without much weight.

United StatesInventor and engineer

James West

born 1931InventionThe electret microphone

Did you know? James West co-invented a small, reliable microphone that converts sound into an electrical signal.

Why it mattersElectret microphones became widely used in phones, hearing aids, computers, and many everyday devices.

United StatesDoctor and inventor

Patricia Bath

1942–2019InventionThe Laserphaco cataract probe

Did you know? Patricia Bath invented a laser-based device and method designed to remove cataracts more precisely.

Why it mattersHer invention advanced eye surgery and her work promoted access to vision care.

United StatesEngineer and inventor

Lonnie Johnson

born 1949InventionThe Super Soaker and energy technology

Did you know? Lonnie Johnson invented the Super Soaker while also working on spacecraft systems and new energy technologies.

Why it mattersHis career inspires young inventors and supports continued experiments in cleaner energy.

United KingdomComputer scientist

Tim Berners-Lee

born 1955InventionThe World Wide Web

Did you know? Tim Berners-Lee invented the World Wide Web, including core ideas for web addresses, links, and web pages.

Why it mattersThe web made it far easier for people around the world to publish, connect, and share information.

United StatesEngineer and inventor

Marian Croak

born 1955InventionVoice over Internet Protocol technology

Did you know? Marian Croak helped advance systems that send voice communication over the internet and holds many technology patents.

Why it mattersHer work contributed to internet calling, video communication, and accessible ways to connect across distances.

NetherlandsInventor and environmentalist

Boyan Slat

born 1994InventionOcean and river cleanup systems

Did you know? Boyan Slat founded The Ocean Cleanup and helped develop systems designed to collect plastic from rivers and ocean currents.

Why it mattersThe project tests how engineering can reduce plastic flowing into and collecting in the ocean.

Good can start small

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