1903 Wilbur and Orville Wright invent the airplane.
1906 Animated cartoons debut.
1909 Synthetic plastics premiere, thanks to Leo Baekeland.
1910 Radio broadcasts Enrico Caruso singing opera.
1914 Smile! It's the 35-min camera!
1927 Philo Farnsworth invents all-electronic TV.
1936 Radio detection and ranging (RADAR) is used at U.K. military base.
1937 IBM Mark 7 mainframe computer and others in the series serve America's military needs.
1938 Roy Plunkett discovers Teflon, but not until 1954 do Louis Hartman and Marc Gregoire discover that burnt food won't stick to it. Chester Carlson makes the first xerographic copy. Plain-paper copiers debut in 1959.
1939 The Heinekel He-178 becomes the firsst jet aircraft flown.
1942 Enrico Fermi directs construction of nuclear reactor in squash court at the University of Chicago.
1945 Nuclear bomb explodes.
1946 Thirty-ton ENIAC computer debuts.
1947 Scientists at Bell Telephone Laboratories invent the transistor.
1954 First transistor radios are sold.
1955 Raytheon sells the first microwave oven.
1957 Blastoff! The Soviet satellite Sputnik / orbits the Earth.
1958 Theodore Maiman builds the ruby laser.
1959 Robert Noyce designs the integrated circuit, or silicon chip, incorporating multiple transistors.
1960 Corning Glass Company develops pure glass for fiber optics.
1961 Blastoff! Humans travel in space.
1962 NASA launches Telstar 1, the first communications satellite.
1968 Intel invents the microprocessor a "computer-on-a-chip."
1969 The Internet's precursor, ARAPNET, links computers at government, offices universities, and defense contractors.
1972 First home video game debuts: Odyssey (no relation!) "Pong" game is addictive!
1975 Cray 1 supercomputer does 100 million operations per second.
1979 Compact disc premieres. Records eventually become obsolete, thanks also to cassettes.
1980 Tim Berners-Lee writes "Enquire." The program and related developments create the World Wide Web by 1990.
1991 Thinking Machines, Inc'.s supercomputer performs over 9 billion operations per second.
1996 Breakthrough software delivers high-quality speech and music via the internet.
1997 Dolly the sheep is cloned.
Terabit transmission: A trillion bits of data travel long distance over a single optical-fiber strand.
What were the 20th century's most important technological achievements? Travel along our time line and find out.
Many people feel the computer is the century's most important invention. "It makes things a lot easier for everybody," explains 13-year-old Chris Safrath. Chris correctly guessed that personal computers debuted in the 1970s.
Digital "mainframe" computers debuted decades earlier. 1946's Electronic Numerical Integrator and Calculator (ENIAC) weighed 30 tons. It had 19,000 tubes and 6,000 switches, but it could add 5,000 numbers in one second.
Invention of the transistor (1947), the integrated circuit (1959), and the microprocessor (1968) made computers smaller, faster, and more powerful. In the 1990s, supercomputers performed over 9 billion operations per second.
"Without the TV," says 14-year-old Brian Urbanija, "you wouldn't know what's going on around you." Brian was unsure of when television was invented, but even historians disagree about this.
Some sources say the Scotsman John Logie Baird built the first TV in 1923. Because of design differences, however, other sources credit American Philo Farnsworth with the first TV transmission in 1927.
Microwave ovens are really convenient. "It's a lot easier to pop something in the microwave and heat it up real quick," notes 11-year-old Kelly Flachbart.
American Percy LeBaron Spencer invented the microwave oven in 1946. Not until the early 1980s, however, did sales of home microwave ovens heat up. Sometimes a good idea takes time to catch on.
Inventions you don't see can make a huge difference. Built on silicon, solid-state transistors replaced fragile vacuum tubes in computers, radios, and televisions. Modern microchips can contain millions of transistors. They're found in computers, automobiles, coffeemakers, and all sorts of appliances.
"You need something to keep your food cold," notes 15-year-old Stephen Wilgus. Modern refrigeration took off when American Thomas Midgley invented Freon (1931). This nontoxic, nonflammable refrigerant helped air conditioning become cool, too.
Sometimes inventions have unintended drawbacks. In the 1980s, scientists discovered that chlorofluorocarbons in Freon could harm the atmosphere's ozone layer. Now refrigerators and air conditioners use more environmentally-friendly refrigerants.
Fourteen-year-old Rachel Thibo feels that health-care advances are the most important technological improvements of the 20th century. "They help people live longer," she says.
Major milestones include antibiotics (discovered in 1928), polio vaccine (1952), heart transplant surgery (1967), and the Computer Tomography (CT) scan (1972).
Do you love your electronic camera (1981)? Go everywhere with your personal stereo (1979)? Listing all of the 20th century's technological achievements would take a tome.
If we've left out your favorite 20th-century invention, send the name of the invention, the date it appeared, and your information source to: ODYSSEY, How Did You Miss This One?, 30 Grove St., Suite C, Peterborough, NH 03458. We'll print some responses in a future issue.
Kathiann M. Kowalski relies on her computer, car, refrigerator, air conditioner, VCR, and microwave. However, she also reads old-fashioned paper books and plays a non-electric piano. She lives in Fairview Park, Ohio, and is a frequent contributor to ODYSSEY.