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Period: 3100 BCE to 3000 BCE
Obelisk
Egyptians used an obelisk, a vertical structure with four sides, as a shadow clock -
Period: 1600 BCE to 1500 BCE
Clepsydra
Early Greeks and Egyptians designed this ~water clock~ -
Period: 350 BCE to 300 BCE
Hour Glass
Also known as the sand glass, first hour glass was found in a sarcophagus dated 350BCE and used commonly until 14th century -
Period: 310 BCE to 300
Sundial
Babylonian, flat surface, 12-hr face, or dial. A gnomon, a vertical marker, fixed to the middle of the dial and cast a shadow showing the hour of the day. At this time, people learned to use the position of the moon, planets, and stars too. -
Period: 1300 to 1301
Mechanical Clocks
Used physics principles of weight and balances to mark out increments of time over a 12-hour period. First ones were large and didn't keep accurate time. -
Period: 1400 to 1450
Watches
Wearable time pieces appeared in Italy first. These were analog -
Period: 1473 to 1543
Heliocentric Systen
Nicolaus Copernicus, Polish astronomoer, argued the earth operated in a sun-centered system. That is, the sun is the center of the Universe. He also hypothesized the earth revolved around the sun annually and every 24hrs it spun/rotated around its own axis. -
Period: to
Pendulum
Rod-like weight that swings from side-to-side and controls a clock mechanism, increasing accuracy of the mechanical clock -
Period: to
Heliocentric Acceptable Standard
By the 1700s, Copernicus' ideas were accepted -
Period: to
Marine Chronometer
Used to determine longitude by means of celestial navigation. Chronometer was coined from the Greek words chronos (meaning time) and meter (meaning counter) in 1714 by Jeremy Thacker -
Period: to
Self-Winding Mechanism
The first self-winding mechanism was invented for pocket watches in 1770 by Abraham-Louis Perrelet,[20] but the first "self-winding", or "automatic", wristwatch was the invention of a British watch repairer named John Harwood in 1923 -
Period: to
Digital Watches
first digital electronic watch, a Pulsar LED prototype in 1970, was developed jointly by Hamilton Watch Company and Electro-Data, founded by George H. Thiess -
Period: to
Smartwatches
A wearable computer in the form of a wristwatch. Software may include digital maps, schedulers and personal organizers, calculators, and various kinds of watch faces. The watch may communicate with external devices such as sensors, wireless headsets, or a heads-up display. It may support wireless technologies like Bluetooth, Wi-Fi, and GPS.