Uses thermal expansion of liquid mercury to indicate temperature. Contains mercury reservoir connected to capillary bore. Temperature scale visible through stem, lower near bulb. Covers temperature range from −37 to 356 °C
Temperature measures hotness or coldness and reflects average kinetic energy of atoms. Temperature scales include Celsius (°C), Fahrenheit (°F), and Kelvin (K). Absolute zero (0 K) is -273.15°C or -459.67°F, never reached experimentally
Celsius was first proposed by Anders Celsius in 1742 as a reverse scale. Scale was originally called centigrade in several languages. Name "Celsius" was adopted in 1948 to honor Anders Celsius
Scoville scale measures chili pepper pungency in Scoville heat units (SHU). Created by American pharmacist Wilbur Scoville in 1912. Uses subjective taste panel testing with pepper extracts. Results vary up to ±50% between laboratories
Thermoscope was first thermometer without scale, showing temperature differences. Galileo invented water thermoscope in 1593 using buoyancy of water. Santorio Santorio added numerical scale to thermoscope in 1612. Ferdinand II created first enclosed liquid-in-glass thermometer in 1654
Smartphones can measure temperature using external sensors or weather stations. External sensors connect via WiFi or Bluetooth to phone. Apps like Room Temperature Thermometer provide accurate readings. Few phones have sensors for accurate room temperature measurement