What could be the utmost lowest temperature in the universe/multiverse?
What temperature means...
Temperature is the measure of the energy of particles. The higher the temperature, the more energized the particles. The more energy particles have the faster they move around. This is the particles' kinetic energy that is rising. As it rises, the particles will begin using up more space. Moving particles need more space. In a vacuum this can be measured as pressure which is the stress of thermal expansion on the closed system. In an open system the matter will expand freely. As the particles increase their speed they also move more erratically so the entropy, or measure of disorder, will also increase.
Now understanding all that, what would the lowest temperature, or energy state, be in the universe? The answer is a state of no energy, 0 K, or absolute zero in the Kelvin scale. It is −273.15° on the Celsius scale and −459.67° on the Fahrenheit scale. At this temperature, which is impossible to occur by only thermodynamic means, the particles are completely still and entropy drops to 0.
Temperature reference points...
- The surface temperature of the sun is 5,778 K.
- Water boils at 373 K.
- Water freezes at 273.15 K.
- The moon’s darkest craters that never receive sunlight are 33 K.
- The cosmic microwave background fluctuates around 2.8 K.
- The Boomerang Nebula, the coolest natural place currently known in the universe, measures 1 K.
- Absolute zero is 0 K.
0 K,"absolute zero" (-273.15°C) is the theorized measurement of energy at which all motion stops. Electrons, atoms, and particles stop all movement and it would likely be the lowest possible temperature possible anywhere in the universe. Now that temperature may or may not actually exist in the universe because of all of the radiation and energy from various stars, however it may be possible in the middle of a supervoid or other places.