What is cold? In the most general sense, cold is the absence of heat. More specifically, cold is the transfer of thermal energy from one object to another object at a lower temperature. When an object absorbs thermal energy, it becomes colder. The opposite of cold is hot.
How does cold work? Cold works by transferring thermal energy from one object to another. The process of transferring thermal energy is called conduction. Conduction happens when two objects are in contact with each other and there is a difference in their temperatures. The warmer object will transfer its heat to the cooler object until both objects reach the same temperature. This process can also happen through radiation and convection, but those are beyond the scope of this article.
What are some everyday examples of cold? Some everyday examples of cold include putting ice cubes in your drink, taking a walk on a chilly day, or eating ice cream on a hot day. All of these involve transferring thermal energy from your body (which is at a higher temperature) to something else (which is at a lower temperature). This makes you feel colder because your body loses heat faster than it can produce it.
Is it possible to create absolute zero? In theory, yes. Absolute zero is the lowest possible temperature where nothing can be colder. It occurs when all particles stop moving and have no kinetic energy left. However, reaching absolute zero would require an infinite amount of time and cooling power, so it’s not really possible in practice.
How do people use cold? People use cold for many different things including keeping food fresh, numbing pain, and cooling down overheated electronic components