ELi5:Why do electronics or objects make crackling or popping noises in cold weather?


Why do they make crackling noise in cold weather such as computers or other electronic gadgets when the room temperature is cold mostly when the A/C is on?
Especially when the appliance is not plugged or not in use.I have also noticed such strange noises in furniture?

In: Technology

Objects expand and contract depending on temperature. Most things always expand when heated, and contract when cooled. There are some exceptions (rubber/heat shrink, water around 0°C), but that’s the general rule. I suspect some of what you are talking about is objects that can heat up quite a bit when in use. For example, a car. When the engine gets turned off, the metal body begins to cool down. This causes sections of the body to shrink slightly. There could be parts of the body that start sliding past each other by tiny amounts. Maybe these parts have a couple of snags on them that aren’t totally smooth. As they catch, they begin to pull on each other. Then they keep cooling, the pull gets bigger, until eventually they pop past each other with an audible *ping*.