How does my ofen know how long a second is if its not connected to the internet?
I set the time once and it just knows the time but how?
In: 1
some good answers about how simple electronic devices keep time. here’s an answer about the Internet keeps time.
We picked out a moment in time to count as the origin of the timeline, the 0 moment that we start counting from. We call this moment the ***Epoch*** and in most computing systems its set to 0:00:00 Jan 1, 1970.
In order to know what moment in time something occurred we count the seconds before or after the epoch. Anything that happened before the epoch is a negative number. Anything that happened after the epoch is a positive number. The current time is +1676394617 seconds since the epoch.
Internet connected computers reference multiple official clocks to stay synchronized about how many seconds have passed since the epoch. They form a consensus by comparing the time measured by various high precision clocks around the world. This consensus is shared through a system called Network Time Protocol. This is the global standard for timekeeping on the internet.
There are lots of ways that high precision clocks can count time, but one of the most important ones is by counting the amount of radiation emissions from a radioactive Cesium atom. Physicists have determined that these emissions happen on an extremely regular interval that is effectively unchanging in its rate over time. This makes it like a natural metronome, if you want to think of it that way. It ticks at a fixed rate and we can count time by counting the ticks.
Latest Answers