IPFS News Link • Science

The Earth Had Its Shortest Day in Recorded History

• arclein

Because the Earth's rotational speed varies, we use a standardized Coordinated Universal Time, or UTC, to make sure our clocks are in sync across the world. Two components determine UTC: International Atomic Time (TAI) and Universal Time (UT1). UT1 is a time standard based on the Earth's rotation, whereas TAI is a time scale that provides the speed at which our clocks should tick. TAI is based on the average of hundreds of precise atomic clocks in timing labs across the world. It's incredibly accurate, but it doesn't take into account slight variations in how the Earth spins. "When you start looking at the real nitty gritty, you realize that Earth is not just a solid ball that is spinning," Fred Watson, Australia's astronomer-at-large, tells ABC. "It's got liquid on the inside, it's got liquid on the outside, and it's got an atmosphere and all of these things slosh around a bit."