# Su Song's Cosmic Engine

The Cosmic Engine is an astronomical observatory and clock tower designed by Su Song and Han Gonglian between between 1088-1092 during the Song Dynasty (960-1279). When the capital of the Song Empire was captured by the Jurchens (later called the Manchus) in 1127 the invaders dismantled the Cosmic engine and carted it away to be reassembled in the Kingdom of Jin (which they were unable to put together). Check out the following videos:

Animation

Note by Steven Zheng
4 years, 10 months ago

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This reminds me of the "The Long Now" clock.

- 4 years, 10 months ago

Wow! Hope it will tick for 10000 years. I think the clock will wear down due to entropic reasons.

- 4 years, 10 months ago

A pulsar can be said to be a "mechanical thing", it's a solid that spins, isn't it? Yet, how long do you think it's going to keep spinning while keep near perfect time? Some millisecond pulsars are actually more precise than atomic clocks, and they'll still be going even after millions of years. So, while entropy does cause decay, there can still be a great variation of timescales. The Long Now clock can feasibly last far longer than a conventional mechanical clock, unattended, if it's designed right, and if it doesn't get hit by a meteorite.

- 4 years, 10 months ago

Nice , so you into Astronomy ?

- 4 years, 10 months ago

Astronomy is cool, but I like physics more.

- 4 years, 10 months ago