Time is Relative

We went to the Naval Observatory Monday night, where we first learned about keeping time and then got to view Saturn through this large 1873 telescope! Plus the floor moved up and down!!

Some history...

For most of human existence, the unit of time that has mattered most was the day. As our capacity for velocity increased (via trains, planes, etc.), the importance of maintaining accurate time also increased. Up to the late 19th century, each community was responsible for its own timekeeping -- which led to train crashes. So Western Union and the U.S. railroads established a single time source. At noon each day, Western Union sent out a time pulse to clocks set up in railroad stations that synchronized them. That pulse originated from the Naval Observatory.

Other cool time tidbits:

• Since 1950, the earth's revolution has slowed down by 33 seconds. This has created a difference between 'scientific time' and 'social time,' leading to the "leap second," which a lot of timekeepers hate. Losing a second now means losing billions in revenue. There's a proposal to do away with the leap second and to instead have a 'leap hour' once every forty years or so.
• No one clock is accurate. Clocks work on the idea of a 'center moment.' The official time comes from not a single clock but an average of many.
• Canadian railroad companies are the ones who came up with time zones.