In 2013, when we went for Glover Park day, there were people from the US Naval Observatory at the USNO table. In talking to them, I found out that they do tours of the facility, and that they have a telescope you can view through when you go on the tour. They also told me that the tours had been stopped for now due the the fiscal cuts. Disappointing. They said to keep checking the website, because they might start up in the future. A few weeks later, I checked, there were no tours. I checked a few times after that too, but there was nothing. I then forgot about checking it for almost 2 years. A couple of months ago, I googled it again, and the tours had started! The dates for August and September were already full. I requested to be on the tour in October, and we go in! :)
The USNO is known as the place where the Vice President lives. Also, when you pass it on Massachusetts Avenue, you notice the large digital atomic clock outside that has the most precise time. Apart from that, people know very little about this place, and it is so well hidden behind darkness, that as you pass by, there is not much you can see apart from the heavy security.
The entrance to the USNO for the tour is from the South gate, up the road from the British Embassy. They check your government issued ID, you walk through a metal detector and they hand you a visitor badge. We were a pretty large tour group, and we were split in half. One half would first go to the telescope, and the other half (our half) would get a tour of the buildings and the history of the USNO.
THE USNO was established as a center to calibrate the navy's chronometers, charts and other navigational instruments needed by their ships. In time, as the navy grew the location of the USNO moved from 17th and G street, to 23rd and D street and finally to its current location at Observatory Circle. The USNO plays an important role in time keeping. It ensures correct time, initially done based on earth's rotation, and now done by hitting a cesium atom with microwaves to get the perfect oscillation to obtain precise timing (the basis of an atomic clock).
 |
| Models of telescopes |
On the tour, we were first in a small circular room, where we were told about the history of USNO, saw portraits of Lieutenant Louis M. Goldsborough who first had the USNO under him and Lieutenant James M. Gilliss who was later put in charge of the USNO, and saw models of telescopes used to observe celestial bodies to help with determining precise time. From this room, we walked down a long corridor that reminded me of colleges in India, it had a high ceiling, the signs of the room were like they were in college and there was a musty smell in the air. The corridor lead us to the best looking library in DC!
 |
| Corridor Leading to the Library - Reminds me of Xavier's hallways for some reason |
The library is circular with a chandelier hanging in the middle. It has 2 winding stairs that take you up to a landing where more books shelves filled with books are. It is the most extensive astronomical library in the United States and has over 90,000 different volumes. They also have a collection of extremely old books. The oldest book there was published in the 1480s! They also have a book written by Newton and one by Galileo (Dialogue Concerning Two Chief World Systems - Ptolmeic and Copernican).
The book by Galileo had a fun story behind its writing. Galileo had come to the conclusion that the earth revolved around the sun, and it wasn't the earth that was the center of the universe as firmly believed at that time by most people and the Catholic Church. In order to be able to write about his conclusions, he approached the Vatican and told them that he would write a book where 2 characters would present the arguments of Ptolmeic and Copernican, and a third character would make sure that everything was going okay. He also told them that he would not draw any conclusions, and leave that to the reader to decide based on the arguments presented. The Vatican granted Galileo permission and he wrote the book and submitted it to them for approval. The character written to defend Ptolmeic's position was given the name "Simplicio"...this was an indication of how the rest of the book was to go, and Galileo was found to be suspect of heresy and the book was placed under the 'Index of Forbidden Books'.
 |
| Some of the old books! |
When we got done at the library, the other tour group started to trickle down. It was now our turn to head to the telescope! It is a 12-inch refracting telescope, housed on the 5th (top) story of Building 1. We got to look through the telescope thrice. The first time, the magnification appeared as if we may just left earth's atmosphere and headed to the moon, the second time, the magnification was as if we are a 1000 miles from the moon and the final time, it was as if we were 200 miles from the moon!! The moon was in quarter stage, so we were able to look at the light and dark side of the moon and where the two sides meet. This meant we were able to see shadows of the mountains and craters. I have never looked through a telescope before and this was absolutely thrilling! :)
After we were done with the telescope, we all went back to the room we initially waited in before the tour began. There, Geoff Chester told us about the significance of time keeping. They can calculate time accurately down to the femtosecond! 1/1,000,000,000,000,000 of a second! He also talked about the different clocks they had over time, as scientific discoveries and technologies improved, the precision of clocks improved and clocks changed. Clocks started out as pendulums, changed in time to be made of different materials so they would not be affected by temperature, were housed in vacuum, so as to be unaffected by weather. They eventually moved to quartz based clocks and now have the atomic clock. A very interesting talk on time and he explained the complicated physics really well so that if you paid attention, you could how the clocks worked, why they didn't and what the significance of the changes on them were.
The atomic clock is so precise that it is a better time keeper than earth's rotation. Earth's rotation changes. It is affected by the moon's gravitational force on the seas. Earth's rotation get slower be 1.4 millisecond per day, every century. So, when the dinosaurs lived, the day was probably 22 hours!
An excellent excellent tour, one that few visitors to DC would look out for or seek to do.
 |
| After we were done viewing through the telescope, we stepped back in to take the elevator down. I saw these spiral stairs and I love how much like a snail shell they looked! |
 |
| As we were leaving the Naval Observatory grounds, we spotted these guys! |
