At the top of the pass between the White and Inyo Mountains is a mysterious sign that says CARMA. I had wondered about it almost every time I drove through the pass, but always forgot to look it up when I got home (no cell coverage up there.) There weren’t any KEEP OUT signs, but there were no Visitors Welcome either, so I had not ventured back that dusty, dirt road. All that came to an end when CARMA held an open house on Saturday.
Since I bypassed the building at first, being drawn by these huge antennas, I didn’t realize I was doing the tour backwards. The physicists, chemists and engineers were busy explaining extremely technical data to clusters of interested observers. I will try to explain in my terms, or click the link at the bottom of the post that explains more fully. 🙂
By receiving, multiplying and averaging the data received by the 3.5 meter – to 10 meter antennas, the scientists can determine what elements make up new stars, galaxies, and what’s left of a black hole and so much more! There are no photographs from the antennas like the Hubble Telescope, but CARMA’s images can be transposed on top of the images to display elemental data about what the colors, stars, rings, or black holes are made of.
One of the large antennas weighs approximately 300,000 lbs. The antennas are anchored by cables because they actually ‘walk’ a few millimeters every month. Lightning antennas surround the disks (little dark spikes on the outside that you can’t actually see in the photos), and the jolts are grounded in four places around the antenna.
You will note the antennas are turned in different directions in these photos. There are separate routines the antennas are programmed to do on any given day, constantly comparing and gathering data. While I was standing on the platform of one antenna, the antennas straight ahead were turning like huge robots. Several minutes later, they were all pointing a different direction. The one aluminum antenna above is in the position where it can be cleaned (if needed) of snow and ice; they use big brushes to reach up from the ground.
Interestingly, there are two completely different antenna configurations. The white disks were developed by the University of California, Berkeley, while the aluminum disks were developed and built by Cal Tech. Each university worked entirely on their own to create their own version of the antenna. The Cal Tech aluminum antennas rest on three legs and are smaller than the UC Berkeley disks which have four legs. The UC Berkeley disks use the honeycomb shape that are fitted together, leaving a gap between each piece. Both varieties require vast amounts of refrigerant to cool the disks to keep them at optimum efficiency. You can hear the high-pitched beep-beep-beep as the freon is pumped into the systems.
In another few days, the antennas will be moved into the most compact configuration they are ever in because of water vapor in the summer air. The 23 antennas are at 7200′ because the humidity is lower than in the valley at 4,000′. There are three more huge antennas down in the valley, perhaps more, but three can be seen from the road. The thin dry air keeps a lot of the ‘noise’ out of the signals that are received practically 24 hours a day from these behemoths.
This is the antenna mover. The chemist who was explaining how it works likened it to fancy farm equipment. He did say that because there are so many wheels to contend with, and even though he was raised on a farm in Iowa, this was nothing like backing up the farm machinery that he used to do so well. The moves are planned with exact precision. The machine backs up to the antenna, picks it up and keeps on backing to its new resting place. Because the driver can’t see anything, lines are drawn in the sand for him to follow in his rear view mirrors. After the antenna is picked up, the generator mounted behind the cab has to kick in to keep the antenna cooled and powered up until it’s placed on the different pad.
This little machine takes the millimeter signals from the antennas and puts them into a sealed cooled vacuum in the beginning of the process to get the true signals away from the noise. Three telescopes usually word in tandem to determine the noise signal.
Inside the building, there are observers on duty 24 hours a day. The newly graduated astrochemist from Cal Tech explained how the millimeter waves are analyzed by the computers to create the center and right image which can be overlaid on the Hubble images.
You may double-click on any of these images to enlarge it enough to read the print.
There are two long rows of these boards – each one with the power of about 7 BIG iMac computers, all running getting the signals, multiplying and averaging the data. All of this takes hundreds and hundreds of pages of computer code to keep running. One section of memory on the back costs $17,000 each!
One more row behind this one with as many motherboards.
These cables connect this observation post with others around the world. The computers have to coordinate the ethernet signals they receive to keep them in real-time.
Click here for more information on CARMA.