Here is part seven (the final part) of my non-fiction work about the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. You can also read parts one, two, three, four, five and six.

The NRAO fleet

The cars used on the NRAO campus are different from what you might expect. You’ll see photos of them below, and in case you’re wondering why they look so old, let me explain.

Gasoline-powered cars generate more RFI than diesel-powered cars because they have spark plugs. That meant that NRAO had to purchase diesel cars when they bought their original fleet, and by the way, these cars are part of that original purchase. When NRAO wanted to renew their fleet, they found out they couldn’t, because the newer diesel-powered cars on the market were all using chips and various other electrical equipment (seat belt buzzers, door buzzers, etc.) that generated unwanted RFI. Any electrical ark (spark plugs, power lines, bad thermostats, etc.) generates broadband radio signals, at various frequencies throughout the spectrum but mostly at the lower frequencies, below 2 GHz or so. So that meant they had to stick with their original fleet, whose diesel engines used no computer chips whatsoever and generated little RFI. You may look at these cars and call them clunkers but to NRAO technicians and scientists, they’re reliable modes of transportation that do not interfere with their research.

You may see newer cars in the parking lot, but they’re not used on campus. Only these blue diesel cars can go under and around the telescopes without causing problems.

Because they have no new technology to warm up the engine block on cold mornings, they keep them plugged in whenever they’re parked, to make sure they can be started right away and to keep down on the wear and tear on the engines.

We were ferried around the NRAO campus in one of these cars by Mr. Sizemore, and they’re quite comfortable.

One thing I can’t get used to in these old cars is the gear shifter. It’s so long and seems so awkwardly placed…

More on the telescopes

One of the telescopes on site is used as a teaching instrument. NRAO, being involved in both research and educational efforts, brings groups of school-age children on-site to teach them about radio astronomy. The telescope is not a fancy, cryogenically cooled machine but a simple wire-mesh dish with simple control and monitoring gear that the kids can play with. It’s fully functional though, and it does pick up many radio waves. It’s sufficient to teach radio astronomy and galactic coordinate systems and such.

The National Youth Science Camp is just up the road from NRAO. For two weeks each summer, groups of teachers (high school and college) come to NRAO for an intense course in radio astronomy. The staff turn on the knowledge firehose and “really pour it on them”, as Mr. Sizemore puts it. They have classes during the day and then do research at night with the telescopes. He says it’s not unusual at the end of two weeks to see them walking around the campus, muttering to themselves.

After they complete the course, they can bring their own students to NRAO (for a day or so) and use the 40-foot learning telescope to teach them about radio astronomy without much intervention from NRAO Staff.

As the young researchers sit and wait by the telescopes for the stars to come into position, they have nothing to do, so they doodle or draw. Sue Ann Heatherly, the NRAO Education Officer, loves to collect the better ones and she puts them up on the walls of various NRAO corridors.

As we drove around, Mr. Sizemore pointed to a dish and told me it was a polar mount, and that I will never see a dish built like that again. It’s mounted on the plane of the galaxy (Milky Way) not the earth coordinate system. It’s a right ascension and declination mount. If you were to stand on the axis of the telescope and look at the sky, you would be looking directly at Polaris, the North Star. (By comparison, the GBT (Green Bank Telescope) is mounted as an elevation and azimuth drive system, which is an earth based system. ) The reason this telescope was built like this in the 1950s is because computer power at that time wasn’t fast enough to translate between the coordinates of the galaxy and the solar system in realtime. Now even a pocket calculator can do it.

Although the telescope has been sitting unused for 10 years, they recently brought it back online in order to do atmospheric research studies with MIT. The study involves bouncing radio signals off the satellites around the Earth, then measuring those signals to see how they were perturbed by the atmosphere. The MIT researchers brought their own trailer on-site, with their own receiver and computer equipment. After some work mitigating RFI leaks from the trailer, they were ready to go and NRAO was happy to see the telescope back in action.

When it comes to the GBT (Green Bank Telescope) one of the things NRAO doesn’t want to do with such a large telescope is to set up vibrations in the structure when it’s started and stopped. The way they handle that is to mount both forward and reverse motors at each drive wheel. In order to stop or start it, all the technicians have to do is to increase the current on the motors that move in the direction they need, and the structure will stop or start as fast or as slow as they want it. When you think about this and other precision equipment mounted on the dish, like the laser leveling equipment and the motors that power each plate in the dish, Mr. Sizemore likened the GBT to “building a battleship with the precision of a Swiss watch”.

Even the track of the telescope is leveled to within 1/5,000th of an inch, and the rest of the structure is comparable to that all the way up. What about the land settling over time, I asked? There are no such problems, he replied, because they went all the way down to bedrock when they laid the foundation (about 40 feet).

The local cement contractor had no competition when it came to the contract for laying the foundation. The closest competitor was about 40 miles away, on the other side of the mountain, so he got the contract and had to rent three additional cement mixer/pouring trucks in order to keep up with the demand. For the entire period (three or four weeks) that it took to pour the foundation, the man kept grinning as his trucks pulled into the construction site, because he stood to make a lot of money.

The NRQZ monitoring station

While I was on-site, Mr. Sizemore showed me his “hiding place” – his monitoring station. It’s a big trailer that can be hauled from place to place, but has been made stationary and hooked up to the power lines. That’s where he does most of his work. Here he monitors the gross violations of the Quiet Zone and also looks at the local environment: powerline noise, illegal use of radios, etc.

For example, at the time of my visit there, the amateur radio bands were being used improperly by a group of people and the signal was strong enough to overload the 140-foot telescope, so it became a serious problem. Wesley told me that the problem will likely be taken care of long before I write up about it, and the likely action taken will be that he calls the FCC in to enforce the rules in place. After 20 years on the job, Wesley has built up a network of contacts he can call upon when he needs help. One of those contacts is the man in charge of the Enforcement Bureau at the FCC, whom Wesley knew when he was still a satellite technician.

While I was recording our talk, I asked Wesley if he could see the interference generated by my recorder, and he worked up a quick setup to find the noise it created. Sure enough, he tuned into the noise generated by my iPod as it was recording our conversation within a couple of minutes.

One of the teaching tools he uses with school groups that visit NRAO is a metal trashcan (a Faraday cage with an antenna and amplifier mounted inside the lid). He takes his spectrum analyzer, connects it to the antenna and amplifier assembly, then gets a student volunteer to put in their phone or laptop or MP3 player, then he shows the whole group the interference those devices create. The only thing the antenna sees is the RFI generated by the device put in the trash can, because it’s a Faraday cage. Everyone is invariably wowed by this.

As we drove around the NRAO campus, we came across a car with a “cantenna” (a directional waveguide antenna for long-range WiFi), and I immediately pointed it out to Mr. Sizemore, as I knew he’d be on the lookout for WiFi transmissions in the area. Smirking, he admitted that was his service car, and he told me the story behind it. The FCC had donated it to NRAO, who had been using it to sniff out illegal transmissions. The car actually had antennas built into its roof and was already fitted with equipment for sniffing out radio transmissions. Mr. Sizemore outfitted it with WiFi “sniffing” equipment as well: a laptop with NetStumbler and a bunch of other apps, a GPS device for marking the location of RFI-causing WiFi and a “cantenna” on the roof, that he could rotate and point at various WiFi sources.

Before retiring from NRAO (years after my interviews with him), Mr. Sizemore outfitted a new Dodge Ram extended cab truck as an RFI vehicle, a feat which was written up in USA Today.

NRAO and the community

As we drove around the campus, Mr. Sizemore pointed to the farmhouses that surrounded NRAO. When the government took over the land, they invoked the right of imminent domain, forcing the farmers to move. That generated animosity toward the observatory, because the land was fertile and it was good for farming.

With time, things got better, to the point where there was only one farmer left who couldn’t stand NRAO and wouldn’t ever let them step on his property. All of the powerlines and phone lines for NRAO were routed around his property. At one point, the man chased Mr. Sizemore’s predecessor off with a stick. If NRAO staff ever had to go visit him, they’d take a deputy sheriff with them. When Mr. Sizemore began working there, he knew to steer clear of the farm.

One day though, he got a call from the man. He had an outside TV amplifier, a tube-type amplifier made by a company called Blonder-Tongue, which had been struck by lightning. The old man couldn’t find anyone to repair it and he didn’t want to spend money to get a new one. He called the only one whom he knew could help. Mr. Sizemore was of course glad to do it, because he’d finally be able to atone for the bad blood between NRAO and the farmer.

He drove out to the man’s place, where he had to wait off the property for the amplifier to be brought to him (he still wasn’t allowed on the farm) and took it back to the lab to see what he could do.

He called Blonder-Tongue and was told they hadn’t made that amplifier model in 20 years, and they hadn’t serviced it for 10 years. They didn’t think they could help. Mr. Sizemore insisted he speak with a supervisor and as luck would have it, the repair supervisor was an elderly guy who remembered working on them when he’d started with the company. He said, “Send it to me, and I’ll show these young technicians how things used to be.” Mr. Sizemore explained the entire situation to the man, about NRAO and the farmer, then mailed off the amplifier to the repair supervisor.

The amplifier came back repaired and it didn’t cost anything either. The old farmer was elated when he got it back. He put it back up and everything was fine until a week later, when he called Mr. Sizemore. You know the old saying about lightning not striking twice? Not true for the old man. His amplifier had been struck again.

He didn’t want to let Mr. Sizemore examine his property, to see if the lightning strikes could be prevented, so all he could do was to mail it off to Blonder-Tongue once more. Sure enough, it came back repaired as new again, at no charge. Thankfully, to the day of the interview, the amplifier evaded other lightning strikes so things were fine between NRAO and the old man.

Thanks to Mr. Sizemore’s efforts, NRAO enjoys a very good relationship with the community. Being an isolated rural community, where all they have is each other, they tend to pull together and help each other.

For example, some people had learned to recognize the interference from awry TV amplifiers, which would show up as a herringbone pattern on their sets, and would call Mr. Sizemore to let him know. They also knew what powerline interference looked like, because it would show up on their sets once again, generating a specific noise pattern.

The NRAO site is basically a wildlife preserve. They let the animals live and roam free. The only practice they instituted a few years back was a controlled deer hunt, because the deer population had gotten out of control. Before they began, the Wildlife Management Institute wanted to do a headcount of the deer, so they fitted a plane with thermal imaging equipment and started to fly over the NRAO site one night.

Because they hadn’t publicized this, the local people didn’t know what was happening and all they could see was a plane which kept circling over NRAO at night. They thought the plane was in trouble, so they all pulled together, drove to the local airport (next to NRAO) and shone their headlights on the landing strip, to help it land. Well, after a while, they figured out the plane wasn’t in trouble and went home, but let’s just say that the next time WMI decided to do nighttime wildlife studies, they publicized it widely, to make sure everyone knew what was going on.

The NEACP encounters

As we talk about flyovers, another good story is that of the NEACP encounters. When the Cold War was going on, the US Military always had an aircraft in the air at all times, an airborne command post (NEACP: National Emergency Airborne Command Post). There were multiple such aircraft in service and one was in flight at all times. One would take off before one would land.

When they would fly over NRAO, all the radio equipment on board those planes (they used 1,000 Watt transmitters) would overload NRAO’s equipment with RFI. Mr. Sizemore found the number for CMOC (Cheyenne Mountain Operations Center) and spoke to one of the people involved with NEACP. He introduced himself and said, “You have this aircraft, using this callsign, operating at this frequency, at this location.” They got upset right away, because they didn’t want anyone to know what their routes were. They started questioning Mr. Sizemore about the source of his information, to which he simply replied, “I used a 300-foot telescope and I looked at your aircraft.” Then he continued to explain: “I have to track this source of interference down. That is my job. I have a solution. Let me send you my observing schedule every month, to tell you what frequencies I’ll be observing on what days and tell you my station, and then you’ll be able to avoid me. And if you can’t avoid me, you can let me know, and I’ll tell the astronomers to take a coffee break.”

As a result of that phone call, Mr. Sizemore got the NEACP to avoid the Green Bank area, and when they couldn’t avoid it, he got a few calls from them when they had to pass over NRAO, after which he would quickly tell the astronomers to take a break, as their equipment would soon get overloaded, making the data unusable.

That’s the end of part seven and the series. As mentioned at the start, this work is unfinished, and that’s why you don’t see a nice story arc with good closure, but I hope that what I’ve published has proven enjoyable and interesting for you and has sparked your interest in radio astronomy and NRAO. You can also read parts one, two, three, four, five, and six.

I’d like to once again thank Wesley Sizemore, without whom this text would not be written (or edited properly). Thank you Mr. Sizemore!

Thank you for reading!

Here is part six of my non-fiction work about the National Radio Astronomy Observatory in Green Bank, West Virginia. You can also read parts one, two, three, four, five and seven.

Tidbits

The NRAO site is around 2,700 acres. It runs along the crest of the adjoining mountains. One big current problem, that will only get bigger in time, are wireless routers folks are starting to use in their homes. Mr. Sizemore has actually gone out and identified every wireless router in the area. At the time of writing there were 45 such routers.

The NRQZ (National Radio Quiet Zone) gives the NRAO the right to file comments to the federal frequency regulation bodies (FCC and NTIA) for permanent, fixed, licensed radio transmitters wishing to be installed in the NRQZ. The NRAO does not have any “power” to regulate radio use. However, the FCC and NTIA “determine”, in most cases, that it is in the public interest to uphold the NRQZ protection requests. However, there is a West Virginia state law that provides protection within a 10 mile radius of a radio telescope from any source, licensed or unlicensed, that causes interference. A wireless router, like a garage door opener, is an unlicensed device and thus falls under the state law.

Still, each case of interference has to be treated individually, and it is in everyone’s interest that it’s resolved it in a friendly way, for the sake of community relations. At the time of writing, Mr. Sizemore was working with the NRAO lawyers and local legislators to see how the problem of wireless routers could be addressed. They’re a real problem when it comes to interference, and they’re unlike past problems, where faulty equipment was to blame, which could be fixed or replaced. Well-functioning routers will emit interference and cause significant problems to NRAO’s daily work.

Of the 45 routers mentioned above, 26 were provided by the local telecommunications company to their customers free of charge, with the contract, so they could be removed by the telecommunications company itself. The rest were privately owned, and NRAO was naturally pursuing a voluntary removal approach with the router owners.

In the office space above the control rooms are the offices of the scientists and staff at NRAO. It’s a long hallway, part of the new construction, cleanly carpeted. The walls are filled with research posters.

Mr. Sizemore and I stopped to talk about one of the posters. Before, folks thought of the galaxy as a fairly uniform soup of fog. With the GBT (Green Bank Telescope), Jay Lockman, one of the senior scientists at NRAO, was able to discern that this fog was more like clouds. To the layperson, this may not seem like a lot, but to astronomy, that’s a big piece of the puzzle. Now they can try to figure out how the clouds work, what they’re made of, how they move, etc. This discovery could not have been made until the GBT was online.

As we continue to walk, one side of the hallway draws particular attention. Framed photos of the various Jansky lecturers are mounted there. Every year one is chosen, and he gives a lecture on a subject of his choosing. A lot of them are Nobel prize winners. Grobe Rieber was one, of course. Frank Drake (the Drake equation) is also one. Arno Penzius and Bob Wilson are also on the wall. They are Nobel Prize winners for their early work on background microwave radiation. They are the two scientists that discovered background radiation.

There’s an interesting story behind their work. In October of 2005, Mr. Sizemore met the technician who did the hands-on work for their experiments. The man and his wife visited NRAO one day, and Mr. Sizemore showed them around. The man acknowledged that he was scared for his life at times, as he worked with them. They had no sense of the practical or common sense, and would often ask him to do very dangerous experiments. Penzius, for example, could not figure out how to unbuckle his seatbelt. The technician had to do that for him. He couldn’t figure out how it worked, and yet he won a Nobel prize for theoretical work in physics!

Mr. Sizemore showed me his old office, the Quiet Zone office. That’s where the administrative work for the NRQZ is done. He used to be responsible for that, but he’s thankfully gotten help in that area in late 2005, when NRAO hired an NRQZ Administrator and let him focus more on chasing down interference. While he was in that office, he conducted more than 10,000 propagation studies. Paulette Woody, the new NRQZ Administrator, started on the 17th of October, 2005.

As we drove on the NRAO campus, Wesley stopped to show me his “hiding place” – his monitoring station, where he does his RFI hunt-work. It’s a big trailer that can be hauled from place to place, but has been made stationary and hooked up to power lines. Here he monitors the gross violations of the Quiet Zone and also looks at the local environment – powerline noise, illegal use of radios, etc. For example, at the time of my visit there, the amateur radio bands were being used improperly by a group of people and the signal was strong enough to overload the 140-foot telescope, so it became a serious problem. Wesley told me that it will likely be taken care of long before I write up about it, and the likely action taken will be that he calls the FCC in, to enforce the rules in place. After 20 years on the job, Wesley has built up a network of contacts he can call upon when he needs help. One of those contacts is the man in charge of the Enforcement Bureau at the FCC, whom Wesley knew when he was still a satellite technician.

Depending on the sorts of studies performed, the data collected by NRAO in a single day can get to be as much as 50 GB (nowadays it’s probably more than that). The data is usually written to LaCie portable drives and either handed out or shipped out to scientists responsible for the studies. The data isn’t archived locally. It’s recorded for the individual astronomers. Once it’s shipped out, it’s someone else’s data and they are responsible for it. If they lose the drive containing the data, they need to re-run the study. NRAO simply doesn’t have the money or the staff to act as a data warehouse for the data. Astronomers, like most scientists, also guard their data quite jealously and consider it proprietary until they decide whether they can publish it.

The sewer system on site is unique. Because NRAO has to worry about interference, they didn’t want any pumps on-site. What happens is that waste fluids from the sewer system flow into a series of sediment ponds that are built on a gentle slope. They are gravity-fed and include absolutely no motors. NRAO actually won an award for this design. As the water flows through the ground from pond to pond and through vegetation, it gets purified and is ready to be discharged into the adjoining streams of water.

The telescopes and their research

Mr. Sizemore had a story to tell about the motors that run the individual plates of the GBT. NRAO ordered a few samples, saw they worked alright, then ordered a whole batch, about 1,500 or so. When they started to do live testing, the motors ran out after a few days. They opened one up to see why and discovered that the carbon brushes were completely burned out. They’d disintegrated. Upon contacting the manufacturer, they found out that he’d switched the type of carbon brush from the harder ones they specified to softer brushes, which were a few cents cheaper per brush. They were basically cheating NRAO. NRAO’s Business Office sent back all the motors and had the brushes replaced. Add to this experience countless similar others over the years and one can see why they’re wary when dealing with contractors and manufacturers.

There are other radio telescopes on the NRAO Campus, all of which are involved in ongoing research. For example, the 45-foot dish is doing a project on solar radio burst spectrometry. They’re looking at the Sun and measuring the bursts of radio noise from it (solar flares and the like).

They also have calibrators, which are rock-solid sources of radio waves. They always emit at the same frequency and strength. Researchers point their equipment at them to see if their equipment is reading correctly and make any needed adjustments.

One of the telescopes on site is used as a teaching instrument. NRAO being involved in both research and educational efforts, brings groups of school-age children on-site to teach them about radio astronomy. The telescope is not a fancy, cryogenically cooled machine, but a simple wire-mesh dish with simple control and monitoring gear that the kids can play with. It’s fully functional though and it does pick up many radio waves. It’s sufficient to teach radio astronomy and galactic coordinate systems and such.

The fastest telescope at NRAO is a 20-meter dish which will go from horizon to horizon in 90 seconds. It’s not being used at the moment. In the past, the most popular program at NRAO was universal time and polar motion.

Time is not a naturally occurring thing. It’s a man-made contrivance. Time is nothing more than your position relative to something else at a given instance. We keep time by the rotation of the earth on its axis, and the rotation around the sun. Einstein said time is all relative depending on your motion and such. In order to keep accurate time, not only do we have to know the rotation of the Earth on its axis and around the Sun, but we have to know the wobble. Because the Earth is a spinning body, just like a spinning top, it tends to wobble.

There’s a plaque next to the telescope, with a plot of the position of the North pole of the Earth over 5 years. You’ll see that it wonders around, it doesn’t stay in one place. In order to have accurate time, we must know what that wobble is. How do you do that? There are quasars. They are quasi-stellar objects. We think they’re the black holes at the centers of galaxies. They’re very far out there, and they’re very strong, so they can act as a point source. Even though the distance to them is enormous and they’re moving relative to us, because of that distance to them, their movement is insignificant compared to the movement of the Earth itself. When we look at those quasars and we see any apparent shift in their position, we can determine what the Earth’s wobble is. That’s a use of radioastronomy that most people can grasp: timekeeping.

Source: NASA, Hubble Telescope

NRAO used to conduct regular time studies. Wesley actually started out at NRAO as an interferometer operator. The program running on the interferometer at that time was the universal time and polar motion. They fed that data into the master clock of the Naval Observatory. If you’ll remember, at the end of 2005, there was some discussion in the news because a leap second would need to be added to clocks. Wesley would take out leap seconds from atomic clocks. It would be done over time, with microsecond increments. NRAO was a major contributor to time-keeping for the US.

We can use those same quasars to monitor tectonic plate movement, geodesic work. This is also documented on a plaque there. There are several major tectonic plates on the Earth’s crust. If you put a radiotelescope on one plate and one on another plate, then look at a quasar, any apparent shift in their position will be due to the movement of the crustal plates. That means we can use radio astronomy for geodesic-type work.

The Howard E. Tatel Telescope was also the first telescope involved in the search for extra-terrestrial intelligence. Dr. Frank Drake, working on Project Osma, used it for his studies. That sort of work isn’t done by NRAO anymore. It’s not part of their primary mission. Now this sort of work is done through private organizations like the SETI (Search for Extra-Terrestrial Intelligence) Institute in California. You, dear readers, can participate in the study if you want, by downloading an application that will let your computer crunch through the data gathered from space in the search for signs of ET intelligence. The processing power of your computer will only be harnessed when your screensaver is active. This is a good example of distributive computing, where the power of many varied computers is put to work on a single task.

The HET Telescope is not being used currently. It’s part of a three-element interferometer. The second element is another 85-foot dish on the NRAO site, and that’s now used to do pulsar studies.

What are pulsar studies? Well, it starts with the sun, which is supposedly a fairly old star. It is hypothesized that in a number of significant years in the future (we’re talking billions), the physical nature, the make-up of the sun will start to change. It will collapse and throw off its outer shell, being left with a big hot center called a white dwarf. Now, if you have a star that is several times larger than the sun, like 6-8 times, when it’s in its death throes and its gravitation collapses, it blows off the outer shell, the nucleus will collapse to a very dense neutron star. A typical neutron star is several miles in diameter.

If we were to compare what’s going to happen to the Sun in Earth-terms, It’s like collapsing our planet to the size of a golf ball. A teaspoon of that sort of matter will weigh hundreds of thousands of tons. It would have an enormous magnetic field, so the only radiation that will escape from that neutron star will be through the poles of the magnetic field. Since the rotational axis and the magnetic poles do not have to align, the star could be spinning on its axis and the magnetic fields could be perpendicular to that axis, so that it will act as a sort of magnetic lighthouse. Every time it will sweeps its magnetic pole in the direction of the Earth, we will get a pulse of energy, hence the word pulsar.

Source: NASA, Hubble Telescope

Why are pulsars interesting? Because the spin of certain pulsars is as accurate as we can time it with an atomic clock. What’s a second? 1/60th of a minute? No! It’s over 9 billion vibrations of a Cesium electron at a certain pressure and temperature. That’s the official definition. The pulsars that NRAO looks at spin at millisecond time intervals. A big research topic now is using the timing of pulsars to prove gravitational waves.

There are certain time standards kept in cities throughout the world, such as Paris, Moscow, DC, but they are susceptible to destruction from natural or terrorist events. With pulsars, we have out of this world time standards that cannot be destroyed. They also serve as perfect navigational beacons, if we will ever do space travel.

The question that’s been asked in the past is, why don’t pulsars slow down? Well, they exist in binary pairs, two of them orbiting each other. Our Sun is an oddity, because it’s alone out there. There can also be trinary star systems, but gravity usually kicks the third star out. You know what they say, three’s a crowd… So, these pulsars are in binary orbit with other stars like red giants, white dwarfs, or other some such thing. They feed off the energy of their companion, and they don’t slow down, they stay in a constant rotation, or at least as constant as we can time it.

There are platforms out in the field at NRAO. They’re actually crossed dipoles. One of the big questions in astronomy is reionization. The dominant theory of the creation of the universe is the Big Bang. When it occurred, that primordial soup was extremely hot, so everything was fragmented into elemental particles, such as quarks, muons, etc. As things cooled down, particles came together and created molecules, then stars, etc. When the stars started to fire up and generate ultraviolet light, they re-fragmented some of the elemental hydrogen left over from the big bang that had not yet coalesced. That hydrogen was re-fragmented to its elemental particles, and sometime later, it re-congealed. NRAO is looking at that reionization process. They’re looking at this cycle of heating and cooling that takes places as the universe expands. Don Backer, one of the astronomers at NRAO, is looking at that extremely red-shifted signal (meaning very big waves) to see if he can determine when the heating/cooling cycles occurred. The signal is somewhere between 125-226 MHz. They’re not sure where that signal is and what frequency they’ll find it at, so they’re hunting background radiation at the moment, trying to discern a “flashlight in a floodlight”. When they do find it, it’ll be interesting.

The powerlines

One of the things you’ll notice at NRAO is that there are no powerlines on-site. All of the power cables are underground. There’s a main cable that feeds the site, which NRAO runs through a generator where the power is conditioned, mostly in its frequency. The cables that run to each building are all buried. It’s easy to understand why. They don’t want any arcing of power lines above ground.

A couple of years back, one of their lines went dead and they started digging around, looking for the cause. It turned out to be a black snake which had crawled across two contact points and shorted itself and the lines. He was still there, unable to move, because he’d been fried!

And that’s the end of part six. You can also read parts one, two, three, four, five and seven.