The Naval Observatory makes an appearance in Blondie
I have gotten phone calls from people expecting the voice announcer telling them what time it is. My original phone number was apparently listed as such in some old government handout. It’s a little like the reaction when people call and were expecting (or hoping for) voicemail.
Reminiscent of my navy days; when the enlisted students would walk around outdoors they had an uncanny knack of separating themselves into individuals or small groups, and you would have to return their salutes as you/they walked by. They only called me “Sir” though, not “My Lord”.
Builder Blames Navy as Brand-New Warship Disintegrates
There are technical terms for this kind of disintegration. Austal USA, Independence’s Alabama-based builder, calls it “galvanic corrosion.” Civilian scientists know it as “electrolysis.” It’s what occurs when “two dissimilar metals, after being in electrical contact with one another, corrode at different rates,” Austal explained in a statement.
A reason you aren’t supposed to mix aluminum and copper wiring in your abode.
It’s not just the guns that are going electromagnetic.
Full Electromagnetics Ahead! EM Naval Launcher Test Successful, Will Replace Steam
Propelling a 5 ton jet to liftoff speed over short distances has been the key to US Naval success for 50 years and the reason why their aircraft carriers are unique. Their steam “catapults” allowed fast enough acceleration for launch.
It was a good run, but it’s time to run out of steam.
The Navy made history Saturday when it launched the first aircraft using the Electromagnetic Aircraft Launch System, or EMALS, technology.
There’s a video at the link, but it’s anticlimactic; acceleration is acceleration. If you watch, I recommend skipping the first 1:50; it’s all boring character development and plot dead-ends that have no bearing on the story line.
In 1861, astronomer Simon Newcomb got a U.S. Naval Observatory job because many Confederate sympathizers left their jobs.
Navy test fires electromagnetic cannon
The story tells you it was a 33 MegaJoule shot, and it traveled (or would travel) 200 km. What it doesn’t say is how big the projectile is. The maximum range for a projectile is going to be v^2/g, in the limit of no air resistance (and also assuming a flat surface, but we’ll ignore that because that’s probably a small effect here). If we pop in the equation for kinetic energy and solve for the mass of the particle, we get m = 2E/dg. The amount of recoil energy given to the ship will be negligible; momentum is conserved and KE = p^2/2m, so the amount of energy scales with the mass ratio, which will be some number measured in kg compared to a kilo-metric-ton or so, which gives us a part in a million. So yeah, we can ignore that.
So 33 MJ gives us a mass of about 33 kg. But that’s assuming the energy of the pulse is the same as the energy of the projectile, i.e. the system is 100% efficient, and still ignores the pesky air resistance. This article mentions an earlier test, and puts the weight of the projectile at 7 pounds, or about 3.3 kg, meaning the system is at least 10% efficient.
The article also mentions the launch happening at five times the speed of sound, which is about 5*340 = 1700 m/s, which for a 3.3 kg projectile, is just under 5 MJ. All of those estimations seem to agree reasonably well. It also predicts the ideal maximum range of about 290 km, so we see just how much loss we have due to the air. Engadget says Mach 7, which is 10 MJ. Still ballpark; I wonder if one is launch speed and the other is impact speed, since the maximum range formula assumes a 45º launch, and in reality this isn’t the case.
The time it takes the shell to travel this path is at least four minutes. I’m guessing that the final version would not be “dumb;” you would attach a gps guidance system to it and have some better control of where it would land.
Yesterday was the 180th birthday of the Naval Observatory (yay, we had cake); it was established on Dec 6th, 1830 as the Depot of Charts and Instruments. One of my colleagues sent out a copy of a 1913 House appropriations committee hearing transcript, in which the USNO superintendent was interviewed regarding his budget requests.
I found it quite compelling, but I’m biased. It’s interesting that congressional failure to grasp science and general dickishness is not something new; there are inquiries into whether the functions of the observatory could be done with a reduced staff, or eliminated completely in order to save money, possibly because it was being duplicated by one of the “great universities” (those being Harvard and Stanford). The answer then, as now, is no; there’s a distinction between basic and applied research. University astronomers of recent times don’t do the systematic position measurements that go into producing an alamanac. I think the attitude displayed by Mr. Burleson implies that he thought that everyone with a telescope must be doing the same thing. He pegs the dick-o-meter when he suggests that the work being done is” rather crude or backward as compared with the work that is being done at the naval observatories connected with the universities.” I don’t really know why one would phrase the inquiry that way.
There’s a bit of bureaucracy tedium as well, such as trying to convince the committee that when the staff is underpaid as compared to other government jobs or the private sector, people tend to move on before they might otherwise do, and retaining people, even at higher salary, is usually cheaper than continually training new employees.
All in all, not very different from what I see today.
Pump-Powered Antennas Could Replace Metal Communications Arrays with Fountains of Saltwater
What they came up with is little more than an electromagnetic ring and a water pump. The ring, called a current probe, creates a magnetic field through which the pump shoots a steam of seawater (the salt is a key ingredient, as the tech relies on the magnetic induction properties of sodium chloride)
I think they meant “stream.”
Last week I stayed late to give a tour of our clock facility, and to show off the fountain, to some brass that were visiting. For me, tours like this are a little bit stressful, because this was more than just the gee-whiz—aren’t—we—cool tour (and tabletop-ish atomic physics makes for some pretty good gee-whiz) we give to some visitors. For those visitors, talking about physics is sufficient, and I’m pretty good at bringing the geek. For visitors who actually have a stake in what we do, I’m trying to make the presentation relevant to the job they do, above and beyond the “timing = navigation, because a nanosecond is a foot.” And really there is more to that message, because timing is also tied in with communication (and more importantly, secure communication) but because I’m the redundant backup for such tours, I don’t have a lot of practice at the high-level discussions. Which makes a feedback loop — because I don’t have a lot of practice to polish the talk (and I’m further down the chain), I don’t get called on to do this often, etc., etc. Iterate.
But things went well enough, and as the admiral shook my hand and thanked me, a coin was transferred into my possession. Challenge coins are a military tradition, that admit I had no awareness of when I was a junior officer in the navy, mostly because they are generally (or admirally) exchanged only when rubbing elbows with top brass of some sort. Wikipedia tells me the tradition probably dates back to WWI. There are coins that reflects one’s unit, and coins that reflect one’s job, especially if one has a job with a large degree of specialization. These are used as identification, and as with so many military traditions, they are often tied into drinking — if challenged to produce your coin and you don’t have it (or sometimes if you are the last one to do so), you are expected to get a round of drinks.
There are other coins that represent one’s command, and still others that are personal coins which will declare the rank of the giver. These can also be presented as a challenge when you’re sitting in a bar, with the owner of the coin representing the highest rank winning, and exempt from having to pay for drinks. The coin I got represents the Admiral’s office at the Joint Chiefs, rather than being a personal coin, so it does not show the rank of Rear Admiral (two stars). The frequency at which one gives out a coin is really a personal decision; I’ve read of flag officers who carried (or, more specifically, had their aids carry) a bag of coins with them because they handed them out so readily, and others who were very stingy. This was my first coin, and was probably given in appreciation for staying fairly late. A true cynic might think this is little different from the kind of cheesy awards you can buy (“You’re a Star” mug, “Celebrate Awesomeness” hunk of plastic or “Team Player” keychain) but I disagree. A coin — especially a nice coin — is not a bulk item, and has a nice tradition behind to back it up. I’m pretty jazzed about it.
Every so often the powers that be™ decide that a reorganization would be a good idea, and that some people should change offices. A few years back this was stimulated by one group of people vacating some desirable office space in the main building (they were ordered to relocate to Crystal City by even higher powers that be™) and the decision to occupy that space set off a domino effect wherein our group made a “land grab” for some extra space, in which we secured offices with windows (yay!) while hanging on to the offices we we already occupying.
We needed the space, too, because, we were getting set to hire two new employees and were also running out of storage space. But storage space is a low priority in the eyes of the beancounters, so you can’t use that need to justify being assigned new space, and can’t fully depend on it to defend space you already have, especially when it’s empty space, for equipment you are planning to buy (logic is a puny weapon against Bureaucracy-Man, and the future is a myth, since it can’t be documented). And since we knew that somebody would do the math (X number of people left, so there must be some empty office space around here) we had to protect and defend the extra space somehow. That’s where Tuttle came in. The empty office would belong to Tuttle.
Jonathan Tuttle is from an episode of M*A*S*H, and is doubly fictitious — within the TV story, he’s also a made-up character, which was a criterion I used in selecting the name. (Another name that would fit this requirement was George Kaplan, from North by Northwest, but we already had someone with that name at work!) Much like the TV episode, the idea was that if anyone asked, one could always come up with an excuse for Tuttle not being around (“He’s in the lab,” “He’s gone up to Building 1,” or even “He’s at a conference/on vacation this week.”)
Tuttle’s office started out as a spare office, complete with a desk and computer and our networked printer, with office supplies and some other minor items on the shelves but the furniture was eventually moved out for someone to use and was replaced with heavy-duty shelving. To keep up appearances, I took a picture of the office and edited it so I could place it in the door’s window and have it look like it was still an office when the door was closed.
And that’s what you see here — a photo in the window. That’s a printer and an old iMac on a table, but what’s really in the office is a bunch of shelving with equipment and supplies. And the printer — we still use it for that. A number of people have been fooled into thinking it’s an office. That red dot on the door trim was a mark left by some beancounter marking it as occupied office space. The equipment staging area (we don’t call it storage) next door, which was never camouflaged, lacks that mark.