Don't Forget to Put a Stitch in it

How Time Is Made

Here’s another timing article that popped up right after Daylight Saving Time ended. (Perhaps a heavy sigh is required here. I’m not sure why the rash of stories has hit is) I’m predisposed to like it, since it’s largely focused on our work, but unlike some articles I’ve critiqued lately, it doesn’t focus on one US timekeeping group and ignore the other one

By law, today the USNO shares the responsibilities for measuring and disseminating time with the Time and Frequency department of the National Institute of Standards and Technology (NIST), which sits under the US Dept. of Commerce. The USNO sets time for GPS and navigational systems and the Dept. of Defense, while NIST sets the standard for the financial sector and other civilian applications. (NIST receives several billion computer requests per day for this service, and broadcasts time to over 50 million radio clocks, wristwatches, and other clocks with radio receivers.) While there is a lively cooperation between the two agencies charged with telling the time—and the occasional competition over talented PhDs—they mostly operate in different domains: NIST performs most of the cutting-edge research, while USNO focuses on counting and disseminating the time to the military, as a matter of national security.

I don’t even object to the observation that NIST is doing most of the cutting-edge research — they are. Their frequency standard results are amazing. Our research in that area is different, since it focuses on developing continuously-running clocks.

What's it Like?

What It Felt Like to Test the First Submarine Nuclear Reactor, with substantial quotes from an earlier article

This was of interest to me, owing to my ~5 year stint as an instructor in the nuke program. Some of the details point toward Rickover’s vision; things like realizing that more could be learned by building the test reactor in the same configuration that a sub’s reactor have in a submarine — starting with a prototype in any other configuration would leave too many unknowns when the “operational” configuration was built (making systems more compact invariably introduces new problems), and too much time would be wasted. And the general attitude of over-engineering the reactor — scaling down features is usually far easier than beefing up or adding new ones.

A Tiny Bit of Insight into this Navy Scandal

Thirty years ago, right about … nnnnow … I was graduating from Officer Indoctrination School in Newport, RI, and would shortly report for duty in Orlando, FL on the USS Disney World as a Nuclear Power Instructor, where I would serve for a little over 4 and a half years.

So this got my attention: AP NewsBreak: Navy Kicks out 34 for Nuke Cheating

At least 34 sailors are being kicked out of the Navy for their roles in a cheating ring that operated undetected for at least seven years at a nuclear power training site, and 10 others are under criminal investigation, the admiral in charge of the Navy’s nuclear reactors program told The Associated Press.

The number of accused and the duration of cheating are greater than was known when the Navy announced in February that it had discovered cheating on qualification exams by an estimated 20 to 30 sailors seeking to be certified as instructors at the nuclear training unit at Charleston, South Carolina.


A lot of things have undoubtedly changed in the 25 years since I separated from active duty — Nuke School moved from Orlando, FL to South Carolina, and they combined it with the hands-on Nuclear Power Training Unit (NPTU) training taking place on moored submarines (originally done at prototype sites, and two of those units still operate) and the Nuclear Field “A” school for the enlisted, which was just getting started when I was teaching.

The report says this was confined to a single unit and the test was called “engineering watch supervisor” which leads me to believe this happened with the NPTU training portion of the school, which happens at the end of the sequence.

There is mention of there being five tests, given in a predictable rotation. The classroom and prototype training were each about six months (IIRC it was 24 weeks), and that probably hasn’t changed much. Each new class arrived at seven week intervals (except if the start were at the end of December, when classes were not held), which means that there were at most four classes in session at a time. The rationale behind five exam templates was that no active student could give useful information to a shipmate in a subsequent class in terms of test questions and answers, since they would not be taking the same test, and because all test were returned after review — they were never out of an instructor’s control. If the students wanted to come up with a master file, it would be by memorizing question and answers, and then passing the information along, with no benefit to the first five sets of students who did this. Not impossible but also not considered a big risk.

Coming up with a completely (or largely) new exam was not really an option, because you want some degree of uniformity of the difficulty of the tests. So you would recycle the tests with maybe a few changes, and that allowed you to compile statistics on test questions. If a particular class did exceptionally bad or good on an exam, you could have some confidence that it was not because the test was too hard/easy. You could replace questions with others in the exam bank and know it shouldn’t wreck the projected score because you had these stats, and brand-new questions were limited to minimize any effect they might have if they proved to be significantly easier or harder than projected. I don’t really find fault with that — potential staff cheating wasn’t the focus. The staff are/were supposed to have more integrity than the students.

Back in the day, of course, none of this was computerized. We barely had word processor technology, and no exam material could go into any digital format (exam writing was literally cut, copy, and paste. As in cut out a question from one sheet and paste it in place on the new exam master, and run it through the copy machine (sometimes twice, so you could white-out any extraneous lines from the cut). So there’s some inertia here in the rules, from the days when greater changes to the exams were just too laborious to carry out.

The blurb about the reactors being operated safely was valid. The sailors were already qualified to do that — this was for teaching certification, not operator certification, which is one reason why this is puzzling. The information should have been material they knew. In my qualification there were oral exams as well and I imagine that’s true for this part of the program, so any knowledge deficiencies could have been uncovered.

While my nominal tour of duty was four years (I extended it to better mesh with the start of graduate school and because I was in a not-yet-known-to-be-doomed relationship) these sailors likely had shorter tours, so if this has been going on since 2007, the cheating franchise has changed hands a few times. It’s not clear if all 34 are currently instructors, or if (as I suspect, now that I think about it) this is going to include sailors much closer to their retirement.

There’s an unfortunate habit of thinking that integrity is not ratting out your friends, so it’s quite possible that some sailors are getting away with cheating because their shipmates won’t turn them in. The navy integrity and ethics I am used to always had, somewhere in the foundation, the idea that cutting corners was bad because lives were at risk. If these were indeed sailors at the latter part of the training, then they had been to sea, where your life depends on your shipmates not shirking their duty (this is not hyperbole; mistakes made 400 feet below the surface do not have a margin of error you have when you can open a door and run outside), and why such things are not tolerated. That makes this all the more shocking, and it’s also refreshing to see it being made public rather than some attempted half-assed coverup. (Though a more cynical me might speculate that there is a coverup of a larger problem and these are scapegoats, but despite this scandal I’m not feeling that cynical at the moment) This serves as a warning for anyone tempted in the future that it’s not worth it.

300th Anniversary of the Longitude Act

Maritime museum finds time for celebration of Harrison’s sea clocks

The exhibition marks the 300th anniversary of the Longitude Act, passed in 1714, which established the Longitude Board and offered a vast £20,000 prize to anyone who could solve the problem of measuring longitude at sea. It includes the actual act of parliament, passed in the last weeks before the death of Queen Anne, on display for the first time.

The story of John Harrison, the carpenter and self-taught genius clockmaker who invented a series of ever more accurate clocks and then a cabbage-sized watch that solved the problem, but never got the full prize from the board, inspired Dava Sobel’s bestselling book and film, Longitude.

This is the reason why my job (making atomic clocks — real clocks) is a navy job — precise navigation requires precise time. The transition to GPS hasn’t changed that fact. Poor navigational ability is costly:

In a storm in 1707, when an entire British fleet was driven onto the rocks at Scilly believing they were safely out at sea, more than 1,400 sailors drowned.

More: Why longitude mattered in 1714

Lincoln the Geek

During the Civil War, Abraham Lincoln blew off steam by looking at the stars

Lincoln himself saw the metaphorical opportunities in the cosmos. When he was asked during the Civil War if his faith in the Union was misplaced, he replied with his memory of a Presbyterian deacon he boarded with in 1833. One night, the deacon had knocked on the door, certain that Judgment Day was at hand: The sky seemed to be falling.

Said Lincoln: “I sprang from my bed and rushed to the window and saw the stars falling in great showers; but looking back of them in the heavens I saw the grand old constellations with which I was so well acquainted, fixed and true in their places. Gentlemen, the world did not come to an end then, nor will the Union now.”

It was probably the Leonid meteor shower that had so shaken the deacon.

I was at the ceremony mentioned in the article. Great stories. I don’t think any recent presidents have come a-knockin’, especially now that we’re further away, though Vice President Gore did avail himself of his proximity and visited the nascent clock development lab, and Cheney did make an appearance nearby wielding a giant pair of scissors (but didn’t venture into the more science-y areas)


The US Naval Observatory was established on Dec 6, 1830, as the Depot of Charts and Instruments under the command of LT Louis Goldsborough. Its function was to maintain, repair and rate navigational instruments and had an annual budget of $330. Its mission expanded in 1842 to include its function as the national observatory, and moved to its current location in 1893. (Back then, it was out in the boondocks and away from the lights of the city.)

Navigational instruments include chronometers, necessary for determining longitude, which is why the Observatory maintains time for the military.

Happy 183rd birthday.

Poe, Poe, Pitiful me

10 physics misconceptions, explained poorly

[This blog post was written by a guest columnist, a D-student in freshman physics who will remain anonymous]

It’s pretty obvious it’s not, even accounting for Poe’s law (as applied in this case, one could not tell the difference between a D- student and a professor pretending to be a D- student, were the professor able to avoid succumbing to snark. Or hyping his book.). The misconceptions are very real, though. One of my favorites, much more plausibly true, is the one about heavy boots.

In my teaching days I saw plenty of these. So much so that we once played a game of “GCE Jeopardy!” at a party my housemates and I threw. The answer was given, and one had to name the Gross Conceptual Error (GCE) that would have elicited the response. For example, if the answer in the “mechanics” topic was “It is always conserved”, the proper GCE question would not be energy, since that’s actually conserved. It would be “what is momentum?” Some students would invariably insist that momentum was always conserved, even in the cases where a net force was acting. Which counts as a gross conceptual error.