Radio-controlled watches receiving a radio frequency that atomically corrects time or radio-controlled clocks on walls or desks are about drift into inaccuracy.
That’s because Japan has two-time frequency broadcasting stations. Watches and clocks that receive signals from these stations are known as “dempa tokei” in Japan, radio controlled watches in Europe and the United States are mistakenly known as “atomic watches.”
“Japan is dependent on two broadcast locations, one at the extreme tip of Kyushu in Saga City and the other in Fukushima Prefecture on top of Ohtakadoya Mountain,” said Hiro Tanaka, a watchmaker in Tokyo.” The mountain is about 17 kilometers from Fukushima Dai-ichi power plant.
The technicians operating the station from Ohtakadoya Mountain were ordered to evacuate March 11 by Japan’s government. Then it stopped broadcasting.
Although there was no damage to the buildings or broadcast equipment, technicians cannot get it operating again until the radiation alert is lifted. This means no time signals will be broadcasted to Japan north of Tokyo, including Hokkaido, and what reception there is in Tokyo will be very spotty reception from the transmitter in Saga.
Radio controlled watches and clocks, analog (watches with hands) and digital, will not be able to automatically synchronize without the time signals, which is accurate to close to one second in a million years.
According to a spokesman for Seiko, a Japanese watch company, “The automatic synchronization and correct function will temporarily be out of commission. Otherwise the watch will be OK.”
The time broadcast from Saga City covers the southern part of Japan, Korea and areas of the Chinese coast, within a radius of about 1,000 kilometers. However, it only reaches as far as the Tokai region with some pick up in Tokyo.
“Even without being able to receive signals anymore, it’s doubtful if any radio controlled wristwatch, digital or analog, will even be off ten seconds a month,” Tanaka said. “However, with some clocks, particularly the less expensive ones you could have problems. Inexpensive clocks are sometimes susceptible to thermal drift.”
Thermal drift is when extreme hot or cold throws off the “quartz” inside the clock, causing the clock to gain or lose time. Quartz watches and clocks work via piezo electricity. Quartz has the unique natural property that it vibrates at a constant rate when electricity runs through it.
This is the “quartz” of a quartz watch. It’s literally a chunk of quartz, not unlike the old quartz radios from your grandfather’s day. The circuitry in the watch translates these vibrations into the numbers of a digital display or turns the hands on an analog watch.
Tanaka pointed to two clocks he has on the wall. “The one on the left is a “Dempa Tokei” and it receives radio signals to correct itself from Ohtakadoya mountain. It’s still OK and the time is correct. But the one on the right is an ordinary quartz clock that I haven’t reset for around a month. It’s about three minutes off.”
Heat and cold, as well as vibration affects the crystal which is the heart of quartz clocks, making it expand and contract and causing different rates of vibration depending on the temperature. This causes the clock to drift. On inexpensive clocks, this can be up to five or more than a minute per month.
“Since the time signal is now out, I would advise checking clocks once or twice a month with the phone signal and resetting them now and then,” Tanaka says. “Cell phone time is good, too. You don’t have to worry about watches. Body heat keeps them at constant temperatures and they usually have a superior grade of crystal.”
Atomic clocks and Cesium
There is concern about the integrity of the system itself. Americans mistakenly call these radio frequency controlled watches “atomic watches,” because the reference for the time signal, like the time on a cell phone or the flow of information over the Internet, is generated by a real atomic clock.
Real Atomic clocks (as opposed to a radio frequency controlled watch, which has nothing atomic about it) observe the decay–the half -life– of cesium 133. This isotope is one of the more than 50 isotopes of cesium. Cesium 133 has an exceptionally stable half-life, so the “clock” counts the number of atoms given off.
Atomic clocks generally have an accuracy of around one second in a million years. The most precise one, in the Bureau of Standards in the US, which has an accuracy better than one second in 30 million years.
The fear is that the area around Fukushima has been contaminated by cesium. In a worse case scenario, this could poison the land around the reactors for generations to come.
Cesium 137 and Strontium 90 are two of the radioactive substances that poisoned the area around Chernobyl for hundreds of years. Cesium 134 and 135, which are by-products of the radiation the core of a nuclear reactor produces, breakdown relatively quickly, but cesium 137 does not. It remains to be seen if the cesium found in the Fukushima area is the more benign type or the long lasting type.
If it is the long lasting virulent type, then the radio control frequency transmitter, which depends on a cesium clock, a peaceful and willing servant of mankind, ironically will have found itself in turn poisoned by cesium, a nightmare unleashed by the same dreams of mankind’s reason.