Sunday, January 29, 2012

Telling Time III: Without hands

In this third of a series of posts, I'll review one of the most common practices in time-telling today:

TELLING TIME WITH NO HANDS
As described in the previous post, we use the term "digital" for the watches and clocks that don't have hands. They simply display the digits. It's important to know that digital displays are NOT new. We have had them for over 100 years.


This  Chronoswiss Delphis watch displays time in a combination of ways - it's a jumping hour display at the top, a 180-degree minute display with jumping retrograde minute hand in the middle, and conventional second hand at the bottom. This is a mechanical watch with no electronic parts.


This is the display on my mobile phone. The date is spelled out underneath. It's an electronic display with no mechanical parts. The Apple guys have also created analog clock displays for these digital devices, because some people just can't do without hands.



Here's a watch for athletes and Timex fans. It dates to 1994 and was in near-perfect condition until it was passed along to a teenager. I haven't had the courage to ask him how it's doing. We can see the day of the week, the month and day (top line) and hours (24 hr), minutes and seconds (bottom line). The array of buttons around the watch control other functions.


This big titanium Swiss Army Watch has both analog and digital displays. You can read the same time either way, or show something else on the two digital display panels. In this photo, the digital panels are showing a stop watch counter (Chronograph).


The Cartier clock in this photo is on the dashboard of a 1970's Lincoln. Revolving drums with numbers show the hours and minutes. The colon separator is stationary. On the right, there's a drum with 10-second intervals in gold.


This digital flip clock demonstrates one of the first digital display technologies. No LEDs are required, just a constant-speed motor and some gears. Two wheels with cards that have numerals on them rotate toward you, and the cards flip over and fall down to show the time. Tiny fingers at the top keep the card from falling too early. This has been running on my desk for about 5 years.


This elaborate digital clock gets its signal from the GPS satellite network. It's designed to stay within 10 nanoseconds of official time! The small indication at the top shows the consecutive day of the year (073), then the hour in 24 hour format (22), then the minutes and seconds. The larger display at the bottom is currently interpreting the days, and showing us that 073 = March 14, 2011. It can also display the time in large numerals, or show consecutive seconds of the year, etc.


I have to admit that I've gone a bit overboard on my master clock array, although some of them are now deployed around the house so I can set all the wind-up timekeepers to nanosecond accuracy! I may devote an entire blog to the stack.


This wild Heathkit clock from the Sixties shows digital time with Roman numerals formed by light-emitting diodes. It's showing 11:33 and 46 seconds.


Finally, the Nixie clock uses heat- and numeral-generating vacuum tubes (valves) to display the time. I tried to catch 3:33:03 but wasn't quick enough. Nor bright enough to wait for 3:33:33. So you see I ended up with 3:33.09.

I could go on and on, but let's advance to the next post where we will tell time with our fingers!