Nowadays, luminescent watches are all the rage with uses in the military and civilian settings. Real-life military men like the Navy Seals and fictional spies like James Bond as well as outdoorsmen and executives are enthusiastic fans of these multi-functional, ultra0-durabke and oft-complimented watches and for good reasons, too.
History of Luminescence as Used in Human Society
Let’s understand the history behind luminescence as applied to human uses so that we can have a better appreciation of the technology. In ancient China, phosphorescent jade stones were grounded to make luminescent beads, decorative cups and other ornaments. Since jade was the sacred stone of the Chinese, these items were prized for their rarity.
History records the discovery of the first luminous paint in Japan over a thousand years ago. Apparently, a painting of a cow was discovered inside a cave that disappeared during the day and reappeared only at night. It was discovered that the paint was made from luminescent sea shells.
It was only in the nineteenth century, however, when the first luminescent watches were manufactured. Of course, the Swiss watchmakers were at the forefront of this glowing development, so to speak, when the dials of their timepieces were treated to natural luminescent paint harking back to the techniques used by the ancient Japanese cave artists.
Development of synthetic luminescent materials was aided by science and technology. At first, barium sulfide was used and then followed by metal sulfide and alkaline metal aluminate. Nowadays, most of the luminescent wristwatches use proprietary compounds like Luminova and SuperLuminova, which are definitely safer than the radioactive paints used in prior years.
How Luminescence Works
So, how exactly do luminescent watches glow in the dark? Well, we have to understand the process known as phosphorescence, a special form of photoluminescence.
Photoluminescence is the process whereby a substances absorbs the photons and then re-radiates these photons, thus, producing the radiated glow. On the atomic level, the atoms are subjected to excitation methods that place them in a higher energy state quickly followed by a lower energy state usually just lasting 10 nanoseconds. But with special methods, the glow can last for minutes and hours.
In the real world, luminescent watches can be made to glow in the dark at will, in a manner of speaking. Just place the room in darkness and observe as the wristwatch starts to glow after a few minutes and then hold its luminescence for as long as necessary. Or at least until the atoms will need recharging through exposure to bright lights, that is.
You also have the benefit of high-tech watches like the Navy Seal watch where almost instantaneous glowing of the phosphorescent materials is possible. Recharging through exposure to bright lights is also unnecessary as the watch is powered by a small vial of stable H3 Tritium gas.
Indeed, luminescent watches are great timepieces because of the many functions that these can offer their users. Not only can many of these watches tell time in daylight but also in darkness, not to mention offer other benefits like telling the depths and location of wherever the user may be.