Eternal light

Did you know that the longest lasting light bulb is more than 110 years old and it is still switched on? The Centennial Light is hanging from the ceiling of the Livermore-Pleasanton Fire Department at 4550 East Avenue, Livermore, California. It is a four-watt, hand-blown, carbon-filament, common light bulb manufactured in Shelby, Ohio, by the Shelby Electric Company in the late 1890s. The bulb was donated to the Fire Department by Dennis Bernal, the owner of the Livermore Power and Water Company in 1901, when he sold the firm.

The Centennial Light was switched off only a very few times which, despite the common belief, is the reason for its longevity. Each time a bulb is swithced on and off, the filament is heated and cooled down which makes the filament to expand and contract. These expansions and contractions create microscopical stress fractures in the material of the filament, which eventually lead to a break causing the bulb to burn out.

The last time was 33 years ago when the Centennial Light was switched off during the move of the Fire Department to its current location. The bulb spent 22 minutes without electricity while it was transferred.

Treasure to Trash

Did you know that the diamonds are slowly being converted to graphite? This is a very-very slow process but undoubtedly exists. Graphite is the most stable form of carbon and has no special value. Diamond is extremely valuable and the second most stable but needs high pressure to remain as it is. Diamonds on (or near) the surface are not under the pressure needed so an unnoticeably slow conversion occurs.

Diamond is the hardest natural material known having extreme resistance to scratching. But it is not tough at all so don't try your hammer on it. If you insist on destroy your diamond then the most spectacular - and nevertheless a very expensive - method is to heat it to more than 800 degree Celsius where it converts to graphite quickly enough to observe.

The largest diamond found on Earth was the Cullinan, in 1905, which weighed 3,106 carats. But this is not the largest one we know about. In 2008, scientists discovered that a star, namely the BPM 37093, which is located 50 light years away from Earth has a diamond core 2,500 mile wide weighting approximately ten billion trillion trillion carats.

Wake up early

Did you know that the first alarm clock of the United States could only ring at 4 AM? It was created by Levi Hutchins in 1787 in order to wake him for his job. The French inventor Antoine Redier patented the first adjustable alarm clock, more than half a century later, in 1847. The alarm clock was invented in the Ottoman Empire almost 300 years earlier, in 1559, by Taqi al-Din. He described it in his book The Brightest Stars for the Construction of Mechanical Clocks.

The production of the alarm clocks in the US ceased during the World War 2 as the factories were converted over to war work, but they were one of the first items to resume manufacture for civilian use after 2 years in November 1944. By that time, a severe shortage of alarm clocks had developed which caused serious problems in critical jobs due to late arrivals.