Would
you like to live a world in which you never have to charge your phone
again. May be scientists inspired by this venerable scientific
curiosity could help you... In the foyer of the Clarendon Laboratory
in the University of Oxford lies an electric bell named as Oxford
Electric Bell or Clarendon Dry Pile which has been ringing
continuously since 176 years and has been recognised as the
longest-lasting battery in the world.
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| Oxford Electric Bell or Clarendon Dry Pile |
Termed
as one of the world’s oldest experiments, still no one knows
exactly why it’s lasted so long. The only way to find out what is
inside for sure is when the battery ultimately dies as opening the
device could potentially ruin an experiment to see how long it will
last. Therefore researchers will have to wait until either the
battery finally loses its charge or else the ringing mechanism breaks
on its own from old age.
Oxford
Electric Bell made by Watkin and Hill, an instrument-making firm in
London, and purchased by Robert Walker, a professor at Oxford was
first displayed in 1840, says a handwritten note attested by his
grandson on the bell. Some accounts at Oxford University says the
bell could have been started even earlier, in 1825. The Guinness Book
of World Records has named its power source the "world's most
durable battery."
It’s
a dry pile battery, which is one of the first electric batteries
invented by a Giuseppe Zamboni during 1800s. They use alternating
discs of silver, zinc, sulfur, and other materials to generate low
currents of electricity. Being a dry pile battery, it’s got a paste
inside with a minimum amount of water needed for the electrolyte to
work. The battery is covered with an insulating layer of molten
sulphur, in order to protect against atmospheric damage (i.e.
moisture),connected in series at their lower ends to two bells. It’s
theorized that the interior contains thousands of discs made of
manganese dioxide and zinc. Between the bells is suspended a metal
sphere or ‘clapper’ about 4mm in diameter which is attracted
alternately by the bells and transfers charge from one to the other
due to an electrostatic force, maintained by the ringing of the
bells. The process is repeated over again and again. The frequency of
its oscillation is about 2Hz and so far the bell would have rung
roughly 10 billion times, and probably more than that, calculations
from the university suggest.
High
humidity can cause the clapper’s movement to slow and even stop,
but when the humidity drops the bell can begin again without external
intervention. As the clapper strikes and rings one bell, the
corresponding dry pile charges and electrostatically repels it. The
clapper then swings toward the other bell, and the same thing
happens.
While
it needs high voltage to create motion, the sphere only carries a
small amount of electricity to the alternating dry piles. Because
there’s just little bits of energy being discharged through the
process, the drain on the battery is very less, and this may be the
reason for its long run..
Presently
the voltage left in the battery is so low that the human ear can't
actually hear the ringing. Instead, the clapper oscillates back and
forth between the bell constantly. A former researcher at the
Clarendon Laboratory, A. J. Croft, described the apparatus in a 1984
paper for the European Journal of Physics. According to him, the
battery pulls 1 nanoAmp each time it oscillates between the bell’s
sides, which is an remarkably a low amount of current. But the
voltage between the bells is 2 Kilovolts, according to guest host,
Sally Le Page, in the
latest video on TOM
SCOTT’s you tube channel.
A
similar type of dry pile batteries were used to power the infrared
telescopes during World War II, because a portable, low-current
electricity source was necessary. Croft further wrote that an Oxford
physicist, inspired by the bell, is working to make a similar one to
boost up the present era telescopes.
I
think we're probably not going to build a better battery than this at
this point. The bell has been ringing nonstop under the glass since
18oos and no one can tell when it will stop, leaving behind a mystery
to be solved… The lifetime of this battery should be incredible,
and if scientists are correct, it should work for thousands of years
and outlive us..
