If you ask Google, then the largest clock in the world
is the one atop the Mecca Clock Tower,
one of the largest buildings in the world, in Saudi Arabia.
Each face is 43 metres in diameter,
and it can be seen for miles around.
No.
This is the actual largest clock in the world right now,
at the Rheinturm, in Düsseldorf, Germany.
I know what you're thinking, that's not a clock,
that's a broadcast tower. In fact,
there's a tower a bit like this in most major cities in Germany.
It's kind of their thing.
The view from the top is wonderful.
But it's also an enormous clock... it's just a digital one.
You see those lights on the side? Read them from top to bottom,
each group as a number. 1, 7, 3, 2.
17 32.
There's some seconds there on the bottom as well,
but it's about half past five.
And at more than a hundred metres high,
that is a clock about twice the height than the one at Mecca,
although admittedly it has a bit less surface area.
But that brings me to a question: what counts as a clock?
If you ask the Guinness Book of Records,
the largest clock was a temporary structure.
It had an area of more than eight square kilometres,
and it was made with lasers at the 2011 Burning Man festival.
That is so much bigger than this tower.
But what if I took lights like the ones on the side of here,
sent them round the world, so America had the hours,
Europe and the Middle East had the minutes and Asia had the seconds,
if I hooked them up so they all flashed together and acted as one big device...
would that count?
Could we, with a fairly small amount of effort,
make a clock as big as the earth?
And if so, would it count?
Or does a clock need to be something that one person can just look at
and actually use to tell the time?
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