Random Jottings

Sloppy journalism, one of my pet hates!

There has been a very interesting find on a 15th Century shipwreck which as a discovery stands-alone, but why must the BBC always mis-represent!

Here is the BBC article:-


All very interesting and a nice article about an astrolobe, a piece of kit that is used to find the height of the sun which is then used to calculate the latitude of the vessel. The calculation and equipment required to determine longitude were not developed until there were truly accurate clocks and watches or should that be chronometers?

Now the nub of my gripe, lumps of concretation were removed from a Greek wreck in around 1900 by sponge divers. Now after years of analysis and x-rays and reconstructions the functions and outputs from the famous Anthikythera mechanism are far greater than those detailed on a simple astralobe! 


The mechanism calculated not only solar details but more recent research details that it could model the moons orbit, so it would imply you could do your navigational fixes at night! Not that this mattered as most ships travelled very close to land around 100BC, easy to navigate but inconvienient for piratical activity!

It is estimated that device was accurate to 1 degree of planetary motion every 500 years, whilst the simple astrolobe reported by the BBC is accurate based upon the user and their skill in shooting the sun this 'computer' did not rely on human intervention other than spinning the handle! 

Dive safe



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