The Inauguration of GranTeCan

Oddly enough, nobody invited me to meet the king of Spain at the official inauguration of GranTeCan (Gran Telescopio Canario or Big Canarian Telescope) so I had to watch it on the TV.

I learned something new. The main mirror is accurate to 15 nanometres (a nanometre is a millionth of a millimetre). So if you scaled up the mirror to 10,400 km (and the radius of the Earth is 6,400 km) then the height difference between the highest mountain peak and the lowest valley would be 15mm.

Posted by sheila

Sheila came to La Palma with a six month contract and has stayed 24 years so far. She used to work as a software engineer at the observatory, but now she's a writer and Starlight guide.