# Significant Figures

I found this post on Facebook: Why is it important to know so many digits of pi?.

My comment:

As someone who started computing with log tables and slide rules, the first question I ask is how many significant digits do the other variables in your calculation have? The smallest such number tells you how many digits of pi you need. With electronic devices there is no harm in using more in your calculation, as many as your device has, but do not let that give you a false idea of the precision of your result.

I learned about significant figures in my high school chemistry in 1967-68. (Thank you, Mr. Wheeler!). Use of appropriate significant figures, also from a chemistry class, clearly explains the concept and its use in practice.

I only first saw Star Trek (TOS) after high school, in reruns. Thanks to that chemistry class I gag every time I hear Mr. Spock reporting some calculation to an absurd number of decimal places. His input data could not possibly be that precise!

# Beam me up Scotty

German scientists invent working teleporter, of sorts

An object at one end of the system is milled down layer-by-layer, creating a scan per layer which is then transmitted through an encrypted communication to a 3D printer. The printer then replicates the original object layer by layer, effectively teleporting an object from one place to another.

# Monday Night Irish Class, July 28, 2014

Irish Class, July 28, 2014

### Rang Gaeilge, 28ú lá Mí na Iúil 2014

<!–

–>

#### Le Meas …

Part of our homework was to write “… a script for a short clip … to be used at a dating site! But it isn’t about you, pick a famous person, dead or alive.”
Here is my effort:

Dia dhuit! Inseoidh mé cupla rud fúm féin:

Is mise an captaen loinge réaltaí Enterprise.</i

• Is maith liom taiscéaladh domhan aisteach nua.
• Is maith liom cuardach saol nua.
• Is maith liom dul go dána go háiteanna atá ní fhaca aon duine sula.
• Is maith liom mná ó gach cine, daonna agus thar.
• Ní maith liom an Phríomhtreoir.

# Cosmos and Giordano Bruno

I saw the first episode of the new Cosmos last week. The first and third parts were fine. The middle part, the cartoon about Giordano Bruno was the story I had heard long ago about how Bruno was a martyr for his scientific beliefs. This story is very widespread, and widely invoked by those who are hostile to religion. Back in 1971 I was in Turkey, on the walls of the formidable late medieval fortress of Rumeli Hisarı, when I saw a Soviet freighter passing through the Bosphorus named, in Cyrillic letters, Giordano Bruno.

# Neil deGrasse Tyson on Star Trek

I have learned three of life’s lessons from this series: (1) in the end, you will be judged on the integrity of your mission, whether or not your mission was successful; (2) you can always outsmart a computer; and (3) never be the first person to investigate a glowing blob of plasma on an alien planet.

Happy anniversary, Star Trek. Live long and prosper.

# More of my favorite television show

‘The Woodwright’s Shop Renewed for Two More Seasons

So woodworkers can look forward to two more years of the never-aging Roy as he continues to champion the power of muscle over that of the electrical machine. He’s got a point: Roy has the same axe that he used in the first season, 33 years ago. How many computers have you had in the last 33 years? And how well do you think they would endure a whack from Roy’s axe? I thought so.