Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    What is the Real Time?
    From: Richard B. Langley
    Date: 2017 Jan 28, 22:49 +0000

    An episode of the BBC World Service program "CrowdScience". A couple of 
    inaccuracies/exaggerations but worth a listen.
    
    "It sounds like a simple question -- what is the time? But look closer and you 
    realise time is a slippery concept that scientists still do not fully 
    understand. Even though we now have atomic clocks that can keep time to one 
    second in 15 billion years, this astonishing level of accuracy may not be 
    enough. The complexity of computer-controlled systems, such as high-frequency 
    financial trading or self-driving cars which rely on the pinpoint accuracy of 
    GPS, could in future require clocks that are even more accurate to ensure 
    everything runs 'on time'.
    
    "But what does that even mean? As Anand Jagatia discovers, time is a very strange 
    thing. He visits the origins of modern time-keeping at the Royal Observatory 
    in Greenwich and meets scientists at the National Physical Laboratory who 
    have been counting and labelling every second since the 1950s. He meets 
    Demetrios Matsakis, the man who defined time and visits the real-life 'Time 
    Lords', at the International Bureau of Weights and Measures (BIPM) in Paris 
    to find out how they co-ordinate the world's time and why the leap second is 'dangerous'."
    
    http://www.bbc.co.uk/programmes/p04q778b
    
    -- Richard Langley
    
    -----------------------------------------------------------------------------
    | Richard B. Langley                            E-mail: lang---.ca         |
    | Geodetic Research Laboratory                  Web: http://gge.unb.ca      |
    | Dept. of Geodesy and Geomatics Engineering    Phone:    +1 506 453-5142   |
    | University of New Brunswick                   Fax:      +1 506 453-4943   |
    | Fredericton, N.B., Canada  E3B 5A3                                        |
    |        Fredericton?  Where's that?  See: http://www.fredericton.ca/       |
    -----------------------------------------------------------------------------
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site