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
    Re: Ups and Downs of reflecting AH's
    From: Lawrie Elms
    Date: 2022 Aug 5, 01:05 -0700

    Good Morning and thanks for the input, David.

    The movement in my water tray isn't the  kind of shimmering that I once did see when I used just a deep open tray without any covering.

    Presently, the water surface  appears to swirl very slowly up and down the length of the tray, the effect is mesmerising, somewhat like the motion of those, 'God's Hankies" made by oil stains atop of sluggish water.

    Practically and certainly most noticable at Local Apparant Noon, I see a sight image which slowwwwly floats the limb to limb contact in and out, over an amplitude of around 2 mins of arc...and I try to chase this measure with the micrometer.. the images would appear to be moving independantly...surely not?.  There is only around a 5 mm depth of water in a 15x10x1.5 cm tray.. a tray made for the hospitality trades, for tipping gratuities, and comes with no apparant magical properties.

    There's something I forgot to include in post 1 and it is that I have been much aware that the water surface is clinging to the inner edges of the plastic tray and has crossed my mind that perhaps this attraction is causing a meniscus effect on the water surface, one which, presumably, counters the effect of gravity wanting to flatten the surface. 

    Anyway, I am happy that  I am not the only one to have the impression that the huge thermal mass of buildings can have the potential to mess up the best of hallowed Refraction formulae.

    Loz Elms

       
    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